Bone formation and remodeling occurs throughout life and requires the sustained activity of osteoblasts and osteoclasts,particularly during periods of rapid bone growth.Despite increasing evidence linking bone cell ac...Bone formation and remodeling occurs throughout life and requires the sustained activity of osteoblasts and osteoclasts,particularly during periods of rapid bone growth.Despite increasing evidence linking bone cell activity to global energy homeostasis,little is known about the relative energy requirements or substrate utilization of bone cells.In these studies,we measured the uptake and distribution of glucose in the skeleton in vivo using positron-emitting^(18)F-fluorodeoxyglucose([^(18)F]-FDG) and non-invasive,high-resolution positron emission tomography/computed tomography(PET/CT) imaging and ex vivo autoradiography.Assessment of [^(18)F]-FDG uptake demonstrated that relative to other tissues bone accumulated a significant fraction of the total dose of the glucose analog.Skeletal accumulation was greatest in young mice undergoing the rapid bone formation that characterizes early development.PET/CT imaging revealed that [^(18)F]-FDG uptake was greatest in the epiphyseal and metaphyseal regions of long bones,which accords with the increased osteoblast numbers and activity at this skeletal site.Insulin administration significantly increased skeletal accumulation of [^(18)F]-FDG,while uptake was reduced in mice lacking the insulin receptor specifically in osteoblasts or fed a high-fat diet.Our results indicated that the skeleton is a site of significant glucose uptake and that its consumption by bone cells is subject to regulation by insulin and disturbances in whole-body metabolism.展开更多
AIM: To define the magnetic resonance imaging(MRI) parameters differentiating urethral hypermobility(UH) and intrinsic sphincter deficiency(ISD) in women with stress urinary incontinence(SUI).METHODS: The static and d...AIM: To define the magnetic resonance imaging(MRI) parameters differentiating urethral hypermobility(UH) and intrinsic sphincter deficiency(ISD) in women with stress urinary incontinence(SUI).METHODS: The static and dynamic MR images of 21 patients with SUI were correlated to urodynamic(UD) findings and compared to those of 10 continent controls. For the assessment of the urethra and integrity of the urethral support structures, we applied the highresolution endocavitary MRI, such as intraurethral MRI, endovaginal or endorectal MRI. For the functional imaging of the urethral support, we performed dynamic MRI with the pelvic phased array coil. We assessed the following MRI parameters in both the patient and thevolunteer groups:(1) urethral angle;(2) bladder neck descent;(3) status of the periurethral ligaments,(4) vaginal shape;(5) urethral sphincter integrity, length and muscle thickness at mid urethra;(6) bladder neck funneling;(7) status of the puborectalis muscle;(8) pubo-vaginal distance. UDs parameters were assessed in the patient study group as follows:(1) urethral mobility angle on Q-tip test;(2) Valsalva leak point pressure(VLPP) measured at 250 cc bladder volume; and(3) maximum urethral closure pressure(MUCP). The UH type of SUI was defined with the Q-tip test angle over 30 degrees, and VLPP pressure over 60 cm H2 O. The ISD incontinence was defined with MUCP pressure below 20 cm H2 O, and VLPP pressure less or equal to 60 cm H2 O. We considered the associations between the MRI and clinical data and UDs using a variety of statistical tools to include linear regression, multivariate logistic regression and receiver operating characteristic(ROC) analysis. All statistical analyses were performed using STATA version 9.0(Stata Corp LP, College Station, TX).RESULTS: In the incontinent group, 52% have history of vaginal delivery trauma as compared to none in control group(P < 0.001). There was no difference between the continent volunteers and incontinent patients in body habitus as assessed by the body mass index. Pubovaginal distance and periurethral ligament disruption are significantly associated with incontinence; periurethral ligament symmetricity reduces the odds of incontinence by 87%. Bladder neck funneling and length of the suprapubic urethral sphincter are significantly associated with the type of incontinence on UDs; funneling reduced the odds of pure UH by almost 95%; increasing suprapubic urethral sphincter length at rest is highly associated with UH. Both MRI variables result in a predictive model for UDs diagnosis(area under the ROC = 0.944). CONCLUSION: MRI may play an important role in assessing the contribution of hypermobility and sphincteric dysfunction to the SUI in women when considering treatment options.展开更多
AIM: To determine the prevalence of unsuspected thyroid nodules on contrast enhanced 16and 64-modified discrete cosine transform (MDCT) of the chest, in a population of adult outpatients imaged for indications other t...AIM: To determine the prevalence of unsuspected thyroid nodules on contrast enhanced 16and 64-modified discrete cosine transform (MDCT) of the chest, in a population of adult outpatients imaged for indications other than thyroid disease. METHODS: This retrospective study involved review of intravascular contrast-enhanced MDCT scans of the chest from 3077 consecutive adult outpatients, to identify unsuspected thyroid nodules. Exclusion criteria included history of thyroid cancer, known thyroid nodules or thyroid disease and risk factors for thyroid cancer, as evidenced by their medical records. One of 9 radiologists recorded number of nodules, location and bidirectional measurement of largest nodule, as well as amount of thyroid visualized on the chest computed tomography (CT). Presence of nodule was correlated with age, gender, race and percentage of thyroid imaged. RESULTS: A total of 2510 (2510/3077 or 81.6%) study subjects were included in the data analysis; among them,one or more nodules were identified in 629 subjects (629/2510 or 25.1%), with 242 (242/629 or 38.5%) having multiple nodules. Patients with nodule(s) were significantly older than those without (64 ± 13 years vs 58 ± 14 years, P < 0.0001), and female gender was associated with presence of nodule(s) (373/1222 or 30.5% vs 256/1288 or 19.9%, P < 0.0001). Women were also more likely having multiple nodules (167/373 or 44.8%) compared to men (75/256 or 29.3%, P < 0.0001). The majority of nodules (427/629 or 67.9%) were less than 1 cm. CONCLUSION: This retrospective review revealed a prevalence of 25.1% for unsuspected thyroid nodules on contrast-enhanced chest CT.展开更多
Small-bowel carcinoid tumors are the most common form(42%) of gastrointestinal carcinoids, which by themselves comprise 70% of neuroendocrine tumors. Although primary small bowel neoplasms are overall rare(3%-6% of al...Small-bowel carcinoid tumors are the most common form(42%) of gastrointestinal carcinoids, which by themselves comprise 70% of neuroendocrine tumors. Although primary small bowel neoplasms are overall rare(3%-6% of all gastrointestinal neoplasms), carcinoids still represent the second most common(20%-30%) primary small-bowel malignancy after small bowel adenocarcinoma. Their imaging evaluation is often challenging. State-of-the-art high-resolution multiphasic computed tomography together with advanced postprocessing methods provides an excellent tool for their depiction. The manifold interactive parameter choices however require knowledge of when to use which technique. Here, we discuss the imaging appearance and evaluation of duodenal, jejunal and ileal carcinoid tumors, including the imaging features of the primary tumor, locoregional mesenteric nodal metastases, and distant metastatic disease. A protocol for optimal lesion detection is presented, including the use of computed tomography enterography, volume acquisition, computed tomography angiography and three-dimensional mapping. Imaging findings are illustrated with a series of challenging cases which illustrate the spectrum of possible disease in the small bowel and mesentery, the range of possible appearances in the bowel itself on multiphase data and extraluminal findings such as the desmoplastic reaction in mesentery and hypervascular liver metastases. Typical imaging pitfalls and pearls are illustrated.展开更多
Human osteogenic progenitors are not precisely defined,being primarily studied as heterogeneous multipotent cell populations and termed mesenchymal stem cells(MSCs).Notably,select human pericytes can develop into bone...Human osteogenic progenitors are not precisely defined,being primarily studied as heterogeneous multipotent cell populations and termed mesenchymal stem cells(MSCs).Notably,select human pericytes can develop into bone-forming osteoblasts.Here,we sought to define the differentiation potential of CD146 f human pericytes from skeletal and soft tissue sources,with the underlying goal of defining cell surface markers that typify an osteoblastogenic pericyte.CD146+CD31~CD45_pericytes were derived by fluorescence-activated cell sorting from human periosteum,adipose,or dermal tissue.Periosteal CD146+CD31—CD45 cells retained canonical features of pericytes/MSC.Periosteal pericytes demonstrated a striking tendency to undergo osteoblastogenesis in vitro and skeletogenesis in vivo,while soft tissue pericytes did not readily.Transcriptome analysis revealed higher CXCR4 signaling among periosteal pericytes in comparison to their soft tissue counterparts,and CXCR4 chemical inhibition abrogated ectopic ossification by periosteal pericytes.Conversely,enrichment of CXCR4+pericytes or stromal cells identified an osteoblastic/non-adipocytic precursor cell.In sum,human skeletal and soft tissue pericytes differ in their basal abilities to form bone.Diversity exists in soft tissue pericytes,however,and CXCR4+pericytes represent an osteoblastogenic,non-adipocytic cell precursor.Indeed,enrichment for CXCR4-expressing stromal cells is a potential new tactic for skeletal tissue engineering.展开更多
A general model for skeletal dosimetry in mice is presented. Geometrical constructs were made for four general regions in the mouse skeleton, and dose factors for90 Sr and90Y were calculated using the MCNP Monte Carlo...A general model for skeletal dosimetry in mice is presented. Geometrical constructs were made for four general regions in the mouse skeleton, and dose factors for90 Sr and90Y were calculated using the MCNP Monte Carlo transport code. Then, an overall skeletal dose factor for the whole skeleton was derived based on the individual values and the fraction of the total skeleton that they were assumed to represent. The whole skeleton average values were 1.56 9 10-11Gy/dis for90 Sr and 1.74 9 10-11Gy/dis for90 Y.展开更多
Intractable bleeding from gastric and duodenal ulcers is associated with significant morbidity and mortality. Aggressive treatment with early endoscopic hemostasis is essential for a favourable outcome. In as many as ...Intractable bleeding from gastric and duodenal ulcers is associated with significant morbidity and mortality. Aggressive treatment with early endoscopic hemostasis is essential for a favourable outcome. In as many as 12%-17% of patients,endoscopy is either not available or unsuccessful. Endovascular therapy with selective catheterization of the culprit vessel and injection of embolic material has emerged as an alternative to emergent operative intervention in high-risk patients. There has not been a systematic literature review to assess the role for embolotherapy in the treatment of acute upper gastrointestinal bleeding from gastroduo-denal ulcers after failed endoscopic hemostasis. Here,we present an overview of indications,techniques,and clinical outcomes after endovascular embolization of acute peptic-ulcer bleeding. Topics of particular relevance to technical and clinical success are also discussed. Our review shows that transcatheter arterial embolization is a safe alternative to surgery for massive gastroduodenal bleeding that is refractory to endoscopic treatment,can be performed with high technical and clinical success rates,and should be considered the salvage treatment of choice in patients at high surgical risk.展开更多
Over the past two decades,transcatheter arterial embolization has become the first-line therapy for the management of upper gastrointestinal bleeding that is refractory to endoscopic hemostasis.Advances in catheter-ba...Over the past two decades,transcatheter arterial embolization has become the first-line therapy for the management of upper gastrointestinal bleeding that is refractory to endoscopic hemostasis.Advances in catheter-based techniques and newer embolic agents, as well as recognition of the effectiveness of minimally invasive treatment options,have expanded the role of interventional radiology in the management of hemorrhage for a variety of indications,such as peptic ulcerbleeding,malignant disease,hemorrhagic Dieulafoy lesions and iatrogenic or trauma bleeding.Transcatheter interventions include the following:selective embolization of the feeding artery,sandwich coil occlusion of the gastroduodenal artery,blind or empiric embolization of the supposed bleeding vessel based on endoscopic findings and coil pseudoaneurysm or aneurysm embolization by three-dimensional sac packing with preservation of the parent artery.Transcatheter embolization is a fast,safe and effective,minimally invasive alternative to surgery when endoscopic treatment fails to control bleeding from the upper gastrointestinal tract.This article reviews the various transcatheter endovascular techniques and devices that are used in a variety of clinical scenarios for the management of hemorrhagic gastrointestinal emergencies.展开更多
AIM:To evaluate neurovascular uncoupling(NVU)associated with low grade gliomas(LGG)using blood oxygen level dependent(BOLD)cerebrovascular reactivity mapping.METHODS:Seven patients with low grade gliomas referred by n...AIM:To evaluate neurovascular uncoupling(NVU)associated with low grade gliomas(LGG)using blood oxygen level dependent(BOLD)cerebrovascular reactivity mapping.METHODS:Seven patients with low grade gliomas referred by neurosurgeons for presurgical mapping were included in this pilot study.Cerebrovascular reactivity(CVR)mapping was performed by acquiring BOLD images while patients performed a block-design breath-hold(BH)hypercapnia task.CVR mapping was expressed as BOLD percentage signal change(PSC)from baseline associated with performance of the BH hypercapnia task.Standard T2*Dynamic Susceptibility Contrast perfusion imaging was performed and relative cerebral blood volume(rCBV)and relative cerebral blood flow(rCBF)maps were generated.Structural T1 weighted MR images were also acquired.A correlation analysis between intratumoral normalized(via ratio with contralateral homologous regions)BOLD BH PSC[referred to as(nCVR)]and intratumoral normalized resting state rCBV(rCBF)values(i.e.,nCBV and nCBF,respectively)was performed.RESULTS:No significant correlation was seen between the normalized BOLD BH PSC(i.e.,nCBV)and nCBV or nCBF.However,the average nCVR(median=0.50,z=-2.28,P=0.01)was significantly less than 1.0,indicating abnormally reduced vascular responses in the tumor regions relative to normal contralesional homologous regions,whereas the average nCBV(median=0.94,z=-0.92,P=0.375)and nCBF(median=0.93,z=-1.16,P=0.25)were not significantly higher or lower than 1.0,indicating iso-perfusion in the tumor regions relative to normal contralesional homologous regions.These findings suggest that in LGG,hyperperfusion that is seen in high grade gliomas is not present,but,nevertheless,abnormally decreased regional CVR is present within and adjacent to LGG.Since the patients all demonstrated at least some residual function attributable to the cortical regions of impaired CVR,but were incapable of producing a BOLD response in these regions regardless of the tasks performed,such regionally decreased CVR is indicative of NVU.The low nCVR ratios indicate high prevalence of NVU in this LGG cohort,which is an important consideration in the interpretation of clinical presurgical mapping with functional magnetic resonance(MR)imaging.CONCLUSION:Our preliminary study shows that BH CVR mapping is clinically feasible and demonstrates an unexpectedly high prevalence of NVU in patients with LGG.展开更多
AIM: To test the incremental value of 3T magnetic resonance neurography(MRN) in a series of unilateral radiculopathy patients with non-contributory magnetic resonance imaging(MRI).METHODS: Ten subjects(3 men,7 women; ...AIM: To test the incremental value of 3T magnetic resonance neurography(MRN) in a series of unilateral radiculopathy patients with non-contributory magnetic resonance imaging(MRI).METHODS: Ten subjects(3 men,7 women; mean age54 year and range 22-74 year) with unilateral lumbar radiculopathy and with previous non-contributory lumbar spine MRI underwent lumbosacral(LS) plexus MRN over a period of one year. Lumbar spine MRI performed as part of the MRN LS protocol as well as bilateral L4-S1 nerves,sciatic,femoral and lateral femoral cutaneous nerves were evaluated in each subject for neuropathy findings on both anatomic(nerve signal,course and caliber alterations) and diffusion tensor imaging(DTI)tensor maps(nerve signal and caliber alterations).Minimum fractional anisotropy(FA) and mean apparent diffusion coeffcient(ADC) of L4-S2 nerve roots,sciatic and femoral nerves were recorded.RESULTS: All anatomic studies and 80% of DTI imaging received a good-excellent imaging quality grading. In a blinded evaluation,all 10 examinations demonstrated neural and/or neuromuscular abnormality corresponding to the site of radiculopathy. A number of contributory neuropathy findings including double crush syndrome were observed. On DTI tensor maps,nerve signal and caliber alterations were more conspicuous. Although individual differences were observed among neuropathic appearing nerve(lower FA and increased ADC) as compared to its contralateral counterpart,there were no significant mean differences on statistical comparison of LS plexus nerves,femoral and sciatic nerves(P > 0.05).CONCLUSION: MRN of LS plexus is useful modality for the evaluation of patients with non-contributory MRI of lumbar spine as it can incrementally delineate the etiology and provide direct objective and non-invasive evidence of neuromuscular pathology.展开更多
AIM: To evaluate the pudendal nerve segments that could be identified on magnetic resonance neurography(MRN) before and after surgical marking of different nerve segments.METHODS: The hypothesis for this study was tha...AIM: To evaluate the pudendal nerve segments that could be identified on magnetic resonance neurography(MRN) before and after surgical marking of different nerve segments.METHODS: The hypothesis for this study was that pudendal nerve and its branches would be more easily seen after the surgical nerve marking. Institutional board approval was obtained. One male and one female cadaver pelvis were obtained from the anatomy board and were scanned using 3 Tesla MRI scanner using MR neurography sequences. All possible pudendal nerve branches were identified. The cadavers were then sent to the autopsy lab and were surgically dissected by a peripheral nerve surgeon and an anatomist to identify the pudendal nerve branches. Radiological markers were placed along the course of the pudendal nerve and its branches. The cadavers were then closed and rescanned using the same MRN protocol as the premarking scan. The remaining pudendal nerve branches were attempted to be identified using the radiological markers. All scans were read by an experienced musculoskeletal radiologist.RESULTS: The pre-marking MR Neurography scans clearly showed the pudendal nerve at its exit from the lumbosacral plexus in the sciatic notch, at the level of the ischial spine and in the Alcock's Canal in both cadavers. Additionally, the right hemorrhoidal branch could be identified in the male pelvis cadaver. The perineal and distal genital branches could not be identified. On post-marking scans, the markers were used as identifiable structures. The location of the perineal branch, the hemorroidal branch and the dorsal nerve to penis(in male cadaver)/clitoris(in female cadaver) could be seen. However, the visualization of these branches was suboptimal. The contralateral corresponding nerves were poorly seen despite marking on the surgical side. The nerve was best seen on axial T1W and T2W SPAIR images. The proximal segment could be seen well on 3D DW PSIF sequence. T2W SPACE was not very useful in visualization of this small nerve or its branches.CONCLUSION: Proximal pudendal nerve is easily seen on MR neurography, however it is not possible to identify distal branches of the pudendal nerve even after surgical marking.展开更多
AIM: To investigate whether congenital lumbar spinal stenosis(CLSS) is associated with a specific degenerative changes of the lumbar spine. METHODS: The lumbar spine magnetic resonance imaging studies of 52 subjects w...AIM: To investigate whether congenital lumbar spinal stenosis(CLSS) is associated with a specific degenerative changes of the lumbar spine. METHODS: The lumbar spine magnetic resonance imaging studies of 52 subjects with CLSS and 48 control subjects were retrospectively evaluated. In each examination, the five lumbar levels were assessed for the presence or absence of circumferential or shallow annular bulges, annular tears, anterior or posterior disc herniations, epidural lipomatosis, Schmorl's nodes,spondylolisthesis, pars defects, and stress reactions of the posterior vertebral elements. RESULTS: Compared to control individuals, subjects with CLSS exhibited increased incidence of circumferential and shallow annular bulges, annular tears, discherniations and spondylolisthesis(P < 0.05). CONCLUSION: CLSS is associated with increased incidence of degenerative changes in specific osseous and soft-tissue elements of the lumbar spine.展开更多
Discriminating sterile inflammation from infection, especially in cases of aseptic loosening versus an actual prosthetic joint infection, is challenging and has significant treatment implications. Our goal was to eval...Discriminating sterile inflammation from infection, especially in cases of aseptic loosening versus an actual prosthetic joint infection, is challenging and has significant treatment implications. Our goal was to evaluate a novel human monoclonal antibody(mAb) probe directed against the Gram-positive bacterial surface molecule lipoteichoic acid(LTA). Specificity and affinity were assessed in vitro. We then radiolabeled the anti-LTA mAb and evaluated its effectiveness as a diagnostic imaging tool for detecting infection via immuno PET imaging in an in vivo mouse model of prosthetic joint infection(PJI). In vitro and ex vivo binding of the anti-LTA mAb to pathogenic bacteria was measured with Octet, ELISA, and flow cytometry. The in vivo PJI mouse model was assessed using traditional imaging modalities, including positron emission tomography(PET) with [^(18)F]FDG and [^(18)F]Na F as well as X-ray computed tomography(CT), before being evaluated with the zirconium-89-labeled antibody specific for LTA([^(89)Zr]SAC55).The anti-LTA mAb exhibited specific binding in vitro to LTA-expressing bacteria. Results from imaging showed that our model could reliably simulate infection at the surgical site by bioluminescent imaging, conventional PET tracer imaging, and bone morphological changes by CT. One day following injection of both the radiolabeled anti-LTA and isotype control antibodies, the anti-LTA antibody demonstrated significantly greater(P < 0.05) uptake at S. aureus-infected prosthesis sites over either the same antibody at sterile prosthesis sites or of control non-specific antibody at infected prosthesis sites. Taken together, the radiolabeled anti-LTA mAb, [^(89)Zr]SAC55, may serve as a valuable diagnostic molecular imaging probe to help distinguish between sterile inflammation and infection in the setting of PJI. Future studies are needed to determine whether these findings will translate to human PJI.展开更多
Coronary computed tomography angiography(CCTA)has become an integral tool in the noninvasive diagnostic workup of patients with suspected coronary artery disease in both elective and emergency settings. Today, it repr...Coronary computed tomography angiography(CCTA)has become an integral tool in the noninvasive diagnostic workup of patients with suspected coronary artery disease in both elective and emergency settings. Today, it represents a mature technique providing accurate, non-invasive morphological assessment of the coronary arteries and atherosclerotic plaque burden. Iterative reconstruction algorithms, low kV imaging, and single-heart beat acquisitions hold promise to further reduce dose requirements and improve the safety and robustness of the technique in several circumstances including imaging of heavily calcified vessels, patients with morbid obesity or irregular heart rates, and assessment in the emergency setting. However, it has become clear over recent years that cardiac radiologists need to take further steps towards the development and integration of functional imaging with morphological CCTA assessment to truly provide a comprehensive evaluation of the heart. Computed tomography myocardial perfusion imaging, including both dynamic and static dual-energy approaches, has demonstrated the ability to directly assess and quantify myocardial ischemia with simultaneous CCTA acquisition with a reasonable contrast medium volume and radiation dose delivered to the patient. In order to promote CCTA in the clinical and research environments, radiologists should prepare to embrace the change from morphological to functional imaging, furnishing all the necessary resources and information to referring clinicians.展开更多
While the activation of primary somatosensory(SI) cortex during pain perception is consistently reported in functional imaging studies on normal subjects and chronic pain patients,the specific roles of SI,particularly...While the activation of primary somatosensory(SI) cortex during pain perception is consistently reported in functional imaging studies on normal subjects and chronic pain patients,the specific roles of SI,particularly the subregions within SI,in the processing of sensory aspects of pain are still largely unknown.Using optical imaging of intrinsic signal(OIS) and single unit electrophysiology,we studied cortical activation patterns within SI cortex(among Brodmann areas 3a,3b and 1) and signal amplitude changes to various intensities of non-nociceptive,thermal nociceptive and mechanical nociceptive stimulation of individual distal finerpads in anesthetized squirrel monkeys.We have demonstrated that areas 3a and 1 are preferentially involved in the processing of nociceptive information while areas 3b and 1 are preferentially activated in the processing of non-nociceptive(touch) information.Nociceptive activations of individual fingerpad were organized topographically suggesting that nociceptive topographic map exits in areas 3a and 1.Signal amplitude was enhanced to increasing intensity of mechanical nociceptive stimuli in areas 3a,3b and 1.Within area 1,nociceptive response co-localizes with the non-nociceptive response.Therefore,we hypothesize that nocicepitve information is area-specifically represented within SI cortex,in which nociceptive inputs are preferentially represented in areas 3a and 1 while non-nociceptive inputs are preferentially represented in areas 3b and 1.展开更多
BACKGROUND In chest computed tomography(CT)scan,bilateral peripheral multifocal groundglass opacities,linear opacities,reversed halo sign,and crazy-paving pattern are suggestive for coronavirus disease 2019(COVID-19)i...BACKGROUND In chest computed tomography(CT)scan,bilateral peripheral multifocal groundglass opacities,linear opacities,reversed halo sign,and crazy-paving pattern are suggestive for coronavirus disease 2019(COVID-19)in clinically suspicious cases,but they are not specific for the diagnosis,as other viral pneumonias,like influenza and some viral pneumonia may show similar imaging findings.AIM To find a specific imaging feature of the disease would be a welcome guide in diagnosis and management of challenging cases.METHODS Chest CT imaging findings of 650 patients admitted to a university Hospital in Tehran,Iran between January 2020 and July 2020 with confirmed COVID-19 infection by RT-PCR were reviewed by two expert radiologists.In addition to common non-specific imaging findings of COVID-19 pneumonia,radiologic characteristics of“pulmonary target sign”(PTS)were assessed.PTS is defined as a circular appearance of non-involved pulmonary parenchyma,which encompass a central hyperdense dot surrounded by ground-glass or alveolar opacities.RESULTS PTS were presented in 32 cases(frequency 4.9%).The location of the lesions in 31 of the 32 cases(96.8%)was peripheral,while 4 of the 31 cases had lesions both peripherally and centrally.In 25 cases,the lesions were located near the pleural surface and considered pleural based and half of the lesions(at least one lesion)were in the lower segments and lobes of the lungs.22 cases had multiple lesions with a>68%frequency.More than 87%of cases had an adjacent bronchovascular bundle.Ground-glass opacities were detectable adjacent or close to the lesions in 30 cases(93%)and only in 7 cases(21%)was consolidation adjacent to the lesions.CONCLUSION Although it is not frequent in COVID-19,familiarity with this feature may help radiologists and physicians distinguish the disease from other viral and noninfectious pneumonias in challenging cases.展开更多
Human functional MRI studies in acute and various chronic pain conditions have revolutionized how we view pain, and have led to a new theory that complex multi-dimensional pain experience(sensory-discriminative,affect...Human functional MRI studies in acute and various chronic pain conditions have revolutionized how we view pain, and have led to a new theory that complex multi-dimensional pain experience(sensory-discriminative,affective/motivational, and cognitive) is represented by concurrent activity in widely-distributed brain regions(termed a network or pain matrix). Despite these breakthrough discoveries, the specific functions proposed for these regions remain elusive, because detailed electrophysiological characterizations of these regions in the primate brain are lacking. To fill in this knowledge gap, we have studied the cortical areas around the central and lateral sulci of the non-human primate brain with combined submillimeter resolution functional imaging(optical imaging and fMRI) and intracranial electrophysiological recording. In this mini-review, I summarize and present data showing that the cortical circuitry engaged in nociceptive processing is much more complex than previously recognized. Electrophysiological evidence supports the engagement of a distinct nociceptive-processing network within SI(i.e., areas 3 a, 3 b, 1 and 2), SII, and other areas along the lateral sulcus. Deafferentation caused by spinal cord injury profoundly alters the relationships between fMRI and electrophysiological signals. This finding has significant implications for using fMRI to study chronic pain conditions involving deafferentation in humans.展开更多
基金supported by NIH grant DK099134 to RCRSteve Wynn Young Investigator Award from the Prostate Cancer Foundation to DLJT+1 种基金the Johns Hopkins University Cancer Center Support Grant (P30 CA006973)supported by a Merit Review Grant (BX001234)
文摘Bone formation and remodeling occurs throughout life and requires the sustained activity of osteoblasts and osteoclasts,particularly during periods of rapid bone growth.Despite increasing evidence linking bone cell activity to global energy homeostasis,little is known about the relative energy requirements or substrate utilization of bone cells.In these studies,we measured the uptake and distribution of glucose in the skeleton in vivo using positron-emitting^(18)F-fluorodeoxyglucose([^(18)F]-FDG) and non-invasive,high-resolution positron emission tomography/computed tomography(PET/CT) imaging and ex vivo autoradiography.Assessment of [^(18)F]-FDG uptake demonstrated that relative to other tissues bone accumulated a significant fraction of the total dose of the glucose analog.Skeletal accumulation was greatest in young mice undergoing the rapid bone formation that characterizes early development.PET/CT imaging revealed that [^(18)F]-FDG uptake was greatest in the epiphyseal and metaphyseal regions of long bones,which accords with the increased osteoblast numbers and activity at this skeletal site.Insulin administration significantly increased skeletal accumulation of [^(18)F]-FDG,while uptake was reduced in mice lacking the insulin receptor specifically in osteoblasts or fed a high-fat diet.Our results indicated that the skeleton is a site of significant glucose uptake and that its consumption by bone cells is subject to regulation by insulin and disturbances in whole-body metabolism.
基金Supported by The Radiological Society of North America and the Society of Computed Body Tomography and Magnetic Resonance
文摘AIM: To define the magnetic resonance imaging(MRI) parameters differentiating urethral hypermobility(UH) and intrinsic sphincter deficiency(ISD) in women with stress urinary incontinence(SUI).METHODS: The static and dynamic MR images of 21 patients with SUI were correlated to urodynamic(UD) findings and compared to those of 10 continent controls. For the assessment of the urethra and integrity of the urethral support structures, we applied the highresolution endocavitary MRI, such as intraurethral MRI, endovaginal or endorectal MRI. For the functional imaging of the urethral support, we performed dynamic MRI with the pelvic phased array coil. We assessed the following MRI parameters in both the patient and thevolunteer groups:(1) urethral angle;(2) bladder neck descent;(3) status of the periurethral ligaments,(4) vaginal shape;(5) urethral sphincter integrity, length and muscle thickness at mid urethra;(6) bladder neck funneling;(7) status of the puborectalis muscle;(8) pubo-vaginal distance. UDs parameters were assessed in the patient study group as follows:(1) urethral mobility angle on Q-tip test;(2) Valsalva leak point pressure(VLPP) measured at 250 cc bladder volume; and(3) maximum urethral closure pressure(MUCP). The UH type of SUI was defined with the Q-tip test angle over 30 degrees, and VLPP pressure over 60 cm H2 O. The ISD incontinence was defined with MUCP pressure below 20 cm H2 O, and VLPP pressure less or equal to 60 cm H2 O. We considered the associations between the MRI and clinical data and UDs using a variety of statistical tools to include linear regression, multivariate logistic regression and receiver operating characteristic(ROC) analysis. All statistical analyses were performed using STATA version 9.0(Stata Corp LP, College Station, TX).RESULTS: In the incontinent group, 52% have history of vaginal delivery trauma as compared to none in control group(P < 0.001). There was no difference between the continent volunteers and incontinent patients in body habitus as assessed by the body mass index. Pubovaginal distance and periurethral ligament disruption are significantly associated with incontinence; periurethral ligament symmetricity reduces the odds of incontinence by 87%. Bladder neck funneling and length of the suprapubic urethral sphincter are significantly associated with the type of incontinence on UDs; funneling reduced the odds of pure UH by almost 95%; increasing suprapubic urethral sphincter length at rest is highly associated with UH. Both MRI variables result in a predictive model for UDs diagnosis(area under the ROC = 0.944). CONCLUSION: MRI may play an important role in assessing the contribution of hypermobility and sphincteric dysfunction to the SUI in women when considering treatment options.
文摘AIM: To determine the prevalence of unsuspected thyroid nodules on contrast enhanced 16and 64-modified discrete cosine transform (MDCT) of the chest, in a population of adult outpatients imaged for indications other than thyroid disease. METHODS: This retrospective study involved review of intravascular contrast-enhanced MDCT scans of the chest from 3077 consecutive adult outpatients, to identify unsuspected thyroid nodules. Exclusion criteria included history of thyroid cancer, known thyroid nodules or thyroid disease and risk factors for thyroid cancer, as evidenced by their medical records. One of 9 radiologists recorded number of nodules, location and bidirectional measurement of largest nodule, as well as amount of thyroid visualized on the chest computed tomography (CT). Presence of nodule was correlated with age, gender, race and percentage of thyroid imaged. RESULTS: A total of 2510 (2510/3077 or 81.6%) study subjects were included in the data analysis; among them,one or more nodules were identified in 629 subjects (629/2510 or 25.1%), with 242 (242/629 or 38.5%) having multiple nodules. Patients with nodule(s) were significantly older than those without (64 ± 13 years vs 58 ± 14 years, P < 0.0001), and female gender was associated with presence of nodule(s) (373/1222 or 30.5% vs 256/1288 or 19.9%, P < 0.0001). Women were also more likely having multiple nodules (167/373 or 44.8%) compared to men (75/256 or 29.3%, P < 0.0001). The majority of nodules (427/629 or 67.9%) were less than 1 cm. CONCLUSION: This retrospective review revealed a prevalence of 25.1% for unsuspected thyroid nodules on contrast-enhanced chest CT.
文摘Small-bowel carcinoid tumors are the most common form(42%) of gastrointestinal carcinoids, which by themselves comprise 70% of neuroendocrine tumors. Although primary small bowel neoplasms are overall rare(3%-6% of all gastrointestinal neoplasms), carcinoids still represent the second most common(20%-30%) primary small-bowel malignancy after small bowel adenocarcinoma. Their imaging evaluation is often challenging. State-of-the-art high-resolution multiphasic computed tomography together with advanced postprocessing methods provides an excellent tool for their depiction. The manifold interactive parameter choices however require knowledge of when to use which technique. Here, we discuss the imaging appearance and evaluation of duodenal, jejunal and ileal carcinoid tumors, including the imaging features of the primary tumor, locoregional mesenteric nodal metastases, and distant metastatic disease. A protocol for optimal lesion detection is presented, including the use of computed tomography enterography, volume acquisition, computed tomography angiography and three-dimensional mapping. Imaging findings are illustrated with a series of challenging cases which illustrate the spectrum of possible disease in the small bowel and mesentery, the range of possible appearances in the bowel itself on multiphase data and extraluminal findings such as the desmoplastic reaction in mesentery and hypervascular liver metastases. Typical imaging pitfalls and pearls are illustrated.
基金A.WJ.was supported by the NIH/NIAMS(R01 AR070773,K08 AR068316),NIH/NIDCR(R21 DE027922)Department of Defense(W81XWH-18-1-0121,W81XWH-18-1-0336,W81XWH-18-10613)+1 种基金American Cancer Society(Research Scholar Grant,RSG-18-027-01-CSM)the Maryland Stem Cell Research Foundation,and the Musculoskeletal Transplant Foundation.The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Health,Department of Defense,or US Army.We thank the JHU microscopy facility,JHMI deep sequencing and microarray core facility,and Hao Zhang within the JHU Bloomberg Flow Cytometry and Immunology Core for their technical assistance.
文摘Human osteogenic progenitors are not precisely defined,being primarily studied as heterogeneous multipotent cell populations and termed mesenchymal stem cells(MSCs).Notably,select human pericytes can develop into bone-forming osteoblasts.Here,we sought to define the differentiation potential of CD146 f human pericytes from skeletal and soft tissue sources,with the underlying goal of defining cell surface markers that typify an osteoblastogenic pericyte.CD146+CD31~CD45_pericytes were derived by fluorescence-activated cell sorting from human periosteum,adipose,or dermal tissue.Periosteal CD146+CD31—CD45 cells retained canonical features of pericytes/MSC.Periosteal pericytes demonstrated a striking tendency to undergo osteoblastogenesis in vitro and skeletogenesis in vivo,while soft tissue pericytes did not readily.Transcriptome analysis revealed higher CXCR4 signaling among periosteal pericytes in comparison to their soft tissue counterparts,and CXCR4 chemical inhibition abrogated ectopic ossification by periosteal pericytes.Conversely,enrichment of CXCR4+pericytes or stromal cells identified an osteoblastic/non-adipocytic precursor cell.In sum,human skeletal and soft tissue pericytes differ in their basal abilities to form bone.Diversity exists in soft tissue pericytes,however,and CXCR4+pericytes represent an osteoblastogenic,non-adipocytic cell precursor.Indeed,enrichment for CXCR4-expressing stromal cells is a potential new tactic for skeletal tissue engineering.
基金supported by National Natural Science Foundation of China (No. 11075040)
文摘A general model for skeletal dosimetry in mice is presented. Geometrical constructs were made for four general regions in the mouse skeleton, and dose factors for90 Sr and90Y were calculated using the MCNP Monte Carlo transport code. Then, an overall skeletal dose factor for the whole skeleton was derived based on the individual values and the fraction of the total skeleton that they were assumed to represent. The whole skeleton average values were 1.56 9 10-11Gy/dis for90 Sr and 1.74 9 10-11Gy/dis for90 Y.
文摘Intractable bleeding from gastric and duodenal ulcers is associated with significant morbidity and mortality. Aggressive treatment with early endoscopic hemostasis is essential for a favourable outcome. In as many as 12%-17% of patients,endoscopy is either not available or unsuccessful. Endovascular therapy with selective catheterization of the culprit vessel and injection of embolic material has emerged as an alternative to emergent operative intervention in high-risk patients. There has not been a systematic literature review to assess the role for embolotherapy in the treatment of acute upper gastrointestinal bleeding from gastroduo-denal ulcers after failed endoscopic hemostasis. Here,we present an overview of indications,techniques,and clinical outcomes after endovascular embolization of acute peptic-ulcer bleeding. Topics of particular relevance to technical and clinical success are also discussed. Our review shows that transcatheter arterial embolization is a safe alternative to surgery for massive gastroduodenal bleeding that is refractory to endoscopic treatment,can be performed with high technical and clinical success rates,and should be considered the salvage treatment of choice in patients at high surgical risk.
文摘Over the past two decades,transcatheter arterial embolization has become the first-line therapy for the management of upper gastrointestinal bleeding that is refractory to endoscopic hemostasis.Advances in catheter-based techniques and newer embolic agents, as well as recognition of the effectiveness of minimally invasive treatment options,have expanded the role of interventional radiology in the management of hemorrhage for a variety of indications,such as peptic ulcerbleeding,malignant disease,hemorrhagic Dieulafoy lesions and iatrogenic or trauma bleeding.Transcatheter interventions include the following:selective embolization of the feeding artery,sandwich coil occlusion of the gastroduodenal artery,blind or empiric embolization of the supposed bleeding vessel based on endoscopic findings and coil pseudoaneurysm or aneurysm embolization by three-dimensional sac packing with preservation of the parent artery.Transcatheter embolization is a fast,safe and effective,minimally invasive alternative to surgery when endoscopic treatment fails to control bleeding from the upper gastrointestinal tract.This article reviews the various transcatheter endovascular techniques and devices that are used in a variety of clinical scenarios for the management of hemorrhagic gastrointestinal emergencies.
文摘AIM:To evaluate neurovascular uncoupling(NVU)associated with low grade gliomas(LGG)using blood oxygen level dependent(BOLD)cerebrovascular reactivity mapping.METHODS:Seven patients with low grade gliomas referred by neurosurgeons for presurgical mapping were included in this pilot study.Cerebrovascular reactivity(CVR)mapping was performed by acquiring BOLD images while patients performed a block-design breath-hold(BH)hypercapnia task.CVR mapping was expressed as BOLD percentage signal change(PSC)from baseline associated with performance of the BH hypercapnia task.Standard T2*Dynamic Susceptibility Contrast perfusion imaging was performed and relative cerebral blood volume(rCBV)and relative cerebral blood flow(rCBF)maps were generated.Structural T1 weighted MR images were also acquired.A correlation analysis between intratumoral normalized(via ratio with contralateral homologous regions)BOLD BH PSC[referred to as(nCVR)]and intratumoral normalized resting state rCBV(rCBF)values(i.e.,nCBV and nCBF,respectively)was performed.RESULTS:No significant correlation was seen between the normalized BOLD BH PSC(i.e.,nCBV)and nCBV or nCBF.However,the average nCVR(median=0.50,z=-2.28,P=0.01)was significantly less than 1.0,indicating abnormally reduced vascular responses in the tumor regions relative to normal contralesional homologous regions,whereas the average nCBV(median=0.94,z=-0.92,P=0.375)and nCBF(median=0.93,z=-1.16,P=0.25)were not significantly higher or lower than 1.0,indicating iso-perfusion in the tumor regions relative to normal contralesional homologous regions.These findings suggest that in LGG,hyperperfusion that is seen in high grade gliomas is not present,but,nevertheless,abnormally decreased regional CVR is present within and adjacent to LGG.Since the patients all demonstrated at least some residual function attributable to the cortical regions of impaired CVR,but were incapable of producing a BOLD response in these regions regardless of the tasks performed,such regionally decreased CVR is indicative of NVU.The low nCVR ratios indicate high prevalence of NVU in this LGG cohort,which is an important consideration in the interpretation of clinical presurgical mapping with functional magnetic resonance(MR)imaging.CONCLUSION:Our preliminary study shows that BH CVR mapping is clinically feasible and demonstrates an unexpectedly high prevalence of NVU in patients with LGG.
文摘AIM: To test the incremental value of 3T magnetic resonance neurography(MRN) in a series of unilateral radiculopathy patients with non-contributory magnetic resonance imaging(MRI).METHODS: Ten subjects(3 men,7 women; mean age54 year and range 22-74 year) with unilateral lumbar radiculopathy and with previous non-contributory lumbar spine MRI underwent lumbosacral(LS) plexus MRN over a period of one year. Lumbar spine MRI performed as part of the MRN LS protocol as well as bilateral L4-S1 nerves,sciatic,femoral and lateral femoral cutaneous nerves were evaluated in each subject for neuropathy findings on both anatomic(nerve signal,course and caliber alterations) and diffusion tensor imaging(DTI)tensor maps(nerve signal and caliber alterations).Minimum fractional anisotropy(FA) and mean apparent diffusion coeffcient(ADC) of L4-S2 nerve roots,sciatic and femoral nerves were recorded.RESULTS: All anatomic studies and 80% of DTI imaging received a good-excellent imaging quality grading. In a blinded evaluation,all 10 examinations demonstrated neural and/or neuromuscular abnormality corresponding to the site of radiculopathy. A number of contributory neuropathy findings including double crush syndrome were observed. On DTI tensor maps,nerve signal and caliber alterations were more conspicuous. Although individual differences were observed among neuropathic appearing nerve(lower FA and increased ADC) as compared to its contralateral counterpart,there were no significant mean differences on statistical comparison of LS plexus nerves,femoral and sciatic nerves(P > 0.05).CONCLUSION: MRN of LS plexus is useful modality for the evaluation of patients with non-contributory MRI of lumbar spine as it can incrementally delineate the etiology and provide direct objective and non-invasive evidence of neuromuscular pathology.
文摘AIM: To evaluate the pudendal nerve segments that could be identified on magnetic resonance neurography(MRN) before and after surgical marking of different nerve segments.METHODS: The hypothesis for this study was that pudendal nerve and its branches would be more easily seen after the surgical nerve marking. Institutional board approval was obtained. One male and one female cadaver pelvis were obtained from the anatomy board and were scanned using 3 Tesla MRI scanner using MR neurography sequences. All possible pudendal nerve branches were identified. The cadavers were then sent to the autopsy lab and were surgically dissected by a peripheral nerve surgeon and an anatomist to identify the pudendal nerve branches. Radiological markers were placed along the course of the pudendal nerve and its branches. The cadavers were then closed and rescanned using the same MRN protocol as the premarking scan. The remaining pudendal nerve branches were attempted to be identified using the radiological markers. All scans were read by an experienced musculoskeletal radiologist.RESULTS: The pre-marking MR Neurography scans clearly showed the pudendal nerve at its exit from the lumbosacral plexus in the sciatic notch, at the level of the ischial spine and in the Alcock's Canal in both cadavers. Additionally, the right hemorrhoidal branch could be identified in the male pelvis cadaver. The perineal and distal genital branches could not be identified. On post-marking scans, the markers were used as identifiable structures. The location of the perineal branch, the hemorroidal branch and the dorsal nerve to penis(in male cadaver)/clitoris(in female cadaver) could be seen. However, the visualization of these branches was suboptimal. The contralateral corresponding nerves were poorly seen despite marking on the surgical side. The nerve was best seen on axial T1W and T2W SPAIR images. The proximal segment could be seen well on 3D DW PSIF sequence. T2W SPACE was not very useful in visualization of this small nerve or its branches.CONCLUSION: Proximal pudendal nerve is easily seen on MR neurography, however it is not possible to identify distal branches of the pudendal nerve even after surgical marking.
文摘AIM: To investigate whether congenital lumbar spinal stenosis(CLSS) is associated with a specific degenerative changes of the lumbar spine. METHODS: The lumbar spine magnetic resonance imaging studies of 52 subjects with CLSS and 48 control subjects were retrospectively evaluated. In each examination, the five lumbar levels were assessed for the presence or absence of circumferential or shallow annular bulges, annular tears, anterior or posterior disc herniations, epidural lipomatosis, Schmorl's nodes,spondylolisthesis, pars defects, and stress reactions of the posterior vertebral elements. RESULTS: Compared to control individuals, subjects with CLSS exhibited increased incidence of circumferential and shallow annular bulges, annular tears, discherniations and spondylolisthesis(P < 0.05). CONCLUSION: CLSS is associated with increased incidence of degenerative changes in specific osseous and soft-tissue elements of the lumbar spine.
基金supported in part by National Institutes of Health T32 AR067708,RO1CA201035the MRB Molecular Imaging Service Center(P50 CA103175)
文摘Discriminating sterile inflammation from infection, especially in cases of aseptic loosening versus an actual prosthetic joint infection, is challenging and has significant treatment implications. Our goal was to evaluate a novel human monoclonal antibody(mAb) probe directed against the Gram-positive bacterial surface molecule lipoteichoic acid(LTA). Specificity and affinity were assessed in vitro. We then radiolabeled the anti-LTA mAb and evaluated its effectiveness as a diagnostic imaging tool for detecting infection via immuno PET imaging in an in vivo mouse model of prosthetic joint infection(PJI). In vitro and ex vivo binding of the anti-LTA mAb to pathogenic bacteria was measured with Octet, ELISA, and flow cytometry. The in vivo PJI mouse model was assessed using traditional imaging modalities, including positron emission tomography(PET) with [^(18)F]FDG and [^(18)F]Na F as well as X-ray computed tomography(CT), before being evaluated with the zirconium-89-labeled antibody specific for LTA([^(89)Zr]SAC55).The anti-LTA mAb exhibited specific binding in vitro to LTA-expressing bacteria. Results from imaging showed that our model could reliably simulate infection at the surgical site by bioluminescent imaging, conventional PET tracer imaging, and bone morphological changes by CT. One day following injection of both the radiolabeled anti-LTA and isotype control antibodies, the anti-LTA antibody demonstrated significantly greater(P < 0.05) uptake at S. aureus-infected prosthesis sites over either the same antibody at sterile prosthesis sites or of control non-specific antibody at infected prosthesis sites. Taken together, the radiolabeled anti-LTA mAb, [^(89)Zr]SAC55, may serve as a valuable diagnostic molecular imaging probe to help distinguish between sterile inflammation and infection in the setting of PJI. Future studies are needed to determine whether these findings will translate to human PJI.
文摘Coronary computed tomography angiography(CCTA)has become an integral tool in the noninvasive diagnostic workup of patients with suspected coronary artery disease in both elective and emergency settings. Today, it represents a mature technique providing accurate, non-invasive morphological assessment of the coronary arteries and atherosclerotic plaque burden. Iterative reconstruction algorithms, low kV imaging, and single-heart beat acquisitions hold promise to further reduce dose requirements and improve the safety and robustness of the technique in several circumstances including imaging of heavily calcified vessels, patients with morbid obesity or irregular heart rates, and assessment in the emergency setting. However, it has become clear over recent years that cardiac radiologists need to take further steps towards the development and integration of functional imaging with morphological CCTA assessment to truly provide a comprehensive evaluation of the heart. Computed tomography myocardial perfusion imaging, including both dynamic and static dual-energy approaches, has demonstrated the ability to directly assess and quantify myocardial ischemia with simultaneous CCTA acquisition with a reasonable contrast medium volume and radiation dose delivered to the patient. In order to promote CCTA in the clinical and research environments, radiologists should prepare to embrace the change from morphological to functional imaging, furnishing all the necessary resources and information to referring clinicians.
文摘While the activation of primary somatosensory(SI) cortex during pain perception is consistently reported in functional imaging studies on normal subjects and chronic pain patients,the specific roles of SI,particularly the subregions within SI,in the processing of sensory aspects of pain are still largely unknown.Using optical imaging of intrinsic signal(OIS) and single unit electrophysiology,we studied cortical activation patterns within SI cortex(among Brodmann areas 3a,3b and 1) and signal amplitude changes to various intensities of non-nociceptive,thermal nociceptive and mechanical nociceptive stimulation of individual distal finerpads in anesthetized squirrel monkeys.We have demonstrated that areas 3a and 1 are preferentially involved in the processing of nociceptive information while areas 3b and 1 are preferentially activated in the processing of non-nociceptive(touch) information.Nociceptive activations of individual fingerpad were organized topographically suggesting that nociceptive topographic map exits in areas 3a and 1.Signal amplitude was enhanced to increasing intensity of mechanical nociceptive stimuli in areas 3a,3b and 1.Within area 1,nociceptive response co-localizes with the non-nociceptive response.Therefore,we hypothesize that nocicepitve information is area-specifically represented within SI cortex,in which nociceptive inputs are preferentially represented in areas 3a and 1 while non-nociceptive inputs are preferentially represented in areas 3b and 1.
文摘BACKGROUND In chest computed tomography(CT)scan,bilateral peripheral multifocal groundglass opacities,linear opacities,reversed halo sign,and crazy-paving pattern are suggestive for coronavirus disease 2019(COVID-19)in clinically suspicious cases,but they are not specific for the diagnosis,as other viral pneumonias,like influenza and some viral pneumonia may show similar imaging findings.AIM To find a specific imaging feature of the disease would be a welcome guide in diagnosis and management of challenging cases.METHODS Chest CT imaging findings of 650 patients admitted to a university Hospital in Tehran,Iran between January 2020 and July 2020 with confirmed COVID-19 infection by RT-PCR were reviewed by two expert radiologists.In addition to common non-specific imaging findings of COVID-19 pneumonia,radiologic characteristics of“pulmonary target sign”(PTS)were assessed.PTS is defined as a circular appearance of non-involved pulmonary parenchyma,which encompass a central hyperdense dot surrounded by ground-glass or alveolar opacities.RESULTS PTS were presented in 32 cases(frequency 4.9%).The location of the lesions in 31 of the 32 cases(96.8%)was peripheral,while 4 of the 31 cases had lesions both peripherally and centrally.In 25 cases,the lesions were located near the pleural surface and considered pleural based and half of the lesions(at least one lesion)were in the lower segments and lobes of the lungs.22 cases had multiple lesions with a>68%frequency.More than 87%of cases had an adjacent bronchovascular bundle.Ground-glass opacities were detectable adjacent or close to the lesions in 30 cases(93%)and only in 7 cases(21%)was consolidation adjacent to the lesions.CONCLUSION Although it is not frequent in COVID-19,familiarity with this feature may help radiologists and physicians distinguish the disease from other viral and noninfectious pneumonias in challenging cases.
基金supported by NIH Grant R01 NS069909an imaging track Grant from the Dana Foundation
文摘Human functional MRI studies in acute and various chronic pain conditions have revolutionized how we view pain, and have led to a new theory that complex multi-dimensional pain experience(sensory-discriminative,affective/motivational, and cognitive) is represented by concurrent activity in widely-distributed brain regions(termed a network or pain matrix). Despite these breakthrough discoveries, the specific functions proposed for these regions remain elusive, because detailed electrophysiological characterizations of these regions in the primate brain are lacking. To fill in this knowledge gap, we have studied the cortical areas around the central and lateral sulci of the non-human primate brain with combined submillimeter resolution functional imaging(optical imaging and fMRI) and intracranial electrophysiological recording. In this mini-review, I summarize and present data showing that the cortical circuitry engaged in nociceptive processing is much more complex than previously recognized. Electrophysiological evidence supports the engagement of a distinct nociceptive-processing network within SI(i.e., areas 3 a, 3 b, 1 and 2), SII, and other areas along the lateral sulcus. Deafferentation caused by spinal cord injury profoundly alters the relationships between fMRI and electrophysiological signals. This finding has significant implications for using fMRI to study chronic pain conditions involving deafferentation in humans.
