Oblique-sagittal black-blood contrast-enhanced magnetic resonance imaging in preoperative evaluation for carotid endarterectomy / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the value of oblique-sagittal black-blood contrast-enhanced magnetic resonance imaging (OB-CEMRI) in atherosclerotic carotid artery (CA) assessment before carotid endarterectomy (CEA).</p><p><b>METHODS</b>Twenty-five patients with symptomatic atherosclerotic stenosis in the carotid artery (involving 26 arteries) were scheduled for CEA. OB-CEMRI and digital subtraction angiography (DSA) were conducted within 1 week prior to CEA, and two radiologists independently assessed the location of maximal lumen stenosis, plaque rupture, degree of maximal lumen stenosis and plaque involvement on DSA and OB-CEMRI images. The differences of DSA and the OB-CEMRI in analyzing the plaque conditions were assessed in comparison with matched histological sections of the excised specimens.</p><p><b>RESULTS</b>Compared with the corresponding histological specimens, both DSA (κ=0.807) and OB-CEMRI (κ=0.812) showed a good consistency in defining the location of the maximal lumen stenosis. OB-CEMRI showed a better performance in detecting plaque rupture with higher sensitivity (90.0%) and specificity (83.3%) than DSA (40.0% and 66.7%, respectively). No significant difference was found between DSA and the OB-CEMRI in evaluating the degree of maximal lumen stenosis [(77.33∓3.79)% vs (76.02∓3.95)%, P=0.648]. Compared with the histological examination, OB-CEMRI appeared to underestimate the stenosis. The plaque extent on OB-CEMRI was larger than that on DSA (18.96∓4.96 mm vs 14.80∓3.78 mm, P=0.004), and similar to that by histological examination (18.13∓4.57 mm, P=0.506).</p><p><b>CONCLUSIONS</b>OB-CEMRI allows noninvasive and objective detection of the location of the maximal lumen stenosis, plaque rupture, and plaque extent, though with a lower accuracy than DSA in the assessment of the maximal lumen stenosis. OB-CEMRI combined with DSA offers a more reliable means for preoperative evaluation of the carotid artery plaques for CEA.</p>

Evaluation of atherosclerotic carotid plaque composition with magnetic resonance imaging using different sequences / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the capability of magnetic resonance imaging (MRI) using different sequences in displaying atherosclerotic carotid plaque composition.</p><p><b>METHODS</b>Thirty-five patients received pre- and post-contrast carotid MRI examination on a 3.0T scanner. TOF, T(1)W, T(2)W, PDW and CE-T(1)W were used for identifying the positive and negative cases for the plaque composition (lipid-rich necrotic core, intraplaque hemorrhage and calcification), and their respective sensitivity, specificity and Cohens κ with 95% CI for displaying the components of the plaques were calculated.</p><p><b>RESULTS</b>A total of 74 plaques were found in the 35 patients, and after exclusion of 6 plaques for a thickness below 3 mm, 68 plaques were included for the analysis. Lipid-rich necrotic core were found in 57 plaques, intraplaque hemorrhage in 30 plaques, and alcification in 43 plaques. CE-T(1)W was the optimal sequence for displaying lipid-rich necrotic core with a sensitivity of 100%, specificity of 90.9%, and κ value of 0.944. Both T(1)W and TOF reliably showed the intraplaque hemorrhage, but the former had a greater sensitivity (100%), specificity (92.1%), and κ value (0.911). Of all the 5 sequences, TOF was the best to show calcification with high sensitivity (100%), specificity (92%), and κ value (0.936).</p><p><b>CONCLUSION</b>CE-T(1)W is the best sequence to show lipid-rich necrotic core with high sensitivity and specificity. T(1)W and TOF show a high level of agreement with the standard to show the intraplaque hemorrhage. TOF is more sensitive and accurate than the other sequences in displaying calcification. The combination of T(1)W, TOF and CE-T(1)W allows accurate evaluation of each component of the plaque.</p>

Atherosclerotic area measurement in the vascular wall of the carotid artery: comparison between 16-slice computed tomography angiography and high-resolution magnetic resonance imaging / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the accuracy of computed tomography angiography (CTA) in quantifying atherosclerotic area in the vascular wall of the carotid artery in comparison with high-resolution magnetic resonance imaging (MRI).</p><p><b>METHODS</b>Eighteen subjects (15 males and 3 females aged 63-/+8 years) with >or=50% stenosis in at least one carotid artery were enrolled in this study. CTA and high-resolution MRI scans (in-plane pixel size of 0.25 mmx0.25 mm for both) were conducted within 1 week on a multi-slice spiral CT scanner and a 1.5T MR scanner (Signa, GE Medical Systems), respectively. CTA images were matched with MR images with the carotid bifurcation as the mark. For each patient, multiple matched slices with carotid atherosclerotic plaques in the bilateral carotid arteries were selected to measure the outer wall boundary (OWB) area, lumen area and wall area. Bland-Altman analysis and Pearson correlation coefficients were used to analyze the correlations of the area measurements between CTA and high-resolution MRI.</p><p><b>RESULTS</b>A wide range of lesion size (vascular wall area) was found in these patients. Strong correlations were noted between CTA and high-resolution MRI with the correlation coefficients for OWB area, lumen area and wall area of 0.98, 0.98 and 0.96, respectively. The mean differences between CTA and high-resolution MRI were 0.16-/+5.71 mm(2), 4.47-/+1.44 mm(2) and -4.31-/+5.73 mm(2) for OWB area, lumen area and wall area, respectively.</p><p><b>CONCLUSION</b>Compared to high-resolution MRI, CTA is also a reliable method to measure carotid vascular wall area. CTA might become an alternative modality to high-resolution MRI for follow-up examination of patients with carotid artery atherosclerosis, especially in uncooperative patients or patients with contra-indications for MRI.</p>

Feasibility of whole body diffusion weighted imaging in detecting bone metastasis on 3.0T MR scanner / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the feasibility of whole body diffusion weighted imaging (DWI) in bone metastasis detection using bone scintigraphy as comparison.</p><p><b>METHODS</b>Forty-five patients with malignancy history were enrolled in our study. All the patients received the whole body DWI and bone scintigraphy scan within 1 week. The magnetic resonance (MR) examination was performed on 3.0T MR scanner using embedded body coil. The images were reviewed separately by two radiologists and two nuclear medicine physicians, who were blinded to the results of the other imaging modality. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the two techniques for detecting bone metastasis were analyzed.</p><p><b>RESULTS</b>A total of 181 metastatic lesions in 77 regions of 34 patients were detected by whole body DWI, and 167 metastatic lesions in 76 regions of 31 patients were identified by bone scintigraphy. The patient-based sensitivity and PPV of whole body DWI and bone scintigraphy were similar (89.5% vs. 81.6%, 97.1% vs. 91.2%), whereas, the patient-based specificity and NPV of whole body DWI were obviously higher than those of bone scintigraphy (85.7% vs. 57.1%, 60.0% vs. 36.4%). Ten regions negative in scintigraphy but positive in whole body DWI, mainly located in spine, pelvis, and femur; nine regions only detected by scintigraphy, mainly located in skull, sternum, clavicle, and scapula. The region-based sensitivity and specificity of whole body DWI were slightly higher than those of bone scintigraphy (89.5% vs. 88.4%, 95.6% vs. 87.6%).</p><p><b>CONCLUSION</b>Whole body DWI reveals excellent concordance with bone scintigraphy regarding detection of bone metastasis, and the two techniques are complementary for each other.</p>

Diffusion-weighted magnetic resonance imaging in diagnosis of Creutzfeldt-Jakob disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Creutzfeldt-Jakob disease (CJD), a rare disease, is uncharacterized by computed tomography (CT) and magnetic resonance imaging (MRI). This study was aimed to evaluate the diffusion-weighted MRI (DWI) manifestations of CJD and to discuss their diagnostic value.</p><p><b>METHODS</b>The findings of T(1)-weighted MRI (T(1)WI), T(2)-weighted MRI (T(2)WI), DWI and post-contrast MRI in 5 patients (3 patients with biopsy-proven CJD and 2 patients with clinically-proven CJD) were retrospectively analyzed in this study.</p><p><b>RESULTS</b>Four out of the 5 patients had cerebral atrophy of various degrees. One patient showed symmetric high signal intensity at the bilateral globus pallidus and the head of the caudate nucleus, with very high signal in the cerebral cortex on the DWI. This patient only had symmetric slightly high signal at the bilateral globus pallidus and putamen on T(2)WI. One patient had high signal intensity at the basal ganglia and cerebral cortex on DWI, but abnormal T(2) signal intensity at the bilateral paraventricular white matter on MRI. Two patients presented with widely gyri-like high signal intensity at the cortex on DWI, but routine MRI showed bilateral paraventricular long T(2) signal intensity in 1 patient and no abnormal findings in another. No abnormalities were shown by both routine MRI and DWI in the last patient.</p><p><b>CONCLUSIONS</b>DWI is more sensitive than its conventional counterpart in the depiction of CJD. DWI is more sensitive to detect cortical abnormal signal intensity in CJD not detected by T(2)WI.</p>

Comparison between cerebral ischemia disease and multiple sclerosis by using MR diffusion tensor imaging / 中华放射学杂志

0.05).Conclusion DTI can noninvasive detect the potential disorder of corpus eallosum in vivo,thus providing useful information to differentiate the cerebral ischemia disease from multiple sclerosis.

Bile cystadenocarcinoma:MRI findings with pathologic correlation / 中华放射学杂志

Objective To describe the MRI features and pathologic findings of biliary cystadenocarcinoma(BCAC)and to assess the diagnostic value of MRI in those tumors.Methods Five cases of BCAC were collected.All cases were proved by pathology.Non-enhanced and multiphase-enhanced MRI were performed in all cases.MRCP were performed in two cases.The MRI features of the five cases were reviewed retrospectively and correlated with pathologic findings.Results Histological evidence demonstrated five cases of BCAC.Four cases were solitary,whereas the other case was multifocal.All cases were solid and cystic lesions.Two cases were unilocular,whereas the other three cases were multilocular. Multiple mural nodules and irregular thickening cystic walls were presented in all cases.The cystic parts of the lesions were homogeneous in signal intensity and showed no enhancement after contrast administration in the five BCAC.Septa were present in three BCAC with multilocular cyst.On MRCP the bile duct dilatation was found in two BCAC.Conclusion MRI can reveal the characteristic findings of BCAC and accurate preoperative diagnosis can be made.