3.0 T高分辨率MR血管壁成像对大动脉炎活动性判断的价值

目的 探讨3.0 T高分辨率MR血管壁成像对大动脉炎活动性判断的价值.方法 26例确诊为大动脉炎的患者(根据Lupi-Herrea分类,为Ⅰ和Ⅲ型,均累及主动脉弓及其主要大分支)接受了颈部及上胸部MR血管壁成像,其中处于病情活动期16例,非活动期10例.分析并比较了2组患者受累动脉管壁的MRI表现特征.采用X~2检验对2组患者的血管壁形态进行统计学分析.结果 所有受累动脉的血管壁均有不同程度的环形增厚.活动期组患者的管壁厚度较非活动期组患者增厚明显[分别为(3.8±0.2)和(2.5±0.8) mm];比较2组增厚的血管壁形态,管壁呈多环征(分别为75/80和18/50)、内壁明显强化(分别为50/80和19/50)、血管外界模糊不清(分别为55/80和18/50)等征象,差异均有统计学意义(X~2值分别为50.39、7.41、13.40,P值均<0.01).结论 大动脉炎高分辨率MR血管壁成像的主要征象是管壁增厚及信号改变,3.0 T MR血管壁成像能精细观察血管壁的形态学变化,对大动脉炎的活动性判断具有重要价值.     

Moyamoya disease: diagnosis with three-dimensional time-of-flight MR angiography.

Twelve patients with moyamoya disease were studied with three-dimensional time-of-flight magnetic resonance (MR) angiography, and the findings were compared with results obtained with conventional arteriography. Of a total of 24 supraclinoid internal carotid arteries studied, 21 arteries (88%) were accurately evaluated with MR angiography and in three arteries the extent of occlusive disease was overestimated. Of a total of 72 large branch basal cerebral vessels, including the bilateral anterior, middle, and posterior cerebral arteries, 61 arteries (85%) were accurately evaluated with MR angiography and in 11 arteries the extent of occlusive disease was overestimated. While conventional arteriography showed basal cerebral moyamoya vessels in all 24 hemispheres, MR angiography showed moyamoya vessels in 20 of these. Of a total of 28 large leptomeningeal and transdural collateral vessels, 18 were identified with MR angiography. In the one surgical collateral vessel evaluated, MR angiography successfully showed its patency. MR angiography may have value in following disease progression and, perhaps, in evaluation of surgical bypass patency.     

Takayasu arteritis: diagnosis with MR imaging and MR angiography in acute and chronic active stages.

Early diagnosis and treatment of Takayasu arteritis is important in prevention of serious complications. Spin-echo magnetic resonance imaging (MRI) can depict early wall thickening of the aorta and cine MRI can evaluate aortic valve function. Significant enhancement in and around the aorta and carotid arteries is observed on postcontrast MR images in acute phase Takayasu arteritis. In the chronic phase, contrast enhancement in the aortic wall stronger than in the myocardium suggests activity of the disease. Breath-hold contrast-enhanced three-dimensional MR angiography is very effective in noninvasive evaluation of luminal change of aortitis. Contrast-enhanced MRI and MR angiography have an important role in early diagnosis, activity determination, and follow-up of Takayasu arteritis. MRI and MR angiography can be utilized for initial diagnosis of Takayasu arteritis and replace catheterization angiography. J. Magn. Reson. Imaging 1999;10:751-757.     

Leptomeningeal high signal intensity (ivy sign) on fluid-attenuated inversion-recovery (FLAIR) MR images in moyamoya disease

PURPOSE: There are a few reports on leptomeningeal high signal intensity (LMHI: ivy sign) on fluid-attenuated inversion-recovery (FLAIR) images in moyamoya disease, but the feature of this finding has not been completely understood. The purpose of this study was to characterize LMHI on FLAIR images in moyamoya disease and to assess usefulness of this finding in the diagnosis of moyamoya disease in conventional MR imaging. MATERIAL AND METHODS: MR imaging of 28 patients with moyamoya disease was retrospectively reviewed. The grade of LMHI on FLAIR images was classified as "absent," "minimal," "moderate" and "marked." Fifty-four hemispheres of 28 patients (2 patients had unilateral disease) were assessed for the frequency of visualization and distribution of LMHI. The correlations between LMHI on FLAIR images, moyamoya vessels on T1- and T2-weighted images and MR angiography findings were also analyzed. RESULTS: Moderate and marked LMHI was seen in 31 out of 54 hemispheres (57%). LMHI was seen more prominently in the frontal and parietal lobes than in the temporal and occipital lobes. Although there was a tendency for LMHI on FLAIR images to be prominent in groups with moderate and marked moyamoya vessels on T1- and T2-weighted images, there was no significant correlation. More prominent LMHI was observed in the hemispheres in which cortical branches of the middle cerebral arteries were poorly visualized on MR angiography. CONCLUSION: Leptomeningeal high signal intensity (ivy sign) on FLAIR images is predominantly seen in the frontal and parietal lobes. Because this sign can be seen in patients with unremarkable moyamoya vessels, LMHI is a useful sign in conventional MR imaging for the diagnosis of moyamoya disease.     

Bowel disease: prospective comparison of CT and 1.5-T pre- and postcontrast MR imaging with T1-weighted fat-suppressed and breath-hold FLASH sequences.

The potential of new high-field-strength magnetic resonance (MR) imaging sequences to evaluate bowel disease was investigated and compared with computed tomographic (CT) studies. Thirty-two patients were studied, 14 with known or suspected gastrointestinal tumors and 18 with known or suspected bowel inflammatory conditions. T1-weighted fat-suppressed spin-echo and breath-hold FLASH (fast low-angle shot) images were obtained before and after intravenous injection of 0.1 mmol/kg gadopentetate dimeglumine. Pathologic confirmation was obtained by biopsy (n = 18), surgical excision (n = 8), or endoscopy (n = 6). CT and MR images were analyzed separately in a prospective fashion and reviewed by consensus. Information from CT and MR images was comparable in cases of confirmed bowel neoplasia. CT scans had better spatial resolution, while fat-suppressed gadolinium-enhanced MR images had better contrast resolution. In the 18 cases of bowel inflammation, CT scans showed concentric wall thickening in 16, while MR images showed concentric wall thickening in 14 and increased contrast enhancement in 17. Contrast enhancement was better appreciated on fat-suppressed images than on FLASH images. The results suggest that MR imaging may play a role in the evaluation of bowel disease.     

Moyamoya disease: evaluation with diffusion-weighted and perfusion echo-planar MR imaging.

PURPOSE: To determine the clinical efficacy of diffusion-weighted and perfusion echo-planar magnetic resonance (MR) imaging in the evaluation of moyamoya disease. MATERIALS AND METHODS: Seventeen patients with moyamoya disease were examined prospectively with diffusion-weighted and perfusion echo-planar MR imaging and conventional angiography. The change in the effective transverse relaxation rate (delta R2*) peak value, delta R2* peak time, and delta R2* integral were calculated to assess regional cerebral perfusion. The MR images were compared with angiographic images. RESULTS: Of the 34 posterior cerebral arteries (PCAs) of the 17 patients, 14 PCAs (41%) in 11 patients showed stenosis or occlusion. The delta R2* peak value ratio in the cerebral hemispheres decreased significantly, and the delta R2* peak time ratio increased significantly, with PCA stenosis and occlusion. However, no correlation was apparent between perfusion and extent of the stenotic or occlusive lesions of the internal carotid artery bifurcation. The frequency of cerebral infarctions was significantly increased in patients with stenotic or occlusive PCA lesions. For three acute infarctions, a decrease in the apparent diffusion coefficient was significantly correlated with a decrease in the delta R2* peak value, an increase in the delta R2* peak time, and a decrease in the delta R2* integral. CONCLUSION: Regional cerebral perfusion in moyamoya disease is decreased and delayed with PCA stenosis, with greater decrease and delay with PCA occlusion. Diffusion-weighted and perfusion imaging are useful for evaluating cerebral ischemia in moyamoya disease.     

MRI和MRA对烟雾病的诊断价值

目的：评价ＭＲＩ和ＭＲ血管成像（ＭＲＡ）在烟雾病中的诊断价值。材料与方法：回顾性分析２３例烟雾病患者的ＭＲＩ和ＭＲＡ资料，ＭＲＡ采用三维时间飞跃法。结果：２３例患者ＭＲＡ图像均有不同程度的颈内动脉分叉处的血管狭窄／闭塞，１８例基底节区异常网状的血管和１４例软脑膜侧支循环血管显示清晰。ＭＲＩ上显示了所有患者的脑实质改变和１５例颈内动脉分叉处的血管狭窄／闭塞改变，所有患者根据其ＭＲ上脑血管的改变均可做出正确的诊断。结论：ＭＲＡ结合ＭＲＩ能对烟雾病患者做出正确的诊断和较准确的分期，同时可用于烟雾病患者的随访检查和术后复查。     

3T MRI Reveals Extra- and Intracranial Involvement in Giant Cell Arteritis

BACKGROUND AND PURPOSE:The frequency and amount of intracranial, intradural inflammatory vessel wall enhancement in giant cell arteritis remain unclear. The purpose of this work was to prospectively assess the intracranial extent of vasculitic changes in patients with giant cell arteritis using a dedicated MR imaging protocol optimized for assessment of mural changes of intracranial arteries.MATERIALS AND METHODS:Twenty-eight patients with suspected giant cell arteritis underwent 3T MR imaging. Imaging included a fat-saturated T1WI pre- and postcontrast application optimized for assessment of intradural vessel wall enhancement and high-resolution fat-saturated T1WI to evaluate superficial extracranial vessels. Temporal artery biopsies were available in 11 cases. Vessel wall enhancement of intradural and extracranial vessels was evaluated by 2 observers independently.RESULTS:Twenty patients had giant cell arteritis; 9 cases were biopsy-proved. Clear vessel wall enhancement of superficial extracranial and intradural internal carotid arteries was detected in 16 and 10 patients, respectively. Slight vessel wall enhancement of the vertebral arteries was seen. Of 9 patients with giant cell arteritis with vessel occlusion or stenosis, 2 presented with cerebral ischemic infarcts. Vessel occlusion or stenosis site coincided with the location of vessel wall enhancement of the vertebral arteries in 4 patients and of the intradural ICA in 1 patient.CONCLUSIONS:Vessel wall enhancement of intradural arteries, mainly the ICA, can be regularly found in patients with giant cell arteritis. Mural inflammatory changes of the intradural ICA detected on MR imaging may identify a subgroup of patients with giant cell arteritis and should be further evaluated in clinical studies.

Giant cell arteritis (GCA) commonly affects large- and medium-sized arteries with predominance in the aorta and the supra-aortic vessels such as the subclavian, carotid, and axillary arteries and the superficial cranial arteries, among others.^1,2 Recent imaging studies have shown inflammatory involvement of the aorta in up to 65% and of the subclavian arteries in up to 35% of patients.^3,4The extent of vasculitic changes to the intracranial vasculature is discussed controversially and is currently not fully understood. Not a single intracranial artery was involved in a postmortem study of patients who died during the phase of active GCA when the extracranial superficial temporal and ophthalmic arteries were severely inflamed. The different composition of the intracranial arteries with less elastic tissue in the media compared with the extracranial arteries may correlate with the inflammatory activity in GCA.⁵ However, a more recent article indicated that intracranial involvement in GCA does occur, presumably less frequently.⁶High-resolution MR imaging studies have been proved to reliably detect mural inflammation such as mural thickening and increased mural contrast enhancement of the superficial temporal and occipital arteries in biopsy-proved GCA.^7,8 Diagnostic criteria for detecting intracranial vasculitis are intramural contrast uptake, in most cases combined with wall thickening.⁹ These criteria are valid for patients presenting with primary angiitis of the central nervous system, childhood primary angiitis of the central nervous system or GCA, and other causes of central nervous system vasculitis.¹⁰A retrospective analysis of high-resolution MR imaging of the superficial cranial arteries of 50 patients with GCA did not reveal any inflammatory mural changes of the intracranial arteries of the circle of Willis.¹¹ However, the MR imaging protocol in that particular study was optimized to depict mural inflammation of the superficial cranial arteries and was not specifically adjusted for visualization of the intradural arteries. The purpose of this work was to prospectively assess the intracranial extent of vasculitic changes in patients with GCA using a dedicated MR imaging protocol optimized for assessment of mural changes of intracranial arteries.     

Diagnostic value of high-resolution MR imaging in giant cell arteritis

BACKGROUND AND PURPOSE: Clinical indications of giant cell arteritis may be unspecific, and noninvasive diagnosis is often difficult. This study investigated the hypothesis that high-resolution MR imaging of the superficial cranial arteries is a noninvasive imaging technique that can detect the occurrence of giant cell arteritis. MATERIALS AND METHODS: Contrast-enhanced, high-resolution MR imaging was performed on 64 consecutive patients with suspected giant cell arteritis. Mural thickness, lumen diameter, and a mural contrast enhancement score were assessed with T1-weighted spin-echo images with submillimeter in-plane spatial resolution. The final rheumatologist's diagnosis according to the clinical criteria of the American College of Rheumatology including laboratory tests and results of temporal artery biopsies from 32 patients was used as a "gold standard" for the evaluation of the MR imaging findings. RESULTS: All of the examinations provided diagnostic image quality. Evaluation of the mural inflammatory MR imaging signs for diagnosing vasculitis resulted in a sensitivity of 80.6% and a specificity of 97.0%. In comparison, histology results alone showed a sensitivity of 77.8% and specificity of 100%. The mean wall thickness increased significantly from 0.39 mm (+/-0.18 mm) to 0.74 mm (+/-0.32 mm; P < .001), and the lumen diameter decreased significantly from 0.84 mm (+/-0.29 mm) to 0.65 mm (+/-0.38 mm; P < .05) for patients with giant cell arteritis. CONCLUSION: Contrast-enhanced, high-resolution MR imaging allows noninvasive assessment of mural inflammation in giant cell arteritis with good diagnostic certainty. Measures of mural thickening and contrast enhancement can be obtained in these small vessels and provide valuable vasculitic MR imaging findings.     

Value of F-18 FDG hybrid camera PET and MRI in early takayasu aortitis

Takayasu aortitis (TA) is a chronic inflammatory and fibrotic vasculitis of large- and medium-sized arteries. Early stages of the disease show a panarteritis and inflammatory wall thickening of the aorta and its branches, whereas advanced (fibrotic) stages comprise stenosis, aneurismatic transformation and occlusion. Magnetic resonance imaging visualises early-stage disease with high accuracy and is considered to be the method of choice in the diagnosis of TA. The aim of this article is the detailed comparison of FDG-PET performed with a hybrid camera and MR imaging in five patients with early TA. Five patients (median age 60 years) were enrolled during an ongoing prospective study on [18F]2'-deoxy-2-fluoro-D-glucose (FDG) hybrid camera PET in patients with fever of unknown origin (FUO). These patients underwent MR imaging after establishing the diagnosis of TA. Abnormal FDG uptake in the wall of the aorta was noted in all patients. The bracheocephalic artery and the common carotid arteries were visualized in 3 cases. Increased uptake of the subclavian artery was found in 3 patients and in 4 patients pathological uptake was noted in the ilio-femoral vessels. Of 34 vascular regions studied, 26 (76%) showed elevated FDG uptake. On transversal MR images vessel wall thickening and contrast enhancement of the thoracic aorta was found in 4 patients (ascending aorta/aortic arch: n=2; descending aorta: n=3; abdominal aorta: n=1). Additionally, vessel wall pathologies of the subclavian and the common carotid arteries could be shown in 1 patient and in another patient in the ilio-femoral arteries. No abnormalities were found using contrast-enhanced MR angiography. Of 28 vascular regions studied, 9 (32%) showed vasculitis on MRI. The FDG-PET is a suitable whole-body screening method in the primary diagnosis of early TA, especially in those cases with early disease that present with uncharacteristic symptoms such as FUO. Both MRI and MRA remain indispensable in the exact determination of the pathomorphological changes and in the documentation of complications such as stenosis, aneurismatic transformation and occlusion. Electronic Publication     

MR angiography of moyamoya disease before and after encephaloduroarteriosynangiosis

OBJECTIVE: Our purpose was to evaluate the usefulness of MR angiography in revealing moyamoya disease before and after encephaloduroarteriosynangiosis. SUBJECTS AND METHODS: Twenty-six patients (51 hemispheres) with angiographically confirmed moyamoya disease who underwent encephaloduroarteriosynangiosis were included in the study. Findings on preoperative MR angiography were compared with those on conventional angiography. Postoperative neurologic status was categorized as poor, fair, good, or excellent. Postoperative MR angiography was examined for the appearance of the superficial temporal artery, changes in moyamoya vessels, and transdural collateral vessels into the middle cerebral artery territory. RESULTS: Preoperative MR angiography revealed moyamoya disease in all patients (diagnostic accuracy, 100%). MR angiography correctly depicted the degree of internal carotid artery stenosis in 37 arteries (73%), moyamoya vessels in 33 hemispheres (65%), and the degree of stenosis in the middle, anterior, and posterior cerebral arteries in 125 (82%) of 153 arteries. After surgery, 39 hemispheres showed an excellent outcome, eight showed a good outcome, two a fair outcome, and two a poor outcome. On postoperative MR angiography, vascular supply to the middle cerebral artery territory via transdural collateral vessels increased in 28 hemispheres (55%) and decreased in four (8%). The size of the superficial temporal artery increased in 41 (80%) of 51 hemispheres. The extent of moyamoya vessels decreased in 27 hemispheres (53%) after surgery. CONCLUSION: MR angiography can show the changes in the superficial temporal artery and development of transdural collateral vessels after encephaloduroarteriosynangiosis. Because MR angiography is noninvasive, it is valuable for evaluating postoperative changes.     

Wegener granulomatosis: MR imaging findings in brain and meninges

PURPOSE: To determine the spectrum of intracranial magnetic resonance (MR) imaging appearances of Wegener granulomatosis. MATERIALS AND METHODS: MR imaging studies in 19 patients with Wegener granulomatosis and possible central nervous system involvement were reviewed by two neuroradiologists. Intermediate-weighted and T2-weighted fast spin-echo MR images of the brain had been acquired in all patients, and spin-echo T1-weighted nonenhanced and gadolinium-enhanced images had been acquired in 18 patients. RESULTS: MR imaging findings included diffuse linear dural thickening and enhancement (n = 6); focal dural thickening and enhancement contiguous with orbital, nasal, or paranasal disease (n = 5); infarcts (n = 4); nonspecific white matter areas of high signal intensity on intermediate-weighted and T2-weighted images (n = 10); enlarged pituitary gland with infundibular thickening and enhancement (n = 2); a discrete cerebellar lesion that was probably granulomatous in origin (n = 1); and cerebral (n = 8) and cerebellar atrophy (n = 2). CONCLUSION: MR imaging demonstrated the wide spectrum of findings of central nervous system involvement in patients with Wegener granulomatosis and was particularly useful for the evaluation of direct intracranial spread from orbital, nasal, or paranasal disease.     

Bowel wall thickening in patients with Crohn's disease: CT patterns and correlation with inflammatory activity

AIM: To assess CT patterns of bowel wall thickening in patients with Crohn's disease and to correlate these patterns with inflammatory activity. MATERIALS AND METHODS: We conducted a retrospective review of 58 helical abdominal CT scans of 53 patients with pathologically proven Crohn's disease. CT patterns of thickened bowel wall were divided into four types based on patterns of mural stratification and enhancement: type A, multilayered mural stratification; type B, two layers with strong mucosal enhancement and prominent low-density submucosa; type C, two layers without strong mucosal enhancement; and type D, homogeneous enhancement. We evaluated CT findings of the bowel and adjacent structures. We also reviewed pathologic features and clinical data to determine inflammatory activity. RESULTS: Fifty-five (95%) of 58 CT examinations showed bowel wall thickening. Of these 55 CT scans, type A pattern was found in 33 (60%), type B in 10 (18%), type C in five (9%), and type D in seven (13%). CT scans with type A showed significantly more wall thickening than those with either type C or type D. Histology revealed 43 cases with active disease and 12 with quiescent appearance. Thirty of 33 CT scans with type A and all 10 with type B were classified as acute disease, and three of five with type C and six of seven with type D as quiescent. CONCLUSION: In patients with Crohn's disease, CT patterns of bowel wall thickening correlated with inflammatory activity. Thickened bowel wall with layering enhancement is predictive of acute disease, and that of homogeneous enhancement suggests quiescence.     

Masticator space abnormalities associated with mandibular osteoradionecrosis: MR and CT findings in five patients

BACKGROUND AND PURPOSE: Imaging of patients with a clinical diagnosis of mandibular osteoradionecrosis (ORN) is often performed to support that clinical suspicion, evaluate the extent of the disease, or exclude coexistent tumor recurrence. The purpose of our study was to describe the clinical, MR imaging, and CT features of five patients with mandibular ORN associated with prominent soft-tissue abnormality in the adjacent masticator muscles. METHODS: The MR and CT examinations of five patients with mandibular ORN associated with soft-tissue abnormalities in the adjacent masticator muscles were reviewed. All patients had received external beam radiotherapy for primary head and neck malignancies, with a total radiation dose range of 60 Gy to 69 Gy in 30 to 38 fractions. RESULTS: CT revealed the typical osseous findings of cortical disruption, trabecular disorganization, and fragmentation in all five patients. Abnormal diffuse enhancement of the adjacent masseter and pterygoid muscles was noted in all patients. Four patients had prominent mass-like thickening of these muscles adjacent to the osseous abnormality. Of the three patients who underwent MR imaging, all showed homogeneous abnormal T1 hypointensity, T2 hyperintensity, and intense enhancement of the bone marrow in the involved mandible. The masticator muscles adjacent to the osseous abnormality also showed abnormal T2 hyperintensity and intense diffuse enhancement on MR images. CONCLUSION: Mandibular ORN can be associated with prominent soft-tissue thickening and enhancement in the adjacent musculature. These changes can appear mass-like and are not related to tumor recurrence or metastatic disease.     

MRA对脑动脉炎的诊断价值(附9例报告)

目的 评价磁共振血管成像（MRA）对脑动脉炎的诊断价值。方法 回顾性分析9例经临床证实为脑动脉炎患的MRA表现，并与MRI表现对照。结果 9例患的所有病灶均局限于一侧大脑半球或小脑半球，形态多呈圆形，斑片状。病灶在T1WI像呈低、等信号，在W2WI像呈稍高、高信号。MRI表现主要为梗塞灶、出血灶、脑炎和脑膜炎的炎症性病灶。MRA更加清晰显示近端脑动脉不规则狭窄或截断，远端脑动脉缺如，两侧血管分布不对称。结论 MRA是一种切实可行的血管成像技术，它不仅可提高脑动脉炎的诊断准确性，而且有助于评估其预后。     

成人型moya moya病的MR和MRA诊断(附6例分析)

目的：分析成人型moyamoya病的MRI和MRA影像特征。方法：回顾性分析6例经DSA证实的成人moyamoya病的MRI及MRA影像资料，采用GE1.5T超导型MR扫描系统行SE、FSE序旬MRI和三维时间飞跃法MRA。结果：成人型moyamoya病主要表现为多发腔隙性梗塞、脑萎缩，或并发脑实质出血、蛛网膜下腔出血。MRI显示闭塞的颅底大血管流空效应消失，兵脑和基底节区侧支循环流空信号增多，脑实质缺血或出血改变。MRA直接显示狭窄或闭塞的预内动脉（ICA）、大脑中动脉（MCA）、大脑前动脉（ACA）及侧支血管网。与DSA对比，MRA能够准确地显示闭塞或狭窄的大血管和代偿的不成形的弯延扭曲的侧支血管网。结论：MRI和MRA相结合可正确诊断moyamoya病，MRA是一种无创、短时、成功率和准确性高的检查方法，也可用于筛选可疑颅内动脉狭窄或闭塞的患者，避免或减少血管造影的次数。     

Takayasu's arteritis: assessment of disease activity with contrast-enhanced MR imaging

OBJECTIVE: The purpose of this study was to evaluate the role of contrast-enhanced MR imaging in the determination of disease activity in patients with Takayasu's arteritis. SUBJECTS AND METHODS: High-resolution contrast-enhanced T1-weighted spinecho MR imaging using small fields of view (14-20 cm) and thin slices (4-5 mm) was performed in 26 patients with Takayasu's arteritis and 16 healthy subjects. The degree of aortic mural enhancement was assessed by measuring signal intensity and by visually estimating it in comparison with that of the myocardium. RESULTS: Contrast-enhanced MR imaging showed more enhancement of thickened aortic wall compared with myocardium, thus suggesting active Takayasu's arteritis on MR imaging in 16 patients. Determination of disease activity using contrast-enhanced MR imaging was concordant with clinical findings in 23 patients (88.5%). Contrast-enhanced MR findings were concordant with laboratory findings in most patients (erythrocyte sedimentation rate in 92.3% [24/26] and C-reactive protein in 84.6% [22/26]). The measured signal intensity of the aortic wall relative to that of myocardium during the early phase of contrast-enhanced MR imaging correlated well with the erythrocyte sedimentation rate (r = 0.78, p < 0.005) and with the C-reactive protein level (r = 0.63, p < 0.005). CONCLUSION: Contrast-enhanced MR imaging provides information about disease activity of Takayasu's arteritis, which may be useful in the diagnosis and treatment of Takayasu's arteritis.     

Dynamic MR imaging of the carotid wall

The purpose of this study was to clarify temporal changes of carotid wall enhancement using dynamic magnetic resonance (MR) and to correlate its findings with pathological conditions. Cervical carotid arteries of 84 consecutive patients were studied with a 1.5 T MR imager using phased array coils. Axial spoiled gradient-echo (SPGR) images (30-58 second scan time) with fat saturation were repeated 4-8 times after the injection of contrast material. We evaluated the presence and thickness of hypointense inner rims and hyperintense outer rims of the carotid wall, temporal changes of outer rim enhancement, and their changes in relation to pathological conditions. Hypointense inner rims and enhanced outer rims were clearly visualized in 87% (73/84) of our subjects. Enhancement of the outer rim was minimal in early phases and gradually increased. Patient age had a significant correlation with outer rim thickness. In the portions with large atheromatous plaques, inner rims were disrupted or thickened. A marked thickening of the outer rim was observed in one patient with arteritis. The outer rims adjacent to malignant tumors were often obscured. Our study suggests that dynamic MR images of the cervical carotid artery can uniquely demonstrate angiogenesis of the wall itself. The outer rim of the artery shows relatively rapid enhancement, and its thickness correlates with age.     

MR imaging and angiography in tuberculous meningitis

MRI was performed on 26 patients with tuberculous meningitis, with particular reference to document the cranial nerve abnormalitics. MR angiography (MRA) was performed in 20 of the patients. Meningeal enhancement in the basal cisterns or over the convexity of brain was seen in all patients; two show ependymal enhancement. Tuberculomas, single (3), multiple (12) or miliary (2) were detected in 17 patients. Of the 9 patients with cranial nerve palsies, 7 showed contrast enhancement with or without thickening of the involved nerve. Abnormality signal intensity of the involved nerve was seen on proton density and T₂-weighted images in one of these patients. MRA revealed focal arterial narrowing in 10 patients, the vessels commonly affected being the terminal segment of the internal carotid artery and the proximal segments of the middle and anterior cerebral arteries. One patient also had a small aneurysm of the proximal middle cerebral artery. Infarcts, haemorrhagic (8) or bland (6), were detected in 14 patients; most were the basal ganglia and internal capsules, large middle or anterior cerebral arterial territory infarcts being seen in only two cases.     

CT and MR characteristics of cerebral sparganosis

BACKGROUND AND PURPOSE: Sparganosis is a rare parasitic infection in humans by a larval cestode of the genus Spirometra. Preoperative diagnosis of cerebral sparganosis in the past has been very difficult. Our objective was to evaluate the CT and MR features of cerebral sparganosis in order to make a definite diagnosis. MATERIALS AND METHODS: We retrospectively reviewed 25 patients (13 male and 12 female; age range, 9-83 years) who proved to have cerebral sparganosis. Fifteen patients underwent MR imaging: 2 patients had CT scanning, and the remaining 8 had both CT and MR scanning. We focused on evaluating the imaging features on CT and MR. RESULTS: All patients showed edema and degeneration of cerebral white matter. All but 1 had a unilateral lesion. Twenty-two patients had ipsilateral ventricular dilation. The new finding was a tunnel sign, approximately 4 cm in length and 0.8 cm in width, column or fusiform shaped on postcontrast coronal and sagittal MR images (n = 10). Thirteen patients showed bead-like enhancement, but solitary ring enhancement was common on the CT images (n = 2). The wall of the ring and tunnel appeared isointense or slightly hyperintense on T2-weighted images. Punctate calcifications were seen in 6 patients on CT images but only in 3 patients on the MR images. Hemorrhage was seen in 4 patients on the MR images. An intact whitish, stringlike, living worm was found (n = 5). CONCLUSION: The most characteristic finding was a tunnel sign on postcontrast MR images. The most common finding was bead-shaped enhancement. MR is superior to CT in demonstrating the extent and number of lesions, except punctate calcifications. Combined with clinical data and enzyme-linked immunosorbent assay, the preoperative diagnosis of cerebral sparganosis could be established on MR imaging.