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.     

Delayed contrast-enhanced MRI of the aortic wall in Takayasu's arteritis: initial experience

OBJECTIVE: Delayed contrast-enhanced MRI is increasingly being used for cardiac viability imaging. Takayasu's arteritis is a rare inflammatory disorder of unknown cause that affects the aorta, its major branches, and the pulmonary artery; it is characterized by inflammation and fibrosis in the arterial wall. We report our initial experience with seven patients (six women, one man; age range, 25-62 years) with delayed (20 min) gadolinium-enhanced MRI (inversion recovery prepared gated fast gradient-echo pulse sequence) in patients with known Takayasu's arteritis. CONCLUSION: Patients with Takayasu's arteritis (particularly those with abnormal laboratory values) have evidence of delayed hyper-enhancement on delayed contrast-enhanced MRI. Thus, delayed contrast-enhanced MRI might be a useful technique to identify inflammation in arterial wall.     

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.     

Radiation-induced arteritis: thickened wall with prominent enhancement on cranial MR images report of five cases and comparison with 18 cases of Moyamoya disease

PURPOSE: To evaluate magnetic resonance (MR) imaging findings of radiation-induced cranial arteritis regarding arterial wall thickening and degree of enhancement, as well as to compare the findings with those of idiopathic moyamoya disease. MATERIALS AND METHODS: We reviewed cerebral MR images in five patients with radiation-induced large cerebral arteritis. All patients had undergone irradiation 2-25 years prior to this study. Conventional nonenhanced MR, MR angiographic, and contrast material-enhanced MR images were evaluated. Special attention was paid to wall enhancement of the affected arteries (distal internal carotid artery). Wall enhancement was staged in three levels by two neuroradiologists. We also reviewed MR images in 18 patients with primary moyamoya disease for comparison and analyzed them statistically (Fisher exact test). RESULTS: Wall thickening and prominent ring enhancement of the wall of the affected large cerebral arteries were observed in all (five of five) patients with radiation-induced arteritis. In contrast, wall thickening and prominent ring enhancement of the wall of the occluded arteries either were not seen (13 of 18 patients) or were faint (five of 18 patients) in patients with moyamoya disease. Contrast enhancement of the arterial walls in patients with radiation-induced arteritis was significantly more prominent than in patients with moyamoya disease (P =.003). CONCLUSION: MR images of wall thickening and prominent ring enhancement of the wall of affected large cerebral arteries may be a diagnostic clue in differentiating radiation-induced arteritis from moyamoya disease.     

Intracranial meningeal disease: comparison of contrast-enhanced MR imaging with fluid-attenuated inversion recovery and fat-suppressed T1-weighted sequences

BACKGROUND AND PURPOSE: Contrast-enhanced fluid-attenuated inversion recovery (FLAIR) imaging has been reported to have higher sensitivity for detecting leptomeningeal disease compared with contrast-enhanced T1-weighted MR imaging. The purpose of this study was to compare contrast-enhanced T1-weighted MR images with fat suppression to contrast-enhanced FLAIR images to determine which sequence was superior for depicting meningeal disease. METHODS: We reviewed MR images of 24 patients (35 studies) with a variety of meningeal diseases. The MR imaging protocol included contrast-enhanced T1-weighted MR images with fat suppression (FS) and contrast-enhanced fluid-attenuated inversion recovery (FLAIR) images that were reviewed by three neuroradiologists and were assigned a rating of positive, equivocal, or negative for abnormal meningeal enhancement. The two sequences were compared side by side to determine which better depicted meningeal disease. RESULTS: Abnormal meningeal enhancement was positive in 35 contrast-enhanced T1-weighted MR images with FS and in 33 contrast-enhanced FLAIR studies. In the first group, which had the T1-weighted sequence acquired first (21 of 33 studies), contrast-enhanced T1-weighted images with FS showed superior contrast enhancement in 11 studies (52%), inferior contrast enhancement in six studies (29%), and equal contrast enhancement in four studies (19%) compared with the contrast-enhanced FLAIR images. In the second group, which had the FLAIR sequence acquired first (12 of 33), contrast-enhanced T1-weighted images with FS showed superior contrast enhancement in seven studies (58%), inferior contrast enhancement in two studies (17%), and equal contrast enhancement in three studies (25%). CONCLUSION: Contrast-enhanced T1-weighted MR imaging with FS is superior to contrast-enhanced FLAIR imaging in most cases for depicting intracranial meningeal diseases.     

Acute myocardial infarction: myocardial viability assessment in patients early thereafter comparison of contrast-enhanced MR imaging with resting (201)Tl SPECT. Single photon emission computed tomography

PURPOSE: To compare contrast material-enhanced magnetic resonance (MR) imaging with resting thallium 201 ((201)Tl) single photon emission computed tomography (SPECT) for predicting myocardial viability in patients early after acute myocardial infarction. MATERIALS AND METHODS: Inversion-recovery contrast-enhanced MR images and resting (201)Tl SPECT images were obtained in 22 patients after acute myocardial infarction. The (201)Tl SPECT images were obtained 4.3 days +/- 0.2 (standard error) after the onset of myocardial infarction. Contrast-enhanced MR imaging was performed 7.9 days +/- 1.6 after (201)Tl SPECT. Transmural extent of hyperenhancement on contrast-enhanced MR images and regional (201)Tl activity were quantitatively analyzed with a 12-segment model. Regional wall thickening on follow-up cine MR images obtained 67 days +/- 17 after contrast-enhanced MR imaging was used as an index for myocardial viability. Statistical analyses were performed with the chi(2) and two-tailed Student t tests. RESULTS: Both contrast-enhanced MR and resting (201)Tl SPECT images showed significant correlations with regional wall thickening on follow-up cine MR images. The sensitivity, specificity, and accuracy of contrast-enhanced MR imaging in the prediction of viable myocardium were significantly higher than those of resting (201)Tl SPECT (98.0% vs 90.3%, P <.01; 75.0% vs 54.4%, P <.05; and 92.0% vs 81.1%, P <.001, respectively). CONCLUSION: Delayed contrast-enhanced MR imaging can help predict myocardial viability as seen on follow-up cine MR images after acute myocardial infarction, with significantly improved sensitivity, specificity, and accuracy in comparison with those of resting (201)Tl SPECT.     

Electron beam CT features of the pulmonary artery in Takayasu's arteritis.

OBJECTIVE: Pulmonary artery involvement in Takayasu's arteritis is suggestive of the disease. Our aim was to use electron beam CT to study pulmonary artery changes in patients with Takayasu's arteritis. CONCLUSION: Diffuse wall thickening and dilatation or stenosis were significantly more frequent on CT in patients with Takayasu's arteritis than in the control subjects. Knowledge of these findings may be of value when assessing pulmonary artery involvement and thus may be helpful for the diagnosis of Takayasu's arteritis.     

The acute diagnosis of Takayasu's arteritis based on helical CT angiography of the chest and neck in the emergency room

Recently, a young woman presented acutely with a left hemispheric stroke and differing blood pressures in the arms as her initial manifestation of Takayasu's arteritis. Helical CT angiography, performed to rule out aortic dissection, revealed a thickened wall of the aortic arch with stenoses and occlusions of the great vessels, suggesting the diagnosis. The sequence of imaging studies and findings in this unusually catastrophic presentation of a typically insidious disease are highlighted.     

Differences in null points between the left and right ventricles in contrast-enhanced inversion recovery MR imaging in patients with cardiac diseases.

Delayed contrast-enhanced inversion recovery (IR) gradient-echo MR imaging has been applied to several cardiac diseases, including myocarditis, sarcoidosis, hypertrophic cardiomyopathy, and myocardial damages induced by medical procedures. Although a preliminary study has indicated the usefulness of this imaging for the detection of right ventricular (RV) myocardial damage associated with arrhythmogenic right ventricular cardiomyopathy, the null points of the RV myocardium have not been assessed on contrast-enhanced IR MR imaging. In this study, the null points of the RV and left ventricular (LV) myocardia were evaluated using an IR fast multi-shot echo-planar imaging (Look-Locker sequence) in 26 patients with various cardiac diseases. In nine of the 26 patients, the null points of the RV myocardium were shorter than those of the LV myocardium in the Look-Locker sequence. The RV myocardial signals were significantly higher than the LV myocardial signals in delayed contrast-enhanced MR images. Thus, more attention should be paid to evaluation of the late enhancement of the RV myocardium, and delayed contrast-enhanced MR imaging with a shorter inversion time may be required in some cases.     

Contrast-enhanced fluid-attenuated inversion recovery imaging for leptomeningeal disease in children

BACKGROUND AND PURPOSE: To develop an MR imaging method that improves detection of leptomeningeal disease when compared with the current reference standard, contrast-enhanced T1-weighted imaging. METHODS: We investigated the cases of 10 children who were at high risk of intracranial leptomeningeal disease (Sturge-Weber syndrome and medulloblastoma). The cases of Sturge-Weber syndrome were investigated by using one MR imaging examination, and the cases of medulloblastoma were investigated by using four MR imaging examinations performed over 18 months. In all cases, contrast-enhanced fluid-attenuated inversion recovery (FLAIR) images were acquired in addition to the routine sequences. The parameters of the FLAIR sequence were chosen to maximize the T1 component of the signal intensity, to maximize detection of leptomeningeal enhancement. We made subjective and objective assessments of the presence and extent of leptomeningeal disease as shown on contrast-enhanced T1-weighted images and contrast-enhanced FLAIR images. RESULTS: In three of the four cases of Sturge-Weber syndrome, the T1 and FLAIR sequences showed comparable extent of leptomeningeal enhancement. For one child, FLAIR images showed unexpected bilateral disease and more extensive leptomeningeal enhancement on the clinically suspected side. In four of six cases of medulloblastoma, no leptomeningeal enhancement was shown on any examinations during the 18-month period. In two cases, FLAIR images showed more extensive leptomeningeal enhancement when compared with T1-weighted images. CONCLUSION: Contrast-enhanced FLAIR imaging seems to improve detection of leptomeningeal disease when compared with routine contrast-enhanced T1-weighted imaging. This seems to be partly because of suppression of signal intensity from normal vascular structures on the surface of the brain by FLAIR, which allows easier visualization of abnormal leptomeninges. We think that these findings can be extrapolated to the investigation of leptomeningeal disease of all causes and at all ages.     

Longitudinal changes in rheumatoid arthritis after rituximab administration assessed by quantitative and dynamic contrast-enhanced 3-T MR imaging: preliminary findings

We retrospectively assessed the longitudinal changes of rheumatoid arthritis under rituximab therapy by use of quantitative and dynamic contrast-enhanced 3-T magnetic resonance (MR) imaging of the metacarpophalangeal joints of 10 patients at baseline and 26 weeks (n = 10). Additional studies were available at 12 weeks (n = 9) and at 52 weeks (n = 5). Clinical activity was assessed by use of the 28-joint disease activity score (DAS28). MR imaging was used to assess volumes of synovial enhancement, osseous enhancement, and erosions and early rapid enhancement. DAS28 and serum C-reactive protein trended down over time and were significantly lower at 26 weeks. Volume of synovial enhancement and early rapid enhancement showed a significant minimum at 26 weeks and increased thereafter. The erythrocyte sedimentation rate paralleled these two trends. Osseous enhancement did not significantly change over time. Erosions showed a significant progression. Trends of DAS28 and erosions were significantly different (P = 0.0075). In conclusion, our preliminary results suggest that rituximab is associated with a decrease of the inflammatory activity of synovitis with a minimum at 26 weeks and increasing activity thereafter suggesting recurrence. Our results further suggest subclinical progression of erosions with an inverse relationship to decreasing disease activity scores. Further studies are needed to confirm these results.     

Radiation-induced optic neuropathy: characteristic appearances on gadolinium-enhanced MR.

PURPOSE: To assess the value of contrast-enhanced MR in the evaluation of radiation-induced optic neuropathy. MATERIALS AND METHODS: Three patients with rapid visual loss 1 1/2 to 3 years after radiation therapy to the optic nerves were studied with gadopentetate dimeglumine-enhanced MR images. All patients received over 5000 cGy, experienced rapid, permanent visual loss over several days to weeks, and underwent MR within weeks of presentation. RESULTS: Enhanced MR images on each patient revealed focal discrete enhancement of the intracranial optic nerve. One patient underwent biopsy of the enhancing segment; this revealed pathologic changes of radiation optic neuropathy. Optic nerve enhancement in a patient with visual loss and a prior history of radiation therapy to the orbits or optic nerves suggests radiation optic neuropathy. CONCLUSION: Contrast-enhanced MR of the orbits, optic nerves, and chiasm is the imaging test of choice in patients with vision loss after radiation therapy for sellar or skull base disease; MR findings may obviate the need for biopsy.     

"Ivy sign" in childhood moyamoya disease: depiction on FLAIR and contrast-enhanced T1-weighted MR images

PURPOSE: To compare contrast material-enhanced T1-weighted and fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) images with or without gadolinium in depicting the leptomeningeal ivy sign in children with moyamoya disease. MATERIALS AND METHODS: Twenty-nine sets of FLAIR and postcontrast T1-weighted MR images were available in 19 consecutive children with primary moyamoya disease confirmed with conventional and MR angiography. Contrast-enhanced FLAIR MR images also were available in 15 sets. Two pediatric radiologists reviewed FLAIR and postcontrast T1-weighted images in separate sessions for the leptomeningeal ivy sign and assigned a rating of "present," "absent," or "equivocal" by consensus. Unenhanced and contrast-enhanced FLAIR MR images were compared side by side to determine which better depicted leptomeningeal high signal intensities. RESULTS: Postcontrast T1-weighted MR images revealed the leptomeningeal ivy sign in 40 hemispheres (frequency of visualization, 71% [40 of 56 hemispheres]), whereas unenhanced FLAIR MR images depicted it in 26 hemispheres (frequency of visualization, 46% [26 of 56 hemispheres]). An equivocal rating was given in 21 hemispheres versus in 11 on FLAIR and postcontrast T1-weighted images, respectively. FLAIR and postcontrast T1-weighted images agreed in 40 hemispheres. There was no case with a positive rating on FLAIR images when postcontrast T1-weighted images were negative. Unenhanced FLAIR MR imaging was superior to contrast-enhanced FLAIR imaging in seven hemispheres, whereas enhanced FLAIR was better in four of 28 hemispheres. In the remaining 17, findings with each sequence were similar. CONCLUSION: Contrast-enhanced T1-weighted images are better than FLAIR images for depicting the leptomeningeal ivy sign in moyamoya disease.     

Aortic aneurysms in patients with Takayasu's arteritis: CT evaluation

OBJECTIVE: The objective of this study was to evaluate the incidence, development, and outcome of aortic aneurysm on CT in a group of patients with Takayasu's arteritis. MATERIALS AND METHODS: We reviewed the files of 31 patients with Takayasu's arteritis between January 1990 and March 1999. All patients were followed up for more than 6 months with CT, and the mean follow-up period was 52.9 months (median, 36.0 months). In all patients, initial CT was performed within 6 months of diagnosis of Takayasu's arteritis. The study group comprised 24 female patients and seven male patients; their ages at the first CT examination ranged from 8 to 72 years (mean, 42. 6 +/- 16.5 years). RESULTS: Seventeen aortic aneurysms were found in 14 (45.2%) of the 31 patients. Patients with severe calcification of the aorta showed significantly lower incidence of aneurysm formation than those without severe calcification of the aorta (p < 0.05). Of the 17 aneurysms, three were not present at the time of initial CT and appeared during the follow-up period. Nine of 17 aneurysms increased in size during the follow-up period. Three of the nine aneurysms rapidly increased in size and ruptured during the follow-up period. In all three of these aneurysms, aortic wall thickening was identified on CT. The remaining six aneurysms slowly increased in size but did not rupture. CONCLUSION: Aortic aneurysm associated with Takayasu's arteritis is not rare. The aorta with little calcification has a greater possibility of aneurysm formation in patients with Takayasu's arteritis. Aortic aneurysms with wall thickening can have fatal consequences.     

Imaging findings in Takayasu's arteritis

OBJECTIVE: The objective of our study was to evaluate the clinical usefulness of cross-sectional imaging for establishing the diagnosis of Takayasu's arteritis (TA), an inflammatory vascular disorder that produces arterial stenoses and aneurysms primarily involving the thoracoabdominal aorta and its branches and the pulmonary arteries. CONCLUSION: CT and MRI findings of TA include vascular wall thickening and enhancement early in the disease, and arterial stenoses, occlusions, and aneurysms later in the disease. Cross-sectional imaging is useful for establishing the diagnosis of TA and for showing response to nonsurgical therapy or for planning a surgical intervention.     

Facial nerve palsy: evaluation by contrast-enhanced MR imaging

AIM: The purpose of this study was to investigate the value of contrast-enhanced magnetic resonance (MR) imaging in patients with peripheral facial nerve palsy. MATERIALS AND METHODS: MR imaging was performed in 147 patients with facial nerve palsy, using a 1.0 T unit. All of 147 patients were evaluated by contrast-enhanced MR imaging and the pattern of enhancement was compared with that in 300 control subjects evaluated for suspected acoustic neurinoma. RESULTS: The intrameatal and labyrinthine segments of the normal facial nerve did not show enhancement, whereas enhancement of the distal intrameatal segment and the labyrinthine segment was respectively found in 67% and 43% of patients with Bell's palsy. The geniculate ganglion or the tympanic-mastoid segment was enhanced in 21% of normal controls versus 91% of patients with Bell's palsy. Abnormal enhancement of the non-paralyzed facial nerve was found in a patient with bilateral temporal bone fracture. CONCLUSION: Enhancement of the distal intrameatal and labyrinthine segments is specific for facial nerve palsy. Contrast-enhanced MR imaging can reveal inflammatory facial nerve lesions and traumatic nerve injury, including clinically silent damage in trauma.     

乳腺癌的MRI诊断

目的　探讨乳腺癌的MRI表现及诊断价值。方法　回顾性分析12例经手术与病理证实的乳腺癌MRI表现,并与其X线表现进行比较。结果　12例乳腺MRI共发现21个病变,X线检查发现17个病变。MRI增强扫描显示致密乳腺组织中的病变优于X线检查,能清楚地显示深部乳腺癌对胸大肌的浸润和胸骨旁淋巴结的转移,X线检查对此却难于估价。“边缘强化征”对乳腺癌的诊断有一定价值。结论　MRI增强扫描的敏感性和准确性优于X线检查,它有助于乳腺癌的早期发现、乳腺癌病人的肿瘤分期和治疗方案的制定。     

MR imaging of leptomeningeal metastases: comparison of three sequences

BACKGROUND AND PURPOSE: Recent work has shown that fluid-attenuated inversion recovery (FLAIR) imaging with contrast enhancement is highly sensitive for detecting subarachnoid space disease. We hypothesized that contrast-enhanced FLAIR imaging has superior sensitivity to contrast-enhanced T1-weighted MR imaging in detecting leptomeningeal metastases. METHODS: Sixty-eight patients referred for suspected leptomeningeal metastases underwent 74 MR imaging studies. The patients had either temporally related cytologic proof of leptomeningeal metastases or negative results of clinical follow-up confirming absence of leptomeningeal metastases. The MR imaging examinations included unenhanced and contrast-enhanced FLAIR images and contrast-enhanced T1-weighted MR images that were independently reviewed by two neuroradiologists blinded to the results of cytology. Each of the three sequences was reviewed individually and separately and was assigned a score of positive or negative for leptomeningeal metastases. Discrepancies were settled by consensus. RESULTS: Of the 17 studies of patients with cytology-proven leptomeningeal metastases, two were positive based on unenhanced FLAIR images, seven were positive based on contrast-enhanced FLAIR images, and 10 were positive based on contrast-enhanced T1-weighted MR images. Of the 57 studies of patients without leptomeningeal metastases, 53 were negative based on unenhanced FLAIR images, 50 were negative based on contrast-enhanced FLAIR images, and 53 were negative based on contrast-enhanced T1-weighted MR images. The sensitivity and specificity of unenhanced FLAIR images for detecting leptomeningeal metastases were 12% (two of 17) and 93% (53 of 57), respectively. The sensitivity and specificity for contrast-enhanced FLAIR images for detecting leptomeningeal metastases were 41% (seven of 17) and 88% (50 of 57), respectively. The sensitivity and specificity of contrast-enhanced T1-weighted MR images for detecting leptomeningeal metastases were 59% (10 of 17) and 93% (53 of 57), respectively. CONCLUSION: Contrast-enhanced fast FLAIR sequences are less sensitive than standard contrast-enhanced T1-weighted MR sequences in detecting intracranial neoplastic leptomeningeal disease.     

Phase-inversion sonography during the liver-specific late phase of contrast enhancement: improved detection of liver metastases

OBJECTIVE: The purpose of our study was to assess whether phase-inversion sonography during the late, liver-specific phase of contrast enhancement using Levovist improves the detection of hepatic metastases relative to unenhanced conventional B-mode sonography. SUBJECTS AND METHODS: Sixty-two patients were studied with unenhanced B-mode sonography and phase-inversion sonography 2.5 min after the injection of Levovist. All patients underwent one reference examination (CT, MR imaging, or intraoperative sonography). The conspicuity, number, size, and distribution of metastases before and after contrast administration as judged by a sonographer (who was unaware of other imaging findings) were compared with each other and with reference imaging. RESULTS: The conspicuity of metastases was improved by contrast-enhanced phase inversion in 94% of patients. Thirty-nine patients showed metastases on reference imaging; 36 of these were positive on baseline sonography and 38 on phase-inversion sonography. Phase-inversion sonography showed more reference imaging-confirmed metastases than baseline sonography in 28 patients (45%). The average number of confirmed metastases per patient was 3.06 for baseline sonography and 5.42 for contrast-enhanced phase-inversion sonography (p < 0.01). The average sensitivity for detecting individual metastases improved from 63% to 91%. Metastases of less than 1 cm were shown in 14 patients on baseline sonography, in 24 patients on phase-inversion sonography, and in 26 on reference imaging. Both sonographic techniques showed false-positive lesions in six patients. CONCLUSION: Contrast-enhanced phase-inversion sonography in the liver-specific phase of contrast enhancement using Levovist provides a marked improvement in the detection of hepatic metastases relative to unenhanced conventional sonography, without loss of specificity. Phase-inversion sonography was particularly advantageous in detecting small metastases and may be a competitive alternative to CT and MR imaging.     

Childhood Guillain-Barré syndrome. MR imaging in diagnosis and follow-up

PURPOSE: To evaluate the value of serially obtained spinal MR images in the diagnosis and clinical follow-up of childhood Guillain-Barré syndrome (GBS), and the time period for resolution of contrast enhancement during the course of illness. MATERIAL AND METHODS: Contrast-enhanced spinal MR images of 11 pediatric patients with GBS were reviewed prospectively. In the first group of 6 patients, follow-up MR was performed three times after the 1st, 3rd and 6th months after onset of the disease. In the second group (the other 5 patients) who had not accepted serial MR examinations, control MR was repeated once after 1 year. Patients were graded clinically into five categories according to their initial clinical signs and symptoms and three grades (mild, moderate and severe) according to level of contrast enhancement on T1-weighted images to correlate the severity of enhancement with clinical findings and recovery. RESULTS: Ten of the 11 patients revealed contrast enhancement in varying degrees in the spinal nerve roots surrounding the conus medullaris and extending the length of the cauda equina. One patient showed no contrast enhancement. Anterior nerve roots enhanced more intensely than the posterior roots in 3 patients. Follow-up MR images in all patients revealed diminishing or resolving contrast enhancement in the nerve roots as the clinical symptoms improved. CONCLUSION: We suggest contrast-enhanced spinal MR imaging as a supplementary diagnostic modality in diagnosing GBS, especially when the clinical and electrophysiological findings are equivocal. Follow-up images may play a role in predicting the clinical course of the disease.