CT and MR of neurofibromatosis of the bladder.

Neurofibromatosis of the genitourinary system is rare. We present the CT and MR findings of neurofibromas of the bladder in three patients with von Recklinghausen disease (neurofibromatosis, Type 1). In one case, genitourinary involvement was the primary presentation of the disease. Both CT and MR imaging revealed diffuse and nodular bladder wall involvement, along with pelvic sidewall and adjacent soft tissue abnormalities. The CT attenuation coefficients measured near soft tissue density. On T1-weighted spin echo MR images the tumors revealed signal intensity slightly greater than that of skeletal muscle. Neurofibromas showed markedly increased signal intensity on T2-weighted images relative to the surrounding soft tissues, with marked enhancement in two cases imaged following Gd-DTPA administration. Obstructive hydronephrosis was present in all cases, presumably due to neurofibromas involving the trigonal region. Pelvic sidewall tumors were visualized as rounded, nodular masses extending into the obturator foramina. In the evaluation of patients with von Recklinghausen disease, MR imaging, compared with CT, more clearly defined tumor extent within the bladder, pelvic sidewalls, and surrounding soft tissues.     

Intracranial and spinal MR imaging findings associated with Krabbe's disease: case report.

Krabbe's disease is an autosomal recessive leukodystrophy with well-documented intracranial findings on both CT scans and MR images. We herein present what is thought to be the second case of Krabbe's disease with spinal involvement shown on MR images as abnormal contrast enhancement of the lumbosacral nerve roots. The typical intracranial findings of T2 hyperintensity without contrast enhancement were present within the periventricular white matter, but there was no area of abnormal signal intensity or enhancement within the substance of the spinal cord. We briefly review the pathophysiology, clinical presentation, and imaging findings of Krabbe's disease. Spinal abnormalities may precede the onset of brain abnormalities, and MR imaging may be a useful diagnostic tool in cases of Krabbe's disease and other leukodystrophies.     

Globoid cell leukodystrophy: distinguishing early-onset from late-onset disease using a brain MR imaging scoring method

BACKGROUND AND PURPOSE: Our purpose was to determine the characteristic MR features of early-onset (before age 2 years) versus late-onset (after age 2 years) globoid cell leukodystrophy (GLD). METHODS: Thirty-four brain MR images in 22 patients with GLD were reviewed. A severity score (0 to 32), based on a point system derived from the location and extent of disease and the presence of focal and/or global atrophy, was calculated for each examination. RESULTS: Of the 22 patients, three were asymptomatic and 19 were symptomatic. Ten patients had early-onset disease, whereas nine had late-onset disease. MR images of all patients showed abnormalities. In the early-onset group (n = 10; mean maximum MR score, 8.1; range, 3-18), 90% had pyramidal tract involvement, 80% had cerebellar white matter involvement, 70% had deep gray matter involvement, 60% had posterior corpus callosal involvement, 50% had parietooccipital white matter involvement, and 40% had cerebral atrophy. Serial MR imaging in four of these patients revealed progressive disease. In the late-onset group (n = 9; mean maximum MR score, 5.6; range, 4-10), 100% had pyramidal tract involvement, 100% had parietooccipital white matter involvement, 89% had posterior corpus callosal involvement, and none had cerebellar white matter involvement, deep gray matter involvement, or cerebral atrophy. Serial MR imaging in one patient with late-onset GLD did not reveal any change. A spectrum of findings was observed in the three patients who were asymptomatic. CONCLUSION: Cerebellar white matter and deep gray matter involvement are present only in early-onset GLD. Pyramidal tract involvement is a characteristic finding in both early- and late-onset GLD. This scoring method for brain MR observations will assist in the objective assessment of the impact of hematopoietic stem cell transplantation in patients with GLD.     

Renal involvement in patients with autoimmune pancreatitis: CT and MR imaging findings

PURPOSE: To retrospectively evaluate computed tomographic (CT) and magnetic resonance (MR) imaging renal findings at clinical presentation, during treatment, and at follow-up in patients with autoimmune pancreatitis (AIP). MATERIALS AND METHODS: This HIPAA-compliant study received institutional review board approval. All patients included had previously consented to the use of their medical records for the purpose of research. Forty-five patients (38 male and seven female patients; mean age, 64 years) with diagnosis of AIP were included. Forty patients underwent CT or MR imaging at clinical presentation; 33 patients (including five without imaging at presentation) underwent follow-up. CT and MR images were reviewed in consensus by two radiologists for the presence of renal involvement. Various features were evaluated. Clinical characteristics at presentation were compared between patients with and patients without renal involvement. RESULTS: Of the 40 patients who underwent imaging at presentation, 14 (35%) had renal involvement (12 with parenchymal involvement and five with extraparenchymal involvement). Renal parenchymal lesions showed decreased enhancement and appeared as small peripheral cortical nodules, round or wedge-shaped lesions, or diffuse patchy involvement. Thirteen patients with renal involvement at presentation underwent a follow-up study. Renal lesions in 10 patients regressed (in nine, after steroid treatment) but progressed in three patients without steroid treatment. Renal lesions were found in two other patients during follow-up. No significant difference in the clinical characteristics was found between patients with and patients without renal involvement. CONCLUSION: Renal involvement in patients with AIP is relatively common and predominantly involves the cortex of the kidney. The lesions improve after steroid treatment but can progress without steroid treatment.     

HTLV-I carrier with unusual brain MR imaging findings

We describe unusual brain MR imaging findings in a patient who is an HTLV-I carrier without myelopathy. T2-weighted MR images showed hyperintense signal abnormalities in the pyramidal tract, superior and middle cerebellar peduncles, and decussation of the superior cerebellar peduncles, in addition to subcortical white matter involvement. Diffusion-weighted images also showed hyperintense signal abnormalities in the same regions by T2 shine-through effect.     

MR imaging of rectal cancer before and after chemoradiation therapy

PURPOSE: This study was done to determine the diagnostic accuracy of magnetic resonance (MR) imaging in patients with rectal carcinoma by comparing post-chemoradiation MR imaging with pathological specimens. MATERIALS AND METHODS: We enrolled 39 patients with locally advanced rectal cancer. All patients received chemoradiation therapy before surgery and neoadjuvant chemoradiation therapy followed by MR imaging. MR images were analysed by a team of two expert radiologists unaware of the clinical and histopathological findings. RESULTS: Following neoadjuvant chemoradiation therapy, the analysis of MR images showed 23 (59%) patients with a rectal disease staged ≤T2 and 16 (41%) with a disease staged >T2. Post-treatment histological staging (TNM) revealed 13 patients with a disease >T2 and 26 patients with a disease ≤T2. Cohen's kappa to measure concordance between post-chemoradiation MR staging and histological response showed 83.6% concordance for disease confined to the serosa (≤T3): concordance was 97.22% for disease ≤N1 and 33.33% for disease >N1. CONCLUSIONS: MR imaging is critical for discovering T3 disease; moreover, morphological MR imaging does not always provide the opportunity to discern small residual cancer cells hidden in fibrotic tissue that could cause involvement of circumferential resection margin (CRM) on histology.     

Diffusion-weighted echo-planar MR imaging of CNS involvement in systemic lupus erythematosus

RATIONALE AND OBJECTIVES: The purpose of this study was to determine the range of findings at diffusion-weighted magnetic resonance (MR) imaging in patients with systemic lupus erythematosus (SLE) and central nervous system involvement. MATERIALS AND METHODS: Diffusion-weighted MR images were reviewed in 20 patients with SLE and correlated with clinical symptoms and findings at computed tomography, conventional MR imaging, MR angiography, or conventional angiography. RESULTS: Diffusion-weighted MR imaging showed acute or subacute lesions in nine of 20 patients (45%). In the other 11, it showed no abnormal findings or chronic lesions. In four of the nine patients with lesions, diffusion-weighted imaging primarily showed hyperintense lesions with decreased apparent diffusion coefficient (ADC), which indicates acute or subacute infarcts. In four other patients, it primarily showed iso- or slightly hyperintense lesions with increased ADC, suggesting vasogenic edema. In two of these four patients, the findings were consistent with hypertensive encephalopathy. In the other two, small hyperintense foci on diffusion-weighted images with decreased ADC were seen within the vasogenic edema. These foci presumably represent microinfarcts associated with SLE vasculopathy. In the ninth patient, diffusion-weighted imaging showed a small linear hyperintense lesion with normal ADC in the left parietooccipital region. CONCLUSION: Diffusion-weighted imaging shows primarily two patterns of acute or subacute parenchymal lesions in patients with SLE: acute or subacute infarction and vasogenic edema with or without microinfarcts.     

MR imaging of acute coccidioidal meningitis

BACKGROUND AND PURPOSE: Our purpose was to describe the MR imaging findings in patients with acute coccidioidal meningitis. METHODS: Fourteen patients (11 men, three women; 22-78 years old; mean age, 47 years) with coccidioidal meningitis underwent neuroimaging within 2 months of diagnosis. Thirteen patients had MR imaging and one had an initial CT study with a follow-up MR examination 5 months later. Initial and follow-up MR images were evaluated for the presence of ventricular dilatation, signal abnormalities, enhancement characteristics, sites of involvement, and evidence of white matter or cortical infarction. The patterns of enhancement were characterized as focal or diffuse. Pathologic specimens were reviewed in two patients. RESULTS: Ten of the 14 images obtained at the time of initial diagnosis showed evidence of meningitis. All of the initially abnormal studies showed enhancement in the basal cisterns, sylvian fissures, or pericallosal region. Subsequent studies, which were available for three of the four patients with normal findings initially, all eventually became abnormal, with focal enhancement seen on the initial abnormal examination. Other abnormalities seen at presentation included ventricular dilatation (six patients) and deep infarcts (four patients). Pathologic specimens in two patients showed focal collections of the organism corresponding to the areas of intense enhancement on MR images. CONCLUSION: Early in its disease course, coccidioidal meningitis may show areas of focal enhancement in the basal cisterns, which may progress to diffuse disease. Pathologically, the areas of enhancement represent focal collections of the organism. Deep infarcts and communicating hydrocephalus are associated findings.     

Rheumatic disease of the temporomandibular joint: MR imaging and tomographic manifestations

Thirty-six temporomandibular joints (TMJs) in 28 symptomatic patients (aged 14-40 years) with rheumatic disease (mostly rheumatoid arthritis) were studied with magnetic resonance (MR) imaging and hypocycloidal tomography. MR images of four TMJs were normal. Another four TMJs showed internal derangement. Of the 28 TMJs presumed to show rheumatic disease involvement (26 with condylar destruction or deformation), 23 showed abnormal disk structure--five showing severe disk destruction and 18 showing less severe abnormalities (inhomogeneous structure, fragmentation, poor delineation, and severe flattening). MR images showed bone abnormalities in 27 of the 36 TMJs, and tomography showed abnormalities in 25 of the 36 TMJs. Good agreement between the two imaging modalities regarding surface irregularities was found. However, MR imaging demonstrated more extensive bone abnormalities than did tomography in 11 TMJs. The potential of MR imaging for depicting bone and soft-tissue abnormalities associated with rheumatic TMJ involvement was clearly demonstrated.     

Small cell lung cancer: staging with MR imaging

Small cell lung cancer is an aggressive neoplasm; metastases are detected in two-thirds of patients at diagnosis with use of conventional staging, which includes bilateral bone marrow biopsy, bone scintigraphy, and computed tomography (CT) of the head and abdomen. In 25 patients, small cell lung cancer was staged prospectively with both conventional staging and a magnetic resonance (MR) imaging protocol that included 1.5-T MR imaging of the pelvis, abdomen, spine, and brain. According to conventional staging, 14 patients had extensive disease and 11 patients had limited disease; according to staging with MR, 19 patients had extensive disease and six had limited disease. All metastatic disease sites seen with conventional staging were identified on MR images. MR images showed additional metastatic involvement in bone (four patients) and liver (three patients) not detected at conventional staging. A low-attenuation hepatic lesion on a CT scan was identified as a hemangioma on MR images. These preliminary data suggest that small cell lung cancer may be accurately staged with use of a single MR imaging study.     

CNS sarcoidosis: evaluation with contrast-enhanced MR imaging.

Reports of findings on unenhanced MR images and contrast-enhanced CT scans in patients with intracranial sarcoidosis have suggested that MR imaging without contrast enhancement may miss meningeal involvement, which is a frequent and prominent finding in neurosarcoidosis. We studied 14 patients with CNS sarcoidosis with T1- and T2-weighted pre- and postcontrast sequences and T1-weighted postcontrast sequences. Eight of 12 patients with intracranial sarcoidosis and one of two with spinal sarcoidosis had meningeal involvement that was not apparent on the unenhanced scans. Eight of 12 patients had intraaxial areas of high signal intensity on T2-weighted images, although only two of these lesions enhanced. Three patients had enhancing extraaxial masses mimicking meningiomas on postcontrast T1-weighted images. In two patients, the lesions decreased markedly in size after steroid treatment. In one patient with sarcoidosis of the optic nerve, the lesion decreased in size and the patient's vision returned to normal after Cytoxan therapy. In five of 14 patients, CNS findings were the initial clinical manifestation of the disease. In nine of 14 patients, the diagnosis of neurosarcoidosis was suggested only after administration of contrast agent. Use of gadopentetate dimeglumine greatly enhances the sensitivity of MR imaging in the detection of CNS sarcoidosis.     

Acute Necrotizing Encephalopathy: Diffusion MR Imaging and Localized Proton MR Spectroscopic Findings in Two Infants

In this report, we describe the findings of diffusion MR imaging and proton MR spectroscopy in two infants with acute necrotizing encephalopathy in which there was characteristic symmetrical involvement of the thalami. Diffusion MR images of the lesions showed that the observed apparent diffusion coefficient (ADC) decrease was more prominent in the first patient, who had more severe brain damage and a poorer clinical outcome, than in the second. Proton MR spectroscopy detected an increase in the glutamate/glutamine complex and mobile lipids in the first case but only a small increase of lactate in the second. Diffusion MR imaging and proton MR spectroscopy may provide useful information not only for diagnosis but also for estimating the severity and clinical outcome of acute necrotizing encephalopathy.     

Diffusion-weighted MR imaging of metastatic disease of the spine: assessment of response to therapy

BACKGROUND AND PURPOSE: In cases of metastatic disease of the spine, monitoring the response to medical therapy with plain radiography, bone scanning, and conventional spin-echo sequence MR imaging is unsatisfactory because of the insensitivity or nonspecific findings of these imaging modalities. The purpose of this study was to investigate signal intensity changes of bone marrow after therapy by using diffusion-weighted MR imaging to monitor the response to medical therapy in cases of metastatic disease of the spine. METHODS: Twenty-four patients with metastatic disease of the spine were examined with MR imaging. Diffusion-weighted MR imaging and spin-echo MR imaging were performed in all patients before and after radiation therapy. Follow-up diffusion-weighted MR imaging and spin-echo MR imaging were performed for comparison purposes in nine cases at 1 month, in seven cases at 2 months, in seven cases at 3 months, and in three cases at 6 months after therapy. The diffusion-weighted MR imaging sequences were based on a steady-state free precession with a low b value (165 s/mm(2)) and a single shot stimulated echo-acquisition mode with a high b value (650 s/mm(2)). Apparent diffusion coefficient maps were obtained using two different b values incorporated in a diffusion-weighted single shot stimulated echo-acquisition mode sequence. Apparent diffusion coefficient maps were obtained in three cases. Signal intensity changes of the metastatic disease of the vertebral bone marrow before and after therapy on conventional spin-echo sequence and diffusion-weighted MR images were evaluated. RESULTS: As shown by diffusion-weighted MR imaging, metastatic disease of the vertebral bone marrow included in our study before therapy was hyperintense to normal vertebral bodies. In 23 patients with clinical improvement, metastatic disease of the spine after therapy was hypointense relative to normal vertebral bodies on the follow-up diffusion-weighted MR images. In one patient with hepatocellular carcinoma, the clinical symptoms did not improve and follow-up bone scanning performed 6 months after therapy showed increased uptake. Persistent hyperintense bone marrow after therapy was also noted on diffusion-weighted MR images. Decreased signal intensity of the metastatic disease of the spine on diffusion-weighted MR images was observed >1 month after therapy. CONCLUSION: Diffusion-weighted MR imaging shows that, with successful therapy, there is decreased signal intensity of metastatic disease of the vertebral bone marrow.     

MR evaluation of wallerian degeneration of the pyramidal tract

This study is based on 135 magnetic resonance (MR) exams of 110 patients with wallerian degeneration of the pyramidal tract shown on MR images acquired on a mid field imaging scanner. The MR findings of wallerian degeneration were abnormal signal band along the course of the pyramidal tract and ipsilateral brain stem shrinkage. In all 110 cases an abnormal signal band was seen on T2-weighted spin-echo images, that is, a hypointense band in four exams between 30 days and 116 days after onset of symptoms, and hyperintense bands in 122 exams. The hyperintense signal on T2-weighted images was shown in most cases after 200 days from the onset. In one case a signal of the pyramidal tract showed a hyperintense band at 7 days, hypointense at 30 days, and hyperintense again at 123 days after onset. Sequential MR exams of another case showed gradual narrowing of the hyperintense signal band and progression of the ipsilateral brainstem shrinkage. The narrowing of the pyramidal tract and the ipsilateral brain stem shrinkage tended to be shown after 6 months from onset.(ABSTRACT TRUNCATED AT 250 WORDS)     

Peyronie's disease: MR findings in 28 patients.

Induratio penis plastica (Peyronie's disease) is a chronic fibrotic process involving the penis. Proper treatment of the disease requires assessment of the degree of inflammation preceding or accompanying the fibrous Peyronie's plaques. Owing to its high tissue contrast and its multiplanar capability, MR imaging offers excellent visualization of penile anatomy. To determine the usefulness of MR imaging in the diagnosis and staging of Peyronie's disease, we used MR imaging with a surface coil to examine 28 consecutive patients with clinical evidence of the disease. Eighteen patients had contrast-enhanced MR imaging with gadopentetate dimeglumine. In seven patients who subsequently had surgery or biopsy, MR findings were correlated with histopathologic findings. On unenhanced images, fibrous plaques were shown in 20 patients. Enhanced MR images showed focal contrast enhancement around or within the plaques in seven patients. Images in three patients with plaques showed no enhancement. Images in five patients showed focal areas of contrast enhancement without evidence of plaques. Histologic studies demonstrated that the degree of contrast enhancement correlated with the extent of inflammatory cell infiltration. In two patients with unenhancing plaques on MR, histology confirmed the absence of inflammation. Our results suggest that MR imaging not only depicts the localization and extent of fibrous plaques in patients with Peyronie's disease but also reveals the presence of inflammation. This makes MR imaging the technique of choice for planning therapy and for evaluating the response to conservative treatment.     

Involvement of the pontomedullary corticospinal tracts: a useful finding in the diagnosis of X-linked adrenoleukodystrophy.

PURPOSETo determine whether pontomedullary corticospinal tract involvement is a common and specific finding of adrenoleukodystrophy on MR images.METHODSMR images of 10 patients with biochemically proved adrenoleukodystrophy who were examined during the last 6 years were reviewed retrospectively to determine the frequency of corticospinal tract involvement in the medulla, pons, mesencephalon, internal capsules, and corona radiata. MR images of 10 patients with other leukodystrophies (three with Krabbe disease, two with Alexander disease, two with metachromatic leukodystrophy, two with Pelizaeus-Merzbacher disease, and one with Canavan disease) were reviewed with specific attention to the pontomedullary corticospinal tracts.RESULTSMedullary and pontine corticospinal tract involvement was present in eight of the 10 patients with adrenoleukodystrophy. Mesencephalic and internal capsular involvement was present in three patients. The coronal radiata portion of the corticospinal tracts was not involved in any of the 10 patients. No pontomedullary corticospinal tract involvement was identified in any of the 10 patients with other leukodystrophies. The difference in the frequency of pontomedullary corticospinal tract involvement between the two groups was highly significant.CONCLUSIONPontomedullary corticospinal tract involvement is a common finding in adrenoleukodystrophy and is unusual in other leukodystrophies. Awareness of this finding can facilitate the radiologic diagnosis of this disease and may expedite management of affected patients.     

MR imaging of superior sulcus carcinoma

Magnetic resonance (MR) imaging was performed in 10 patients with biopsy proven superior sulcus carcinomas to determine the extent of local tumor invasion. Chest wall invasion or extension into the base of the neck was demonstrated in five patients. This finding was facilitated by the contrast between the bright signal intensity of tumor and the low signal intensity of muscle on T2-weighted images. In three patients, MR clearly depicted direct invasion of the mediastinum. This finding was facilitated on the MR image because of inherent contrast between the mediastinal fat and tumor. Coronal and sagittal images showed the relationship of tumor to the subclavian artery and brachial plexus in all cases. Encasement of the artery was confirmed in two cases and brachial plexus involvement in three. However, MR failed to detect evidence of rib destruction in five patients in whom rib involvement was confirmed by other studies. Magnetic resonance appears to be a useful imaging modality in determining the extent of local disease and, therefore, the selection of patients for surgical resection. Multiplanar imaging and contrast between tumor and muscle and tumor and fat allow assessment of invasion of the mediastinum and base of the neck, subclavian artery, and brachial plexus.     

Sarcoidosis of the CNS: comparison of unenhanced and enhanced MR images

Sarcoidosis involving the CNS has a predilection for the leptomeninges, although parenchymal involvement occurs. We retrospectively evaluated the appearance of CNS sarcoidosis on unenhanced and enhanced MR images. MR studies were abnormal in 17 of 20 patients with CNS sarcoidosis. In all 17 patients, meningeal disease was detected on the gadopentetate-dimeglumine-enhanced T1-weighted images; the disease was detected on unenhanced images in three patients. Well-defined leptomeningeal patterns of enhancement were present in 15 patients. Other areas of involvement were the dura; brain parenchyma including hypothalamus, periventricular white matter, and ventricular ependyma; optic chiasm; and pituitary gland. Gadopentetate dimeglumine optimally evaluates meningeal disease and highlights the importance of the leptomeninges and Virchow-Robin spaces in the pathogenesis of CNS sarcoidosis. Enhanced MR is the preferred imaging technique for the evaluation of CNS sarcoidosis.     

Sarcoidosis of the CNS: comparison of unenhanced and enhanced MR images

Sarcoidosis involving the CNS has a predilection for the leptomeninges, although parenchymal involvement occurs. We retrospectively evaluated the appearance of CNS sarcoidosis on unenhanced and enhanced MR images. MR studies were abnormal in 17 of 20 patients with CNS sarcoidosis. In all 17 patients, meningeal disease was detected on the gadopentetate-dimeglumine-enhanced T1-weighted images; the disease was detected on unenhanced images in three patients. Well-defined leptomeningeal patterns of enhancement were present in 15 patients. Other areas of involvement were the dura; brain parenchyma including hypothalamus, periventricular white matter, and ventricular ependyma; optic chiasm; and pituitary gland. Gadopentetate dimeglumine optimally evaluates meningeal disease and highlights the importance of the leptomeninges and Virchow-Robin spaces in the pathogenesis of CNS sarcoidosis. Enhanced MR is the preferred imaging technique for the evaluation of CNS sarcoidosis.