Wegener granulomatosis: CT and MR findings.

PURPOSETo demonstrate the spectrum of CT and MR imaging findings in patients with Wegener granulomatosis and to determine how often these findings could be attributed to either direct extension from paranasal or orbital disease sites, remote granulomas, or central nervous system (CNS) vasculitis.METHODSWe retrospectively reviewed the CT or MR studies of 15 patients with Wegener granulomatosis.RESULTSAbnormal findings were seen in 7 patients (5 examined with MR imaging, 2 with CT). Findings included dural thickening and contrast enhancement (3 patients), infarcts (2 patients), regions of hyperintense signal on T2-weighted MR images (2 patients), and abnormal MR signal in the brain stem (2 patients). Three patients with imaging findings of dural enhancement and thickening were thought to have remote granulomatous lesions involving the dura. No patients had extension from sites external to the CNS or clinical findings suggestive of CNS vasculitis.CONCLUSIONThe spectrum of CT and MR findings in Wegener granulomatosis includes dural thickening and enhancements cerebral infarction, and MR signal abnormalities in the brain stem and white matter. Presumed remote granulomatous lesions were the most common causes of CNS findings in this study. Complications related to non-CNS disease (eg, hypertension, endocarditis) also appear to have played a role in some patients.     

MR imaging findings of spinal dural involvement with Wegener granulomatosis

Involvement of the brain and meninges is rare in cases of Wegener granulomatosis, occurring in 2% to 8% of cases. Meningeal involvement in association with Wegener granulomatosis has scarcely been reported as being confined to the dura mater of brain on images and is thought to represent granulomatous infiltration. There are a few reported cases of Wegener granulomatosis that document involvement of dura at the level of the spinal cord. We present the case of a 52-year-old man with Wegener granulomatosis involving the cervical spinal dura and include detailed MR imaging findings.     

MR imaging of cardiac mass in Wegener granulomatosis

Wegener granulomatosis is a disorder of unknown etiology characterized by a necrotizing granulomatous vasculitis that primarily affects the paranasal sinuses, lungs, and kidneys. It is usually a disease of adults with infrequent cardiac involvement. We report the unusual presentation of this disorder in an adolescent with a cardiac mass. The findings on two-dimensional echocardiography and MR imaging are discussed.     

MR imaging of the brain in lymphomatoid granulomatosis

BACKGROUND AND PURPOSE: Clinical diagnosis of lymphomatoid granulomatosis (LG) of the brain, in patients without skin or chest lesions, usually is difficult because of the nonspecific neurologic manifestations, laboratory data, and CT appearance. Our aim was to characterize the MR appearance of LG of the brain. METHODS: We retrospectively reviewed the MR images in four patients (35 to 72 years old) with histologically confirmed LG of the brain. RESULTS: On T2-weighted images, we noted diffuse hyperintense lesions in the cerebral white matter bilaterally (n = 3), in the brain stem and cerebellar hemisphere (n = 1), and patchy hyperintense lesions the brain stem (n = 2). On contrast-enhanced T1-weighted images, we observed multiple punctate or linear enhancements residing along the perivascular space (n = 4), nodular enhancements (n = 2), ringlike enhancements (n = 1), and a large, enhanced mass (n = 1). All patients had multifocal lesions. CONCLUSION: Although the MR appearance of LG of the brain varies, multiple punctate or linear enhancements that reside along the perivascular space suggest LG.     

MR Imaging in Wegener granulomatosis of the spinal cord

Wegener granulomatosis is a multisystemic disorder characterized by necrotizing vasculitis that primarily involves the respiratory tract. The orbits, heart, skin, joints, and nervous system are frequently involved. We describe the MR imaging findings of Wegener granulomatosis in the cervical spine and correlate them with the histopathologic features. MR imaging showed epidural liquid masses surrounded by granulomatous masses that compressed the cervical myelin from behind.     

Whistling face syndrome: MR imaging findings in the brain

Whistling face syndrome or cranio-carpotarsal dysplasia is a very rare disorder that consists of a characteristics facies and digital abnormalities. Magnetic resonance imaging investigation of the brain in this syndrome has not been reported previously. This communication describes the brain malformations in an infant with the syndrome, which covered delayed myelination, thickened and infolded cortices (cortical dysplasia), dysplastic corpus callosum, and agenesis of the inferior vermis.     

Traumatic brain injury: diffusion-weighted MR imaging findings.

BACKGROUND AND PURPOSE: Diffuse axonal injury (DAI) accounts for a significant portion of primary intra-axial lesions in cases of traumatic brain injury. The goal of this study was to use diffusion-weighted MR imaging to characterize DAI in the setting of acute and subacute traumatic brain injury. METHODS: Nine patients ranging in age from 26 to 78 years were examined with conventional MR imaging (including fast spin-echo T2-weighted, fluid-attenuated inversion-recovery, and gradient-echo sequences) as well as echo-planar diffusion-weighted MR imaging 1 to 18 days after traumatic injury. Lesions were characterized as DAI on the basis of their location and their appearance on conventional MR images. Trace apparent diffusion coefficient (ADC) maps were computed off-line with the diffusion-weighted and base-line images. Areas of increased signal were identified on the diffusion-weighted images, and regions of interests were used to obtain trace ADC values. RESULTS: In the nine patients studied, isotropic diffusion-weighted images showed areas of increased signal with correspondingly decreased ADC. In one case, decreased ADC was seen 18 days after the initial event. CONCLUSION: Decreased ADC can be demonstrated in patients with DAI in the acute setting and may persist into the subacute period, beyond that described for cytotoxic edema in ischemia.     

Chest radiograph in lymphomatoid granulomatosis: comparison with Wegener granulomatosis

A form of angiitis and granulomatosis principally involving the lung was identified as a variant form of Wegener granulomatosis only 15 years ago. Recent experience indicates that the most common form of pulmonary angiitis and granulomatosis is lymphomatoid granulomatosis. Chest radiographs of 16 patients with this condition were reviewed and the findings compared with those of Wegener granulomatosis. The frequency and distribution of nodular masses, cavitation, and migratory lesions were similar in the two disorders, but reticulonodular infiltrates occurred only in lymphomatoid granulomatosis. The study suggests that lymphomatoid granulomatosis and Wegener granulomatosis occasionally can be distinguished by radiographic criteria. Although radiologic patterns will suggest the diagnosis of pulmonary angiitis and granulomatosis, the specific diagnosis of lymphomatoid granulomatosis must rely on clinical, immunologic, and pathologic evidence. Accurate differentiation is essential since treatment of Wegener granulomatosis with cyclophosphamide is highly effective while treatment of lymphomatoid granulomatosis is infrequently successful.     

Subcortical arteriosclerotic encephalopathy: brain stem findings with MR imaging

Magnetic resonance images of 44 patients who had varying degrees of supratentorial signal abnormalities compatible with subcortical arteriosclerotic encephalopathy (SAE) were reviewed for posterior fossa findings. Brain stem lesions frequently accompanied supratentorial SAE and were seen as multiple, fairly symmetric areas of poorly defined, increased signal intensity on axial T2-weighted images. Involvement was generally confined to the central portions of the mid and upper pons. The typical appearance of brain stem involvement by SAE and its probable pathogenesis are reviewed.     

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.     

Sacroiliitis: MR imaging findings

Magnetic resonance (MR) imaging was performed in seven asymptomatic volunteers and 17 patients with clinical and radiologic evidence of sacroiliitis. MR imaging findings were compared with those at computed tomography (CT) to determine the MR imaging appearance of the sacroiliac joint when normal and in sacroiliitis. The normal articulation was well depicted with MR imaging. Findings of sacroiliitis were identified in 20 sacroiliac joints (12 patients). MR imaging findings characteristic of sacroiliitis included abnormal cartilage signal intensity (95% of joints) and erosions (75% of joints) on T1-weighted images. Areas of increased intensity in the articulation (80% of joints) or in erosions (60% of joints) were seen on T2-weighted images. MR imaging was superior to CT for evaluation of cartilage and detection of erosions. Four sacroiliac joints (20%) and two patients (17%) with MR imaging findings of sacroiliitis were negative at CT. The authors conclude that MR imaging is a valuable method for detecting sacroiliitis, particularly when results of other imaging techniques are inconclusive.     

CT and MR imaging of CNS lymphomatoid granulomatosis

Summary The clinical CT and MR imaging features of a pathologically confirmed case of lymphomatoid granulomatosis are presented. The disease was clinically confined to the central nervous system and the diagnosis was only made after brain biopsy had been performed. MR imaging revealed extensive non-confluent regions of white matter abnormality. Although uncommon, lymphomatoid granulomatosis should be included in the differential diagnosis of causes of periventricular and deep white matter lesions, even in the absence of pulmonary lesions. Specific therapy may produce clinical regression of disease.     

Paget disease: MR imaging findings

Magnetic resonance (MR) images of 13 patients with Paget disease were reviewed, and findings were correlated with those from computed tomographic (CT) scans, radiographs, and, in two patients, surgical biopsy. MR imaging findings correlated with CT and radiographic findings of cortical thickening, increased size of bone, and coarse thickened trabeculae. Focal or diffuse decreased signal intensity, representing dense bone, was seen on images obtained with short and long repetition times (TRs) and echo times (TEs); high-signal foci, representing fat collections, were seen on short TR/TE images; and high-signal foci, representing fibrovascular marrow in active Paget disease, were seen on long TR/TE images. Complications of Paget disease-including basilar invagination, spinal stenosis, and sarcoma--were well identified on MR images. Although MR imaging is not generally used in diagnosis of Paget disease, the disease will be encountered more frequently as more MR imaging examinations are performed. An awareness of the range of findings in Paget disease is useful in evaluating MR images of the musculoskeletal and other systems.     

Sneddon's syndrome: MR imaging findings

Sneddon's syndrome is a systemic disease characterized by generalized livedo racemosa and cerebrovascular disease. We present a case of Sneddon's syndrome which has typical dermatological lesions and occipital infarct demonstrated by both CT and MRI.     

Tongue abscesses: MR imaging findings

BACKGROUND AND PURPOSE: A lingual abscess is difficult to diagnose in the absence of physical signs. MR imaging may provide an excellent and invaluable adjunct to clinical examination, but the literature is incomplete in defining the various MR imaging findings of abscess. The objective of this study was to determine the MR imaging features of tongue abscesses. METHODS: Seven surgically proved tongue abscesses were evaluated with MR imaging. Four patients underwent MR imaging because of suspected tumor, and 3 patients, to show the extent and precise anatomic location of the lesion. Lesions were assessed with regard to the location, size, signal-intensity characteristics, and pattern of contrast enhancement. RESULTS: Five lesions were located in the anterior tongue and 2, in the posterior tongue. The central parts of 4 anterior tongue abscesses were hypointense, surrounded by a hyperintense wall on T1-weighted precontrast images. On postcontrast images, marked wall enhancement was detected. On T2-weighted images, a markedly hyperintense central part surrounded by a hypointense rim was seen. In 2 of these patients, there was a hypointense halo surrounding the wall (target sign). In 3 patients, a perilesional hyperintense area that enhanced diffusely after contrast administration was detected on T2-weighted images. The smallest lesion located in the anterior tongue was hypointense on T1-weighted images and enhanced diffusely on postcontrast images. On T2-weighted images, a markedly hyperintense central part surrounded by a mildly hyperintense peripheral part was depicted. Posterior tongue lesions appeared as polypoid ill-defined masses and were hypointense on T1-weighted images and heterogeneously hyperintense on T2-weighted images. On postcontrast images, the lesion in 1 patient showed diffuse and heterogeneous contrast enhancement, whereas the lesion in another patient enhanced peripherally. The lesions were totally excised in 4 patients and drained with surgical incisions in 3 patients. No recurrence was detected on follow-up. CONCLUSION: An abscess typically presents as a cystic lesion surrounded by an enhancing capsule formation, but lesions may also present as solid masses that enhance diffusely or peripherally.     

Fibrolipomatous hamartoma: MR imaging findings

 Objective. To analyze the MR imaging features of fibrolipomatous hamartoma (FLH) of nerves. Design and patients. MR imaging studies from six patients (three men and three women) were retrospectively reviewed by three musculoskeletal radiologists. In four patients, a biopsy of the nerve lesion was performed. In two patients, biopsy data were unavailable and the diagnosis was based on the clinical history combined with the MR imaging findings. Results and conclusion. MR imaging demonstrated fusiform nerve enlargement that was caused by fatty proliferation and thickening of nerve bundles. Nerve bundles appeared as serpentine tubular structures, hypointense on both T1- and T2-weighted images. The degree of fatty proliferation varied among patients. In addition, significant variation in the distribution of fat along the course of the nerves was noted. In three patients, FLH followed the branching pattern of the nerves, a characteristic pathologic finding. In two patients, intramuscular fat deposition (biceps and tibialis posterior muscles) was present. MR imaging findings of FLH are typical, allowing a confident diagnosis. The variation of fatty proliferation among patients and involved nerves as well as the tendency of the abnormalities to follow the branching pattern of the nerves is well demonstrated with MR imaging. FLH may present as an isolated nerve lesion, may be associated with intramuscular fat deposition, or may occur as a feature of macrodystrophia lipomatosa (MDL).