Primary lymphoma of the cervix: MRI findings with gadolinium

MRI evaluation of primary cervical lymphoma has not been reported. We report such a case of primary cervical lymphoma, a lesion well seen and well delineated from normal tissue by MRI. Although primary lymphoma of the cervix is a rare entity, the disease does exist and can be well demonstrated by MRI. We evaluated the MR appearance of this lesion with both nonenhanced and gadolinium-enhanced imaging.     

Granulomatous hepatitis: MRI findings.

The purpose of this study was to describe the magnetic resonance imaging findings of granulomatous hepatitis on T1-weighted, T2-weighted and postgadolinium images. Eight patients with histopathological diagnosis of granulomatous hepatitis were evaluated in this study. MRI examinations included precontrast T1-weighted breath-hold spoiled gradient echo, breathing independent STIR sequences, and T1-weighted breath-hold spoiled gradient-echo sequence following after i.v. gadolinium administration in arterial, intermediate and late phases. Diffuse nodular liver involvement was visualized in all patients. Nodules were consistent with granulomas and were 0.5-4.5 cm in diameter. Caseating granulomas were intermediate and high signal on T2-weighted, low signal on T1-weighted images. They revealed no enhancement in two patients, and enhanced in one patient. Noncaseating granulomas revealed intermediate signal on T1, and T2-weighted images and increased enhancement on arterial phase images with persisting enhancement in late phase images. Portal lymph nodes were visible in five patients. Splenomegaly was present in five patients. Granulomatous hepatitis has spectrum of MRI features, to be considered in differential diagnosis with other diffuse nodular liver pathologies.     

Hepatic alveolar echinococcosis: MRI findings

The purpose of this study was to describe the magnetic resonance imaging (MRI) appearance of hepatic alveolar echinococcosis (HAE) on T(1)-weighted, T(2)-weighted and postgadolinium images. A total of 13 lesions were demonstrated in 13 patients. All patients underwent MR examination at 1 T imager. MR examinations included precontrast T(1)-weighted breathing averaged spin echo (SE), breath-hold spoiled gradient echo, T(2)-weighted TSE sequences with and without fat suppression, and T(1)-weighted breath-hold spoiled gradient echo (SGE) sequence following i.v. after gadolinium administration. All lesions were confirmed with histopathology. HAE hepatic lesions revealed geographic patterns of variable signal intensities on noncontrast T(1)- and T(2)-weighted images. Slightly hyperintense, iso- and hypointense signal on T(1)-weighted images corresponded to calcified regions, which appeared hypo-isointense signal on T(2)-weighted images. Necrotic areas were hypointense signal on T(1)-weighted and hyperintense signal on T(2)-weighted images. On postgadolinium images, lesions did not reveal enhancement. Dilatation of intrahepatic bile ducts distal to HAE abscesses were observed in five patients and portal vein invasion or compression was observed in four patients, lobar atrophy of the liver was coexistent finding in cases with portal vein compression. The MRI appearance of HAE abscesses included large irregularly marginated masses with heterogenous signal on T(1)- and T(2)-weighted images and lack of enhancement with gadolinium.     

Liver schwannoma: findings on MRI

Magnetic resonance imaging features of benign liver schwannoma in a 52-year-old woman are described. An oval shaped, 4.4×3.6×2.9-cm lesion was located in Segment 7 of the right hepatic lobe. The lesion was hypointense on T₁-weighted images and mixed hypo- and hyperintense on T₂-weighted images. On serial contrast-enhanced images, the lesion revealed gradually increasing centrilobular enhancement. The tumor was surgically removed thereafter.     

Renal subcapsular pseudocyst: findings on MRI

Pancreatic pseudocysts are common complications of pancreatitis. They may occur in unusual places as a result of spread along the path of least resistance. Penetration of Gerota's fascia and spread into the renal subcapsular space are uncommon. Their appearance on magnetic resonance imaging has not been previously documented. Given the increased use of magnetic resonance cholangiopancreatography for the investigation of patients with pancreatitis, the recognition that a complicated renal cyst in this clinical context could represent a benign condition is important.     

Renal-related perinephric fluid collections: MRI findings

We retrospectively reviewed MR studies on 10 patients with renal-related perinephric fluid collections who underwent MRI in three institutions between January 2001 and August 2004. All patients underwent MRI of the abdomen and T1-weighted, T2-weighted and serial contrast-enhanced images, including delayed-phase contrast-enhanced images 10-12 min after contrast injection, were obtained. Perinephric fluid collections in 5 patients revealed MRI findings of simple fluid content (i.e., hypointense on T1-weighted images and hyperintense on T2-weighted images). In another 5 patients, a complex perinephric fluid content (i.e., mixed hyper/hypointense on T1-weighted images and mixed hypo/hyperintense on T2-weighted images compatible with blood breakdown products and pus) was observed. In 5 patients, contrast extravasation on late-phase images that was compatible with urine leak was demonstrated. Our results suggest that MRI may determine the content of perinephric fluid collections on noncontrast T1-weighted and T2-weighted images and that contrast extravasation on late-phase images is associated with urine extravasation from renal collecting systems.     

MRI findings of intraosseous lipoma: case report

Intraosseous lipoma is one of the rarest benign bone tumors and usually presents in the fourth to fifth decades. Except for minor symptoms, they are usually asymptomatic. Metaphysis of long bones, especially proximal parts of femur and fibula, are involved in most cases. We present intraosseous lipoma to discuss the benefits of MRI and contrast-enhanced MRI findings for differential diagnosis.     

Acute and subacute liver-related hemorrhage: MRI findings

We retrospectively reviewed the MR studies on all patients with liver-related fluid collections compatible with acute or early subacute hemorrhage, who underwent MR imaging at our center between June 1994 and January 1998. All patients had a clinical history of an underlying liver lesion or injury with a duration of symptomatology of less than 5 days. In three patients with only 2-3 days of symptoms, the liver-related hemorrhagic fluid was hypointense on T1-weighted images and markedly hypointense on T2-weighted images relative to liver, consistent with intracellular deoxyhemoglobin. The fluid was relatively homogeneous in signal intensity. In three patients with 3-5 days of symptoms, the majority of liver-related fluid was hyperintense on T1-weighted images and hypointense on T2-weighted images relative to liver, consistent with intracellular methemoglobin. Three of these latter four patients also had fluid collections of varying T1-and T2-weighted signal intensity consistent with blood breakdown products of varying ages. Clinical findings matched the MR findings of acute/early subacute blood in all cases. Our results describe the findings of acute and early subacute liver hemorrhage. The most helpful MR feature of bleeding of recent origin is very low signal intensity of the fluid on T2-weighted imaging.     

MRI findings in pulmonary sarcoidosis

Postero-anterior radiographs and magnetic resonance imaging (MRI) of the chest were performed in nine biopsy proven cases of sarcoidosis. MRI was more sensitive than a postero-anterior chest roentgenogram in detecting hilar and mediastinal adenopathy but less informative in detecting pleural and parenchymal disease.     

MRI findings in osteofibrous dysplasia

A case of osteofibrodysplasia of the long bones in a 4-year-old girl is reported with ipsilateral tibial and fibular involvement. The radiological pattern of the lesions suggested fibrodysplasia but not their MRI signal characteristics. This diagnostic imaging mismatch and the bifocality of the lesion were the tell-tale indications for the confirmatory bone biopsy yielding osteofibrous dysplasia of Campanacci.     

Rhombencephalosynapsis diagnosed in childhood: clinical and MRI findings

Rhombencephalosynapsis is an unfrequent malformation of the posterior fossa essentially characterized by vermian agenesis or hypogenesis, fusion of the cerebellar hemispheres and fusion of the dentate nuclei. Supratentorial abnormalities are usually associated. No specific clinical syndrome can be described in relation with this disorder. We report a case diagnosed by MRI in a living patient.     

Pediatric primary and metastatic neuroblastoma: MRI findings: pictorial review

Magnetic resonance imaging (MRI) has become one of the most valuable modalities for initial and follow-up imaging of suspected or known neuroblastoma (NBL) owing to its excellent inherent contrast, lack of ionizing radiation and multiplanar imaging capability. Importantly, NBL has a variable appearance on different imaging modalities, and this is particularly pertinent to MRI. MRI is a cornerstone for management of NBL, providing essential information at initial presentation regarding diagnosis, staging, resectability and relation to vital structures. It can also define the extent of residual disease after surgical resection or assess the efficacy of treatment. Follow-up MRI is frequently performed to ensure sustained complete remission or to monitor known residual disease. This pictorial review article aims to provide the reader with a concise, yet comprehensive, collection of MR images of primary and metastatic NBL lesions with relevant correlation with other imaging modalities.     

Mass-like hepatic hypertrophy: MRI findings with histologic correlation.

Hepatic parenchyma may hypertrophy following asymmetrical injury. The histologic characteristics of hypertrophic hepatic parenchyma are more similar to normal hepatic parenchyma than is the more severely damaged liver. We present four cases where large hypertrophic masses resembled neoplasm on other imaging modalities or at surgery, but had MRI signal characteristics similar to those of normal liver.     

Plexiform neurofibroma of the pelvis: CT and MRI findings

We present a case of plexiform neurofibroma of the pelvis in a patient with neurofibromatosis using magnetic resonance imaging (MRI) with computed tomography (CT) correlation. We discovered an extensive pelvic mass with a slightly greater signal intensity than muscle in T1-weighted images and a marked increased signal intensity in T2-weighted images. Multiple hypointense septations were identified throughout the tumor, particularly in the T2-weighted images. The MR appearance of pelvic plexiform neurofibroma is identical to those found in spinal and paraspinal locations. In the presence of an extensive pelvic mass in a patient with neurofibromatosis, MRI is recommended in evaluating and diagnosing plexiform neurofibroma. Since the MRI appearance of this tumor is characteristic, other lesions can possibly be ruled out. In addition, MRI's multiplanar capability is ideally suited to demonstrate the extension of these large tumors.     

Early MRI findings of rapidly destructive coxopathy

To diagnose rapidly destructive coxopathy (RDC) in its early stages and understand the pathomechanism of associated joint destruction, ten cases of RDC were followed by periodic MRI from onset of the disease. In the initial stage (stage 1) of RDC, when radiographs revealed slight narrowing of the joint space, a small subchondral area of low signal intensity was observed on T(1)-weighted images (T1WI) and inhomogeneous high intensity was observed on T(2)-weighted images (T2WI) in the antero-lateral portion of the femoral head. When radiographs showed obliteration of the joint space (stage 2), MRI revealed a diffuse area of low intensity on TIWI and high intensity on T2WI in the proximal femur, including the femoral neck and head, suggesting extensive bone marrow edema. The femoral head and acetabulum were aggressively destroyed (stage 3) in all cases 3 to 6 months after the diffuse abnormal pattern was observed on MRI. MRI in stage 3 cases showed low intensity areas on both T1WI and T2WI. RDC did not show the band-like pattern of low intensity on T1WI and high intensity on T2WI that typify MRI findings in cases of osteonecrosis. When joint space narrowing is observed radiographically, the diffuse abnormal pattern of low intensity on T1WI and high intensity on T2WI induced by a subchondral small lesion might be an early sign of RDC.     

Primary malignant mesothelioma of the liver: MR imaging findings

We report the MR imaging findings of a primary malignant mesothelioma of the liver arising from Glisson's capsule. A 54-year-old woman, presenting with acute abdominal pain and a large liver mass previously shown on CT, underwent MR imaging to characterize the lesion. The tumor was a greater than 12 cm tumor located in the right lobe of the liver, which was sharply marginated, with heterogeneous internal signal, septations and central necrosis. The tumor was considered a hepatocellular carcinoma. The diagnosis of malignant mesothelioma was established by immunohistochemical staining and electron microscopy of the resected tumor.     

MRI findings in nonalcoholic steatohepatitis: correlation with histopathology and clinical staging

Purpose

To evaluate magnetic resonance imaging (MRI) findings of nonalcoholic steatohepatitis (NASH) and to determine the correlation of MRI findings with histopathology and Mayo End-Stage Liver Disease (MELD) score.

Materials and Methods

Thirty patients (18 males, 12 females; mean age: 57±8.9 years; age range: 35–71 years) with histopathologically proven NASH who underwent MRI examinations between January 2001 and October 2005 were included in the study. Two radiologists retrospectively reviewed all magnetic resonance (MR) examinations in consensus to evaluate the presence and extent of predetermined findings of NASH including liver steatosis, early patchy liver enhancement indicating inflammation and liver fibrosis. The findings detected on MRI were correlated and compared to histopathological findings and MELD score by using nonparametric Spearman correlation coefficient and Kruskal–Wallis analysis of variance.

Results

Liver steatosis was observed in 10 of 30 patients; early patchy liver enhancement, in 8 of 30 patients and liver fibrosis in 19 of 30 patients on MR images. Liver fibrosis was reticular in all these patients. There were statistically significant moderate correlations between MRI findings of liver steatosis and histopathologic grades of steatosis (r=0.43; P<.05), and between MRI findings of fibrosis and histopathologic stages of fibrosis (r=0.61; P<.001). Early patchy enhancement did not demonstrate statistically significant correlation with inflammation (P=.28). There was no statistically significant overall correlation between MRI findings of NASH and MELD score.

Conclusion

MRI findings of liver steatosis and fibrosis in NASH showed moderate correlations with histopathologic grades of steatosis and stages of fibrosis, but MRI findings of NASH did not demonstrate any significant correlations with MELD score.     

MRI findings of primary small-cell carcinoma of kidney

We report the MRI findings of primary small-cell carcinoma of the kidney (PSCCK) in a 59-year-old female. This tumor appeared as a 16-cm mass that arose from the right kidney. This lesion had diminished signal on T1-weighted images and heterogeneous mixed signal on T2-weighted images. The tumor primarily involved the renal medulla with persistent thin renal cortex. Despite the tumors' large size, no substantial central necrosis was present. The predominant medullary location and the lack of central necrosis in this large tumor were features unusual for renal cell carcinoma and should raise the suspicion of another malignancy, the differential diagnosis of which should contain extrapulmonary small-cell carcinoma of the kidney.