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PURPOSE: To determine whether adrenal adenomas can be differentiated from metastases on fat-saturated magnetic resonance (MR) images. MATERIALS AND METHODS: Twenty-eight adrenal adenomas and 20 metastatic lesions were imaged at 1.5 T by means of fat-saturated T1- and T2-weighted and gadolinium-enhanced T1-weighted sequences. The authors evaluated visually whether structures of high signal intensity (hyperintense rim sign) could be observed in the outer margin of the adrenal masses. RESULTS: Twenty-six of 28 adrenal adenomas revealed the hyperintense rim sign on at least one kind of fat-saturated image, compared with only one of 20 metastases. The sensitivity of the hyperintense rim sign as suggestive of adrenal adenoma was 92%, specificity was 95%, and overall accuracy was 94%. CONCLUSION: The hyperintense rim sign is characteristic of adrenal adenomas. Thus, adrenal adenomas can be differentiated from metastases by means of this new imaging sign on fat-saturated MR images.

Patients whose Ga-67 whole-body images showed increased uptake by the bone/bone marrow of the lower extremities were selected and classified into three types according to the extent and the grade of the visualization. These types were then compared with their serum iron levels, iron-binding capacities, and the results of several other serum biochemical tests. Of 374 consecutive whole body 72-hr images reviewed, 59 (15.8%) showed increased uptake of the tracer by the bone/bone marrow of the lower extremities. The three classified types were as follows: type T--visualization of both tibiae and femurs; type S--strong visualization of the femurs; and type W--weak visualization of the femurs. The serum iron concentration was significantly high in type T and low in type S. In conclusion, the pattern of Ga-67 uptake by the bone/bone marrow of the lower extremities fairly closely reflects the status of iron metabolism.

Chronic hepatic schistosomiasis japonica is a disorder characterized by broad fibrous septa in the liver. The ability to recognize these septa on MR images might enable distinction of this lesion from other cirrhotic disorders. The purpose of this study was to analyze the MR appearance of these septa.MR images of 18 patients who had typical calcifications of hepatic septa on CT scans were reviewed. The diagnosis was proved by biopsy in six patients. In the remaining 12, stool examinations were positive for schistosomiasis. T1-weighted MR images and T2-weighted and intermediate (long repetition time and short echo time) MR images acquired with the use of gradient-moment nulling were obtained in all 18 patients. In eight of 18 patients, additional T2-weighted and intermediate images were obtained without gradient-moment nulling. Fifteen patients had contrast-enhanced T1-weighted images. The presence of abnormal MR signal and its intensity at sites corresponding to the septa seen on CT scans were studied.MR images showed the septa as linear abnormalities frequently seen in the subdiaphragmatic portion of the right lobe of the liver. On T1-weighted images, septa had low signal intensity and were identified in nine of 18 patients. On T2-weighted images obtained with gradient-moment nulling, septa had high signal intensity and were seen in 13 of 18 patients. On T2-weighted images obtained without gradient-moment nulling, the septa had primarily low signal intensity and were seen in five of eight patients. On intermediate MR images obtained with gradient-moment nulling, the septa had primarily high signal intensity and were seen in nine of 18 patients. On intermediate images obtained without gradient-moment nulling, the septa had primarily low signal intensity and were seen in four of eight patients. In nine of 15 patients, septa were visualized as high-signal-intensity lesions on contrast-enhanced T1-weighted images. In 14 of 18 patients, the septa were detected in one or more sequences.Our experience suggests that MR imaging in patients with chronic schistosomiasis of the liver depicts the morphologic features of hepatic septa. MR signal characteristics of septa are not unique, but use of gradient-moment nulling alters the signal intensity of septa, similar to that of blood vessels, on intermediate and T2-weighted images.

PURPOSE: To determine whether decreased signal intensity of the motor cortex (T2 shortening) at magnetic resonance (MR) imaging is a useful finding for supporting the diagnosis of amyotrophic lateral sclerosis (ALS). MATERIALS AND METHODS: High-field-strength (1.5-T) MR images of 15 patients (seven men and eight women, aged 28-80 years) and 49 neurologically normal age-matched control patients were examined for T2 shortening in the motor cortex. In addition, brains of patients with ALS were examined at autopsy. RESULTS: The MR images of 14 of the 15 patients showed T2 shortening in precentral cortices, while the images of all but one of the control patients showed no such finding. In three of eight brains at autopsy, sections from the precentral cortex showed sparsely distributed, intensely stained astrocytes and macrophages. CONCLUSION: Abnormal iron deposition associated with the degenerative process could be the source of T2 shortening, which is a useful MR imaging finding in the diagnosis of ALS.

Iodized-oil CT in a patient with chronic liver disease revealed focal accumulation of iodized oil in an exophytic mass. Single photon emission CT (SPECT) with [99mTc]phytate showed the existence of functioning Kupffer cells, excluding hepatocellular carcinoma. Biopsy revealed a regenerating nodule. Positive iodized-oil CT does not always indicate hepatoma. In such cases, SPECT with [99mTc]phytate will help to make a correct diagnosis.

Direct communication between portal branches and the hepatic vein [macroscopic intrahepatic portal-hepatic venous shunt (IPHVS)] is a rare entity. We have recently studied five patients with this condition. Magnetic resonance imaging (MRI) clearly demonstrated in each case the portal-hepatic venous shunt due to “flow void. “ Multiple diffuse shunts were present in one case and a solitary shunt was demonstrated in the others. The solitary shunt was either tubular, focally dilated or racemose in configuration. The MRI findings and clinical significance of this rare entity are discussed.

Out of 79 consecutive cases of hepatocellular carcinoma (HCC) examined with computed tomography (CT), five patients revealed metastatic swollen abdominal lymph nodes. Involved were portal, retropancreatic, common hepatic, superior mesenteric, and paraaortic nodes. CT appeared to be an excellent modality in the diagnosis of metastatic abdominal lymph nodes of HCC.

Twenty-seven consecutive cases with a prospective diagnosis of cancer of the gallbladder were analyzed to clarify the computed tomographic (CT) and ultrasonographic features, behavior, and prognosis of intraluminal papillary carcinoma (n = 7) of the organ. With CT and ultrasonography, these intraluminal carcinomas were further classified into 3 subtypes: single polyp, multiple polyp, and jam-packed gallbladder. Preoperative diagnosis, evaluation of local invasiveness, and detection of metastatic lesions were reliably done. Carcinomas of this type were locally less invasive, less frequently metastasized, and resulted in a longer survival than the other massive and thickened-wall carcinomas.

67Ga scintigrams in a patient with malignant lymphoma before and after chemotherapy are presented. 67Ga did not accumulate in the mostly necrotic mass with some viable cells. Negative uptake of 67Ga might reflect necrosis of the tumor; however, it is difficult to detect some residual tumor cells. Therefore, negative uptake of 67Ga in the mass seen in X-ray CT may not be totally reliable evidence of eradication of viable tumor cells.

Cis-Diamminedichloroplatinum (CDDP)-lipiodol suspension (CLS) was developed as a transarterial chemoembolization (TACE) material. The CLS was injected into the proper hepatic artery or distal branches of patients with hepatocellular carcinoma. Strong anticancer effects were observed. Plasma concentrations of total and filtrable CDDP following TACE were much lower than those following intravenous administration of CDDP solution. No major adverse complications were noted, presumably due to low CDDP concentrations in circulating plasma. The CLS appears to be an excellent TACE material.