Makiko Jimi

MRI of groove pancreatitis.

PURPOSE The purpose of this work is to describe the findings on MRI in patients with groove pancreatitis, a specific form of chronic pancreatitis affecting the groove between the pancreatic head, the duodenum, and the common bile duct. METHOD MR images, including MR cholangiopancreatography, of five patients with groove pancreatitis were reviewed. Three patients underwent pancreatoduodenectomy due to serve duodenal stenosis, and the MR findings were compared to the histologic findings. RESULTS A sheet-like mass was demonstrated between the pancreatic head and the duodenum in all patients. The masses were hypointense relative to pancreatic parenchyma on T1-weighted images and iso- to slightly hyperintense on T2-weighted images. After administration of Gd-DTPA, the masses showed delayed enhancement. Histologically, fibrous scar tissue was detected in the groove. CONCLUSION MR images can clearly demonstrate the fibrous tissue in the groove in groove pancreatitis, and MR cholangiopancreatography can also provide useful information.

MR detection of cytoplasmic fat in clear cell renal cell carcinoma utilizing chemical shift gradient-echo imaging.

We attempted to determine whether cytoplasmic fat in clear cell renal cell carcinoma (RCC) can be identified by chemical shift gradient‐echo magnetic resonance imaging (CSI). CSI was performed for 22 clear cell RCCs and 30 other renal tumors (including 16 non‐clear cell RCCs), all of which were surgically proven. Signal reduction in out‐of‐phase images of these tumors was retrospectively evaluated and compared. The signal loss ratio (SLR) was defined and calculated. Fat staining of specimens from 16 tumors was performed and correlated with SLR. SLR was significantly higher in clear cell RCCs than in non‐clear cell RCCs (P < 0.001). There was a significant correlation between degree of fat staining positivity of the specimens and SLR (P < 0.01). When signal reduction in out‐of‐phase images suggested the diagnosis of clear cell RCC, correct diagnosis of this entity was made in resected renal tumors with sensitivity, specificity, and accuracy of 82%, 90%, and 87%, respectively. CSI can demonstrate cytoplasmic fat in clear cell RCCs, which helps to differentiate this entity from other RCCs.J. Magn. Reson. Imaging 1999;9:579–585.

Pseudolesion in segment II of the liver observed on CT during arterial portography caused by the aberrant left gastric venous drainage.

A rare case with a pseudolesion in segment II of the liver observed on computed tomography (CT) during arterial portography caused by the aberrant left gastric venous drainage is presented. Close observation of the celiac angiography was helpful in recognizing this pseudolesion. Selective catheterization of the left gastric artery and CT during its venous phase confirmed the etiology of the pseudolesion.

Hepatic angiomyolipoma : Report of changing size and internal composition on follow-up examination in two cases

We present two cases of hepatic angiomyolipoma in which the size and internal composition of the tumor changed during the course of follow-up study. The tissue elements composing the tumor are thought to grow or regress independently during the diseases clinical course. Radiologists should be aware that hepatic angiomyolipoma can change in size and internal composition during its natural course.

Correlation of three-dimensional gradient echo dynamic MR imaging with CT during hepatic arteriography in patients with hypervascular hepatocellular carcinomas: preliminary clinical experience.

The purpose of this study is to elucidate the usefulness of dynamic MR study of the whole liver using 3DFISP with double dose gadolinium (Gd) enhancement in detecting enhancing lesions in 20 patients. Twenty patients with hepatocellular carcinoma (HCC) underwent 3DFISP dynamic study with double dose Gd. The demonstration of enhancing hypervascular lesions regardless of etiology was evaluated on a segment‐by‐segment basis with receiver operating characteristic (ROC) analysis, using findings on CT during hepatic arteriography as a gold standard. Diagnostic accuracy of 3DFISP in the detection of HCC was also evaluated. As to the demonstration of enhancing lesions, the Az value of the ROC curve was 88%. The detection rate of HCC with 3DFISP was 98%. 57% of enhancing pseudolesions were not detected on 3DFISP. We concluded that Dynamic MR study of the whole liver using 3DFISP with double dose Gd enhancement is a useful method to demonstrate hypervascular HCC. J. Magn. Reson. Imaging 2001;13:258–262.

Fat detection in granular-cell renal cell carcinoma using chemical-shift gradient-echo MR imaging: another renal tumor that contains fat.

Preoperative chemical-shift magnetic resonance images in a 56-year-old man suggested the presence of microscopic fat in the tumor. The surgical specimen showed a granular-cell renal cell carcinoma with papillary architecture, associated with abundant fat-containing foamy histiocytes in the interstitium. The radiologist should include this entity in the differential diagnoses of renal tumors that contain microscopic fat.