Moon Gyu Lee

Pyogenic hepatic abscesses: MRI findings on T1- and T2-weighted and serial gadolinium-enhanced gradient-echo images.

The purpose of this study was to determine the magnetic resonance imaging (MRI) features of pyogenic hepatic abscesses on T1‐weighted, T2‐weighted, and serial gadolinium (Gd)‐enhanced T1‐weighted spoiled gradient‐echo (SGE) images including images acquired in the immediate, intermediate, and late phases of enhancement. The MRI studies of 20 patients with pyogenic liver abscesses were retrospectively reviewed. All patients were examined on 1.5 (n = 19) and 1.0 (n = 1) T MR scanners. MR studies included T1‐weighted, T2‐weighted, and serial Gd‐enhanced SGE images. The following determinations were made: signal intensity of the abscess cavity and perilesional liver tissue, and the presence of internal septations, layering material, or air in the abscess cavity. The pattern of enhancement of the abscess wall, internal septae and peri‐abscess liver were evaluated on serial Gd‐enhanced SGE images. A total of 53 abscesses were observed in the 20 patients. Forty‐eight abscesses were hypointense on T1‐weighted and hyperintense on T2‐weighted images. Internal septations were present in four abscesses. Lower signal intensity material was observed in a dependent location on T2‐weighted images in one abscess. Signal void foci of air located on the nondependent surface was observed in two abscesses. Two other abscesses contained signal void air that occupied the entire abscess cavity, observed on all imaging sequences. On serial gadolinium‐enhanced images, all abscesses revealed early enhancement of the wall, which persisted with negligible change in degree of enhancement or thickness on delayed images. Abscess walls ranged in thickness from 2 to 5 mm. Internal septations ranged in thickness from 2 to 3 mm. Abscess walls and septations were relatively uniform in thickness with no evidence of focal nodularity. Periabscess liver tissue was mildly hypointense on T1‐weighted and mildly hyperintense on T2‐weighted images in 20 lesions, which were either circumferential (n = 12) or wedge‐shaped (n = 8). All these regions enhanced more than the remainder of the liver on immediate post‐gadolinium images and remained relatively hyperintense on late phase images. Periabscess liver parenchyma was isointense on both T1‐ and T2‐weighted images in 18 lesions, and in these lesions wedge‐shaped subsegmental (n = 6) or segmental (n = 12) enhancement was observed on immediate gadolinium‐enhanced images, which faded to isointensity on intermediate phase images. No perilesional signal changes and enhancement difference was observed in 15 lesions. Characteristic features of abscesses include: intense mural enhancement on early gadolinium‐enhanced images, which persists with negligible change in thickness and intensity on later post‐gadolinium images, and the presence of periabscess increased enhancement on immediate post‐gadolinium images. These MRI features may help to distinguish abscesses from other focal liver lesions during differential diagnosis.J. Magn. Reson. Imaging 1999;9:285–290.

Nodular regenerative hyperplasia of the liver in Budd–Chiari syndrome: CT and MR features

We report the imaging findings of spiral computed tomography (CT), magnetic resonance (MR) imaging, and MR angiography in a patient with nodular regenerative hyperplasia of the liver associated with Budd–Chiari syndrome. Spiral CT showed multiple enhancing nodules during the hepatic arterial and portal venous phases. MR images showed multiple hyperintense nodules on T1-weighted images and hypointense or isointense nodules on T2-weighted images. MR angiography showed thrombotic occlusion of three hepatic veins, suggesting Budd–Chiari syndrome.

US findings of xanthogranulomatous cholecystitis

The ultrasound (US) scans of eleven patients with histologically proven xanthogranulomatous cholecystitis have been reviewed. The thickness of the gallbladder (GB) wall, echogenicity of the thickened GB wall, the presence of intramural nodules, gallstones, pericholecystic fluid, loss of wall definition with the liver, and intrahepatic ductal dilatation were specifically assessed by two radiologists. The range of thickness of the GB wall was 3-20mm (mean, 11.2 mm). Thickening was diffuse in nine cases and focal in two. The thickened GB wall, excluding intramural nodules, was echogenic in seven, isoechoic in three and hypoechoic in one, compared with hepatic echogenicity. Intramural nodules were found in eight cases. These were discrete, oval or flat, and of low echogenicity. These ranged in size from 6 to 12 mm (mean, 10.5 mm). Gallstones were present in six cases and there was intrahepatic duct dilatation in two of these. Definition between the liver and the GB was obliterated in seven cases. One case of GB perforation, confirmed at operation, demonstrated pre-operatively a GB wall defect and connection with the surrounding pericholecystic fluid. Pericholecystic fluid was absent in the other 10 cases. Xanthogranulomatous cholecystitis presents ultrasonically as GB wall thickening, and the majority of cases in this series also demonstrated intramural hypoechoic nodules. These findings can be helpful in the diagnosis of xanthogranulomatous cholecystitis.

Use of methylcellulose in small bowel follow-through examination: comparison with conventional series in normal subjects

Abstract.Background: To evaluate and optimize a modified small bowel follow-through examination (SBFT) by using an oral administration of a large amount (600 mL) of methylcellulose after taking a small amount of barium.n Methods: Ninety-nine normal subjects underwent modified SBFT with an oral administration of 600 mL of 0.5% methylcellulose after taking 100 mL of 120% or 100, 150, or 200 mL of 70% w/v barium. The transradiancy and distensibility of the bowel and the transit time were compared with those of 39 other normal subjects who underwent conventional SBFT with 500 mL of 70% w/v barium.n Results: Except for two subjects who developed diarrhea immediately after examination, no patients complained of acute symptoms, such as abdominal pain or vomiting. Modified SBFT was much superior to conventional series for obtaining good bowel transradiancy and rapid transit time (range = 37–49 min), but bowel distention was not significantly improved. The use of 150 mL of 70% w/v barium was better than the other three modified techniques for achieving good bowel transradiancy, rapid transit time, and less occurrence of flocculation.n Conclusion: Modified SBFT is a simple method for easily improving the image quality in terms of bowel transradiancy and transit time.

Intragastric metastasis in a patient with gastric cancer: unusual CT manifestation

AbstractnWe describe computed tomographic findings of intragastric metastasis in a patient with gastric cancer. On computed tomography, the intragastric metastatic lesion appeared as an exophytically growing cystic masss with minimal thickening of the adjacent gastric wall, thus mimicking an exophytically growing submucosal tumor or adenocarcinoma.