Antoine Scherrer

Comparison between ultrasonographic signs and the degree of portal hypertension in patients with cirrhosis.

The sensitivity of ultrasonography (US) for the diagnosis of portal hypertension was assessed in 48 patients with known cirrhosis. These results were compared to the hemodynamic values obtained on the same day by hepatic vein catheterization. The sensitivity of US in detecting portal hypertension was about 40% considering either a > 13 mm diameter of the portal vein, or the lack of mild caliber variation of the superior mesenteric vein. The sensitivity was more than 80% considering the presence of portosystemic venous collaterals. Presence of numerous portosystemic shunts was significantly associated with high hepatic venous pressure gradients which reflected the severity of portal hypertension.

Intraperitoneal splenosis: diagnosis by ultrasound and computed tomography.

Splenosis is an unusual complication of abdominal trauma. We report a case of splenosis identified on ultrasonography (US) and computed tomography (CT). Usually it is a latent disease and an incidental finding, but it may be diagnosed by US and CT.

Differentiation between hepatic cavernous hemangioma and malignant tumor with t2-weighted mri: comparison of fast spin-echo and breathhold fast spin-echo pulse sequences

PURPOSE The goal of our study was to compare a T2-weighted breathhold fast spin-echo (BHFSE) technique with T2-weighted nonbreathhold fast spin-echo (FSE) technique for characterizing cavernous hemangioma of the liver and differentiating this entity from malignant tumor. MATERIALS AND METHODS Eighteen patients with cavernous hemangiomas and 18 patients with malignant hepatic tumors were studied with T2-weighted MRI with a nonbreathhold FSE technique with and without fat suppression and with a BHFSE technique without fat suppression. Hepatic lesions were analyzed quantitatively using signal intensity (SI) and contrast-to-noise (C/N) ratio. In addition, images were qualitatively compared for accuracy in characterizing hepatic lesion. RESULTS Quantitatively, hemangioma had significantly higher SI and C/N ratios than did the malignant tumor on every pulse sequence (P < 0.01). Qualitatively, all malignant tumors were correctly categorized; differentiation between cavernous hemangioma and malignant tumor was impossible in three cases of cavernous hemangioma with the three pulse sequences (92% accuracy, 100% sensitivity, and 83% specificity). CONCLUSION T2-weighted FSE and BHFSE MRI shows comparable levels of accuracy for differentiating between hepatic cavernous hemangioma and malignant tumor. Because overlap may exist using quantitative measurement, morphologic patterns must be carefully analyzed, supporting that quantitative analysis and morphologic evaluation are complementary.

Focal nodular hyperplasia of the liver: assessment of hemodynamic and angioarchitectural patterns with gadolinium chelate-enhanced 3D spoiled gradient-recalled MRI and maximum intensity projection reformatted images.

PURPOSE Our goal was to determine the relative merits of gadolinium chelate-enhanced 3D spoiled gradient-recalled (GRE) MRI versus maximum intensity projection (MIP) reformatted images in assessing the morphologic, hemodynamic, and angioarchitectural patterns of focal nodular hyperplasia (FNH) of the liver. METHOD Ten consecutive patients with 10 FNHs had prospectively gadolinium chelate-enhanced 3D spoiled GRE MRI (TR/TE/FA = 10.1/1.9/30) of the liver at 1.5 T. Gadolinium chelate-enhanced 3D spoiled GRE source images and MIP reformatted images were separately analyzed with respect to morphologic and hemodynamic features and angioarchitectural patterns by two independent readers. RESULTS Gadolinium chelate-enhanced 3D spoiled GRE source images and MIP reformatted images showed the most intense degrees of enhancement of FNH during the arterial phase of hepatic parenchymal enhancement in all cases. Gadolinium chelate-enhanced 3D spoiled GRE source images were superior to MIP reformatted images for the assessment of morphologic features of FNH (p < 0.02). MIP reformatted images were superior to the corresponding source images for showing the main branches of the hepatic artery, an arterial branch going to the FNH, and a small artery within the FNH radiating to peripheral areas (p < 0.05). There was excellent agreement between the two observers for analysis of the MIP reformatted images (p < 0.05). CONCLUSION The combination of gadolinium chelate-enhanced 3D spoiled GRE source images and MIP reformatted images allows the analysis of morphologic, hemodynamic, and angioarchitectural patterns of FNH of the liver. Further study and comparison with currently applied strategies will determine the value of these two techniques for diagnosing FNH of the liver.

T1-weighted spoiled gradient-echo MR imaging of focal hepatic lesion: comparison of in-phase vs opposed-phase pulse sequence

Abstract The goal of our prospective study was to compare quantitatively and qualitatively in-phase and opposed-phase T1-weighted breath-hold spoiled gradient-recalled-echo (GRE) MR imaging technique for imaging focal hepatic lesion. Thirty-eight patients with 53 focal hepatic lesions had in-phase (TR = 12.3 ms, TE = 4.2 ms) and opposed-phase (TR = 10.1 ms, TE = 1.9 ms) GRE (flip angle = 30°, bandwidth ± 32 kHz, matrix size 256 × 128, one signal average) MR imaging at 1.5 T. Images were analyzed quantitatively by measuring the lesion-to-liver contrast and for lesion detection. In addition, images were reviewed qualitatively for lesion conspicuity. Quantitatively, lesion-to-liver contrast obtained with in-phase (3.22 ± 1.86) and opposed-phase pulse sequence (3.72 ± 2.32) were not statistically different (Students t-test). No difference in sensitivity was found between in-phase and opposed-phase pulse sequence (31 of 53, sensitivity 58 % vs 30 of 53, sensitivity 57 %, respectively). Two lesions not seen with opposed-phase imaging were detected with in-phase imaging. Conversely, one lesion not seen on in-phase imaging was detected on opposed-phase imaging so that the combination of in-phase and opposed-phase imaging yielded detection of 32 of 53 lesions (sensitivity 60 %). Qualitatively, lesion conspicuity was similar with both techniques. However, in-phase images showed better lesion conspicuity than opposed-phase images in 9 cases, and opposed-phase images showed better lesion conspicuity than in-phase images in 7 cases. No definite advantage (at a significant level) emerged between in-phase and opposed-phase spoiled GRE imaging. Because differences in lesion conspicuity and lesion detection may be observed with the two techniques in individual cases, MR evaluation of patients with focal hepatic lesion should include both in-phase and opposed-phase spoiled GRE imaging.

Magnetic resonance imaging of the spleen: Influence of the dose of a gadolinium chelate on the degree of parenchymal enhancement

RATIONALE AND OBJECTIVES We examined how the dose of an intravenous (i.v.) gadolinium chelate (gadoterate meglumine) would affect the degree of splenic enhancement on magnetic resonance (MR) imaging. METHODS Forty patients had breath-hold three-dimensional fast spoiled gradient-recalled MR imaging of the abdomen done before and after i.v. administration of one of four doses of gadoterate meglumine (0.075, 0.100, 0.150, or 0.200 mmol/kg). Peak enhancement values and the time to peak enhancement of splenic parenchyma were compared (values are reported as means +/- standard deviations). RESULTS Peak enhancement values were 154 +/- 99%, 215 +/- 109%, 276 +/- 170%, and 349 +/- 144 +/- for the doses of 0.075, 0.100, 0.150, and 0.200 mmol/kg, respectively. A high correlation was found between the dose and mean peak enhancement values (R2 = .998), which varied as a linear function of the dose. The mean times to peak enhancement obtained with the four doses were not significantly different. CONCLUSION Using doses ranging from 0.075 to 0.200 mmol/kg, the peak enhancement of splenic parenchyma is a linear function of the dose of the gadolinium chelate administered. The time to peak splenic enhancement is not affected.