Diffusion-weighted imaging of the liver at 3 T using section-selection gradient reversal: emphasis on chemical shift artefacts and lesion conspicuity.

AIM: To assess the value of section-selection gradient reversal (SSGR) in liver diffusion-weighted imaging (DWI) by comparing it to conventional DWI with an emphasis on chemical shift artefacts and lesion conspicuity. MATERIALS AND METHODS: Forty-eight patients (29 men and 19 women; age range 33-80 years) with 48 liver lesions underwent two DWI examinations using spectral presaturation with inversion recovery fat suppression with and without SSGR at 3 T. Two reviewers evaluated each DWI (b = 100 and b = 800 image) with respect to chemical shift artefacts and liver lesion conspicuity using five-point scales and performed pairwise comparisons between the two DWIs. The signal-to-noise ratio (SNR) of the liver and the lesion and the lesion-liver contrast-to-noise ratio (CNR) were also calculated. RESULTS: SSGR-DWI was significantly better than conventional DWI with respect to chemical shift artefacts and lesion conspicuity in both separate reviews and pairwise comparisons (p < 0.05). There were significant differences in the SNR of the liver (b = 100 and b = 800 images) and lesion (b = 800) between SSGR-DWI and conventional DWI (p < 0.05). CONCLUSION: Applying the SSGR method to DWI using SPIR fat suppression at 3 T could significantly reduce chemical shift artefacts without incurring additional acquisition time or SNR penalties, which leads to increased conspicuity of focal liver lesions.

Brachial artery aneurysm rupture in a patient with neurofibromatosis: a case report.

Peripheral vascular manifestations of neurofibromatosis are rare but may result in fatal haemorrhaging when they rupture. Surgeons should be aware of this life-threatening condition. We report a case of 35-year-old woman with neurofibromatosis who presented with a swollen and tender mass around her right arm. Angiography revealed 2 aneurysms in the brachial artery. Surgical occlusion revealed a large amount of clotted blood within the subfascial space, and the bleeding point was identified as a pinpoint opening in the aneurysm. The brachial artery abutting the aneurysm and the surrounding soft tissues was extremely brittle and fragile, with massive oozing during dissection. The brachial artery was irreparable and was resected after ligation of the artery and surrounding soft tissues and the aneurysm. Despite an uneventful recovery, the patient died on day 4.

Colour Doppler sonography of hepatic haemangiomas with arterioportal shunts.

OBJECTIVES: To determine the frequency of intratumoural flow and peritumoural hepatofugal portal flow using colour Doppler sonography (CDS) on hepatic haemangiomas with arterioportal shunt (APS), and to investigate possible factors that may affect the capability of CDS to depict such findings. METHODS: The study included 45 patients (35 men, 10 women; mean age, 56 years) with hepatic haemangiomas with APS on CT or MRI. Locating the tumour on greyscale sonography, the depth, size and echogenicity of the tumour were evaluated. CT or MR images were evaluated for fatty liver. CDS was performed to determine the presence of intratumoural flow and peritumoural hepatofugal portal flow. Differences in frequency of intratumoural flow and peritumoural hepatofugal portal flow according to the depth, size, echogenicity and fatty liver were evaluated by Student's t-test and Fisher's exact test. RESULTS: On CDS, intratumoural flow and peritumoural hepatofugal portal flow were found in 66.7% and 60%, respectively. The tumour depth was the significant variable that affected the capability of CDS to depict such findings. The frequencies of intratumoural flow and peritumoural hepatofugal portal flow were as high as 88% and 80% for shallow (≤30 mm) lesions, and they were 40% and 35% for deep (>30 mm) lesions (p=0.0012; p=0.0051). CONCLUSION: CDS can commonly depict intratumoural flow and peritumoural hepatofugal portal flow in patients with hepatic haemangiomas with APS. Therefore, CDS should be routinely performed when an incidental mass is encountered during the screening sonography, especially when the lesion is shallow.

Increase of modified retrograde to antegrade flow ratio on doppler ultrasounds of the hepatic vein indicating tricuspid regurgitation during follow-up of liver transplantation: correlation with echocardiographic results.

The purpose of this study was to explore the best parameter of hepatic vein (HV) Doppler ultrasounds (DUS) that correlated with echocardiographic findings of and particularly the optimal cutoff value for tricuspid regurgitation (TR) following liver transplantation (LT). Thirty-six patients underwent echocardiography and DUS after LT from January 2006 to July 2007. Echocardiographic records were searched for TR grade and peak velocity of TR flow. The HV DUS parameters included peak velocity of retrograde flow (R), peak velocity of antegrade flow (A), the difference between R and A (R-A), the ratio of R to A (R/A ratio), and a modified R/A ratio, namely, the product of the R/A ratio and the R/A duration ratio. Correlation tests and receiver-operator characteristic analyses explored their interrelations and to obtained cutoff values to diagnose moderate and severe TR. TR grade best correlated with the modified R/A ratio (rho = 0.585), followed by the R/A ratio (rho = 0.503) and R (rho = 0.455). The modified R/A ratio was the most accurate parameter for the diagnosis of moderate and severe TR (Az = 0.825 and 0.895, respectively); its cutoff value was > or =0.11 for moderate TR (sensitivity and specificity both 77.78%) and 0.13 for severe TR (sensitivity, 100%; specificity, 81.2%). The modified R/A ratio best correlated with echocardiographic results of TR, although the strength of correlation was only moderate. Additionally, the modified R/A ratio was an accurate DUS parameter to diagnose moderate and severe TR among patients following LT.