Prediction of Memory Impairment in Epilepsy Surgery by White Matter Diffusion.

OBJECTIVE: To analyze the relationship between cognitive performance and white matter integrity in patients with temporal lobe epilepsy (TLE) to establish radiologic criteria to help with patient selection for surgery. METHODS: The study included 19 adults with temporal lobe epilepsy. A tractography analysis of fractional anisotropy and mean diffusivity (MD) of the following fascicles was performed: arcuate fascicle, cingulum, fornix, inferior fronto-occipital fascicle, inferior longitudinal fascicle, parahippocampal fibers of the cingulum, and uncinate fascicle. The Wechsler Memory Scale-Third Edition neuropsychological test was performed to evaluate short- and long-term verbal (Logical Memory I and II subtests) and nonverbal (Visual Reproduction I and II subtests) memory. Relationships between memory scores and diffusion were calculated. RESULTS: Lower Logical Memory I subtest scores were correlated with lower MD of the right inferior fronto-occipital fascicle, while lower Logical Memory II subtest scores were related to higher values of fractional anisotropy in bilateral cingulum, right uncinate, and right parahippocampal fibers of the cingulum and lower MD in left cingulum fascicle. Finally, lower values in Visual Reproduction I subtest scores were associated with lower values in MD in right cingulum and inferior fronto-occipital fascicles. CONCLUSIONS: Structural changes of some white matter tracts were associated with deterioration of both short- and long-term memory. These alterations were more associated with verbal memory than with nonverbal memory. These changes mainly consist of an increase in fractional anisotropy and a decrease in MD, which could be interpreted as reorganization phenomena. Diffusion tensor imaging could be a useful tool for cognitive assessment in surgical candidates with temporal lobe epilepsy who are not suitable for neuropsychological testing or in whom their results do not lead to definitive conclusions.

Contrast-enhanced ultrasound of liver lesions related to arterial thrombosis in adult liver transplantation.

PURPOSE: To describe the contrast-enhanced ultrasound (CEUS) features of liver and biliary lesions related to hepatic artery thrombosis in adult patients with orthotopic liver transplantation. METHODS: Gray-scale ultrasound (US), Doppler US, and CEUS using a hexafluoride-based US contrast media were performed on a series of eight patients with liver transplantation and hepatic artery thrombosis. RESULTS: Six of the cases presented infarctions, seen as parenchymal geographic areas of lack of enhancement. Biliary necrosis, seen as nonenhancing periportal cuff, was seen in one case. Infected biloma, seen as a nonenhancing hilar collection, was present in two cases. Infarction and biloma coexisted in one patient. Two abscesses were seen as a late complication in one case. One of them was seen as a typical necrotic abscess with a central nonenhancing area and peripheral rim enhancement higher than the surrounding liver. The other one was seen as a partially liquefied abscess. CONCLUSION: CEUS was useful to diagnose lesions related to hepatic artery thrombosis in liver transplantation. It enabled distinguishing between them and to define their size and extension better than conventional gray-scale US.

Acute complicated pyelonephritis: contrast-enhanced ultrasound.

Imaging is required if complication is suspected in acute pyelonephritis to assess the nature and extent of the lesions, and to detect underlying causes. The current imaging modality of choice in clinical practice is computed tomography. Because of associated radiation and potential nephrotoxicity, CEUS is an alternative that has been proven to be equally accurate in the detection of acute pyelonephritis renal lesions. The aims of this study of 48 patients are to describe in detail the CEUS findings in acute pyelonephritis, and to determine if abscess and focal pyelonephritis may be distinguished. Very characteristic morphologic and temporal patterns of enhancement are described. These allow differentiation of focal pyelonephritis from renal abscess, and detection of tiny suppurative foci within focal pyelonephritis. The detection of abscesses is important because follow-up in 25 patients revealed a longer clinical course. Typical pyelonephritis CEUS features permit distinction from other renal lesions. As a whole, CEUS is an excellent tool in the work-up of complicated acute pyelonephritis, so it may be considered as the imaging technique of choice in the evaluation and follow-up of these patients who frequently are very young, so as to minimise radiation exposure.

Acoustic radiation force impulse elastography and contrast-enhanced sonography of sinusoidal obstructive syndrome (Veno-occlusive Disease): preliminary results.

We report quantitative liver acoustic radiation force impulse (ARFI) elastographic findings in 2 cases of sinusoidal obstructive syndrome and liver contrast-enhanced sonographic features in one of these cases. To our knowledge, findings in this condition from these techniques have not been reported previously. Acoustic radiation force impulse elastography showed median high shear wave velocities (case 1, 2.75 m/s; case 2, 2.58 m/s) that normalized after specific treatment for sinusoidal obstructive syndrome; therefore, ARFI elastography provided quantitative information that helped diagnose this condition as well as monitor the response to treatment. Contrast-enhanced sonographic findings in one of the cases showed patchy liver enhancement that correlated with the high-velocity patchy distribution on ARFI elastography in that case and enhanced multidetector row computed tomographic findings in the other case. This contrast-enhanced sonographic pattern progressively normalized during follow-up after specific treatment. The elastographic features in both cases and contrast-enhanced sonographic features in one of them contributed to early diagnosis and follow-up of sinusoidal obstructive syndrome in both patients. Further prospective studies are necessary to define the role of ARFI elastography and contrast-enhanced sonography in the early diagnosis and clinical follow-up of this condition.