[Multi-slice spiral CT imaging in the post-operative assessment of cochlear implanted electrode].

OBJECTIVE: To evaluate the usefulness of multi-slice spiral CT (MSCT) in the post-operative assessment of cochlear implanted electrode. METHODS: Twenty-three cochlear implant recipients were enrolled in this study. All patients were examined with a SOMATOM Sensation 16-slice CT scanner (Siemens) using the following parameters: 120 kV, 100 mAs, 0. 75 mm collimation, 1 mm reconstruction slice thickness and increment, a pitch factor of 1, and a FOV of 100 mm. The axial images of interested ears were reconstructed with 0.1 mm increment and a FOV of 50 mm, and then volume rendering technique (VRT) reconstruction were done on the work station. RESULTS: The electrode arrays were detected on axial CT images. Both inner ear and electrode array could be displayed on one image simultaneously. VRT provided an intuitionistic view of the relationship between electrode array and cochlea VRT showed the number of the electrode array in 20 patients implanted with Combi 40 + standard electrode array and demonstrated the shape, position, and insertion depth. The electrode array number determined by VRT was in accordance with the surgical findings in 18 patients, and was underestimated in two patients. In 3 patients with Combi 40 + compressed electrode array, only 4 to 5 electrodes arrays were clearly identified and others were not observed. CONCLUSION: MSCT with VRT can provide useful three-dimensional information of the electrode array and indicate the exact relationship between electrode array and cochlea.

Assessment of hepatocellular carcinoma vascularity before and after transcatheter arterial chemoembolization by using first pass perfusion weighted MR imaging.

AIM: To assess the vascularity of hepatocellular carcinoma (HCC) before and after transcatheter arterial chemoembolization (TACE) with the quantitative parameters obtained by first pass perfusion weighted MR imaging (FP-MRI). METHODS: Seventeen consecutive patients with one to three lesions in liver underwent FP-MRI before treatment. FP-MRI was also performed one, three, six, nine months, and one year after TACE. The baseline signal intensity (S0) of pre-TACE and one month after TACE was analyzed, the vascularity of HCC assessed by steepest slope of the signal intensity versus time curves (SS) was blindly correlated with their DSA feature and clinical outcome. RESULT: No significant difference was found on baseline signal intensity (S0) between pre-TACE and one month after TACE (F=0.309, P=0.583), The SS (mean, 32% per second) of lesion one month after TACE was lower than that of pre-TACE (mean, 69% per second), but with no statistical significance (F=3.067, P=0.092). When local recurrence occurred, the time intensity curves became steeper. The vascularity of HCC before and after TACE graded by SS closely correlated with that by DSA (K=0.453, P<0.05). CONCLUSION: FP-MRI is a useful criterion for selecting effective interventional treatment for patients with HCC in their initial treatment and during follow up.