Novel Technique of Aortic Valve Repair

BACKGROUND AND OBJECTIVES: The purpose of this study was to assess the results of a newly developed aortic valve repair technique. SUBJECTS AND METHODS: Between December 1997 and April 2005, 75 aortic valvuloplasties were performed using a new technique that addressed the 3 main components of the aortic root; annulus, sinotubular junction and leaflet. An internal synthetic strip and ring were implanted along the fibrous annulus to reduce the annulus and sinotubular junction, and additional leaflets were implanted for leaflet correction. Based on the primary pathology, there were 35, 22 and 18 cases of isolated aortic regurgitation, aortic regurgitation due to ascending aortic aneurysm and aortic regurgitation due to annuloaortic ectasia, respectively. RESULTS: The average age of the subjects was 46.4+/-16 years; there were 51 and 24 males and females, respectively. There was no operative mortality, with a 2-year freedom from reoperation rate of 97%. Follow up echocardiograms showed significant improvements in the grade of aortic regurgitation, from a preoperative mean of 3.1+/-1.2 to 1.08+/-0.7 immediate postoperatively, to 1.15+/-0.6 at the final follow up. CONCLUSION: The results of the current study showed this technique to be effective in the treatment of aortic regurgitation of various causes. Although long-term results are pending, it is our contention that this aortic valve repair technique will be a reliable method in the future.

Localized Single-Voxel Spin-Echo Proton MR Spectroscopy of Normal Hippocampal Area at 1.5 T : Optimal Voxel Volume and Reproducibility of Metabolite Ratios

PURPOSE: To determine the optimal voxel volume covering the hippocampal area in single-voxel proton magnetic resonance (MR) spectroscopy and to evaluate the reproducibility of metabolite ratios of the spectra. MATERIALS AND METHODS: Localized single-voxel proton MR spectroscopy was applied to the right hippocampal area of five healthy volunteers at 1.5 T (Siemens Vision), using a standard head coil, and we employed the spin-echo or point resolved spectroscopy sequence. Voxel volume was changed from 1ml to 5ml but other operator-dependent measurement parameters were fixed, as follows: repetition time/echo time=1500/135 msec, number of scans=300. Using the same voxel volume, five consecutive measurements were obtained in each subject. Signal to noise ratio (SNR) of N-acetylaspartate (NAA), NAA / Choline containing compounds (Cho) and NAA / Cr (creatine and phosphocreatine) +Cho ratios were calculated for all 25 spectra. RESULTS: The SNR of NAA peaks increased significantly as voxel volume was increased to 3 ml (p 0.1) ; in those obtained with voxel volume of 2-4ml, the standard deviations of NAA / Cho (10.6-13.2% of mean values) were similar to those of NAA /Cr+Cho (8.5-13.2% of mean values). CONCLUSION: For spin-echo proton MR spectroscopy of the hippocampal area, the optimal voxel volume may be more than 3 ml in a setting of TR/TE=1500/135 msec and number of scans=300. In this situation, standard deviations of metabolite ratios may reach about 8-13% of mean values.

Pulmonary Sarcoidosis: CT Findings and Correlation with sACE Level and PFT

PURPOSE: To assess CT findings of pulmonary sarcoidosis and correlate these with sACE level and PFT. MATERIALS AND METHODS: Between 1989 and 1995, 14 patients (4 men and 10 women, aged between 28 and 55 years) with histologically confirmed pulmonary sarcoidosis were consecutively selected. HRCT scans were performed in 12 patients and conventional CT scans in two. CT findings were reviewed by three radiologists, and were correlated with the index of disease activity based on sACE level and pulmonary function test. RESULTS: Pulmonary parenchymal abnormalities were seen in all patients ; small nodules of less than 3 mm in diameter were seen in eight. Other abnormalities were nodules of more than 3 mm in diameter (n=7), confluent nodules (n=5), ground glass opacity (n=5), patchy areas of consolidation with air bronchogram (n=5), and architectural distortion (n=3). The upper lung zone was more frequently involved than the middle or lower zone. In ten patients, the peripheral interstitum was predominantly involved, while only three patients showed predominant peribronchovascular involvement. Lymphadenopathy was noted in 13. There was no correlation between sACE level, the results of a pulmonary function test and the extent of parenchymal involvement. CONCLUSION: HRCT is valuable for the identification, characterization, and determination of the extent to which parenchymal lung is involved in sarcoidosis. The extent of this involvement does not correlate with sACE level and pulmonary function test results.

Special Focus on cerebral Myo-Inositol in Patients with Hepatic Encephalopathy: Proton MR Spectroscopic Evaluation

PURPOSE: To determine whether or not cerebral myo-inositol/creatine-phosphocreatine (MI/Cr) leval can beused as a criterion of hopatic encephalopathy(HE). METHODS: Single voxel stimulated echo sequence with short echotime (30 ms) was applied to parietal white matter of 14 healthy control subjects, 11 patients with chronic viral hepatitis, 29 cirrhotic patients without HE, and 33 cirrhotic patients with HE. The metabolite ratios of N-acetylaspartate (NAA), choline containing compounds (Cho), and myo-Inositol (MI) were calculated using creatine/phosphocreatine (Cr) as an internal reference. Clinical data including modified Child-pugh score, estimated serum osmolarity, and grade of HE, were obtained at the day of MR spectroscopy. RESULTS: MI/Cr was 34% lower in cirrhotic patients with HE than in control subjects. It was reduced below two standard deviation from normal in 17 of 33 cirrhotic patients with HE(52%). MI/Cr did not correlate with grade of HE(r=0.15, p=0.45) but correlate with modified Child-Pugh score(r=-0.55, p=0.00). In the analysis of Child class C patients, there was no significant difference of MI/Cr between cirrhotic patients with HE and those without HE(0.38 +/-0.11, n=29 vs.0.39+/-0.11, n=15, p=0.59, respectively). CONCLUSION: A reduction of cerebral MI/Cr cannot be used as a diagnostic criterion of HE.