ABSTRACT
Objective To evaluate the clinical application of regulating bone removal ratio in dual-energy cerebral subtraction angiography.Methods A total of 45 patients who underwent two phases dual-energy CT angiography (CTA) were recruited and divided into several groups by the value of bone removal ratio,as follows: group A (Ratio=1.6), group B (Ratio=1.7), group C (Ratio=1.8) and group D (Ratio=1.9,default), as well as group E (100kV Neuro-DSA).The image quality of dual-energy CTA was evaluated by double blind method according to bone suppression and integrity of the vessel lumen (1-5 points, 1=poor, 5=excellent, 3-5=satisfactory).The bone removal ratio dependence of the image quality was analyzed using the self-control method.Moreover,the signal-to-noise ratio (SNR),contrast-to-noise ratio (CNR) and image scores were compared with the Neuro-DSA subtraction among these groups.Results The overall satisfaction of basis cranii images that were executed by dual-energy CTA with different bone removal ratios was listed as below: group A 73.33%, group B 91.11%, group C 78.52%, group D 70.37%.The satisfaction of siphon segment and petrous segment reached the maximum when the value of ratio was 1.7,and with significantly difference (P0.05).Conclusion With optimal bone removal ratio,the single enhanced dual-energy subtraction image quality with flash dual-source CT is consistent well with that of conventional 100 kV Neuro-DSA subtraction.Thus,this method is recommended in clinical emergency cerebrovascular examination for the improved image quality,which can compensate the shortage of vascular defect in basis cranill.
ABSTRACT
This prospective study reported a one year follow up of seven patients (8 hips) with avascular necrosis of the femoral head, Ficat stage Ilb and III. All necrotic bone at the avascular areas were removed and repleaced with iliac bone graft. The average age of the patients was 39.3 years (range 31-35). The mean modified Harris Hip Score was 52.4 (range 35-73) preoperatively, 81 (range 67-95) at six months and 59.6 (range 38-91) at one year follow up. The mean visual analogue scale was 5.8 (range 3.0-10.0) preoperatively, 3.1 (range 0.7-5.2) at six months and 5.4 (0.6-7.9) at one year follow up. Four patients (4 hips) and successful results. Three patients (4 hips) had clinical and radiographic progression. One of them required bipolar hemiarthroplasty at 11 months postoperatively. The others (3 hips) have been planned for arthroplasty. Removing and replacing necrotic bone with iliac bone graft is an alternative method to preserving the femoral head in the treatment of nontraumatic avascular necrosis, Ficat stage IIb and III. Initial pain relief and clinical improvement were obtained by most patients. Patient selection is considered to be one of the important factor in predicting long term outcomes.