Objective To evaluate the characteristics and the value of dual-source CT single-energy high pitch scanning technology in postoperative follow-up of endovascular graft exclusion to DeBakey Ⅲ aortic dissection.Methods All of 58 patients with endovas-cular graft exclusion to Debakey Ⅲ aortic dissection underwent dual-source CT checkup.30 patients (group A)were scanned with single-energy high pitch technology,voltage 120 kV,pitch 3.2;28 patients (group B)were scanned with dual-energy standard pitch technology,voltage 100 kV and 140 kV,pitch 1.0;both groups were used CareDose4D technology to automatically track the cur-rent.Image post-processing was completed at the workstation.The stent condition,endoleak and residual dissection were observed and analyzed.The differences of image quality and radiation dose between two scanning modes were compared.Results All of 58 cases,postoperative conditions to 9 cases were perfect,the proportion was 1 5.52%;43 cases were with distal residual dissection,the proportion is 74.14%;and 12 cases were accompanied with endoleaks,the proportion was 20.69%.The endoleaks manifestation in-cluded punctuate,band-like,and patchy high density around the stent in enhanced images.The difference of scan length between group A and group B was not statistically significant,the image quality of both groups met excellent standard .The acquisition time and effective radiation dose to group A were 1/4 and 56% of group B respectively.the differences of both groups were statistically significant.Conclusion Dual-source CT with single-energy high pitch scanning technology can ensure image quality and significantly reduce the effective radiation dose,it is a more advantageous scanning mode.

Objective To assess the diagnostic value of magnetization transfer contrast (MTC) gradient echo (GRE) T2WI sequence in bone injury of knee joint. Methods MRI data of 56 patients with knee injury were analyzed retrospectively. All patients underwent SE sequence (sagittal T1WI, T2WI) and sagittal MTC-GRE T2WI sequence. The size, signal intensity and margin of bone contusion with different MRI sequence were analyzed and compared. Results Among 56 patients, 43 and 45 cases were demonstrated on SE T1WI and T2WI, respectively; 50 cases were displayed on MTC-GRE T2WI sequence. The size, border of bone contusions and sensitivity displayed on MTC-GRE T2WI sequence were statistically higher than those on SE sequence (P<0.05). Conclusion MTC-GRE T2WI sequence has great diagnostic value in contusion of knee joint, which is superior to FSE sequence.