Detection Of Bone Marrow Lesions Of The Knee Bone With Low Dose Dual-Energy CT Virtual Noncalcium Technique

ObjectiveBased on AIDR 3D (adaptive iterative dose reduced three-dimensional) reconstruction algorithm and combined with low tube current technology of dual-energy computed tomographic(CT) virtual noncalcium technique to detect post traumatic bone marrow lesions of the knee.MethodsThirty patients underwent DECT imaging with either a standard dose (group M) or a low dose (group N) and magnetic resonance imaging for knee trauma workup. Calcium was virtually subtracted from the images. Two groups of image scanning is carried out in the AIDR 3D technology, and combined with low tube current technology, divided into two groups:group M (135KV,25mAs,80KV, 145mAs), group N (135KV,20mAs,80KV,115mAs,). Measurement of M(135KV,25mAs) and N(135KV,20mAs) of two groups of patients with knee joint adipose tissue CT value and its standard deviation (SD) and signal-to-noise ratio (SNR), compared two groups of image quality. Two radiologists rated the presence of abnormal bone marrow in a total of 12 femoral and tibial regions and performed Hounsfield unit measurements thereafter.And the sensitivity and specificity of the two groups of different doses of VNCa on knee joint injury of bone marrow was observed by ROC curve. To test the consistency of the two physicians in two groups of different dose groups of bone marrow damage diagnosis using Kappa.ResultsMagnetic resonance imaging depicted 120BMLs(20/120 femoral,20/120 tibial). Bone marrow lesions in T1WI showed low signal shadow, PDWI FS showed high signal shadow. Image quality of M group and N group P>0.05 and there was no significant difference. The consistency of bone marrow damage was better in the two group of physicians who judged the two groups, the Kappa values of M group and N group were 0.601and 0.509 respectively, the area under the ROC curve was 0.921and 0.941, respectively. MRI and VNCa maps showed good agreement in the bone marrow damage (P＜0.05). The consistency of bone marrow damage was very good in the M group and the N group in the VNC group, P=0.276.ConelusionDose reduction does not affect the detect ability of post traumatic BMLs with a dual-energy CT virtual noncalcium technique. Through ADIR 3D technology combined with low tube current technology, it can not only guarantee the quality of the image, but also can meet the clinical requirements of the diagnosis of occult bone marrow damage in acute knee joint.