The Clinical Research Of The Dual-energy Technique CT For The Diagnosis Of The Anterior Cruciate Ligament Injury

Objective:1. To explore the feasibility of the dual-energy technique of CT to display the anterior cruciate ligament.2. To explore the feasibility of the dual-energy technique of CT for the diagnosis of the anterior cruciate ligament injury and find the related sign.Methods:1. Animal experiment8 goats received dual-source CT(DSCT) dual-energy technique examination. The shapes, orientations and the dual-energy staining profiles of their anterior cruciate ligaments were performed in dual-energy tendon module.2. Clinical study89 patients who received DSCT dual-energy technique examination before the arthroscopy were analyzed prospectively from April 2010 to March 2011, including 74 males and 15 females, ranged in age from 16 to 59 (mean age:26.7±11.07) years.60 patients were experiencing suspected left knee pain while 29 patients were experiencing suspected right knee pain.3. Instruments and parametersSiemens Dual-source CT (Siemens Somatom Definition 2008G) and dual-energy imaging mode were used. Patients were scanned with both knees simultaneously. Scanning parameters and specifications are listed as follow:56 mA and 234mA for tube currents of tube A and B, and 140Kv and 80Kv for tube voltage, respectively. The collimation was set at 20×0.6mm, the screw pitch at 0.7, the effective thickness at 0.75 mm, and the field of view at 250mm. The scanning dimension ranged from the superior border of femoral condyle upwards to the interior border of tibial condyle and fibular head downwards.4. Post-processing of imagesThe Volume Wizard workstation was used to perform three-dimensional (3D) MPR reconstruction. Shapes and orientations of bilateral anterior and posterior cruciate ligament were reconstructed on oblique sagittal plan, respectively. Dual-energy staining and developing were performed in dual-energy tendon module. Both stained anterior and posterior cruciate ligament were displayed on oblique sagittal plan. The staining profiles of bilateral cruciate ligament were subsequently compared.5. Statistical treatmentThe data statistic software is SPSS13.0. The Kappa test procedure was used to evaluate the concordance between the results of CT and arthroscopy.Results:The Shapes and orientations of the goats' anterior cruciate ligaments were displayed clearly. And the dual-energy staining were uniformity with the orange. colour. Dual-energy staining diminution sign was found. Under the dual-energy tendon mode, dual-energy staining of the injured anterior cruciate ligament was lower than that of the contralateral normal anterior cruciate ligament of the patient.53 cases of anterior cruciate ligament (ACL) injury were diagnosed by this sign,52 of which were in accordance with arthroscopy results and 1 case was misdiagnosed.36 cases of normal anterior cruciate ligament were diagnosed,33 of which were in accordance with arthroscopy result and 3 cases were misdiagnosed. The sensibility was 94.5%, the specificity was 97.1% and the diagnostic accordance rate using staining diminution in dual energy CT imaging was 95.5%(85/89). The value of the Kappa test procedure was 0.906 (excellent agreement)Conclusions:1. It was feasible to use the dual-energy technique of CT to display the anterior cruciate ligament and also feasible for the diagnosis of the anterior cruciate ligament injury.2. The diminution sign on dual-energy staining could be used to diagnose effectively the anterior cruciate ligament injury. The sensibility was 94.5% and the specificity was 97.1%...