Application Study On Image Fusion From Stand-alone CCTA And MPI In Chronic Total Occlusions Disease

It has long been a big issue for the cardiologist to diagnose the chronic total occlusions (CTO), to predict its risks, to perform surgical operations and to evaluate its therapeutic effects. Coronary CT angiography (cCTA) and myocardial perfusion imaging (MPI) or 3D fusion images combination the cCTA with the MPI are the essential methods to provide valuable information for the clinicians. But there exists some limitations in the devices and checking procedures using the methods above. Even if the current used image fusion method from stand-alone cCTA and MPI might overcome the limits, it required more experienced operator to the device and lacked of objective and repeatable location. In this dissertation, we studied a general-purpose fusion method that can fuse images from different machines, in order to produce a 3D fusion image with structural and functional information. Furthermore, we applied these techniques to diagnose CTO, to predict risks of operations and to evaluate the therapeutic effects.Stand-alone dual-source 64-slice CT (DSCT) can produce high quality cCTA in normal heart rate circumstances. Moreover, single photon emission computed tomography (SPECT) can generate MPI images, which is the classic inspection means for myocardial ischemia. Therefore, fusion of the two different images not only provide clear anatomical information, but also reveal the functional information of myocardial perfusion, which has been increasingly recognized by clinicians. It’s long been the twists and turns to accurately register the cCTA and MPI images when subject’s body position changes. SPECT / CT fusion machines, which is equipped with a positioning tube or double spiral CT referred to as positioning CT, have been popular in clinical practice, but due to the weak features of CT, cCTA examination is impossible, thus, no ideal cCTA and MPI fusion images can be acquired from the same machine. We, therefore, proposed a set of techniques that can fuse images from a DSCT and a hybrid SPECT/CT. These techniques solved the difficulties in image registering with previous methods and improve the objectivityFirst of all, ECG-gated cCTA screening was performed to select subjects for the subsequent research with a 64-slice DSCT. Then, a double gamma probe SPECT/CT was used to give rest-MPI and stress-MPI, with synchronous 3D chest CT scans. The image fusion was twofold. One, fusion was conducted on images from the hybrid SPECT/CT and attenuation correction (AC) was performed on MPI using positioning CT. Two, fusion was further conducted by bridging the 3D chest CT with the SPECT/CT to produce fused image from cCTA and MPI. This study proved the necessity of AC on SPECT-MPI with positioning CT, and also proved the feasibility, accuracy and generalizability of the proposed fusion techniques.CTO patients can be assessed by utilizing the 3D fusion image with the additional image data, the independent cCTA, MPI and CAG images. The coronary artery disease (CAD) patients with stenosis of coronary artery were selected to prove the clinical availability of the fusion image. Firstly, 15 subjects took part in the study after checked by using CT combined with cCTA.Then the 3D fusion images were obtained stand alone from the cCTA and MPI by the location CT as a bridge. Finally, the fusion images and the data from each subject were processed to comprehensively evaluate the clinic values, including the diagnosis, risks and effects in treatment of the CTO disease.The results showed that it was more suitable for practical operation using the method of the 3D image fusion from stand-alone cCTA and MPI with the help from the bridged positioning CT. The location registration was more objective and repeatable using this method. The positioning CT could be used to get more effective AC for the results of MPI. The image fusion from stand-alone cCTA and MPI could provide more information for the diagnosis and therapy of CAD, including the culprit vessels, the location and the range of the ischemic areas, the wall motion and the heart function. It was more suitable to be used to evaluate the pathological changes in hearts with apparently myocardial ischemia and could provide the evidence for the necessity of the operation for CTO patients. The results of the rechecking confirmed that the operation for CTO disease could effectively relieve the pathogenetic condition and prevent the ventricular remodeling using the fused image from stand-alone cCTA and MPI. With the help of the fused images, clinicians could decide the operation program and estimate the surgical risks and postoperative effects more easily and accurately.In a word, the method of the 3D image fusion from stand-alone cCTA and MPI with the help from the bridged positioning CT is more objective and operable and has high values in clinical application.