Diagnostic accuracy of 3D time-of-flight MR angiography compared with digital subtraction angiography for follow-up of coiled intracranial aneurysms: influence of aneurysm size.

BACKGROUND AND PURPOSE: 3D time-of-flight MR angiography (3D TOF MRA) may be used as noninvasive alternative to digital subtraction angiography (DSA) for the follow-up of patients with intracranial aneurysms treated with Guglielmi detachable coils (GDCs). We aimed to determine the influence of aneurysm size and location on diagnostic accuracy of 3D TOF MRA for follow-up of intracranial aneurysms treated with GDCs. MATERIALS AND METHODS: Two hundred and one 3D TOF MRAs in 127 consecutive patients with 136 aneurysms were compared with DSA as standard of reference. Sensitivity and specificity of 3D TOF MRA for detection of residual or reperfusion of the aneurysms was calculated with regard to aneurysm size and location. RESULTS: Overall sensitivity and specificity of MRA was 88.5% and 92.9%, respectively. Sensitivity was lower for aneurysms

Helical CT angiography with maximum intensity projection in the assessment of aortic coarctation after surgery.

OBJECTIVE: The value of CT angiography and three-dimensional (3D) reconstructions was investigated in the postoperative care after surgical repair of aortic coarctation and compared with conventional angiography. SUBJECTS AND METHODS: Twenty-five patients referred because of suspicion of stenosis in the area of former coarctation were prospectively studied with CT angiography and catheter angiography. We determined the morphometric and morphologic findings such as aortic diameter, stenosis, aneurysm, intimal flaps, circumscribed pouch, or arteriosclerotic plaques with 3D reconstructions, using maximum-intensity-projection (MIP) technique and catheter angiography. The results of both techniques were compared. The ratio of the narrowest diameters of the former coarctation and the descending aorta was correlated with the systolic pullback blood pressure gradient in all patients. RESULTS: The former coarctation was normal in 11 patients, (44%), group A; narrowed in 12 children (48%), group B; and dilated in two children (8%), group C. An intimal flap and a circumscribed pouch were delineated in four subjects. MIP reconstructions and catheter angiography revealed identical results regarding the classification into groups A, B, C; intimal flaps; and circumscribed pouches. Statistical analysis revealed good correlation between the narrowest aortic diameters measured on MIP reconstructions and catheter angiography, whereas no correlation between the systolic pullback blood pressure gradient and the diameter ratio of the former coarctation and the descending aorta was found. CONCLUSION: CT angiography and 3D reconstructions using MIP represent a reliable noninvasive technique to replace diagnostic catheter angiography in the postoperative care of patients with coarctation and provide the clinician with valuable information concerning further invasive procedures.

Digital image fusion of CT and PET data sets--clinical value in abdominal/pelvic malignancies.

PURPOSE: We investigated the clinical relevance of digital image fusion of CT and 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) positron emission tomography (PET) studies in patients with suspected abdominal and/or pelvic metastasis. METHOD: Nineteen patients with suspected residual/recurrent malignancies underwent CT and [18F]FDG PET studies of the abdomen and/or pelvis. The data sets of both modalities were fused on a digital workstation by automatic adaptation of the pixel size and the slice thickness. Different body positions were corrected by semiautomatic adaptation of the body axes. The fused images were reconstructed in sagittal, coronal, and axial planes. RESULTS: Good spatial correlation between both modalities was achieved in all patients. Image fusion improved the spatial allocation of pathologically increased [18F]FDG uptake in 7 of 35 lesions (20%). CONCLUSION: This work suggests that digital image fusion of CT and [18F]FDG PET data sets improves the anatomical localization of foci with increased [18F]FDG enhancement of the retroperitoneum and the abdominal/pelvic wall, respectively.