European journal of radiology
-
In diffusion-weighted magnetic resonance imaging (DWI), the intensity of the acquired magnetic resonance signal depends on the self-diffusion of the excited spins, i.e., on the microscopic stochastic Brownian molecular motion. Since the extent and orientation of molecular motion is influenced by the microscopic structure and organization of biological tissues, DWI can depict various pathological changes of organs or tissues. While DWI of the brain can be considered an established technique since the mid-1990s, significantly fewer studies have been published about DWI in body imaging, mainly because of the relatively low robustness of conventional DWI methods in non-neurological applications. ⋯ Hence, several alternative (non-echo-planar) diffusion-weighting pulse sequence types were proposed and evaluated for DWI applications in the body. In this review article, first the basics of molecular diffusion and of diffusion-weighted MRI are introduced and then several specific MRI techniques, which have been used for DWI of the body, are described. Finally, protocol recommendations for different DWI applications in the body are provided.
-
MRI of the kidney currently makes the transition from depiction of morphology to assessment of function. Functional renal imaging methods provide information on diffusion and perfusion on a microstructural level. This review article presents the current status of functional renal imaging with focus on DWI (diffusion-weighted imaging) and DCE-MRI (dynamic contrast-enhanced MRI), as well as BOLD (blood-oxygenation level dependent) MRI, DTI (diffusion tensor imaging) and arterial spin labeling (ASL). Technical background of these techniques is explained and clinical assessment of renal function, parenchymal disease, transplant function and solid masses is discussed.
-
Evaluate the use of MDCT with 3D CT angiography (CTA) and CT portal venography (CTPV) reconstruction for the diagnosis of small bowel volvulus (SBV). ⋯ Multiphasic MDCT with CTA/CTPV reconstruction can play an important role in the diagnosis of SBV. The location, direction and degree of SBV can all be defined preoperatively using this method.
-
It has recently been reported that intravenous recombinant tissue plasminogen activator improves the clinical outcome after acute stroke. Computed tomography (CT) is the standard imaging method used to determine the indication for thrombolysis. However, detection of early ischemic change often results in an increase in local radiation exposure. Therefore, the effects of decreased matrix size and use of a noise reduction filter were evaluated. ⋯ This study was performed to determine whether the converted matrix size and use of imaging filters could improve the detectability of early ischemic change on CT images in acute stroke. To reduce the dose of radiation exposure for patients, it was effective to use an optimal noise reduction filter and reasonable matrix size. In particular, changing the matrix size to 256×256 was the most effective for detection of early ischemic change in examinations using clinical images.
-
The purpose of this study was to assess the efficacy of multidetector-row CT (MDCT) for the diagnosis of non-occlusive mesenteric ischemia (NOMI) by analyzing morphology and diameter of superior mesenteric artery (SMA). We assessed whether MDCT was as useful as angiography for the diagnosis of NOMI. ⋯ Angiography has been recognized essential for the diagnosis of NOMI. This study shows the possibility of MDCT to be an equivalently useful modality compared to angiography for the diagnosis of NOMI by interpreting morphologic appearance and diameter of SMA. Introduction of MDCT in the decision tree of NOMI treatment may bring the benefit of prompt diagnosis and subsequent early and efficient initiation of therapy, which may improve the mortality.