Evaluation of prospective living renal donors for laparoscopic nephrectomy with multisection CT: the marriage of minimally invasive imaging with minimally invasive surgery

Laparoscopic technique for excision of a kidney from a living donor has advantages over conventional open surgery, but operative visibility and surgical exposure are limited. Preoperative multisection computed tomography (CT) can provide necessary anatomic information in a minimally invasive procedure. A three-phase examination is suggested: (a) imaging from the top of the kidneys to the pubic symphysis with a section width of 2.5 mm and no contrast medium, (b) scanning of the kidneys and upper pelvis during the arterial phase of enhancement with a section width of 1.0 mm, and (c) scanning of the kidneys and upper retroperitoneum during the nephrographic phase of enhancement with a section width of 1.0 mm. Emphasis in this article is placed on analysis of the venous anatomy because most radiologists are unfamiliar with the anatomic variations. Conventional radiography of the abdomen and pelvis is performed after CT to evaluate the collecting system and ureters and to provide a lower total radiation dose than if CT were used. Of several postprocessing techniques that may be used, the authors prefer maximum intensity projection for arterial evaluation and multiplanar reformatting for venous evaluation.

Stent grafting of abdominal aortic aneurysms: pre-and postoperative evaluation with multislice helical CT

Endovascular stent grafting of abdominal aortic aneurysms is a new technique that may replace open surgery in selected cases. Pre-and postoperative angiography can be replaced by helical CT. This pictorial essay describes and illustrates the use of multislice helical CT where maximum intensity projection and multiplanar reformats play a central role in the evaluation.

Multisection CT: scanning techniques and clinical applications

Multisection computed tomography (CT) was introduced in 1992 with the advent of dual-section-capable scanners and was improved in 1998 following the development of quad-section technology. With a recent increase in gantry speed from one to two revolutions per second, multisection CT scanners are now up to eight times faster than conventional single-section helical CT scanners. The benefits of quad-section CT relative to single-section helical CT are considerable. They include improved temporal resolution, improved spatial resolution in the z axis, increased concentration of intravascular contrast material, decreased image noise, efficient x-ray tube use, and longer anatomic coverage. These factors substantially increase the diagnostic accuracy of the examination. The multisection CT technique has enabled faster and superior evaluation of patients across a wide spectrum of clinical indications. These include isotropic viewing, musculoskeletal applications, use of multiplanar reformation in special situations, CT myelography, long coverage and multiphase studies, CT angiography, cardiac scoring, evaluation of brain perfusion, imaging of large patients, evaluation of acute chest pain or dyspnea, virtual endoscopy, and thin-section scanning with retrospective image fusing. Multisection CT is superior to single-section helical CT for nearly all clinical applications.