Multidetector CT evaluation of active extravasation in blunt abdominal and pelvic trauma patients.

Timely localization of a bleeding source can improve the efficacy of trauma management, and improvements in the technology of computed tomography (CT) have expedited the work-up of the traumatized patient. The classic pattern of active extravasation (ie, administered contrast agent that has escaped from injured arteries, veins, or urinary tract) at dual phase CT is a jet or focal area of hyperattenuation within a hematoma that fades into an enlarged, enhanced hematoma on delayed images. This finding indicates significant bleeding and must be quickly communicated to the clinician, since potentially lifesaving surgical or endovascular repair may be necessary. Active extravasation can be associated with other injuries to arteries, such as a hematoma or a pseudoaneurysm. Both active extravasation and pseudoaneurysm (unlike bone fragments and dense foreign bodies) change in appearance on delayed images, compared with their characteristics on arterial images. Other clues to the location of vessel injury include lack of vascular enhancement (caused by occlusion or spasm), vessel irregularity, size change (such as occurs with pseudoaneurysm), and an intimal flap (which signifies dissection). The sentinel clot sign is an important clue for locating the bleeding source when other more localizing findings of vessel injury are not present. Timely diagnosis, differentiation of vascular injuries from other findings of trauma, signs of depleted intravascular volume, and localization of vascular injury are important to convey to interventional radiologists or surgeons to improve trauma management.

Interventional radiologic management of renal transplant dysfunction: indications, limitations, and technical considerations.

Renal transplantation is the treatment of choice for most patients with end-stage renal disease. However, in spite of continuous progress in surgical techniques and immunosuppressive therapy, a wide variety of vascular and nonvascular complications can arise postoperatively. Vascular complications include transplant renal artery stenosis, arteriovenous fistulas or intrarenal pseudoaneurysms following renal transplant biopsy, extrarenal pseudoaneurysms, and graft thrombosis. Nonvascular complications include urologic complications (eg, ureteral obstruction, urine leak) and perigraft fluid collections (eg, lymphocele, abscess, hematoma, urinoma). These postoperative complications can be diagnosed and managed with minimally invasive techniques; however, an understanding of renal transplant anatomy and the risks of posttransplantation immunosuppressive therapy unique to this patient population is essential to their successful application. In addition, familiarity with the indications for and limitations of these techniques as well as collaboration between the radiologist and the transplantation surgeon are vital for maximizing the chances of renal allograft survival.

Endovascular and interventional procedures in obese patients: a review of procedural technique modifications and radiation management.

As the prevalence of obesity in the United States continues to increase, the volume of endovascular and fluoroscopically guided procedures is also increasing. With obese patients, it often seems the only consideration is whether the table weight tolerance can accommodate the patient. This is a naive approach to performing procedures in obese patients, as there are multiple considerations involved in providing state-of-the-art endovascular and interventional care to obese patients. A growing collection of literature is beginning to surface regarding the appropriate modifications in the interventional care of these patients. This article reviews the relevant literature on this important subject.