The "O" sign, a simple and helpful tool in the diagnosis of laparoscopic adjustable gastric band slippage.

OBJECTIVE: The purpose of this article is to describe a sign on radiography for gastric band slippage, a complication of adjustable gastric banding surgery, and to emphasize the importance of this finding to radiologists and clinicians. MATERIALS AND METHODS: We reviewed the radiologic findings in 55 consecutive patients who underwent laparoscopic gastric banding. Between January 2007 and September 2008, gastric band slippage was diagnosed in four patients at our institution. All patients underwent an upper gastrointestinal examination at the time of presentation. On the basis of either radiographic findings or clinical presentation, all patients underwent exploratory surgery. RESULTS: In all four patients with surgically proven gastric band slippage, the initial abdominal radiograph showed an O-shaped configuration of the gastric band, which we have termed the "O" sign. Baseline upper gastrointestinal examinations were available for comparison in all patients. In each case, the O-shaped configuration of the band was a change from its rectangular appearance when in the proper position. CONCLUSION: As laparoscopic adjustable gastric banding is increasingly used, more patients will present to the emergency department with complications of the procedure, particularly complications from band slippage. Because the consequences of slippage may require acute surgical intervention, it is imperative that the radiologist is familiar with the surgical technique to correctly position the band and the appearances of a gastric band when correctly and incorrectly positioned. Identification of the O sign on radiography can potentially aid the radiologist, surgeon, or emergency department physician in the early detection of gastric band slippage and appropriate patient triage.

Use of 64-row multidetector CT angiography in blunt and penetrating trauma of the upper and lower extremities.

Computed tomographic (CT) angiography is rapidly becoming the preferred imaging test for the initial evaluation of patients suspected to have arterial injuries after blunt and penetrating trauma to the extremities. The increasingly widespread use of 64-row multidetector CT technology offers considerable benefits in extremity CT angiography in the trauma setting. These include the ability to generate isotropic data sets of long vascular territories, with the acquisition performed in a short time (10 seconds or less). Isotropic voxels make CT a fully multiplanar modality, a capability that is particularly useful for evaluating tortuous vessels. Sixty-four-row multidetector CT angiography of the extremities has the ability to demonstrate a variety of vascular injuries such as occlusion, pseudoaneurysm, active extravasation, and intimal dissection. Radiologists should be aware of the various potential pitfalls and limitations of extremity CT angiography in evaluation of trauma patients suspected to have extremity vascular injuries, including inadequate arterial enhancement, motion artifact, inadequate positioning, and streak artifact. By demonstrating the extent, location, and type of injury, CT angiography aids in the decision-making process to determine the appropriate management for each injury in each patient.

Extremity CT angiography: application to trauma using 64-MDCT.

Evolving multi-row detector computed tomography (MDCT) technology has resulted in increasing utility of CT angiography (CTA) in extremity vascular trauma diagnosis and characterization. Given the widespread availability as well as the ease of acquiring CTA in the trauma setting, CTA is increasingly being used as the initial diagnostic evaluation in extremity vascular trauma, replacing digital subtraction angiography in many institutions. One of the significant advantages of the application of 64-MDCT to extremity vascular trauma is the ability to integrate CTA into routine trauma torso protocols. This ultimately yields an efficient, tailored examination to evaluate the multi-trauma patient in a timely manner, a critical concern in this patient population. Although 64-MDCT offers increasing improvement in image quality, technical quality hinges on strict attention to protocol considerations in its implementation. This review article aims to detail the myriad injuries, which may be detected and characterized with CTA. Protocol considerations in the application of 64-MDCT technology to extremity vascular trauma are discussed, drawing from our experience in an urban, Level I trauma center. Finally, the advantages and techniques of integrating extremity CTA into torso trauma protocols will be described.

Detection of vascular injuries in patients with blunt pelvic trauma by using 64-channel multidetector CT.

Vascular injuries are a major source of morbidity and mortality in patients with blunt pelvic trauma. Digital subtraction angiography (DSA) has traditionally been used to detect pelvic arterial injuries and to treat active arterial hemorrhage. Improvements in the technology of computed tomography (CT) have facilitated the implementation of CT angiography, which is beginning to replace DSA in the evaluation of patients with acute trauma. Pelvic CT angiography can reliably depict various pelvic arterial injuries and can help differentiate arterial hemorrhage from venous hemorrhage on the basis of multiphasic acquisitions, a method that may be used to tailor the subsequent clinical approach. With the use of a 64-channel multidetector CT scanner, multiphasic pelvic CT angiography can be integrated into the evaluation of trauma patients by using 1.25-mm reconstructed section thickness, pitch of 1:0.987, and gantry revolution time of 0.5 second to achieve near-isotropic results. A standard dose of 100 mL intravenous contrast material is injected at a rate of 5 mL/sec, and 30 mL saline solution, also at 5 mL/sec, is injected as a "chasing" bolus to follow the contrast material.