Luis A. Rivas

Multislice CT in thoracic trauma

The introduction of CT imaging in the 1970s revolutionized all aspects of medical care, perhaps nowhere more so than in the evaluation of acutely injured patients. Just as single-slice helical scanning was a great advance over conventional CT, the capabilities of MSCT are proving to be dramatically superior to single-slice methods. Improved contrast bolus imaging, thinner slices, and isotropic voxels should enable the trauma radiologist to identify both major organ system disruption and subtle injuries more promptly. Multiplanar and three-dimensional reconstructions, a forte of MSCT, facilitate rapid communication of disease states with surgeons and others involved in the care of injured patients. In many centers, whole-body CT is beginning to supplant plain films of the chest and spine in the evaluation of severe trauma victims; the cost-effectiveness of such methods is still under evaluation.

Imaging Evaluation of Adult Spinal Injuries: Emphasis on Multidetector CT in Cervical Spine Trauma

As computed tomography (CT) technology has evolved, multidetector CT has become an integral part of the initial assessment of many injured patients, and the spine is easily included in the total body screening performed in patients with severe blunt polytrauma. Despite all the advantages of multidetector CT, clearing the spine in which injury is suspected continues to be a daily challenge in clinical practice. The purpose of this review is to present the evidence and the controversies surrounding the practice of imaging in patients suspected of having spine injury. The discussion is centered on the increasing reliance on multidetector CT in the work-up of these patients but also considers the important contributions of clinical trials to select patient for appropriate imaging on the basis of risk and probability of injury. Available protocols, injury classification systems, and issues awaiting future research are addressed.

64-MDCT Angiography of Blunt Vascular Injuries of the Neck

OBJECTIVE CT angiography (CTA) using 64-MDCT enables timely evaluation of injuries associated with blunt neck trauma. The purpose of this article is to familiarize the reader with the most frequent CTA signs of blunt vascular injury. CONCLUSION CTA is a valuable tool to detect blunt vascular injuries, especially using its multiplanar and 3D reconstruction capabilities.

Inter- and Intrarater Reliability in Computed Axial Tomographic Grading of Splenic Injury: Why So Many Grading Scales?

OBJECTIVE After splenic trauma, critical decisions regarding operative intervention are often made with the aid of computed axial tomographic (CT) scan findings. No CT scan-based grading scale has been demonstrated to predict accurately which patients require operative or radiologic intervention for their splenic injuries. We hypothesized that use of the most common grading scale, the American Association for the Surgery of Trauma scale, would be associated with low intra- and interreliability scores. We assessed the ability of experienced trauma radiologists to differentiate grade III from grade IV splenic injuries. METHODS The films of patients who had undergone abdominal CT scanning before splenectomy for grade III or IV injuries were serially evaluated by four trauma radiology faculty weekly for 3 weeks. We assessed intra- and interrater reliability for grading and for presence of contrast blush. RESULTS Intrarater reproducibility yielded a weighted kappa score of 0.15 to 0.77. Interrater reliability weighted kappa scores ranged from 0 to 0.84, with a mean value of 0.23. CONCLUSION CT imaging is not reliable for identifying grades III and IV splenic injury, as experienced radiologists often underestimate the magnitude of injury. Interrater reliability is poor. Factors other than the CT grade of splenic injury should determine whether patients require operative or angiographic therapy.

Penetrating Diaphragmatic Injury: Accuracy of 64-Section Multidetector CT with Trajectography

PURPOSE To (a) determine the diagnostic performance of 64-section multidetector computed tomography (CT) trajectography for penetrating diaphragmatic injury (PDI), (b) determine the diagnostic performance of classic signs of diaphragmatic injury at 64-section multidetector CT, and (c) compare the performance of these signs with that of trajectography. MATERIALS AND METHODS This HIPAA-compliant retrospective study had institutional review board approval, with a waiver of the informed consent requirement. All patients who had experienced penetrating thoracoabdominal trauma, who had undergone preoperative 64-section multidetector CT of the chest and abdomen, and who had surgical confirmation of findings during a 2.5-year period were included in this study (25 male patients, two female patients; mean age, 32.6 years). After a training session, four trauma radiologists unaware of the surgical outcome independently reviewed all CT studies and scored the probability of PDI on a six-point scale. Collar sign, dependent viscera sign, herniation, contiguous injury on both sides of the diaphragm, discontinuous diaphragm sign, and transdiaphragmatic trajectory were evaluated for sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV). Accuracies were determined and receiver operating characteristic curves were analyzed. RESULTS Sensitivities for detection of PDI by using 64-section multidetector CT with postprocessing software ranged from 73% to 100%, specificities ranged from 50% to 92%, NPVs ranged from 71% to 100%, PPVs ranged from 68% to 92%, and accuracies ranged from 70% to 89%. Discontinuous diaphragm, herniation, collar, and dependent viscera signs were highly specific (92%-100%) but nonsensitive (0%-60%). Contiguous injury was generally more sensitive (80%-93% vs 73%-100%) but less specific (50%-67% vs 83%-92%) than transdiaphragmatic trajectory when patients with multiple entry wounds were included in the analysis. Transdiaphragmatic trajectory was a much more sensitive sign of PDI than previously reported (73%-100% vs 36%), with NPVs ranging from 71% to 100% and PPVs ranging from 85% to 92%. CONCLUSION Sixty-four-section multidetector CT trajectography facilitates the identification of transdiaphragmatic trajectory, which accurately rules in PDI when identified. Contiguous injury remains a highly sensitive sign, even when patients with multiple injuries are considered, and is useful for excluding PDI.

Sticking our neck out: is magnetic resonance imaging needed to clear an obtunded patient's cervical spine?

BACKGROUND Evaluating the cervical spine in the obtunded trauma patient is a subject fraught with controversy. Some authors assert that a negative computed tomography (CT) scan is sufficient. Others argue that CT alone misses occult unstable injuries, and magnetic resonance imaging (MRI) will alter treatment. This study examines the data in an urban, county trauma center to determine if a negative cervical spine CT scan is sufficient to clear the obtunded trauma patient. METHODS Records of all consecutive patients admitted to a level 1 trauma center from January 2000 to December 2011 were retrospectively analyzed. Patients directly admitted to the intensive care unit with a Glasgow Coma Scale score ≤13, contemporaneous CT and MRI, and a negative CT reading were included. The results of the cervical spine MRI were analyzed. RESULTS A total of 309 patients had both CT and MRI, 107 (35%) of whom had negative CTs. Mean time between CT and MRI was 16 d. Of those patients, seven (7%) had positive acute traumatic findings on MRI. Findings included ligamentous injury, subluxation, and fracture. However, only two of these patients required surgical intervention. None had unstable injuries. CONCLUSIONS In the obtunded trauma patient with a negative cervical spine CT, obtaining an MRI does not appear to significantly alter management, and no unstable injuries were missed on CT scan. This should be taken into consideration given the current efforts at cost-containment in the health care system. It is one of the larger studies published to date.

Incidental findings on trauma ultrasonography

Purpose: To determine the prevalence of incidental findings detected on the focused abdominal sonogram for trauma. Methods: From November 1996 to February 1998, 1914 radiologist-assisted trauma ultrasound examinations were performed. Incidental findings were tabulated by retrospective review of the trauma radiology daily logbooks. Results: Incidental nontraumatic findings were detected in 160 (8.36 %) of the acutely injured patients. Most findings were benign, including echogenic liver, renal cysts, and cholelithiasis. However, significant pathology was detected in several patients, including renal masses, hepatic metastases, and gynecologic disease. Conclusion: The radiologist-assisted trauma ultrasound examination can provide valuable diagnostic information beyond the detection of free fluid. This may have important implications, as nonradiologists are increasingly involved in the practice of trauma ultrasonography. Even in the setting of trauma, significant occult pathology can be detected on a targeted ultrasound examination.

THE NON-OPERATIVE MANAGEMENT OF PENETRATING INTERNAL JUGULAR VEIN INJURY

OBJECTIVE The objective of this study was to review the outcome of nonoperative treatment for penetrating internal jugular vein (IJ) injuries in a continuous series of prospectively identified, hemodynamically stable patients. METHODS All penetrating neck injuries assessed from February 1, 2004, to August 31, 2004, were prospectively identified. Patients without an indication for urgent neck exploration underwent diagnostic assessment with multislice helical computed tomographic angiography with or without vascular ultrasonography. All IJ injuries with no other indication for surgical exploration were treated nonoperatively. All patients were discharged home and followed up for a minimum of 1 week to document outcomes. RESULTS From 51 neck injuries penetrating the platysma, 7 required urgent neck exploration, during which 2 IJ injuries were ligated. Forty-four patients underwent multislice helical computed tomographic angiography. Eight IJ injuries (two gunshot wounds and six stab wounds) with no other indication for neck exploration were identified and managed nonoperatively. One external wound was in zone 1, five were in zone 2, one was in zone 3, and one traversed all three zones. The average length of stay was 4.5 days. At follow-up, ranging from 1 week to 5 months, all patients were asymptomatic, and no patient required delayed operation for IJ injury. CONCLUSIONS In hemodynamically stable patients with no other indication for exploration, the nonoperative management of penetrating jugular vein injuries should be considered as a safe alternative.