Sravanthi Reddy

Prospective Evaluation of Multidetector Computed Tomography for Extremity Vascular Trauma

BACKGROUND Multidetector computed tomographic angiography (MDCTA) is increasingly being used for the assessment of extremity vascular injury. However, to date, there are only retrospective series and a single small prospective study evaluating its efficacy. Therefore, the objective of this study was to prospectively evaluate the ability of MDCTA to detect arterial injury in the injured upper and lower extremities. METHODS After institutional review board approval, all trauma patients aged 16 years or older admitted to a Level I trauma center who sustained extremity trauma and underwent initial evaluation with a 64-channel MDCTA from March 2009 to June 2010 were prospectively enrolled. The sensitivity and specificity of MDCTA were tested against an aggregate gold standard of operative intervention, conventional angiography, and clinical follow-up. RESULTS During the 20-month study period, 635 patients with extremity trauma underwent a structured clinical examination. Hard signs of vascular injury was observed in 5.5% of patients with a 97.1% incidence of clinically significant injury requiring operative intervention. Eighty-three percent of patients had no signs of vascular injury with no missed injuries detected during follow-up. Eighty-nine MDCTAs were performed in the remaining 73 patients (11.5%) with soft signs. The mechanism of injury was penetrating in 69.9% (42 gunshot wound, 5 stab wound, and 4 shotgun). There were 24 positive studies, 23 of which were confirmed at operation (5 brachial artery injuries, 2 radial, 1 ulnar, 1 external iliac, 2 common femoral, 5 proximal superficial femoral, 2 distal superficial femoral, 4 popliteal, and 1 posterior tibial artery injury). A left posterior tibial artery occlusion was managed nonoperatively. There were 58 negative studies with clinical follow-up available in 100%, for a mean of 10.6 days ± 11.7 days (median, 6 days; range, 1-41 days). MDCTA was nondiagnostic in seven patients (9.6%), five secondary to artifact from retained missile fragments (3 shotgun and 2 gunshot wound), and two secondary to technical errors in reformatting. In the absence of artifact, MDCTA achieved 100% sensitivity and 100% specificity in detecting all clinically significant arterial injuries. CONCLUSIONS Physical examination is critical in the decision-making process for the injured extremity and can accurately reduce unnecessary imaging. If imaging is required, MDCTA is a sensitive and a specific noninvasive modality for arterial evaluation and may replace conventional angiography as the diagnostic modality of choice for the evaluation of the acutely injured extremity.

Evaluation of multidetector computed tomography for penetrating neck injury: A prospective multicenter study

BACKGROUND: The purpose of this prospective multicenter study was to evaluate a clinical protocol integrating multidetector computed tomographic angiography (MDCTA) as the initial screening examination for the work-up of penetrating neck injury. METHODS: All penetrating neck injuries assessed at two Level I trauma centers (January 2009-July 2011) prospectively underwent a structured clinical examination. Those with hard signs of injury (active bleed, instability, expanding/pulsatile hematoma, bruit/thrill, hemoptysis, hematemesis, and air bubbling) underwent exploration, those who were asymptomatic were observed. The remainder, with soft signs underwent MDCTA. Sensitivity and specificity were tested against an aggregate gold standard of operative intervention, clinical follow-up, and when obtained, conventional angiography, bronchoscopy, esophagogram, and esophagoscopy. RESULTS: Four hundred fifty-three penetrating neck injuries were evaluated. Hard signs of vascular or aerodigestive tract injury were observed in 8.6% with an 89.7% incidence of clinically significant injury. 41.7% had no signs of injury and were observed with no missed injuries (follow-up, 2.6 days ± 1.1 days [1–58 days]). The remaining 225 (49.7%) underwent MDCTA (stab wound, 61.3%; gunshot wound, 37.8%; shotgun, 0.9%). The external wounds were in zone II (38.2%), multiple (28.9%), zone I (16.9%), and zone III (16.0%). Twenty-eight injuries were found in 22 patients (5 internal jugular-V, 2 external jugular-V, 1 vertebral-A, 7 common carotid-A, 2 internal carotid-A, 3 external carotid-A, 2 subclavian-A, 3 esophagus, and 3 tracheas). Five patients had false-positive findings (2 vascular and 3 aerodigestive tract). The 194 negative studies (follow-up, 5.5 days ± 7.5 days [1–27 days]) had no delayed diagnosis of injury. MDCTA was nondiagnostic in four patients (1.8%), secondary to artifact. One of these had a vertebral-A injury diagnosed at angiography. MDCTA achieved 100% sensitivity and 97.5% specificity in detecting all clinically significant injuries. CONCLUSION: In the initial evaluation of patients who have sustained penetrating neck trauma, physical examination can safely reduce unnecessary imaging. If imaging is required, MDCTA is a highly sensitive and specific screening modality for evaluating the vascular and aerodigestive structures in the neck. LEVEL OF EVIDENCE: II, prospective study.

Radiologic Evaluation of Alternative Sites for Needle Decompression of Tension Pneumothorax

OBJECTIVE To compare the distance to be traversed during needle thoracostomy decompression performed at the second intercostal space (ICS) in the midclavicular line (MCL) with the fifth ICS in the anterior axillary line (AAL). DESIGN Patients were separated into body mass index (BMI) quartiles, with BMI calculated as weight in kilograms divided by height in meters squared. From each BMI quartile, 30 patients were randomly chosen for inclusion in the study on the basis of a priori power analysis (n = 120). Chest wall thickness on computed tomography at the second ICS in the MCL was compared with the fifth ICS in the AAL on both the right and left sides through all BMI quartiles. SETTING Level I trauma center. PATIENTS Injured patients aged 16 years or older evaluated from January 1, 2009, to January 1, 2010, undergoing computed tomography of the chest. RESULTS A total of 680 patients met the study inclusion criteria (81.5% were male and mean age was 41 years [range, 16-97 years]). Of the injuries sustained, 13.2% were penetrating, mean (SD) Injury Severity Score was 15.5 (10.3), and mean BMI was 27.9 (5.9) (range, 15.4-60.7). The mean difference in chest wall thickness between the second ICS at the MCL and the fifth ICS at the AAL was 12.9 mm (95% CI, 11.0-14.8; P < .001) on the right and 13.4 mm (95% CI, 11.4-15.3; P < .001) on the left. There was a stepwise increase in chest wall thickness across all BMI quartiles at each location of measurement. There was a significant difference in chest wall thickness between the second ICS at the MCL and the fifth ICS at the AAL in all quartiles on both the right and the left. The percentage of patients with chest wall thickness greater than the standard 5-cm decompression needle was 42.5% at the second ICS in the MCL and only 16.7% at the fifth ICS in the AAL. CONCLUSIONS In this computed tomography-based analysis of chest wall thickness, needle thoracostomy decompression would be expected to fail in 42.5% of cases at the second ICS in the MCL compared with 16.7% at the fifth ICS in the AAL. The chest wall thickness at the fifth ICS AAL was 1.3 cm thinner on average and may be a preferred location for needle thoracostomy decompression.

The increasing burden of radiation exposure in the management of trauma patients

BACKGROUND As trauma care evolves, there has been increased reliance on imaging. The purpose of this study was to examine changes in trauma imaging and radiation exposure over time. Our hypothesis was that there has been an increased usage of imaging in the management of trauma patients without measurable improvements in outcomes. METHODS A continuous series of injured patients admitted to a Level I trauma center during a 2-month period in 2002 was compared with the same period in 2007. All computed tomography (CT)s and plain radiographs performed for each patient were tabulated. Effective radiation dose estimates for each patient were then calculated. The outcome measures were length of stay, mortality, and missed injuries. RESULTS The 495 patients in 2007 and 497 patients in 2002 demonstrated no significant differences in demographics, clinical data, or outcomes between groups. However, from 2002 to 2007, for blunt trauma, the mean CTs per patient increased significantly (2.1 ± 1.6 vs. 3.2 ± 2.0, p < 0.001), as did plain radiographs (8.8 ± 12.9 vs. 14.9 ± 17.0, p < 0.001). For penetrating trauma, roentgenogram usage increased significantly (4.2 ± 5.3 vs. 9.1 ± 14.4, p = 0.01) with a trend toward increased CTs (0.7 ± 1.1 vs.1.0 ± 1.6, p = 0.11). Total radiation dose estimates demonstrated significantly increased radiation exposure in 2007; blunt (11.5 ± 11.3 mSv vs. 20.7 ± 14.9 mSv, p < 0.05) and penetrating (2.9 ± 4.9 mSv vs. 5.4 ± 7.9 mSv, p < 0.05). CONCLUSION From 2002 to 2007, there was a significant increase in the use of CT and plain radiographs in the management of trauma patients, leading to significantly higher radiation exposure with no demonstrable improvements in the diagnosis of missed injuries, mortality, or length of stay.

Clinical examination is insufficient to rule out thoracolumbar spine injuries.

PURPOSE The role of clinical examination in the diagnosis of thoracolumbar (TL) spine injuries is highly controversial. The aim of this study was to assess the sensitivity and specificity of a standardized clinical examination for diagnosing TL spine injuries after blunt trauma. METHODS This was a prospective observational study conducted at a level I trauma center from March 2008 to September 2008. After Institutional Review Board approval, all evaluable blunt trauma patients older than 15 years were evaluated by a senior resident or attending surgeon for TL spine deformity, tenderness to palpation, and neurologic deficits. Patients were followed through their hospital course to capture all TL spine injury diagnoses, all imaging performed, and any immobilization or stabilization procedures. RESULTS Of the 884 patients enrolled, 81 (9%) had a TL spine injury. More than half (55.6%) had two or more fractures with 30.9% having three or more. Isolated L-spine fractures occurred in 56.8%, T-spine fractures occurred in 34.6% only, and combination injuries sustained in 8.6%. The most commonly identified fractures were of the transverse process (67.9%) followed by the vertebral body (30.9%) and spinous process (12.3%). Among the 666 patients who were evaluable, 56 (8%) had a TL spine fracture. Of these, 29 (52%) had a negative clinical examination, of which 2 (7%) had clinically significant compression fractures. For evaluable patients who had localized pain or tenderness elicited on examination, although the finding triggered imaging appropriately, the site of pain correlated to the site of actual injury in only 61.5% of cases. The sensitivity and specificity of clinical examination for TL spine fractures were 48.2% and 84.9%, respectively, for all fractures and 78.6% and 83.4% for those that were clinically significant. CONCLUSION Clinical examination as a stand-alone screening tool for evaluation of the TL spine is inadequate. In this series, all the clinically significant missed fractures were diagnosed on computed tomography (CT) obtained for evaluation of the visceral torso. A combination of both clinical examination and CT screening based on mechanism will likely be required to ensure adequate sensitivity with an acceptable specificity for the diagnosis of clinically significant injuries of the TL spine. Further research is warranted, targeting the at-risk patient with a negative clinical examination, to determine what injury mechanisms warrant evaluation with a screening CT.

State of the art trends in imaging renal of colic

Radiology has a primary role in the work-up of renal colic, both to confirm urolithiasis and to help determine management. The traditional imaging has been conventional radiography and intravenous urogram with multidetector non-contrast-enhanced helical computed tomography (NCECT) now the modality of choice. Nuclear medicine studies for renal colic are done now infrequently at most institutions. Ultrasound (US) is often done, especially in the emergency department, and magnetic resonance imaging (MRI) is promising. Radiation dose reduction is now on everyone’s minds: Lower-dose CT techniques are being tested and used, and US and MR are considered as first modalities of choice in pregnant women and children.

Clinical Relevance of Magnetic Resonance Imaging in Cervical Spine Clearance: A Prospective Study

IMPORTANCE A missed cervical spine (CS) injury can have devastating consequences. When CS injuries cannot be ruled out clinically using the National Emergency X-Radiography Utilization Study low-risk criteria because of either a neurologic deficit or pain, the optimal imaging modality for CS clearance remains controversial. OBJECTIVE To investigate the accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) for CS clearance. DESIGN, SETTING, AND PARTICIPANTS A prospective observational study was conducted from January 1, 2010, through May 31, 2011, at a level I trauma center. Participants included 830 adults who were awake, alert, and able to be examined who experienced blunt trauma with resultant midline CS tenderness and/or neurologic deficits and were undergoing CT of the CS. Initial examinations, all CS imaging results, interventions, and final CS diagnoses were documented. The criterion standard for the sensitivity and specificity calculations was final diagnosis of CS injury at the time of discharge. MAIN OUTCOMES AND MEASURES Clinically significant CS injuries, defined as injuries requiring surgical stabilization or halo placement. RESULTS Overall, 164 CS injuries (19.8%) were diagnosed, and 23 of these (2.8%) were clinically significant. All clinically significant injuries were detected by CT. Fifteen of 681 patients (2.2%) with a normal CT scan had a newly identified finding on MRI; however, none of the injuries required surgical intervention or halo placement. There was no change in management on the basis of MRI findings. The sensitivity and specificity of CT for detecting CS injury was 90.9% and 100%, respectively. For clinically significant CS injuries, the sensitivity was 100% and specificity was 100%. CONCLUSIONS AND RELEVANCE Computed tomography is effective in the detection of clinically significant CS injuries in adults deemed eligible for evaluation who had a neurologic deficit or CS pain. Magnetic resonance imaging does not provide any additional clinically relevant information.

Prospective Evaluation of the Role of Computed Tomography in the Assessment of Abdominal Stab Wounds

IMPORTANCE An important adjunct in the management of abdominal gunshot wounds, the role of computed tomography (CT) in the diagnostic workup of abdominal stab wounds remains controversial. OBJECTIVE To prospectively compare CT against serial physical examination in the evaluation of patients who have sustained a stab wound to the abdomen. DESIGN, SETTING, AND PATIENTS Prospective single-center observational study of all patients sustaining abdominal stab wounds from March 1, 2009, through March 31, 2011. Patients who were hemodynamically unstable, unevaluable, peritonitic, or eviscerated proceeded directly to laparotomy (n = 249). The remainder underwent CT evaluation. The impact of CT findings and physical examination on the decision to operate was analyzed. MAIN OUTCOMES AND MEASURES Diagnostic accuracy of CT vs physical examination in determining the need for therapeutic laparotomy. RESULTS A total of 249 patients were enrolled (94% male; mean [SD]: age, 30.8 [12.9] years [range, 16-87 years]; systolic blood pressure, 128 [28] mm Hg; Glasgow Coma Scale score, 14 [2]; Injury Severity Score, 6.8 [6.5]). Forty-five patients (18.1%) underwent immediate laparotomy, 27 (10.8%) had superficial injuries allowing immediate discharge, and the remaining 177 (71.1%) underwent CT. Of these, 154 (87.0%) were successfully observed, with 20 (11.3%) requiring laparotomy, 2 (1.1%) thoracotomy, and 1 (0.6%) sternotomy. Of the 20 laparotomies, 16 (80.0%) were therapeutic. All patients who underwent therapeutic laparotomy did so based on their physical examination. The most common finding leading to laparotomy was the development of peritonitis in 70%. The CT scan findings did not alter clinical decision making. The sensitivity and specificity of physical examination were 100.0% and 98.7%, respectively, while those of CT were 31.3% and 84.2%, respectively. CONCLUSIONS AND RELEVANCE In this prospective evaluation of abdominal stab wound management, serial physical examination was able to discriminate between patients requiring a therapeutic laparotomy and those who could be safely observed. A physical examination-based diagnostic algorithm was effective and decreased radiation burden in the management of abdominal stab wounds.

Clinical examination is highly sensitive for detecting clinically significant spinal injuries after gunshot wounds.

BACKGROUND The optimal method for spinal evaluation after penetrating trauma is currently unknown. The goal of this study was to determine the sensitivity and specificity of a standardized clinical examination for the detection of spinal injuries after penetrating trauma. METHODS After Institutional Review Board approval, all evaluable penetrating trauma patients aged 15 years or more admitted to the Los Angeles County + University of Southern California Medical Center were prospectively evaluated for spinal pain, tenderness to palpation, deformity, and neurologic deficit. RESULTS During the 6-month study period, 282 patients were admitted after sustaining a penetrating injury; 143 (50.7%) as a result of gunshot wound (GSW) and 139 (49.3%) as a result of stab wound (SW). None of the patients sustaining a SW had a spinal injury. Of the 112 evaluable GSW patients, 9 sustained an injury: 6 with a true-positive and 3 with a false-negative clinical examination. The overall sensitivity, specificity, positive predictive value, and negative predictive value were 66.7%, 89.6%, 46.2% and 95.2%, respectively. For clinically significant injuries requiring surgical intervention, cervical or thoracolumbar spine orthosis, or cord transections, however, the sensitivity of clinical examination was 100.0%, specificity 87.5%, positive predictive value 30.8%, and negative predictive value 87.5%. CONCLUSION Clinically significant spinal injury, although rare after SWs, is not uncommon after GSWs. A structured clinical examination of the spine in evaluable patients who have sustained a GSW is highly reliable for identifying those with clinically significant injuries.

The utility of chest X-ray as a screening tool for blunt thoracic aortic injury☆

BACKGROUND The early and accurate identification of patients with blunt thoracic aortic injury (BTAI) remains a challenge. Traditionally, a portable AP chest X-ray (CXR) is utilized as the initial screening modality for BTAI, however, there is controversy surrounding its sensitivity. The purpose of this study was to assess the sensitivity of CXR as a screening modality for BTAI. METHODS After IRB approval, all adult (≥18 yo) blunt trauma patients admitted to LAC+USC (01/2011-12/2013) who underwent CXR and chest CT were retrospectively reviewed. Final radiology attending CXR readings were reviewed for mediastinal abnormalities (widened mediastinum, mediastinal to chest width ratio greater than 0.25, irregular aortic arch, blurred aortic contour, opacification of the aortopulmonary window, and apical pleural haematoma) suggestive of aortic injury. Chest CT final attending radiologist readings were utilized as the gold standard for diagnosis of BTAI. The primary outcome analyzed was CXR sensitivity. RESULTS A total of 3728 patients were included in the study. The majority of patients were male (72.6%); mean age was 43 (SD 20). Median ISS was 9 (IQR 4-17) and median GCS was 15 (IQR 14-15). The most common mechanism of injury was MVC (48.0%), followed by fall (20.6%), and AVP (16.9%). The total number of CXRs demonstrating a mediastinal abnormality was 200 (5.4%). Widened mediastinum was present on 191 (5.1%) of CXRs, blurred aortic contour on 10 (0.3%), and irregular aortic arch on 4 (0.1%). An acute aortic injury confirmed by chest CT was present in 17 (0.5%) patients. Only 7 of these with CT-confirmed BTAI had a mediastinal abnormality identified on CXR, for a sensitivity of 41% (95% CI: 19-67%). CONCLUSION The results from this study suggest that CXR alone is not a reliable screening modality for BTAI. A combination of screening CXR and careful consideration of other factors, such as mechanism of injury, will be required to effectively discriminate between those who should and should not undergo chest CT.