Sixty-Four Multi-Detector Row Computed Tomography in Multitrauma Patient Imaging: Early Experience

Selective Computed Tomography (CT) Imaging is Superior to Liberal CT Imaging in the Hemodynamically Normal Pediatric Blunt Trauma Patient

BACKGROUND

The optimal imaging strategy in hemodynamically stable pediatric blunt trauma remains to be defined. The purpose of this study was to determine the differences between selective and liberal computed tomography (CT) strategy in a pediatric trauma population with respect to radiation exposure and outcomes.

METHODS

We performed a retrospective analysis of hemodynamically stable blunt pediatric trauma patients (≤16 y) who were admitted to a Level I trauma center between 2013-2016. Patients were stratified into selective and liberal imaging cohorts. Univariate and multivariate regression analyses were used to compare outcomes between the groups. Outcomes included radiation dose, hospital and ICU length of stay, complications and mortality.

RESULTS

Of the 485 patients included, 176 underwent liberal and 309 selective CT imaging. The liberal cohort were more likely to be severely injured (ISS>15: 34.1 versus 8.4%, P< 0.001). The odds of exposure to a radiation dose of >15 mSv were higher with liberal scanning in patients with both ISS > 15 (OR 2.78, 95% CI 1.76-5.19, P< 0.001) and ISS ≤ 15 (OR 3.41, 95% CI 2.19-8.44, P < 0.001). Adjusted outcomes regarding mortality, ICU length of stay, and complications were similar between the cohorts.

CONCLUSION

Selective CT imaging in hemodynamically stable blunt pediatric trauma patients was associated with reduced radiation exposure and similar outcomes when compared to a liberal CT strategy.

Extended-FAST plus MDCT in pneumothorax diagnosis of major trauma: time to revisit ATLS imaging approach?

BACKGROUND AND OBJECTIVE

Pneumothorax (PNX) detection is of the utmost clinical relevance because it may quickly progress to cause hemodynamic instability as a consequence of invasive ventilation. Radiography is characterized by a low sensitivity to detect this disease; in recent years, chest ultrasound (US) has gained increased visibility in the diagnosis of acute respiratory emergencies including PNX. The aim of this retrospective study was to evaluate the clinical impact of extended focused assessment with sonography in trauma (E-FAST) during the past 6 years of experience with this technique in our Level I trauma center.

METHODS

Between January 2013 and December 2018, we performed a retrospective case-series study including 3320 consecutive patients admitted to the emergency department of our hospital because of major trauma. Extended-US was always performed and reported immediately after FAST during primary survey and before multidetector computed tomography (MDCT) scans. The presence of PNX was determined using the well-known accepted US criteria. US findings were compared with computed tomography (CT) findings, the reference standard for PNX detection.

RESULTS

Of the 6640 lungs observed with E-FAST, there were 1244 PNX cases, while 1328 PNX cases were detected either on the basis of MDCT or on the basis of the presence of air flush during the thoracic decompression in the emergency room. Among the 84 false negatives, 12 patients had subcutaneous emphysema, 38 had a body mass index higher than 27, 6 had a thoracic wall hematoma, and 4 had chest penetrating trauma. There were 10 false positives in the diagnosis of PNX at US examination, with mild extension and not clinically significant. The overall sensitivity of E-FAST for PNX detection was 93.6% (1244/1328), the specificity of E-FAST was 99.8% (5312/5322), the negative predictive value (NPV) was 98.4% (5312/5396), and the positive predictive value (PPV) was 99.2% (1328/1338).

CONCLUSION

Our results demonstrate that bedside thoracic US is characterized by a very good accuracy in the diagnostic work-up of major trauma patients, even in difficult conditions, allowing rapid diagnosis of PNX.

ADVANCES IN KNOWLEDGE

The novelty of this research lies in the possibility of diagnosing potential life-threatening conditions in a very short time by means of US, thus proposing a revision of the Advanced Trauma Life Support (ATLS) guidelines in order to incorporate it in the work-up of high-energy injured patients.

Clinical significance of computed tomography contrast extravasation in blunt trauma patients with a pelvic fracture

INTRODUCTION

Blunt pelvic fractures can be associated with major pelvic bleeding. The significance of contrast extravasation (CE) on computed tomography (CT) is debated. We sought to update our experience with CE on CT scan for the years 2009-2014 to determine the accuracy of CE in predicting the need for angioembolization.

METHODS

This is a retrospective review of the trauma registry and our electronic medical record from a Level I trauma center. Patients seen from July 1, 2009, to September 7, 2014, with blunt pelvic fractures and contrast-enhanced CT were included. Standard demographic, clinical, and injury data were obtained. Patient records were queried for CE, performance of angiography, and angioembolization. Positive patients were those where CE was associated with active bleeding requiring angioembolization. All other patients were considered negative.

RESULTS

There were 497 patients during the study time period with blunt pelvic fracture meeting inclusion criteria, and 75 patients (15%) had CE. Of those patients with CE, 30 patients (40%) underwent angiography, and 17 patients (23%) required angioembolization. The sensitivity, specificity, positive predictive value, and negative predictive value of CE on CT were 100%, 87.9%, 22.7%, and 100%, respectively. Two patients without CE underwent angiography but did not undergo embolization. Patients with CE had higher mortality (13 vs. 6%, p < 0.05) despite not having higher ISS scores.

CONCLUSIONS

This study reinforces that CE on CT pelvis with blunt trauma is common, but many patients will not require angioembolization. The negative predictive value of 100% should be reassuring to trauma surgeons such that if a modern CT scanner is used, and there is no CE seen on CT, then the pelvis will not be a source of hemorrhagic shock. All of these findings are likely due to both increased comfort with observing CEs and the increased sensitivity of modern CT scanners.

LEVEL OF EVIDENCE

Therapeutic/care management study, level IV.

Diagnostic Imaging in pediatric thoracic trauma

Thoracic trauma accounts for approximately 14% of blunt force traumatic deaths, second only to head injuries. Chest trauma can be blunt (90% of cases) or penetrating. In young patients, between 60 and 80% of chest injuries result from blunt trauma, with over half as a consequence of impact with motor vehicles, whereas in adolescents and adults, penetrating trauma has a statistically more prominent role. Pulmonary contusions and rib fractures are the most frequent injuries occurring. Chest X-ray is the first imaging modality of choice to identify patients presenting with life-threatening conditions (i.e., tension pneumothorax, huge hemothorax, and mediastinal hematoma) and those who require a CT examination. Multi-Slice Computed Tomography is the gold standard to evaluate chest injuries. In fact, the high spatial resolution, along with multiplanar reformation and three-dimensional (3D) reconstructions, makes MDCT the ideal imaging method to recognize several chest injuries such as rib fractures, pneumothorax, hemothorax, lung contusions and lacerations, diaphragmatic rupture, and aortic injuries. Nevertheless, when imaging a young patient, one should always keep into account the ALARA concept, to balance an appropriate and low-dose technique with imaging quality and to reduce the amount of ionizing radiation exposure. According to this concept, in the recent years, the current trends in pediatric imaging support the rising use of alternative imaging modalities, such as US and MRI, to decrease radiation exposure and to answer specific clinical questions and during the observation period also. As an example, ultrasound is the first technique of choice for the diagnosis and treatment of pleural and pericardial effusion; its emerging indications include the evaluation of pneumothoraces, costocondral and rib fractures, and even pulmonary contusions.

Hypotension does not always make computed tomography scans unfeasible in the management of blunt abdominal trauma patients

INTRODUCTION

Computed tomography (CT) scans have been used worldwide to evaluate patients with blunt abdominal trauma (BAT). However, CT scans have traditionally been considered to be a part of a secondary survey that can only be performed after the patient's haemodynamics have stabilised. In this study, we attempted to evaluate the role of the CT scan in managing BAT patients with hypotension.

MATERIAL AND METHODS

Patients who fulfilled the criteria for a major torso injury in our institution were treated according to the Advanced Trauma Life Support guidelines. The selection of diagnostic modalities for patients with stable and unstable haemodynamics was discussed. Furthermore, patients with hypotension after resuscitation who were administered haemostasis procedures were the focus of our analysis. We also delineated the influence of CT scans on the time interval between arrival and definitive treatment for these patients.

RESULTS

During the study period, 909 patients were enrolled in this study. Ninety-one patients (10.0%, 91/909) had a systolic blood pressure (SBP) <90mmHg after resuscitation. Fifty-eight of the patients (63.7%) received CT scans before they received definitive treatment. There was no significant difference in the CT scan application rate between the patients with and without hypotension after resuscitation (63.7% vs. 68.8%, p=0.382). Among the 79 patients with hypotension after resuscitation who underwent a haemostasis procedure (surgery or angioembolisation), there was no significant difference in the time between arrival and definitive haemostasis between the patients who received CT scans and those who did not (surgery: 57.8 (standard deviation (SD) 6.4) vs. 61.6 (SD 14.5)min, p=0.218; angioembolisation: [147.0 (SD 33.4) vs. 139.3 (SD 16.7)min, p=0.093).

CONCLUSION

The traditional priority of diagnostic modalities used to manage BAT patients should be reconsidered because of advancements in facilities and understanding of BAT. With shorter scanning times and transportation distances, hypotension does not always make performing a CT scan unfeasible.

Early computed tomography scanning in multisystem trauma: The evidence

The utility of computed tomography as a radiological investigation following multisystem trauma is already well established in current practice. This article examines the existing evidence and rationale behind the use of early computed tomography scanning in the management of the multisystem trauma patient, with a particular emphasis on the use of ‘whole body’ computed tomography scanning as a component of their initial management in the Emergency Department.

The use of computed tomography has been shown to be superior to plain radiography for the detection of injuries in important body regions including the spine, thorax, abdomen and pelvis. Computed tomography scan of the head and cervical spine is also well established as the first investigation of choice for significant traumatic brain injury. The potential benefits of whole body computed tomography include reduced time to diagnosis and intervention, as well as significant improvements in clinical outcome and survival. Concerns regarding a whole body computed tomography approach relate to the increased ionising radiation dosage that patients will be exposed to, and perceived risks of the secondary transfer and scanning room environment itself. Potential barriers to the use of whole body computed tomography are also explored and discussed.

This article also presents a proposed clinical algorithm derived from the results of a recent Delphi study into whole body computed tomography following blunt multitrauma, along with conclusions and recommendations from the subject matter panel review process.

Blunt polytrauma: evaluation with 64-section whole-body CT angiography

Blunt polytrauma remains a leading cause of death and disability worldwide. With the major advances in computed tomography (CT) technology over the past decade, whole-body CT is increasingly recognized as the emerging standard for providing rapid and accurate diagnoses within the narrow therapeutic window afforded to trauma victims with multiple severe injuries. With a single continuous acquisition, whole-body CT angiography is able to demonstrate all potentially injured organs, as well as vascular and bone structures, from the circle of Willis to the symphysis pubis. As its use becomes more widespread, the large volume of information inherent to whole-body CT poses new challenges to radiologists in providing efficient and timely interpretation. An awareness of trauma scoring systems and injury mechanisms is essential to maintain an appropriate level of suspicion in the search for multiple injuries, and the use of multiplanar reformation and three-dimensional postprocessing techniques is important to maximize efficiency in the search. Knowledge of the key injuries that require urgent surgical or percutaneous intervention, including major vascular injuries and active hemorrhage, diaphragmatic rupture, unstable spinal fractures, pancreatic injuries with ductal involvement, and injuries to the mesentery and hollow viscera, is also necessary.

Is contrast exposure safe among the highest risk trauma patients?

BACKGROUND

Despite improvements in the diagnosis and management of acute kidney injury (AKI), posttraumatic renal dysfunction continues to be associated with increased morbidity and mortality. Intravenous (IV) contrast is known to induce AKI in high-risk groups including the elderly and critically ill. We sought to determine whether IV contrast exposure among high-risk trauma patients resulted in renal dysfunction as defined by the Acute Kidney Injury Network criteria.

METHODS

We performed a 3-year retrospective analysis of all patients admitted to our Level I trauma center surgical intensive care unit for >48 hours. Patients with preexisting chronic renal dysfunction were excluded. We performed univariate and bivariate analyses to identify risk factors for AKI. Multivariable logistic regression analysis identified independent predictors for AKI. Subgroup analysis was undertaken among high-risk groups to include elderly patients (aged ≥65 years) with admission hypotension (systolic blood pressure <90 mm Hg) and an Injury Severity Score (ISS) ≥25.

RESULTS

Of the 6,317 patients, 571 (9.0%) patients met the inclusion criteria; 170 (29.8%) patients developed AKI. Age ≥65 years (odds ratio [OR] 2.26, 95% confidence interval [CI] = 1.06-4.80, p <0.034) and ISS ≥25 (OR 1.86, 95% CI = 1.12-3.07, p <0.015) were determined to be independent predictors of AKI. IV contrast was not identified to be a predictor of AKI. Upon subgroup analysis, IV contrast exposure was not a predictor of AKI among the elderly, hypotensive, or severely injured patients (ISS ≥25).

CONCLUSION

A complete trauma workup including studies requiring IV contrast exposure should be considered safe even among high-risk trauma patients.

The diagnostic accuracy of 64-slice computed tomography in detecting clinically significant arterial bleeding after pelvic fractures

The purpose of this study was to determine the diagnostic accuracy of the 64-slice multidetector computed tomography (MDCT) in detecting active pelvic arterial bleeding associated with blunt pelvic fractures. We hypothesized that this modality yields high accuracy. We conducted a retrospective review of all MDCT detected pelvic fractures over an 18-month period admitted to LAC+ USC Medical Center, a Level 1 trauma center. The main outcome was the presence of contrast extravasation (CE) on admission MDCT, consistent with clinically significant arterial bleeding requiring a subsequent embolization or intraoperative ligation of pelvic arteries. Overall, 127 patients met study criteria and 12 per cent (n = 15) had CE on admission MDCT of which four were managed conservatively. Eighty-two per cent (n = 9) of the remaining 11 patients who went on to have invasive procedure had active arterial bleeding that required embolization or surgical ligation. Two of the 112 (1.8%) patients without CE on their admission MDCT were subjected to embolization after further investigation with angiography as a result of the severity of their pelvic fracture and continuous transfusion requirements. The calculated sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of the 64-slice MDCT to identify clinically relevant arterial bleeding were 82, 95, 60, 98, and 94 per cent, respectively. The modern 64-slice MDCT provides relatively high diagnostic accuracy in detecting a clinically relevant arterial hemorrhage after blunt pelvic fracture. Nevertheless, in patients with clinical signs of ongoing hemorrhage, timely angiography or operative intervention is warranted, even in the absence of MDCT contrast extravasation.

A comparison of the diagnostic performances of visceral organ-targeted versus spine-targeted protocols for the evaluation of spinal fractures using sixteen-channel multidetector row computed tomography: is additional spine-targeted computed tomography necessary to evaluate thoracolumbar spinal fractures in blunt trauma victims?

BACKGROUND

It remains to be determined whether spine-targeted computed tomography (thoracolumbar spine computed tomography [TLS-CT]) images and visceral organ-targeted CT (abdominopelvic [AP]-CT) images are comparable for the evaluation of thoracolumbar spinal fractures using 16-channel multidetector row CT. The elimination of an additional spine-targeted CT protocol would substantially reduce time, the storage burden, and potential patient radiation exposure.

METHODS

A total of 420 vertebrae in 72 consecutive patients who underwent AP-CT to assess blunt traumatic injury and an additional CT examination using a TLS-CT protocol to evaluate spinal fractures were retrospectively evaluated. The AP-CT set (set A, reconstructed with using a wide display field of view [FOV] and a soft algorithm) and the TLS-CT set (set S, reconstructed using a narrow display FOV and a hard algorithm) were composed of axial plus reformatted sagittal or coronal images or both. Three radiologists independently reviewed all CT data retrospectively. Performances for detecting and typing fractures were compared by using areas under receiver operating characteristic curves and by determining concordance rates.

RESULTS

The overall areas under the curves for sets S and A for fracture detection were 0.996 and 0.995, respectively; no significant difference was found between the two sets. Concordance rates for typing performance also showed no statistical significance between the two sets for any of the three observers.

CONCLUSION

Sixteen-channel multidetector row CT images reconstructed using a soft algorithm and a wide display FOV that cover the entire abdomen using a visceral organ-targeted protocol with 1.5-mm collimation are sufficient for the evaluation of spine fractures in trauma patients, given that multiplanar-reformatted images are provided.

The diagnostic value of the sagittal multiplanar reconstruction CT images for nasal bone fractures

AIM

To compare the diagnostic performance of sagittal multiplanar reconstruction (MPR) images and axial images for the detection of a nasal bone fracture.

MATERIALS AND METHODS

This prospective study included 533 consecutive patients who underwent three-dimensional images with 64-section multidetector-row CT for the evaluation of a facial bone fracture between June 2007 and May 2008 (366 males; 167 females; mean age +/- standard deviation 31.1+/-21.2 years; age range 1-92 years). Two observers independently scored the possibility of a nasal bone fracture on axial and sagittal images. Receiver operating characteristic (ROC) curve analysis was performed.

RESULTS

The Az values of the sagittal images were higher than those of the axial images for both observers (p=0.002 and 0.010, respectively) with higher accuracy (p<0.001 and 0.016, respectively). The sensitivities of sagittal images were superior to those of axial images, especially for type 1simple nasal bone fractures with no or minimal displacement (observer 1, 98.6 versus 72.8%; observer 2, 84.9 versus 71%).

CONCLUSION

Sagittal MPR facial bone CT images provided superior diagnostic performance, and their addition to axial images is useful for the evaluation of nasal bone fractures.

Three-dimensional scanning with dual-source computed tomography in patients with acute skeletal trauma

OBJECTIVE

The aim of this study was to compare the efficiency of multiplanar reformatted images and three-dimensional images created after multidetector computed tomography examination in detecting acute posttraumatic osseous pathology of the skeletal system.

METHOD

Between October 2006 and December 2008, 105 patients with a history of acute trauma were referred to our service. Patients were evaluated with multidetector computed tomography using multiplanary reconstructed images initially (R-I), and six months after this initial evaluation, three-dimensional images were assessed of each patient (R-II). Axial images were used for guiding as a reference Data obtained was recorded and graded according to importance levels of the pathologies.

RESULTS

The R-II score was higher in the non-articular and highest in periartricular fractures of the extremities, and thoracic and pelvic cage injuries. For the spinal column, while R-I data was more significant In patients referred with polytrauma, R-II data, was more statistically significant, for short processing and adaptation time to acquiring immediate critical information. For all cases it was seen that three dimensional scans were more efficient in providing the orientation, within a short time.

CONCLUSION

By dual source multidedector tomography systems trauma patients may be evaluated by multiplanary and three dimensionally reconstructed images. When used correctly, three dimensional imaging is advantageous and can help determine the exact nature and extension and also importance of osseous injuries.

A prospective validation of a current practice: the detection of extremity vascular injury with CT angiography

INTRODUCTION

Arteriography is the current "gold standard" for the detection of extremity vascular injuries. Less invasive than operative exploration, conventional arteriography (CA) still has a 1% to 3% risk of morbidity and may delay definitive repair. Recent improvements in computed tomography (CT) technology has since broadened the application of CT to include the diagnosis of cervical, thoracic, and now extremity vascular injury. We hypothesized that CT angiography (CTA) provides equivalent injury detection compared with the more invasive CA, but is more rapidly completed and more cost effective.

METHODS

A prospective evaluation of patients, ages 18 to 50, with potential extremity vascular injuries was performed during 2006-2007. Ankle-brachial indices (ABI) of injured extremities were measured on presentation in all patients without hard signs of vascular injury. Patients whose injured extremity ABI was <0.9 were enrolled and underwent CTA followed by either CA or operative exploration if CTA findings were limb threatening. Interventionalists were blinded to CTA findings before performing and reading CAs.

RESULTS

Twenty-one patients (mean age, 26.1 +/- 7.1 years) had 22 extremity CTAs after gunshot (82%), stab (9%), or pedestrian struck by automobile (9%) injuries to either upper (32%) or lower (68%) extremities. Eleven of 22 (50%) extremities had associated orthopedic injuries while the mean ABI of the study population was 0.72 +/- 0.21. Twenty-one of 22 (96%) CTAs were diagnostic and all CTAs were confirmed by either CA alone (n = 18), operative exploration (n = 2), or both CA and operative exploration (n = 2). Diagnostic CTAs had 100% sensitivity and specificity for clinically relevant vascular injury detection. Unlike rapidly obtained CTA, CA required 131 +/- 61 minutes (mean +/- SD) to complete. In our center, CTA saves $12,922 in patient charges and $1,166 in hospital costs per extremity when compared with CA.

CONCLUSIONS

With acceptable injury detection, rapid availability, and a favorable cost profile, our results suggest that CTA may replace CA as the diagnostic study of choice for vascular injuries of the extremities.

Initial clinical experience with a 64-MDCT whole-body scanner in an emergency department: better time management and diagnostic quality?

BACKGROUND

The objective of this study was to assess time management and diagnostic quality when using a 64-multidetector-row computed tomography (MDCT) whole-body scanner to evaluate polytraumatized patients in an emergency department.

METHODS

Eighty-eight consecutive polytraumatized patients with injury severity score (ISS) > or = 18 (mean ISS = 29) were included in this study. Documented and evaluated data were crash history, trauma mechanism, number and pattern of injuries, injury severity, diagnostics, time flow, and missed diagnoses. Data were stored in our hospital information system. Seven time intervals were evaluated. In particular, attention was paid to the "acquisition interval," the "reformatting and evaluation time" as well as the "CT time" (time from CT start to preliminary diagnosis). A standardized whole-body CT was performed. The acquired CT data together with automatically generated multiplanar reformatted images ("direct MPR") were transferred to a 3D rendering workstation. Diagnostic quality was determined on the basis of missed diagnoses. Head-to-toe scout images were possible because volume coverage was up to 2 m. Experienced radiologists at an affiliated workstation performed radiologic evaluation of the acquired datasets immediately after acquisition.

RESULTS

The "acquisition interval" was 12 minutes +/- 4.9 minutes, the "reformatting and evaluation interval" 7.0 minutes +/- 2.1 minutes, and the "CT time" 19 minutes +/- 6.1 minutes. Altogether, 7 of 486 lesions were recognized but not communicated in the "reformatting and evaluation interval", and 10 injuries were initially missed and detected during follow-up.

CONCLUSION

This study indicates that 64-MDCT saves time, especially in the "reformatting and evaluation interval." Diagnostic quality is high, as reflected by the small number of missed diagnoses.

Is chest x-ray an adequate screening tool for the diagnosis of blunt thoracic aortic injury?

BACKGROUND

Blunt thoracic aortic injuries (BTAI) have a high mortality rate. For survivors, chest X-ray (CXR) findings are used to determine the need for further diagnostic testing with chest computerized tomography with angiography (CTA) or conventional angiography. We set to determine the adequacy of utilizing CXR alone as a screening tool for BTAI.

METHODS

All patients diagnosed with BTAI at a level I trauma-center during a 7-year-period were identified. CXRs of these patients and those of a control group of blunt trauma patients with an injury severity score >15 were reviewed by four trauma surgeons blinded to the diagnosis. Based on each CXR viewed, the surgeons decided if they would have proceeded to chest CTA, angiography, or required no further studies to rule out BTAI.

RESULTS

In the 7-year-period, 83 patients had BTAI. CXRs were available in 45 patients. The four surgeons viewed 96 CXRs including those of 51 controls. Based on the CXR appearance in patients with BTAI, the surgeons chose to proceed to chest CTA in 38 patients (84.4%), conventional aortography in two patients (4.4%), and no further testing in five patients (11.2%). A widened mediastinum (75%) and loss of the aorto-pulmonary window (40%) were the most frequent CXR abnormalities. Patients with BTAI were more likely to have an abnormal CXR-40 of 45 (88.8%) patients when compared with the controls-25 of 51 (49%)patients-p < 0.001.

CONCLUSIONS

Although CXR is a sensitive screening modality, it failed to identify the possibility of BTAI in 11% of patients. The liberal use of chest CTA after high speed motor vehicle crashes is recommended to minimize the incidence of missed BTAI.

Blunt splenic trauma: delayed-phase CT for differentiation of active hemorrhage from contained vascular injury in patients

PURPOSE

To retrospectively evaluate delayed-phase computed tomography (CT) in the differentiation of active splenic hemorrhage requiring emergent treatment from contained vascular injuries (pseudoaneurysms or arteriovenous fistulas) that can be treated electively or managed conservatively.

MATERIALS AND METHODS

The institutional review board approved this HIPAA-compliant retrospective study; the informed consent requirement was waived. Forty-seven patients with blunt splenic injury diagnosed at CT after blunt abdominal trauma were evaluated. Abdominal and pelvic dual-phase CT was performed; images were obtained 60-70 seconds and 5 minutes after contrast material injection. Scans were reviewed in consensus by two radiologists. Splenic injuries were graded with the American Association for the Surgery of Trauma Splenic Injury Scale. Patients with intrasplenic hyperattenuating foci on portal venous phase images were classified as having active splenic hemorrhage (group 1) or a contained vascular injury (group 2) on the basis of delayed-phase imaging findings. Findings suggestive of active hemorrhage included areas that remained hyperattenuating or increased in size on delayed-phase images. The clinical outcome of these patients was determined by reviewing their medical records. Relationships between several factors were tested with the Fisher exact test, including (a) the presence or absence of hyperattenuating foci and management and (b) the presence of contained vascular injury or active extravasation and management.

RESULTS

Portal venous phase CT revealed a focal high-attenuation parenchymal contrast material collection in 19 patients: nine patients were classified as group 1 and 10 were classified as group 2. All patients in group 1 underwent emergent splenectomy, and all patients in group 2 were initially treated without surgery. Significant differences in management were noted on the basis of whether hyperattenuating foci were seen on portal venous phase images (P < .001) and whether hyperattenuating foci seen at portal venous phase imaging were further characterized as active splenic hemorrhage or a contained vascular injury at delayed-phase CT (P < .001).

CONCLUSION

In blunt splenic injury, delayed-phase CT helps differentiate patients with active splenic hemorrhage from those with contained vascular injuries.

CT Angiography of Extremity Trauma

With the advent of multi-detector computed tomography, CT angiography (CTA) has rapidly become the first line imaging modality for detecting extremity arterial injuries in blunt and penetrating trauma patients. A variety of significant injuries are detected with high sensitivity and specificity. The information provided by CTAs in this patient population is often sufficient for making therapeutic decisions, such as the need for and type of surgical or endovascular interventions. Technological advances have allowed for isotropic imaging and improved quality of multi-planar and three-dimensional reformations, which aid in diagnosis and surgical planning. The rapid acquisition speed of 64 multi-detector CT scanners has facilitated integration of CTA into routine trauma CT imaging using a single contrast bolus injection.