Pelvic CT angiography: application to blunt trauma using 64MDCT

The evolution of multi-row detector computed tomography (MDCT) technology has resulted in evolving applications of CT angiography (CTA) in the trauma setting. In patients with significant blunt pelvic injuries, the immediate diagnosis and characterization of vascular injuries is of significant import given their morbidity and mortality in this patient population. The application of MDCT technology, specifically 64MDCT, to pelvic CTA is useful in evaluating for potential vascular injuries and may be integrated into admission trauma imaging in order to triage patients with blunt pelvic trauma to appropriate emergent intervention. This paper will discuss the use of pelvic CTA in blunt pelvic trauma and its utility in detecting and characterizing vascular injury, including the differentiation of arterial from venous hemorrhage. Protocol considerations in pelvic CTA using 64MDCT technology will be detailed as well as the integration of pelvic CTA into torso CT trauma protocols.     

The cost-effectiveness of routine pelvic radiography in the evaluation of blunt trauma patients

Objective. To determine the cost-effectiveness of routine protocol-driven pelvic radiography in the evaluation of blunt trauma patients. Design and patients. A retrospective review was performed on 319 blunt trauma patients who underwent protocol-driven pelvic radiography to record the frequency of pelvic fracture. Medical records of the patients in whom fractures were identified radiographically were then examined to determine the clinical suspicion of injury prior to radiography. Using Medicare reimbursement data, the cost-effectiveness of routine pelvic radiography was calculated in terms cost per pelvic radiograph with evidence of fracture. These values were then compared with literature values of other screening studies, namely mammography and colonoscopy. Results. Thirty-eight of 319 patients (11.9%) were found to have fractures identified on routine pelvic radiography. Using the 1997 Medicare reimbursement charge of $27.79 for a single anteroposterior radiograph of the pelvis, the total cost of performing these 319 trauma protocol-driven studies was calculated as $8865.01. The cost per protocol-driven pelvic radiograph with evidence of pelvic fracture was subsequently determined to be $233.29. Only 18 (47.4%) of these 38 patients were suspected to have pelvic fracture on the basis of the clinical findings alone. Conclusions. Trauma protocol-driven pelvic radiography is a necessary and cost-effective means of identifying acute pelvic injury in all trauma patients regardless of clinical presentation. Received: 20 April 1998 Revision requested: 2 June 1998 Revision received: 3 February 1999 Accepted: 22 February 1999     

MDCT of renal trauma: correlation to AAST organ injury scale

Renal injuries affect 8–10% of patients presenting with blunt abdominal trauma. Imaging with multidetector computed tomography (MDCT) is the preferred modality at most trauma centers. Renal injuries have been categorized by several grading schemes in the literature. The classification proposed by the American Association for the Surgery of Trauma (AAST) predicts clinical outcome with reasonable accuracy. Although the AAST classification for renal injury is primarily based on findings during surgery, it has a strong correlation with MDCT findings.     

Blunt pancreatic trauma: evaluation with MDCT technology

The purpose of this paper is to determine the relative frequency of multi-detector CT (MDCT) findings of pancreatic injury in blunt trauma and to determine their diagnostic accuracy in predicting main pancreatic duct injury. Fifty-three patients (31 male, 22 female; mean 44.1 years) with blunt trauma and admission MDCT findings suspicious for pancreatic injury or who underwent MDCT and had a discharge diagnosis of pancreatic trauma were included in this study. Two radiologists reviewed all images and recorded findings suspicious for pancreatic injury, which were subsequently compared to surgical findings to generate diagnostic accuracy. MDCT imaging findings suggestive of pancreatic injury included low attenuation peripancreatic fluid (n?=?51), hyperattenuating peripancreatic fluid (n?=?13), pancreatic contusion (n?=?7), active hemorrhage (n?=?2), and pancreatic laceration (n?=?16). Diagnostic accuracy of the various imaging findings varied for diagnosing main duct injury; there were highly sensitive, nonspecific imaging findings such as the presence of low attenuation peripancreatic fluid (sensitivity, 100 %; specificity 4.9 %) as well as insensitive, specific findings such as visualizing a pancreatic laceration involving >50 % of the parenchymal width (sensitivity, 50 %; specificity, 95.1 %). In the setting of blunt abdominal trauma, MDCT imaging findings can be grouped into two categories for determining integrity of the main pancreatic duct: indirect, highly sensitive but nonspecific findings and direct, specific but insensitive findings. Awareness of the clinical implications of the various MDCT imaging findings of pancreatic trauma is useful in interpreting their significance.     

Role of multidetector-row CT in assessing the source of arterial haemorrhage in patients with pelvic vascular trauma. Comparison with angiography

Purpose

We investigated the role of multidetector-row computed tomography (MDCT) in identifying active bleeding and its source in polytrauma patients with pelvic vascular injuries with or without associated fractures of the pelvis.

Materials and methods

From January 2003 to December 2007, 28 patients (19 men and nine women, age range 16–80 years) with acute symptoms from blunt pelvic trauma and a drop in haematocrit underwent MDCT and angiography. Conventional radiography of the pelvis was performed in all patients at the time of admission to the emergency department. MDCT was performed with a four-row unit in 15 patients and a 16-row unit in the remaining 13 patients. The study included whole-body CT to identify craniocerebral, vertebral, thoracic, abdominal and pelvic injuries. CT was performed before and after rapid infusion (4–5 ml/s) of intravenous contrast material (120 ml) using a power injector. A triphasic contrast-enhanced study was performed in all patients. MDCT images were transferred to a workstation to assess pelvic fracture, site of haematoma and active extravasation of contrast material, visibility of possible vascular injuries and associated traumatic lesions. At angiography, an abdominal and pelvic aortogram was obtained in all cases before selective catheterisation of the internal iliac arteries and superselective catheterisation of their branches for embolisation purposes. Results related to identifying the source of bleeding at MDCT were compared with sites of bleeding or vascular injury identified by selective pelvic angiography. The sensitivity and positive predictive value (PPV) of MDCT were determined.

Results

MDCT allowed us to identify pelvic bleeding in 21/28 patients (75%), with most cases being detected in the delayed contrast-enhanced phase (13/21 cases, 61.9%). Injured arteries were identified on MDCT in 12/21 cases (57%): the obturator artery (n=9), internal iliac artery (n=6), internal pudendal artery (n=6) and superior gluteal artery (n=5) were most frequently injured. In 8/21 patients (28.6%), more than one artery was injured. Among the 12 patients in whom MDCT showed the presence of pelvic haemorrhage, there was agreement between MDCT and angiography in ten cases. Angiography confirmed the site of bleeding detected on MDCT and identified a second arterial haemorrhage in one patient. There was no agreement between MDCT and angiography in the last patient. MDCT showed a sensitivity of 42.85% and a PPV of 100% in identifying the injured arteries.

Conclusions

Arterial haemorrhage is one of the most serious problems associated with pelvic fracture, and it remains the leading cause of death attributable to such fractures. MDCT provides diagnostic information regarding the presence of small pelvic fractures and, thanks to the contrast-enhanced angiographic technique, it is capable of identifying pelvic bleeding, with the demonstration in some cases of it source. The presence of contrast material extravasation is an indicator of injury to a specific artery passing through the region of the pelvis where the extravasation is noted on MDCT. Urgent angiography and subsequent transcatheter embolisation are the most effective methods for controlling ongoing arterial bleeding in pelvic injuries.     

Multidetector computed tomography and blunt thoracoabdominal trauma

Computed tomography has had an increasing role in the evaluation of patients after blunt trauma. Important findings in thoracic trauma include acute traumatic aortic injury, pneumothorax, hemothorax, pulmonary contusions and lacerations, mediastinal hematoma, and diaphragmatic rupture. The solid abdominal viscera may lacerate; infarct; or suffer vascular, ductal, or pyelocalyceal disruption. The bladder and intestines may rupture. In abdominal pelvic trauma, the direction of applied force often results in an identifiable constellation of injuries. This article reviews how multidetector computed tomography (MDCT) is used in the trauma patient. Technical advances of increased cephalocaudad coverage speed and improved z-axis resolution intrinsic to MDCT, together with effective contrast utilization, make MDCT invaluable in the setting of trauma.     

Low-dose MDCT findings of blunt hepatobiliary trauma

This pictorial essay shows low-dose multi-detector computed tomography (MDCT) findings of blunt hepatobiliary trauma, and describes the indications and protocol for MDCT. Given the universal usage of MDCT in assessing the liver in blunt abdominal trauma, reduction of patient dose is essential. The new l0se MDCT protocol presented here can achieve up to 50% dose reduction while maintaining diagnostic image quality and thus facilitate dose sensitive patient management. Our institution’s blunt hepatobiliary MDCT imaging algorithm can help determine which patients require operative therapy. Injury to the liver is graded on various schemes, one being the Organ Injury Scale devised by the American Association for the Surgery of Trauma classification based on the extension of the lesion and bleeding.     

External validation of the Ottawa knee rules in an urban trauma center in the United States

OBJECTIVE: We evaluated the Ottawa knee rules in a high-volume teaching hospital in the United States to determine whether the rules could be safely used to decide whether patients with acute blunt knee trauma should undergo radiography. SUBJECTS AND METHODS: During a 13-month period, 378 patients with acute blunt knee trauma were prospectively examined using the Ottawa knee rules. Data collected included the presence or absence of fracture predictors and the results of radiography. RESULTS: A fracture was seen in 43 (11%) of the 378 patients who met inclusion criteria. The knee rules predicted 42 of the 43 fractures; sensitivity was 98%, and specificity was 19%. Radiography of 65 patients (17%) who had no predictors for fracture could have been avoided if the knee rules had been used to screen for radiography. CONCLUSION: The Ottawa knee rules are highly sensitive for fracture in this setting and may safely be used to decide whether patients with acute blunt knee trauma should undergo radiography.     

Imaging in spinal trauma

Because it may cause paralysis, injury to the spine is one of the most feared traumas, and spinal cord injury is a major cause of disability. In the USA approximately 10,000 traumatic cervical spine fractures and 4000 traumatic thoracolumbar fractures are diagnosed each year. Although the number of individuals sustaining paralysis is far less than those with moderate or severe brain injury, the socioeconomic costs are significant. Since most of the spinal trauma patients survive their injuries, almost one out of 1000 inhabitants in the USA are currently being cared for partial or complete paralysis. Little controversy exists regarding the need for accurate and emergent imaging assessment of the traumatized spine in order to evaluate spinal stability and integrity of neural elements. Because clinicians fear missing occult spine injuries, they obtain radiographs for nearly all patients who present with blunt trauma. We are influenced on one side by fear of litigation and the possible devastating medical, psychologic and financial consequences of cervical spine injury, and on the other side by pressure to reduce health care costs. A set of clinical and/or anamnestic criteria, however, can be very useful in identifying patients who have an extremely low probability of injury and who consequently have no need for imaging studies. Multidetector (or multislice) computed tomography (MDCT) is the preferred primary imaging modality in blunt spinal trauma patients who do need imaging. Not only is CT more accurate in diagnosing spinal injury, it also reduces imaging time and patient manipulation. Evidence-based research has established that MDCT improves patient outcome and saves money in comparison to plain film. This review discusses the use, advantages and disadvantages of the different imaging techniques used in spinal trauma patients and the criteria used in selecting patients who do not need imaging. Finally an overview of different types of spinal injuries is given.     

Multi-detector row computed tomography and blunt chest trauma

Blunt chest trauma is a significant source of morbidity and mortality in industrialized countries. The clinical presentation of trauma patients varies widely from one individual to another and ranges from minor reports of pain to shock. Knowledge of the mechanism of injury, the time of injury, estimates of motor vehicle accident velocity and deceleration, and evidence of associated injury to other systems are all salient features to provide for an adequate assessment of chest trauma. Multi-detector row computed tomography (MDCT) scanning and MDCT-angiography are being used more frequently in the diagnosis of patients with chest trauma. The high sensitivity of MDCT has increased the recognized spectrum of injuries. This new technology can be regarded as an extremely valuable adjunct to physical examination to recognize suspected and unsuspected blunt chest trauma.     

Chest wall, lung, and pleural space trauma

Chest radiographs frequently underestimate the severity and extent of chest trauma and, in some cases, fail to detect the presence of injury. CT is more sensitive than chest radiography in the detection of pulmonary, pleural, and osseous abnormalities in the patient who has chest trauma. With the advent of multidetector CT (MDCT), high-quality multiplanar reformations are obtained easily and add to the diagnostic capabilities of MDCT. This article reviews the radiographic and CT findings of chest wall, pleural, and pulmonary injuries that are seen in the patient who has experienced blunt thoracic trauma.     

Severe pelvic injury: vascular lesions detected by ante- and post-mortem contrast medium-enhanced CT and associations with pelvic fractures

Objectives

The objectives of this study were to compare arterial and venous contrast medium extravasation in severe pelvic injury detected by ante- and post-mortem multi-detector CT (MDCT) and determine whether vascular injury is associated with certain types of pelvic fracture.

Methods

We retrospectively included two different cohorts of blunt pelvic trauma with contrast medium extravasation shown by MDCT. The first group comprised 49 polytrauma patients; the second included 45 dead bodies undergoing multi-phase post-mortem CT-angiography (MPMCTA). Two radiologists jointly reviewed each examination concerning type, site of bleeding and pattern of underlying pelvic ring fracture.

Results

All 49 polytrauma patients demonstrated arterial bleeding, immediately undergoing subsequent angiography; 42 (85%) had pelvic fractures, but no venous bleeding was disclosed. MPMCTA of 45 bodies revealed arterial (n = 33, 73%) and venous (n = 35, 78%) bleeding and pelvic fractures (n = 41, 91%). Pelvic fracture locations were significantly correlated with ten arterial and six venous bleeding sites in dead bodies, with five arterial bleeding sites in polytrauma patients.

In dead bodies, arterial haemorrhage was significantly correlated with the severity of pelvic fracture according to Tile classification (p = 0.01), unlike venous bleeding (p = 0.34).

Conclusions

In severe pelvic injury, certain acute bleeding sites were significantly correlated with underlying pelvic fracture locations. MPMCTA revealed more venous lesions than MDCT in polytrauma patients. Future investigations should evaluate the proportional contribution of venous bleeding to overall pelvic haemorrhage as well as its clinical significance.

     

Urinary tract injury in patients with blunt chest trauma: The value of postaortographic abdominal radiographs

Patients who require thoracic aortography for blunt decelerating chest trauma often sustain injury to other organ systems due to the magnitude and mechanism of injury. Hospital records and radiographs of 117 consecutive, injured patients studied with thoracic aortography were evaluated to assess the accuracy, value, and limitations of postaortographic abdominal plain radiography for detection of major genitourinary injury. In summary, major urinary tract injury occurred with a frequency of 6%, enough to justify a rapid, low cost, noninvasive screening procedure. Postaortographic plain films of the abdomen were found to be an accurate (95%) screen for detection of major urinary tract injury. The sensitivity for detection of patients with renal injury was 100%. The ability to correctly predict patients who may be safely observed (no significant renal injury) was 100%. One limitation of this technique was the poor diagnostic quality found in 15% of the abdominal radiographs, most commonly caused by excessive superimposed bowel gas. Postaortographic pelvic radiographs were believed to be valuable for detection, but not exclusion, of bladder rupture.     

Multi-detector computed tomography imaging of blunt chest trauma

Background and purpose

Chest trauma is a significant cause of mortality and morbidity, especially in the younger population. The purpose of this study was to evaluate the role of multi-detector computed tomography (MDCT) in the assessment of patients with blunt chest trauma.

Patients and methods

A prospective study was conducted on thirty (30) patients with blunt chest trauma (21 males and 9 females, aged from 6 to 62 years) and 29 control patients presented with any trauma other than blunt chest trauma (23 males and 6 females, aged from 10 to 68 years) at the Emergency Department, Tanta University Hospital, from January 2013 to February 2014. Cases were subjected to clinical evaluation and radiological assessment of the chest using conventional chest X-ray (CXR) and multi-detector computed tomography.

Results

The most common mode of injury was motor vehicle accidents (56.7%). On MDCT scan, the frequency of chest injuries were; chest wall injuries (86.7%), pleural injuries (80%), parenchymal injuries (56.7%), mediastinal injuries (30%) and finally the dorsal spine injuries (16.7%). MDCT is more sensitive, specific, and accurate than CXR in the assessment of blunt chest trauma and management of patients.

Conclusion

MDCT is the modality of choice for rapid assessment of emergency chest trauma patients, when chest X-ray was inconclusive.     

Fractures of the thoracic spine in patients with minor trauma: Comparison of diagnostic accuracy and dose of biplane radiography and MDCT

Objectives

To investigate the accuracy of biplane radiography in the detection of fractures of the thoracic spine in patients with minor trauma using multidetector computed tomography (MDCT) as the reference and to compare the dose of both techniques.

Methods

107 consecutive trauma patients with suspected fractures of the thoracic spine on physical examination were included. All had undergone biplane radiography first, followed by a MDCT scan between October 2008 and October 2012. A fourfold table was used for the classification of the screening test results. Both the Chi-square test (χ²) and the mean dose-length product (DLP) were used to compare the diagnostic methods.

Results

MDCT revealed 77 fractures in 65/107 patients (60.7%). Biplane radiography was true positive in 32/107 patients (29.9%), false positive in 19/107 patients (17.8%), true negative in 23/107 (21.5%) and false negative in 33/107 patients (30.8%), showing a sensitivity of 49.2%, a specificity of 54.7%, a positive predictive value (PPV) of 62.7%, a negative predictive value (NPV) of 41.1%, and an accuracy of 51.4%. The presence of a fracture on biplane radiography was highly statistical significant, if this was simultaneously proven by MDCT (χ² = 7.6; p = 0.01). None of the fractures missed on biplane radiography was unstable. The mean DLP on biplane radiography was 14.5 mGy cm (range 1.9–97.8) and on MDCT 374.6 mGy cm (range 80.2–871).

Conclusions

The sensitivity and the specificity of biplane radiography in the diagnosis of fractures of the thoracic spine in patients with minor trauma are low. Considering the wide availability of MDCT that is usually necessary for taking significant therapeutic steps, the indication for biplane radiography should be very restrictive.     

Ankle and foot injuries: analysis of MDCT findings

OBJECTIVE: The purpose of our study was to assess MDCT findings and the advantages of MDCT compared with radiography in patients referred to a level 1 trauma center for diagnostic evaluation of acute ankle and foot trauma. MATERIALS AND METHODS: During a period of 37 months, 388 patients underwent MDCT of the ankle and foot due to an acute trauma. Imaging studies (MDCT and radiography) were retrospectively reevaluated with respect to fracture location, fracture type, and mechanism of injury, and findings from the primary radiographs of the ankle and foot were compared with MDCT findings. RESULTS: Of the 388 patients, 344 (89%) had one or more fractures in the ankle or foot. A total of 517 fractures were found in all anatomic regions: ankle, calcaneus, talus, midfoot, and forefoot. The three most common occult fractures in the ankle not detected on primary radiography were isolated fractures of the posterior and medial malleolus and Tillaux fractures. The calcaneus was the most commonly fractured bone, and the sensitivity of radiography in the detection of calcaneal fractures was 87%. The sensitivity of radiography in the detection of talar fractures was 78%, whereas it was only 25-33% in the detection of midfoot fractures. A Lisfranc fracture-dislocation was not detected on primary radiography in five (24%) of 21 cases. The three main injury mechanisms were falling from a height (164 patients [48%]), a simple fall (68 patients [20%]), and a traffic accident (47 patients [14%]). CONCLUSION: In patients with injuries from high-energy polytrauma and in those with complex ankle and foot fractures, the sensitivity of radiography is only moderate to poor; in these cases, MDCT is recommended as the primary imaging technique.     

Lung parenchymal injury and its frequency in blunt thoracic trauma: the diagnostic value of chest radiography and thoracic CT

PURPOSE: The aims of this study were to determine the value of chest radiography in diagnosing lung parenchymal injury in patients with thoracic trauma, and to evaluate the frequency of lung parenchymal injury by using thoracic computed tomography (CT). MATERIALS AND METHODS: Between January 2005 and June 2006, we retrospectively evaluated the anteroposterior chest radiographs and thoracic CTs of 60 patients that presented to our emergency department and were hospitalized due to multi-organ trauma. RESULTS: Chest radiography revealed parenchymal injury in 32 of the patients, while thoracic CT confirmed parenchymal injury in only 27 of these 32 patients. Chest radiographs did not reveal any parenchymal injury in 28 of the patients, whereas thoracic CT detected parenchymal injury in 12 of these 28 patients. Thoracic CT results were accepted as the gold standard in the evaluation of patients with chest trauma and showed that the sensitivity, specificity, positive predictive value, and negative predictive value of chest radiography in determining parenchymal injury were 69%, 76%, 84%, and 57%, respectively. In addition, thoracic CT revealed that 65% of the patients with blunt thoracic trauma suffered parenchymal injury. CONCLUSION: The sensitivity of anteroposterior chest radiography in identifying lung parenchymal injury was low, with a high false negative rate; therefore, we think that early evaluation with thoracic CT is extremely helpful in the diagnosis and treatment of patients with thoracic trauma, adding to the cooperative work that exists between radiologists and emergency physicians.     

Sternal fracture in the emergency department: diagnostic value of multidetector CT with sagittal and coronal reconstruction images

Background

Multidetector CT (MDCT) is being increasingly used for patients with traumatic injuries in the emergency room. This is the first study to evaluate the diagnostic performance of MDCT for sternal fracture.

Patients and methods

For 87 patients who had motor vehicle accidents, we evaluated the diagnostic performance of MDCT for the sternal fractures. For 31 patients who underwent both MDCT and lateral radiography for the sternum, we compared the diagnostic performance of two examinations for the evaluation of sternal fracture.

Results

Thirty-two patients had sternal fractures and all the sternal fractures (sensitivity = 100%) were detected on MDCT, especially on the sagittal reconstruction images. However, the axial and coronal images detected 65% and 59% of all sternal fractures, respectively. For 31 patients who underwent both MDCT and lateral radiography for the sternum, MDCT showed superior diagnostic performance compared to that of radiography (accuracy = 97% and 77%, respectively, P = .02). For the one case that showed false positivity for sternal fracture on MDCT due to respiratory artifact, the lateral radiography enabled making the correct diagnosis.

Conclusion

Sternal fracture is frequently seen in patients who have blunt trauma injury secondary to motor vehicle accidents. MDCT, particularly sagittal images detect all of the sternal fractures, is superior to lateral radiography for diagnosis of sternal fracture. In the limited case that CT has severe motion artifact, additional radiography could help the diagnosis of sternal fracture.     

Occult and secondary injuries missed by plain radiography of the cervical spine in blunt trauma patients

Background: Plain radiography does not visualize every cervical spine injury sustained by blunt trauma victims. The purpose of this study was to examine the prevalence and types of injuries missed by plain radiographs of the cervical spine and determine how frequently such radiography fails to detect any cervical spine injury. Methods: Images from all radiographic studies performed on blunt trauma victims presenting to 21 participating institutions were reviewed to compile an exhaustive list of all CSIs sustained by each individual. These injuries were then compared with the injuries detected by plain radiography alone. Patients were classified as having a “sentinel” injury if one or more of their injuries were visible on plain radiographs. Patients were classified as having a radiographically “occult” injury if none of their injuries were visible on plain radiographs. The number and types of injuries missed on plain radiographs were then separately tabulated for the sentinel and occult injury groups. Results: Plain radiographs were completed in 570 of 818 victims of acute cervical spine injury and revealed 702 of 1,056 injuries. Plain films failed to detect 98 occult injuries present in 60 patients (10.5 %), and failed to detect 256 secondary injuries in 510 patients (89.5 %) who had a sentinel injury identified. Plain radiographs failed to reveal 79 of 136 (58.1 %) lateral mass injuries and 67 of 105 (63.8 %) lamina injuries, making these the most frequent sites of missed injury. Conclusions: Plain radiographs frequently fail to reveal injuries to the cervical spine, particularly those involving the lamina and lateral mass. The majority of the missed injuries represent secondary injuries in patients with a sentinel injury identified on these films. However, plain films fail to detect any injury in a minority of injured patients.     

Multidetector CT evaluation of abdominal trauma

CT is the imaging modality of choice to evaluate blunt abdominal trauma. With the advent of multidetector CT (MDCT), scanning times have progressively decreased while image resolution has increased owing to thinner collimation and reduced partial volume and motion artifacts. MDCT also allows high quality two-dimensional and three-dimensional multiplanar reformatted images to be obtained, which aid in the diagnosis of the complex multisystem injuries seen in the trauma patient. This article describes the authors' current imaging protocol with 16-detector MDCT, the spectrum of CT findings seen in patients with blunt abdominal injuries, and the role MDCT has in guiding injury management.