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.     

Value of CT in determining the need for angiography when findings of mediastinal hemorrhage on chest radiographs are equivocal

The role of CT in determining the need for angiography in patients with possible thoracic vascular injury resulting from blunt trauma is controversial. During a 24-month period, we prospectively evaluated the results of CT to screen 90 patients with a history of decelerating thoracic trauma for evidence of mediastinal hemorrhage or great vessel abnormality. All patients either had equivocally abnormal mediastinal contours on chest radiographs (64%) or had technically suboptimal chest radiographs owing to body habitus or restriction to the supine projection (36%). Patients with unequivocal signs of mediastinal hemorrhage on chest radiographs underwent immediate arteriography without prior CT. Thoracic CT was interpreted as normal in 63 (77%) patients and no further imaging was performed. Five patients had technically suboptimal CT studies, and CT scans were interpreted as equivocal in six. These 11 patients had normal arteriograms. Sixteen CT scans (18%) demonstrated evidence of mediastinal hemorrhage and/or great vessel contour abnormality. Four (27%) of 15 patients who underwent arteriography had injury to the great vessels. One patient refused to undergo angiography. In 11 patients with CT evidence of mediastinal hemorrhage, major vascular injury was not seen on arteriography. These results suggest a valuable role for CT in determining the need for arteriography to detect potential great vessel injury in patients with blunt decelerating thoracic trauma and equivocally abnormal mediastinal contours on chest radiographs.     

Blunt injury to mesentery and small bowel: CT evaluation

Helical CT now allows rapid acquisition of sections through the abdomen and pelvis with optimal vascular opacification and minimal motion artifact. Oral contrast may aid in the identification of subtle bowel and mesenteric injuries and does not have any significant deleterious effects. CT findings of extraluminal enteric contrast, active hemorrhage, or free intraperitoneal-retroperitoneal air allow accurate diagnosis of SBMI in the setting of blunt abdominal trauma. Mesenteric hematoma in association with bowel wall thickening or the presence of significant amounts of free fluid without solid organ injury is highly suspicious for SBMI requiring laparotomy. CT alone or in concert with DPL and physical examination is a valuable tool in the timely diagnosis and treatment of bowel and mesenteric injury caused by blunt trauma.     

CT of blunt trauma bowel and mesenteric injury: typical findings and pitfalls in diagnosis.

Detection of bowel and mesenteric injury can be challenging in patients after blunt abdominal trauma. Early diagnosis and treatment are critical to decrease patient morbidity and mortality. Computed tomography (CT) has become the primary modality for the imaging of these patients. Signs of bowel perforation such as free air and contrast material are virtually pathognomonic. Bowel-wall thickening, free fluid, and mesenteric infiltration may be seen with this type of injury and partial thickness injuries. The authors present and discuss the range of CT findings seen with bowel and mesenteric injuries. Examples of observation and interpretation errors are also provided to highlight pitfalls encountered in the evaluation of abdominopelvic CT scans in patients after blunt trauma.     

CT diagnosis of internal mammary artery injury caused by blunt trauma

AIM: To describe the computed tomography (CT) findings associated with active bleeding from the internal mammary artery (IMA) in blunt trauma victims and to assess complications related to IMA haemorrhage. MATERIAL AND METHODS: All cases of active IMA haemorrhage identified in blunt trauma patients on admission CT were identified from a trauma radiology data base covering 1990-1999. Computed tomography examinations, operative and medical records were reviewed to ascertain CT findings, complications, and patient outcome. The determination of active bleeding required CT evidence of a central contrast blush of CT density within 10 HU of an adjacent artery surrounded by haematoma. RESULTS: Four patients with CT evidence of active IMA haemorrhage were identified. All cases had surgical confirmation of an IMA source of haemorrhage. There were three patients with unilateral and one patient with bilateral IMA disruption. Three patients exhibited clinical signs of cardiac tamponade related to compression of one or more cardiac chambers by the anterior mediastinal haematoma. Sudden clinical deterioration compatible with tamponade developed in all three patients. CONCLUSION: Early CT recognition of active bleeding within the chest can direct rapid surgical or angiographic intervention. On-going blood loss and, in particular, the threat of cardiac tamponade must be considered with IMA injury.     

Role of CT in excluding major arterial injury after blunt thoracic trauma

The role of CT in the diagnosis of major vascular rupture following blunt decelerating chest trauma is controversial. Its value in excluding major arterial injury has not yet been determined. During a 12-month period we obtained dynamic enhanced thoracic CT studies in 20 patients with blunt decelerating thoracic trauma who had abnormal or equivocal mediastinal contours on chest radiographs. In all cases diagnosis was confirmed by either digital subtraction (18 patients) or conventional thoracic angiography (two patients). CT scans showed evidence of direct aortic injury in three patients and evidence of mediastinal hematoma in five others. Four of these eight patients had major arterial injury verified angiographically and at surgery. In two patients the CT scan was considered equivocal; both patients had normal thoracic angiograms. CT excluded direct vascular injury or mediastinal hematoma in 10 patients. All 10 had normal thoracic angiograms. This preliminary study suggests that, in patients sustaining blunt decelerating thoracic trauma, thoracic CT may be more valuable than chest radiography in excluding major vascular injury and, in some cases, may reduce the need for thoracic angiography.     

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.     

CT diagnosis of cardiac and pericardial injuries

The purpose of this retrospective study was to determine the CT findings diagnostic of cardiac and pericardial injury, including signs of pericardial tamponade, in patients suffering from blunt and penetrating trauma. A search of the CT radiology database at a level I trauma center was performed to identify cases in which injury to the heart or pericardium was diagnosed, as well as to identify cases of pericardial tamponade. All cases were reviewed to ascertain the specific CT findings, and medical records were reviewed to assess the influence of CT findings on management and to assess for clinical evidence of pericardial tamponade. Eighteen patients had direct CT evidence of cardiac or pericardial injury, including nine cases of pneumopericardium, eight cases of hemopericardium, and one case of intrapericardial gastric herniation. Four of these patients were found to have direct cardiac injuries. Three additional cases with CT evidence of pericardial tamponade were identified, two secondary to cardiac compression by an anterior mediastinal hematoma and one following repair of left ventricular rupture. Of 11 patients with CT evidence of tamponade, only three were suspected clinically. Cardiac and pericardial injuries are usually diagnosed surgically and are often clinically unsuspected, particularly in blunt trauma. As CT is increasingly utilized as a general screening test for thoracic/abdominal trauma, these injuries may be first suspected on the basis of CT findings, and knowledge of the CT findings of cardiac injury or tamponade is crucial.     

增强CT对腹部实质脏器损伤的诊断价值

目的：探讨增强CT扫描检查对腹部实质脏器损伤的诊断价值。方法：回顾性分析63例经手术、血管造影及CT随访证为腹部钝性损伤病人的平扫及增强CT表现征象,并比较分析各种征象的作用。结果：本组63例中,11例（2例脾损伤,3例肝损伤,6例肾损伤）平扫换明显异常,增强CT扫描呈明显的低工改变;11例器官内或周围斑点状造影剂外渗,提示为活动性出血;29例增强 CT扫描后清楚显示裂伤部位,结论：增强CT检查对肝肾损伤的诊断明显优于平扫,还可以判断有无活动性出血等情况,对损伤程度的判断和治疗方案的制定较平扫更有价值。     

Imaging of blunt pancreatic trauma

Blunt pancreatic trauma is an exceedingly rare but life-threatening injury with significant mortality. Computed tomography (CT) is commonly employed as the initial imaging modality in blunt trauma patients and affords a timely diagnosis of pancreatic trauma. The CT findings of pancreatic trauma can be broadly categorized as direct signs, such as a pancreatic laceration, which tend to be specific but lack sensitivity and indirect signs, such as peripancreatic fluid, which tend to be sensitive but lack specificity. In patients with equivocal CT findings or ongoing clinical suspicion of pancreatic trauma, magnetic resonance cholangiopancreatography (MRCP) may be employed for further evaluation. The integrity of the main pancreatic duct is of crucial importance, and though injury of the duct may be strongly suggested upon initial CT, MRCP provides clear delineation of the duct and any potential injuries. This article aims to review and illustrate the CT and magnetic resonance imaging findings of blunt pancreatic trauma and delineate the integration of these modalities into the appropriate imaging triage of severely injured blunt trauma patients.     

Multidetector CT: detection of active hemorrhage in patients with blunt abdominal trauma

OBJECTIVE: The aim of this study was to determine the imaging findings and the prevalence of active hemorrhage on contrast-enhanced multidetector CT in patients with blunt abdominal trauma. MATERIALS AND METHODS: Contrast-enhanced multidetector CT images of 165 patients with blunt abdominal trauma were reviewed for the presence of extravasated contrast agent, a finding that represents active hemorrhage. The site and appearance of the hemorrhage were noted on multidetector CT images. These findings were compared with surgical and angiographic results or with clinical follow-up. RESULTS: On multidetector CT images, active hemorrhage was detected in 22 (13%) of 165 patients with a total of 24 bleeding sites (14 intraperitoneal sites and 10 extraperitoneal sites). Active hemorrhage was visible most frequently as a jet of extravasated contrast agent (10/24 bleeding sites [42%]). Diffuse or focal extravasation was less frequently seen (nine [37%] and five [21%] bleeding sites, respectively). CT attenuation values measured in the aorta (mean, 199 H) were significantly higher than those measured in extravasated contrast material (mean, 155 H) (p < 0.001). Sixteen (73%) of 22 patients with active bleeding on multidetector CT images underwent immediate surgical or angiographic intervention. One patient received angiographic therapy 10 hr after undergoing multidetector CT, and five patients died between 1 and 3 hr after multidetector CT examination. CONCLUSION: Active hemorrhage in patients after blunt abdominal trauma is most frequently visible as a jet of extravasated contrast agent on multidetector CT. When extravasation is detected, immediate surgical or angiographic therapy is required.     

Blunt thoracic aortic injury in children

Thoracic aortic injury (TAI) in children secondary to blunt chest trauma is rare and less well documented than TAI in adults. To further establishe the incidence and radiographic manifestations of this severe injury, we reviewed our experimence with TAI in children over an 8-year period. We performed a computer search from the Trauma Registry at our level I trauma center for all cases of TAI among patients 16 years of age or younger who were admitted after sustaining blunt chest trauma between August 1984 and September 1992. We reviewed our records of all thoracic aortograms performed on children for blunt trauma during this same time period. Indication for angiography was determined by review of chest radiographs and medical records of all patients who underwent thoracic aortography. We reviewed medical records and all available chest radiographs, computed tomography (CT) examinations, and thoracic aortograms of children diagnosed with TAI. Of 308 children admitted with blunt chest trauma, 26 (8.4%) underwent angiography to exclude aortic or great vessel injury. Of these 26 patients, three (11.5%) were diagnosed with TAI, and one patient demonstrated a traumatic pseudoaneurysm of the proximal left subclavian artery. The incidence of TAI among children who sustained blunt chest trauma was 1.0% in our series. All three patients with TAI in our series were male, ages 10–12 (mean: 11 years). Chest radiographs on two of the patients with TAI revealed mediastinal widening, ill-defined aortic outline, shift of the trachea and nasogastric tube, and depression of the left main stem bronchus. The chest radiograph in one patient with TAI was technically inadequate. CT demonstrated abnormalities in two patients. Angiographic findings were similar to those seen in adults. TAI in children is rare, occurring in 1% of children sustaining blunt chest trauma in our series. Our findings support previous reports that the plain film, CT, and angiographic findings with this injury resemble those found in adults.     

Evaluation of blunt abdominal trauma using PACS-based 2D and 3D MDCT reformations of the lumbar spine and pelvis

OBJECTIVE: The purpose of this study was to show the value of 2D and 3D reformations of CT data from abdominal and pelvic CT performed immediately at the workstation using a PACS-based software program to evaluate the lumbar spine and pelvis in patients with blunt abdominal trauma. MATERIALS AND METHODS: We reviewed the abdominopelvic CT scans and conventional radiographs of the lumbar spine or pelvis of 156 consecutive patients with blunt abdominal trauma. The CT data were compared with the radiographic findings and also with the findings of dedicated repeat CT of the spine or pelvis, when performed. RESULTS: CT depicted 80 fractures of the lumbar spine and 178 pelvic fractures. Radiography showed 40 fractures of the lumbar spine and 138 pelvic fractures. No additional fractures were identified on dedicated repeat CT. CONCLUSION: Conventional radiographs to clear the lumbar spine are no longer required when abdominopelvic CT data are available. CT and reformatted CT data show more fractures than radiography and miss no fractures compared with dedicated CT of the lumbar spine or pelvis. Having these images immediately available through the PACS workstation saves time for the trauma team in the management of critically ill patients.     

Pelvic imaging in the stable trauma patient: is the AP pelvic radiograph necessary when abdominopelvic CT shows no acute injury?

The purpose of the study was to determine the utility of anteroposterior (AP) pelvic radiographs in stable trauma patients who will undergo or have undergone abdominopelvic CT as part of the initial trauma imaging evaluation. Radiology reports of all stable trauma patients who underwent both abdominopelvic CT and AP pelvic radiograph from 25 January through 30 April, 2003 were reviewed for findings of acute pelvic injuries. A total of 509 consecutive patients were included in this series. Of these, 449 patients (88.2%) had no acute pelvic injury revealed by abdominopelvic CT. CT showed 163 acute injuries in 60 patients. AP radiographs showed 132 acute injuries in 52 patients. No patients with a negative CT had an acute finding on the radiograph. There were eight false-negative pelvic radiographs (negative predictive value 98.25%). CT is highly accurate in excluding acute osseous pelvic injuries. In the stable trauma patient whose CT does not reveal an acute pelvic injury or who is scheduled to undergo an abdominopelvic CT as part of the initial imaging evaluation, the pelvic radiograph may be unnecessary.Comment Abstract originally presented at the American Society of Emergency Radiology 14th Annual Scientific Meeting, Las Vegas, Nevada, October 2003.     

Retroperitoneal fluid resulting from rapid intravascular resuscitation in trauma: CT mimic of retroperitoneal injury

Objective: We postulate that retroperitoneal fluid density (RFD) observed on computed tomography (CT) following blunt abdominal trauma can result from aggressive intravascular volume resuscitation. The purpose of this study was to determine associated CT findings useful in distinguishing RFD related to rapid intravascular volume expansion from primary retroperitoneal injuries that produce a similar CT appearance. Subjects and Methods: All admission CT scans performed for blunt abdominal trauma over a 13-month period demonstrating RFD were reviewed. If CT findings, as determined by consensus of the authors, clearly indicated a primary retroperitoneal injury to account for the RFD, such as duodenal or pancreatic injury, the study was excluded from further analysis. There were 11 patients with RFD whose CT scans showed no primary retroperitoneal injury. The admission and any follow-up CT studies of these 11 patients were assessed for CT signs of intravascular volume expansion. Medical records were reviewed to determine the quantity and rate of intravenous (IV) fluid administration, serum amylase level(s), and operative findings if performed. Results: All 11 patients had CT signs of intravascular volume expansion including periportal low density in the liver (11 patients), distention of the inferior vena cava (11 patients), and diffuse edema of the small bowel (7 patients). Identification of RFD as edema was confirmed directly at celiotomy in 3 patients and by rapid resolution of RFD on follow-up CT in 8. No follow-up CT showed evidence of delayed retroperitoneal hemorrhage or signs of primary retroperitoneal injuries. Postadmission IV fluids were administered at 210 to 2400 ml/hr (mean 840 ml/hr) at the time of CT with total volume resuscitation from 4.7 to 57.0 L (mean, 11.6 L) given over a 24-hour period postadmission. Serial serum amylase levels did not show a rising trend to suggest pancreatic injury. paConclusion: The CT demonstration of RFD after blunt trauma suggests primary retroperitoneal injury, including the bowel, pancreas, kidneys, and cisterna chyli, and could prompt exploratory laparotomy. However, if this CT finding is accompanied by periportal low density, vena caval distention, or diffuse bowel edema, it suggests that RFD results from interstitial edema related to aggressive IV resuscitation. If no other clinical or CT evidence of primary retroperitoneal injury is identified, these patients should be managed conservatively.     

Fatal traumatic subarachnoid hemorrhage due to assault-related tear of the basilar artery

Traumatic subarachnoid hemorrhage after blunt head injury or neck trauma most often occurs due to intracranial or extracranial vertebral artery rupture. A literature review confirms that subarachnoid hemorrhage related to basilar artery disruption is a rare event. Strong associations have been made between basal subarachnoid hemorrhage and relatively minor blunt force injuries to the face, head, or neck. Moreover, the degree of hemorrhage may appear striking and disproportionate to the external and internal evidence of injury. We present a case of an assault-related basilar artery tear causing fatal subarachnoid hemorrhage, despite minimal external injury. This report provides an overview of potential mechanisms accounting for vertebrobasilar system rupture, with application to our case.     

CT of bowel and mesenteric trauma in children.

Although most traumatic abdominal injuries in children are treated with conservative nonsurgical management, traumatic perforation or infarction of the gastrointestinal tract still necessitates surgical management. It is imperative to recognize the often subtle computed tomographic (CT) findings of bowel or mesenteric trauma in children. Pediatric patients with bowel perforation or infarction due to trauma usually demonstrate multiple abnormalities at CT. A specific history of lap belt injury, bicycle handlebar injury, or child abuse with an abdominal injury should heighten suspicion for a bowel injury. CT findings in children with bowel or mesenteric trauma include free intraperitoneal air, free retroperitoneal air, extraluminal oral contrast material, free intraperitoneal fluid, bowel wall defect, bowel wall thickening, mesenteric stranding, fluid at the mesenteric root, focal hematoma, active hemorrhage, and mesenteric pseudoaneurysm. Some findings, such as free intraperitoneal air and focal bowel wall thickening, are associated with a strong likelihood of a bowel injury that requires surgical repair. Other findings, such as free intraperitoneal fluid, mesenteric stranding, fluid at the mesenteric root, and focal hematoma, are less specific for an injury that requires surgical repair. The hypoperfusion complex can usually be differentiated from a traumatic bowel injury; however, in some patients the imaging findings overlap.     

CT cystography versus conventional cystography in evaluation of bladder injury.

OBJECTIVE: The objective of this study was to evaluate prospectively the use of CT cystography, using retrograde filling of the bladder with diluted iodinated contrast material, versus conventional cystography to identify bladder injury in patients with hematuria after blunt abdominal trauma. SUBJECTS AND METHODS: Inclusion criteria consisted of the adult hemodynamically stable abdominal trauma patient with hematuria referred for abdominopelvic CT and also being considered for cystography. An initial abdominopelvic CT scan using IV iodinated contrast material was obtained, as would have been done routinely in the trauma victim. A second CT scan through the pelvis was obtained after retrograde distention of the bladder with dilute iodinated contrast material. CT cystography revealing bladder injury was followed with appropriate therapy. CT cystograms not revealing injury were followed by conventional cystography. Results of patient outcome were evaluated. RESULTS: Over a 21-month period from January 1995 through September 1996, CT cystography was performed on 55 patients who presented with hematuria after blunt abdominal trauma. Five of the 55 patients had bladder injury on CT cystography. The injury in each of these five patients was confirmed intraoperatively. In the remaining 50 patients, both CT and conventional cystography did not reveal bladder injury. CONCLUSION: CT cystography is an accurate method for evaluating bladder injury in the blunt abdominal trauma victim with hematuria. CT cystography, performed in conjunction with routine CT of the abdomen and pelvis for evaluating traumatic hematuria, would therefore preclude conventional cystograms in these patients.     

Pearls and pitfalls of hepatobiliary and splenic trauma: what every trauma radiologist needs to know

With the universal acceptance of contrast-enhanced computed tomography (CT) as the imaging modality of first resort in the assessment of blunt abdominal injury, the trauma radiologist must be able to accurately and rapidly identify the range of CT manifestations of the traumatized abdomen. In this article, we lay out the fundamental principles in CT interpretation of blunt trauma to the hepatobiliary system and spleen, including vascular injury, with a focus on technical and interpretive pearls and pitfalls. This review will help radiologists and trainees become more familiar with key aspects of abdominal CT trauma protocol selection, CT-based solid organ injury grading, and the various appearances and mimics of hepatobiliary and splenic injury.     

The halo sign and peripancreatic fluid: useful CT signs of hypovolaemic shock complex in adults

AIM: To report two new, useful computed tomography (CT) signs of the hypovolaemic shock complex (HSC) in adults admitted after blunt abdominal trauma: the halo sign (ring of fluid around a collapsed intra-hepatic inferior vena cava (IVC)), and peripancreatic retroperitoneal fluid. MATERIALS AND METHODS: CT images of 498 consecutive patients admitted after blunt abdominal trauma were reviewed, of which 27 had CT signs of the HSC. The CT images of these 27 patients were analysed. A control group of 101 patients examined using CT for suspected blunt abdominal trauma who did not have the HSC were chosen for comparison. RESULTS: The most common features involved the vascular compartment: diminished IVC diameter n = 27 a positive halo sign n = 21 diminished anteroposterior diameter of the aorta n = 13 and abnormal vascular enhancement n = 10. Peripancreatic retroperitoneal fluid in the absence of pancreatic injury, pancreatitis or pancreatic disease was observed in eight patients. Hollow visceral abnormalities included: diffuse increased mucosal enhancement of both the small and large bowel n = 19 diffuse thickening of the small bowel wall n =11 and small bowel dilatation n = 7. Solid visceral abnormalities included both decreased and or increased enhancement. Several concomitant intra- and extra-abdominal injuries were also identified. CONCLUSION: In the setting of blunt abdominal trauma, early abdominal CT can show diffuse abnormalities due to the HSC, which occasionally may alert clinicians of unsuspected shock. Recognition of these signs as distinguished from injured viscera is important in order to avoid unnecessary laparotomy. Two new signs are described: the halo sign and peripancreatic retroperitoneal fluid.