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.     

Splenic Trauma: What is New?

Evaluation for splenic injury is an important component of patient assessment after blunt abdominal trauma. Key imaging modalities include ultrasound, particularly for rapid identification of hemoperitoneum, and computed tomography (CT), which permits a more detailed and accurate determination of splenic integrity. Specific findings at contrast-enhanced multidetector CT (MDCT) should prompt the consideration of catheter angiography with arterial embolization as an adjunct to nonsurgical management. This article reviews the roles of imaging in the management of splenic trauma, illustrates the MDCT appearance of various splenic injuries, and discusses imaging-based indications for operative and angiographic intervention.     

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.     

The trauma concept: the role of MDCT in the diagnosis and management of visceral injuries

The imaging concept in the acute trauma victim includes abdominal ultrasonography during initial triage, and contrast-enhanced computed tomography (CT) for further assessment of visceral organ injuries and active bleeding sites if haemodynamic stability can be established during initial resuscitation. Integration of modern multidector CT (MDCT) scanners in the emergency admission area greatly facilitates initial assessment of the extent of injuries in all body regions, and is therefore the emerging standard in all major centres involved in acute trauma care. Initial assessment of visceral injuries by means of CT not only allows determining the presence and extent of organ injuries and detecting active bleeding sources that may require transarterial embolisation for haemostasis, but also serves as a baseline for monitoring of conservative treatment. Specific indications for CT monitoring of conservative treatment exist in each individual organ. This concept enables the vast majority of blunt injuries of the parenchymal abdominal organs in the haemodynamically stable trauma victim to be managed without surgery.     

Multi-modality imaging of the leaking ureter: why does detection of traumatic and iatrogenic ureteral injuries remain a challenge?

Ureteral injuries are uncommon in trauma patients, accounting for fewer than 1% of all injuries to the urinary tract. These uncommon, yet problematic, injuries can often be overlooked in the standard search pattern on abdominal and pelvic multi-detector CT (MDCT) images, as radiologists focus on more immediate life-threatening injuries. However, early diagnosis and management are vital to reduce potential morbidity. If there is a high clinical index of suspicion for ureteral injuries with penetrating or blunt trauma, or if there is suspected iatrogenic ureteral injury, delayed-phase/urographic-phase MDCT images are essential for confirming the diagnosis. Moreover, making the distinction between partial and complete ureteral transection is critical, as it will guide management. The aim of this pictorial review is to overview the key imaging findings in blunt and penetrating traumatic and iatrogenic injuries of the ureter, as well as to discuss the advantages and disadvantages of different imaging modalities for accurately and rapidly establishing or excluding the diagnosis of ureteral injuries, with an emphasis on MDCT. The potential causes of missed ureteral injuries will also be discussed.     

腹部钝性创伤中肠道及肠系膜损伤的CT表现

肠道及肠系膜损伤在腹部钝性伤中的发生率较高且易出现诊断延迟或漏诊。多层X线计算机断层成像具有较高的空间、时间和对比度分辨率,提高了肠道及肠系膜损伤诊断率。可显示腹腔内脏器损伤的直接和间接影像,指导非手术治疗或手术治疗的选择和效果评估。本文就肠道及肠系膜损伤在CT中特异性和非特异性征象作一论述。     

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.     

Multidetector CT Findings of Bowel Transection in Blunt Abdominal Trauma

Objective

Though a number of CT findings of bowel and mesenteric injuries in blunt abdominal trauma are described in literature, no studies on the specific CT signs of a transected bowel have been published. In the present study we describe the incidence and new CT signs of bowel transection in blunt abdominal trauma.

Materials and Methods

We investigated the incidence of bowel transection in 513 patients admitted for blunt abdominal trauma who underwent multidetector CT (MDCT). The MDCT findings of 8 patients with a surgically proven complete bowel transection were assessed retrospectively. We report novel CT signs that are unique for transection, such as complete cutoff sign (transection of bowel loop), Janus sign (abnormal dual bowel wall enhancement, both increased and decreased), and fecal spillage.

Results

The incidence of bowel transection in blunt abdominal trauma was 1.56%. In eight cases of bowel transection, percentage of CT signs unique for bowel transection were as follows: complete cutoff in 8 (100%), Janus sign in 6 (100%, excluding duodenal injury), and fecal spillage in 2 (25%). The combination of complete cutoff and Janus sign were highly specific findings in patients with bowel transection.

Conclusion

Complete cut off and Janus sign are the unique CT findings to help detect bowel transection in blunt abdominal trauma and recognition of these findings enables an accurate and prompt diagnosis for emergency laparotomy leading to reduced mortality and morbidity.     

Visceral injury without hemoperitoneum: A limitation of screening abdominal sonography for trauma

Abdominal sonography for the detection of hemoperitoneum has become increasingly popular as a screening test for visceral injury after blunt trauma. The purpose of this study was to determine the frequency, severity, and clinical significance (outcome) of abdominal organ injuries that occur without hemoperitoneum on the initial evaluation of blunt abdominal trauma patients.During a 12-month period, 3392 blunt trauma patients were admitted to our center. Sonographic studies were performed as an initial screening evaluation to determine the presence of hemoperitoneum in 772 (22.7%) of these patients. Abdominal visceral injuries were verified by computed tomography (CT) or surgery in 196 (5.8%) of all blunt trauma admissions. Sonography, CT, and operative findings were reviewed to determine the presence or absence of hemoperitoneum in patients with abdominal injury. Patients with abdominal visceral injury without hemoperitoneum were further analyzed to identify the type of injury and the management required.A total of 246 abdominal injuries were identified in 196 patients. Fifty (26%) patients with abdominal visceral injuries diagnosed by admission CT scan had no evidence of hemoperitoneum. Admission sonography performed in 15 (30%) of these 50 patients also showed no evidence of hemoperitoneum. Visceral injuries detected by CT in the patients without hemoperitoneum included 22 of 100 splenic injuries (22%), 18 of 91 hepatic injuries (20%), 12 of 26 renal injuries (46%), and 1 of 9 mesenteric injuries (11%). Surgery was required to manage injuries in 10 of these patients.Up to 26% of blunt trauma patients with abdominal visceral injuries do not have associated hemoperitoneum identified on admission abdominal CT or sonography. Dependence on hemoperitoneum as the sole criterion of abdominal visceral injury after blunt trauma will result in falsely negative examinations and will miss potentially significant injuries.     

CT features of blunt abdominal aortic injury

Abdominal aortic injuries are uncommon following blunt trauma, with relatively few reported series in the radiology literature. This study was conducted to identify common locations and imaging features of blunt traumatic abdominal aortic injury, the presence of associated visceral and osseous injuries, and the mechanisms of trauma. A retrospective review of 9,213 trauma registry entries over a 7-year period yielded 103 patients with aortic injuries, 12 of which had direct signs of abdominal segment involvement (dissection flap, focal intimal injury, intramural hematoma, active extravasation of contrast, or pseudoaneurysm formation). The majority (75 %) was isolated to the abdomen-67 % of which was infrarenal, 33 % suprarenal-while the other 25 % was a contiguous extension from a thoracic injury. Abdominal aortic injuries were uncommonly seen in isolation: all but one patient (92 %) demonstrated either retroperitoneal blood or stranding, hemoperitoneum, and/or CT signs of hypoperfusion complex, and only one patient (8 %) had no associated solid organ or skeletal injuries. All patients had a mechanism of injury which involved direct trauma to the abdomen, most commonly a motor vehicle collision. Similar to other recent series, there was an increased rate of abdominal segment injury (11.7 % of all aortic injuries) in this series compared to more remote autopsy series. This difference is likely due to detection of injuries which went undiagnosed before the widespread use of multidetector CT, which has become the standard of care for both acute evaluation following blunt trauma and for follow-up.     

Traumatic injuries: imaging of abdominal and pelvic injuries

The availability of new imaging modalities has altered the diagnostic approach to patients with abdominal and pelvic trauma. Computed tomography and ultrasound have largely replaced diagnostic peritoneal lavage. Ultrasound is used in most trauma centers as the initial imaging technique for the detection of hemoperitoneum and helps to determine the need for emergency laparotomy. Computed tomography allows for an accurate diagnosis of a wide range of traumatic abdominal and pelvic conditions. The speed of single-detector helical and multi-detector row CT (MDCT) permits a rapid CT examination of the seriously ill patient in the emergency room. In particular, the technology of MDCT permits multiple, sequential CT scans to be quickly obtained in the same patient, which is a great advance in the rapid assessment of the multiple-injured patient. The evolving concepts in trauma care promoting non-operative management of liver and splenic injuries creates the need for follow-up cross-sectional imaging studies in these patients. Computed tomography and, less frequently, MR or ultrasound, are used for this purpose.     

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.     

螺旋CT诊断钝性肠管和肠系膜损伤的临床价值

目的 探讨螺旋CT对急性钝性大小肠和肠系膜损伤的诊断价值.方法 2004-02-2008-05, 急性腹部钝性损伤螺旋CT扫描300例.CT诊断大小肠或/和肠系膜损伤18例,其中16例剖腹手术.2例临床随访.CT表现与手术探查对照分析.结果 肠管和系膜损伤的CT各种表现的诊断准确率分别为:肠壁增厚63%,肠壁破裂100%,肠系膜血肿71%,肠系膜血管中断100%,系膜束带征56%及气腹或肠壁或系膜间积气50%.结论 综合分析肠和肠系膜损伤的直接和间接CT征象,可以较准确地评估肠和肠系膜损伤的程度及损伤部位.     

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.     

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.     

Evaluation of abdominal trauma by computed tomography

Computed tomography (CT) was used in the evaluation of 100 patients suffering abdominal trauma. The type of trauma was blunt in 78 patients, penetrating in eight, and iatrogenic in 14. Forty per cent of cases had normal CT scans, while 60% showed substantial abdominal or retroperitoneal injuries. Surgery, clinical follow-up, and repeated radiologic examinations confirmed the accuracy of CT, and there were no cases in which medical or surgical management was inappropriately guided by CT. A wide variety of injuries was detected, including 19 splenic, eight hepatic, six pancreatic, 13 renal, 13 retroperitoneal or abdominal wall, and one intraperitoneal. CT has major advantages over plain radiography, radionuclide imaging, and angiography in assessment of trauma-induced injuries.     

MDCT diagnosis of penetrating diaphragm injury

The purpose of the study was to determine the diagnostic sensitivity and specificity of multidetector CT (MDCT) in detection of diaphragmatic injury following penetrating trauma. Chest and abdominal CT examinations performed preoperatively in 136 patients after penetrating trauma to the torso with injury trajectory in close proximity to the diaphragm were reviewed by radiologists unaware of surgical findings. Signs associated with diaphragmatic injuries in penetrating trauma were noted. These signs were correlated with surgical diagnoses, and their sensitivity and specificity in assisting the diagnosis were calculated. CT confirmed diaphragmatic injury in 41 of 47 injuries (sensitivity, 87.2%), and an intact diaphragm in 71 of 98 patients (specificity, 72.4%). The overall accuracy of MDCT was 77%. The most accurate sign helping the diagnosis was contiguous injury on either side of the diaphragm in single-entry penetrating trauma (sensitivity, 88%; specificity, 82%). Thus MDCT has high sensitivity and good specificity in detecting penetrating diaphragmatic injuries.     

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.     

Blunt trauma to the spleen: ultrasonographic findings

The spleen is the most frequently injured organ in adults who sustain blunt abdominal trauma. Splenic trauma accounts for approximately 25% to 30% of all intra-abdominal injuries. The management of splenic injury has undergone rapid change over the last decade, with increasing emphasis on splenic salvage and non-operative management. Identifying the presence and degree of splenic injury is critical in triaging the management of patients. Imaging is integral in the identification of splenic injuries, both at the time of injury and during follow-up. Although CT remains the gold standard in blunt abdominal trauma, US continues to play an important role in assessing the traumatized spleen. This pictorial review illustrates the various ultrasonographic appearances of the traumatized spleen. Correlation with other imaging is presented and complications that occur during follow-up are described.     

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.