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.     

Chest injury in children with blunt abdominal trauma: evaluation with CT

One or more significant chest injuries were identified in 62 of 512 children (12%) examined with computed tomography (CT) after blunt abdominal trauma. Thirty-eight percent of all abnormalities identified on CT scans were underestimated or missed on the initial chest radiograph. Pleural and parenchymal abnormalities were missed in 50% and 34% of initial chest radiographs, respectively. Chest injuries occurred more frequently in children less than 7 years of age than in older children (62% vs 38%, P less than .02). Children with chest injuries tended to be more physiologically unstable than children without, as determined with lower (worse) mean trauma scores (P less than .001). Both the presence and severity of chest injuries strongly affected outcome. Mortality was 1.3% in children with no chest injury, 10.8% in children with significant unilateral chest injury, and 40% in children with significant bilateral or mediastinal chest injury (P less than .0001). Significant unsuspected or underestimated thoracic injuries are relatively common in children, and CT scans of the chest obtained while examinations of the upper abdomen are being performed can be helpful in the early recognition of such injuries.     

腹部闭合性创伤的急诊CT评价

目的：探讨急诊CT扫描在腹部闭合性创伤中的应用价值。方法：收集整理经手术或临床证实的腹部闭合性创伤65例急诊CT检查的影像资料,进行回顾性分析,所有病例均行CT平扫。结果：腹部闭合性创伤的急诊CT扫描主要表现为混杂高密度影像,多伴腹腔出血。本组65例腹部闭合性创伤中,肝脏损伤15例、脾26例、肾13例,肠系膜与肠管损伤2例,膀胱破裂2例,复合性实质性脏器损伤7例。其中51例伴腹腔出血,22例合并肋骨骨折。结论：急症CT扫描对诊断腹部闭合性创伤具有很大的价值,能明确腹部脏器损伤的部位、程度及复合性脏器损伤等信息,以指导临床医师制定有效的治疗方案。     

闭合性腹膜内型膀胱破裂的CT诊断

目的　确定闭合性腹膜内型膀胱破裂的CT诊断价值。方法　对 9例闭合性腹膜内型膀胱破裂的CT资料和临床处理进行回顾性分析。结果　所有 9例腹膜内型膀胱破裂 ,CT均明确诊断。CT显示腹膜腔内低密度液体积聚 9例 ,其CT值比血液低 ,主要分布在膀胱侧隐窝、盆腔陷凹、结肠旁沟、肝脾周围和肠袢内。膀胱壁局部缺损 3例 ,泪滴状变形 2例 ;其他支持膀胱破裂的CT征象包括 :膀胱充盈不良 8例 ,膀胱壁挫伤 4例 ,膀胱内血凝块 6例。结论　在创伤情况下 ,腹膜腔内出现CT值比血液小的低密度液体积聚 ,强烈提示尿外渗 ,根据尿外渗的分布范围 ,CT还可以区别腹膜内和腹膜外型膀胱破裂。CT有时还可以观察到膀胱破裂的准确位置 ,有利于手术修补     

Evaluation of non-contrast-enhanced CT in blunt abdominal trauma]

We compared the findings of noncontrast-enhanced CT with those of contrast-enhanced CT in 126 patients with blunt abdominal trauma to evaluate the usefulness of noncontrast-enhanced CT. In 112 of the patients, visceral injuries were confirmed by surgery or clinical follow-up including CT. Although noncontrast-enhanced CT diagnosed all patients with 12 intestinal injuries requiring immediate surgery, contrast-enhanced CT missed two of these patients because high density hematomas on noncontrast-enhanced CT became isodense after IV administration of contrast material. However, contrast-enhanced CT was superior to noncontrast-enhanced CT in the diagnosis of hepatic and renal injuries. A case of renal artery occlusion was only visualized on contrast-enhanced CT. We conclude that both noncontrast- and contrast-enhanced CT should be performed for the CT evaluation of blunt abdominal trauma.     

The value of non-contrast-enhanced CT in blunt abdominal trauma

The usefulness of non-contrast CT, limited to the upper abdomen, in conjunction with conventional IV contrast-enhanced scanning was studied prospectively in 190 patients who had sustained blunt abdominal trauma. In 78, visceral injuries were confirmed at surgery or at follow-up CT. Of the patients with injuries, 14 (18%) had hyperdense hematomas on the non-contrast studies that became isodense after IV administration of contrast material. These hematomas generally were small and posed an immediate threat to life in only one patient (0.5% of all subjects). In 13% of patients with injury (5% of the total), the additional information did influence treatment planning (surgery in two and intensive conservative treatment in eight). Compared with conventional contrast scanning, the combined non-contrast-contrast technique increased the scanning time only by about 5 1/2 min, but it improved the sensitivity and accuracy of CT in detecting visceral injuries from 74% and 84% to 92% and 91%, respectively (p less than or equal to .003 and p less than or equal to .04). Although contrast-enhanced scanning alone accurately depicts visceral injuries requiring surgical treatment, the incorporation of a non-contrast sequence can detect a subgroup of patients who require intensive conservative management with bed rest and close observation. This additional information can be obtained expeditiously, with minimal additional effort or intervention. The use of non-contrast scanning alone is not recommended.     

多层螺旋CT对腹部闭合性损伤的诊断价值

<正>腹部损伤约占所有损伤的0.4%～4.2%,常合并多脏器、多部位损伤而危及生命,其死亡率占所有损伤死亡率的10%。早期确诊腹部损伤的类别和准确定位有助于对伤者采取果断有效的处理措施、提高抢救成功率、降低死亡率、减少并发症。MSCT     

Bowel and mesenteric injury following blunt abdominal trauma: evaluation with CT

Computed tomography (CT) used in cases of blunt abdominal trauma has been found sensitive in detection of bowel and mesenteric injuries and discrimination of operable from nonoperable candidates. In 51 patients with suspected bowel or mesenteric injury following blunt abdominal trauma, CT correctly depicted bowel hematoma or mesenteric injury in 17 of 19 nonoperable patients (89%) and severe injuries in one patient who died preoperatively. In 26 of 28 patients who underwent therapeutic laparotomy (93%), initial CT enabled identification of surgically confirmed injuries. In two cases, initial scan misinterpretation delayed diagnosis of serious bowel injuries. The correct interpretation was rendered preoperatively and at blind retrospective review. CT findings that correlated with bowel or mesenteric injury requiring surgery were free peritoneal fluid (27 of 28, 96%), mesenteric infiltration (24 of 28, 86%), thick-walled bowel (17 of 28, 61%), associated abdominal injuries (12 of 28, 43%), and free air (nine of 28, 32%). In nonoperable cases, CT scans demonstrated bowel thickening (84%) but less frequently peritoneal fluid (21%), mesenteric infiltration (26%), or associated injuries (5%). In three of four patients who underwent nontherapeutic laparotomy, preoperative CT correctly imaged the limited abdominal injuries.     

Pediatric blunt abdominal trauma: periportal tracking at CT.

Periportal zones of decreased attenuation at computed tomography (CT) have been described in a variety of disorders. In the setting of blunt abdominal trauma, the zones have been attributed to dissection of blood along the portal tracts. Because of the observation of isolated periportal tracking (PPT) in children after blunt trauma, the authors retrospectively reviewed CT scans of the abdomen obtained in 114 children to determine the frequency of PPT, liver injury, and peritoneal fluid. PPT was present in 22% of patients (25 of 114); it was associated with liver injury in 10 and was the only liver abnormality in 15. Pathologic correlation was available in two patients: In one it revealed marked periportal lymphedema and in the other, PPT of blood. This study indicates that both hemorrhage and lymphatic edema may be represented as PPT in children after blunt abdominal injury.     

Rupture of the bowel after blunt abdominal trauma: diagnosis with CT.

OBJECTIVE. The accuracy of CT in the detection of injuries of the solid viscera after blunt trauma is well established, but the value of CT in diagnosing bowel rupture resulting from blunt trauma is controversial. This study was conducted to determine the sensitivity of CT in diagnosing posttraumatic bowel rupture. SUBJECTS AND METHODS. During a 51-month period, 17 preoperative CT scans were obtained in 16 patients who subsequently had bowel ruptures verified surgically. Both preoperative (prospective) and retrospective CT findings were analyzed in these patients. Retrospective interpretation was made by consensus of two radiologists. RESULTS. Surgically confirmed bowel ruptures occurred in the duodenum (five), ileum (four), jejunum (four), colon (four), and stomach (two). CT findings considered diagnostic of bowel perforation were detected prospectively on 10 (59%) of 17 scans; these included pneumoperitoneum without prior peritoneal lavage (six), mesenteric, intramural, or retroperitoneal free air (six), or direct visualization of discontinuity of the bowel wall or extravasation of luminal contents (four). Prospective CT findings considered suggestive of bowel rupture were present on five (29%) of the 17 scans; these included intraperitoneal fluid of unknown source (three), thickened (> 4-5 mm) bowel wall (two), gross anterior pararenal fluid without a recognized source (one), and a mesenteric-bowel wall hematoma (one). On two of 17 scans, findings were seen in retrospect only; these included free intraperitoneal blood without a source (findings on a second CT scan were diagnostic) and pneumoperitoneum. CT findings diagnostic or suggestive of bowel injury were detected prospectively on 15 (88%) of 17 scans and were noted in all retrospectively. CONCLUSION. CT is sensitive for the diagnosis of bowel rupture resulting from blunt trauma, but careful inspection and technique are required to detect often subtle findings.     

Hypotensive patients with blunt abdominal trauma: performance of screening US

PURPOSE: To determine retrospectively the accuracy of screening ultrasonography (US) in patients with hypotension (systolic blood pressure or =2) (consensus by three readers) and were assigned to a low- or high-risk group according to the presence of hematuria and/or axial fracture on radiographs. Screening US results were compared with findings with the best available reference standard (computed tomography [CT]), repeat US, other diagnostic test, laparotomy, autopsy, clinical course). Data were compared by using chi(2) or Fisher exact test, depending on expected frequencies, with Bonferroni correction for multiple comparisons. Continuous variables were compared by using unpaired Student t test or Mann-Whitney U test, depending on data distribution. RESULTS: The study included 77 male and 51 female patients (mean age, 42 years). Sensitivity was 85% (44 of 52) for detection of any injuries, 97% (30 of 31) for surgical injuries (ie, injuries requiring surgery), and 100% (10 of 10) for fatal injuries. Specificity was 96% (73 of 76), 82% (80 of 97), and 69% (81 of 118), and accuracy was 91% (117 of 128), 86% (110 of 128), and 71% (91 of 128), for respective injury categories. One nonfatal surgical injury was missed in a high-risk patient. For each injury category, frequency of injury in patients with a fluid score of 2 or more was nine times that in patients with a score of 0 (P < .001 for all comparisons). Frequency of false-negative US findings in high-risk patients was eight times that in low-risk patients (P < .01). CONCLUSION: In patients who are hypotensive after blunt abdominal trauma and not hemodynamically stable enough to undergo diagnostic CT, negative US findings virtually exclude surgical injury, while positive US findings indicate surgical injury in 64% of cases.     

The clinical impact of CT for blunt abdominal trauma

The use of computed tomography (CT) has had a tremendous impact on the evaluation and management of blunt abdominal trauma. It is noninvasive, easy to perform, and has been shown to be highly sensitive (100%), specific (96.8%), and accurate (97.6%). The use of CT has helped decrease the total number of laparotomies performed for abdominal trauma at this institution (231 in 1975-1976, 74 in 1983) as well as the number of negative and nontherapeutic laparotomies. The use of other diagnostic tests such as radionuclide scans and angiography in blunt abdominal trauma has been virtually replaced by CT. Of the 41 peritoneal lavages performed in 1983, 39 were in patients who were in the operating room for treatment of other extraabdominal injuries (i.e., closed head injury, severe extremity trauma).     

CT of false-negative peritoneal lavage following blunt abdominal trauma

The CT findings are presented in a patient with blunt trauma and a false-negative peritoneal lavage due to extraperitoneal insertion of the lavage catheter. Computed tomography correctly identified the presence of hemoperitoneum and the site of injury involving the small bowel mesentery. The diagnostic accuracy in peritoneal lavage and its relationship to abdominal CT is reviewed.     

CT diagnosis of unsuspected pneumothorax after blunt abdominal trauma

Review of abdominal CT scans for evaluation of blunt abdominal trauma yielded 35 cases of pneumothorax, 10 of which had not been diagnosed before CT by clinical examination or plain radiographs. Of the 10 cases initially diagnosed on CT, seven required tube thoracostomy for treatment of the pneumothorax. CT detection of pneumothorax is especially important if mechanical assisted ventilation or general anesthesia is used. Demonstration of pneumothorax requires viewing CT scans of the upper abdomen (lower thorax) at lung windows in addition to the usual soft-tissue windows.     

CT evaluation of blunt abdominal trauma in children: comparison of ultrafast and conventional CT

Previous reports describing the use of ultrafast CT have emphasized its value in evaluating the heart, chest, and airway. We describe our experience using this technology on children with blunt abdominal trauma. We retrospectively reviewed 54 consecutive ultrafast CT studies and 30 consecutive conventional dynamic CT studies performed on children after blunt abdominal trauma. Thirty percent of the scans showed abnormalities. CT or pathologic follow-up was available for all abnormal cases. We compared scans made with these two techniques for diagnostic accuracy, amount of visible motion on each slice, and contrast enhancement seen on each study. A protocol of 0.4-sec images and 2 ml/kg IV contrast material administered before scanning was used for the ultrafast CT scans. A standard protocol of 2-sec scanning and 3 ml/kg IV contrast material was used for conventional CT studies. There was no difference in diagnostic accuracy between the two techniques. There was significantly less visible motion (p less than .0001) and significantly better contrast enhancement (p less than .0001) seen on the ultrafast CT studies. Two of 54 ultrafast scans had images with sufficient motion to require repeated scanning, compared with 13 of 30 conventional CT studies. In addition, ultrafast scans required less sedation, decreased radiation dose, and improved accessibility of the patient to support personnel. Ultrafast CT is a valuable technique for abdominal imaging, offering equal diagnostic accuracy with improved image quality and important benefits to the patient.     

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.