Gastric pneumatosis and portal vein gas: incidental findings at helical CT after blunt abdominal trauma

Gastric pneumatosis is a rare form of intestinal pneumatosis related to a wide range of abnormalities, which by itself may not engender adverse consequences. Portal vein gas, on the other hand, has traditionally been regarded as a life-threatening condition associated with mesenteric ischemia and immediate surgery; however, recent observations have demonstrated a greater spectrum of etiologies associated with portal vein gas in which the prognosis seems to be more favorable and surgery is not necessary. We report the case of a 42-year-old man who developed gastric pneumatosis and portal vein gas after major abdominal trauma. The patient was conservatively treated. Follow-up CT performed 4 days later revealed that portal vein gas and gastric pneumatosis had resolved spontaneously.     

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。     

Role of contrast-enhanced helical CT in the evaluation of acute thoracic aortic injuries after blunt chest trauma

The purpose of this retrospective study was to determine the value of contrast-enhanced helical CT for detecting and managing acute thoracic aortic injury (ATAI). Between June 1995 and February 2000, 1419 consecutive chest CT examinations were performed in the setting of major blunt trauma. The following CT findings were considered indicative of ATAI: intimal flap; pseudoaneurysm; contour irregularity; lumen abnormality; and extravasation of contrast material. On the basis of these direct findings no further diagnostic investigations were performed. Isolated mediastinal hematoma on CT scans was considered an indirect sign of ATAI: In these cases, thoracic aortography was performed even if CT indicated normal aorta. Seventy-seven patients had abnormal CT scans: Among the 23 patients with direct CT signs, acute thoracic aortic injuries was confirmed at thoracotomy in 21. Two false-positive cases were observed. The 54 remaining patients had isolated mediastinal hematoma without aortic injuries at CT and corresponding negative angiograms. The 1342 patients with negative CT scans were included in the 8-month follow-up program and did not show any adverse sequela based on clinical and radiographic criteria. Contrast-enhanced helical CT has a critical role in the exclusion of thoracic aortic injuries in patient with major blunt chest trauma and prevents unnecessary thoracic aortography. Direct CT signs of ATAI do not require further diagnostic investigations to confirm the diagnosis: Isolated aortic bands or contour vessel abnormalities should be first considered as possible artifacts or related to non-traumatic etiologies especially when mediastinal hematoma is absent. In cases of isolated mediastinal hematoma other possible sources of bleeding should be considered before directing patients to thoracic aortography.     

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.     

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.     

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.     

Spontaneous pyelosinus extravasation in blunt abdominal trauma: Radiographic findings and treatment implications

Spontaneous pyelosinus extravasation (SPE) occurs rarely. It is observed on intravenous urograms performed for the evaluation of “obstructive” processes. SPE is hypothesized to be caused by an acute or subacute increase in renal pelvic pressure secondary to a urinary calculus or other processes that leads to a sudden increase in hydrostatic pressure. Only two cases of SPE secondary to blunt abdominal trauma have been described. We report three additional cases, all of which demonstrated pyelosinus extravasation on their initial intravenous urograms. All patients were followed conservatively without surgical intervention, and each had a benign course without complication. Herein, we present the radiographic findings, pathophysiologic mechanisms, and treatment implications of SPE with the emphasis on expectant management.     

CT signs of duodenal perforation secondary to blunt abdominal trauma

Two cases of duodenal perforation secondary to blunt abdominal trauma demonstrate CT findings of focal bowel wall thickening, interruption of progress of bowel contrast medium, and extraluminal gas and fluid.     

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.     

Value of contrast-enhanced CT for managing mesenteric injuries after blunt trauma: review of five-year experience

Objective: The purpose of this retrospective study was to determine the value of contrast-enhanced computed tomography (CT) in the detection and management of mesenteric injuries after blunt trauma. Materials and methods: Between June 1995 and December 2000, 1,619 consecutive abdominal CT examinations were performed in the setting of major blunt trauma. Findings at CT were evaluated before patients were classified as having grade 1 or grade 2 lesions or none. Grade 1 represented the presence of minor injuries: mesenteric haziness, confined fluid, and/or small hematomas (<30 mm) within the mesenteric folds and abdominal injuries; grade 2 was appropriate to evidence of major injuries: moderate to large hematomas (>30 mm), active bleeding, hemoperitoneum, and further abdominal injuries. Results: On the basis of the CT findings, 161 (9.9%) of 1,619 patients were classified as having grade 1 and 25 (1.5%) of 1,619 patients as having grade 2 injuries. Of the 161 (77.6%) patients with grade 1 injuries, 125 were managed conservatively, while 36 (22.4%) underwent surgery. Of the 25 (84%) patients with grade 2 injuries, 21 were treated surgically and 1 (4%) patient was followed medically. Three (12%) of the 25 patients underwent laparotomy after 24 h close clinical observation and monitoring. Initial CT findings in 1,433 (88%) of the 1,619 patients were negative for mesenteric injuries, and in 1,430 of these cases no delayed mesenteric hemorrhage was observed. Conclusion: Contrast-enhanced CT has a critical role in the identification and exclusion of mesenteric injuries. Persistent, active extravasation of contrast material, in isolation or associated with further abdominal lesions, is a sign of a high likelihood of injury requiring urgent laparotomy. Haziness, isolated confined clotted mesenteric hemorrhage, and small hematomas within the mesentery are nonspecific findings and should be considered in the appropriate clinical context. Close clinical observation, monitoring, and surgical expertise are mandatory for appropriate management. Electronic Publication     

Screening US and CT for blunt abdominal trauma: a retrospective study

OBJECTIVE: To assess the accuracy of screening US and CT in patients with blunt abdominal trauma admitted to the trauma centre of our General Hospital. MATERIALS AND METHOD: The abdominal US reports of 864 primary trauma patients (139 with major and 725 with minor injuries) and 162 CT reports of a subgroup of the same subjects (64 with major and 98 with minor injuries) were reviewed and compared to the best available reference standard. The accuracy of screening US was assessed by evaluating its overall ability to distinguish negative from positive cases by showing at least one of the lesions documented by the reference standard and its specific ability to depict all lesions; CT reports were evaluated only for the method's performance in depicting all lesions. RESULTS: Screening US exhibited a satisfactory overall ability to distinguish negative from positive patients (91.5% sensitivity and 97.5% specificity in major trauma patients versus 73.3% sensitivity and 98.1% specificity in the minor trauma group) and a satisfactory specific ability to depict all injuries in major trauma patients. In minor trauma cases sensitivity was satisfactory for free fluid but unsatisfactory for organ injuries. Of the 21/864 false negative reports (5 in patients with major and 16 in cases with minor traumas), only one affected patient management, a major trauma case, by delaying an emergency laparotomy. The performance of CT in detecting each single lesion was predictably excellent in both patient groups. CONCLUSION: Its satisfactory accuracy for major trauma suggests that US could be employed not only to screen cases for emergency laparotomy but also as an alternative to CT. However, since major traumatic injuries generally carry an imperative indication for CT, especially as regards neurological, thoracic and skeletal evaluation, US should be employed to perform a prompt preliminary examination using a simplified technique in the emergency room simultaneously with resuscitation.     

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.     

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.     

The value of CT in detecting bowel perforation in children after blunt abdominal trauma

In this era of conservative management for most infants and children with blunt abdominal trauma, there is a concern that the diagnosis of bowel perforation may be missed or delayed. To determine the sensitivity of CT in the detection of perforated viscus in this population, we reviewed the CT examinations of 547 consecutive children who had had blunt abdominal trauma. Of six patients (1%) with documented bowel perforation, four (67%) had free intraperitoneal air detected preoperatively by CT. The remaining two cases had secondary signs of bowel thickening and unexplained peritoneal fluid. Free intraperitoneal air was not a specific indicator for bowel perforation. Of nine patients in whom CT studies showed pneumoperitoneum, only four (44%) had a ruptured bowel. The remaining five patients had pneumoperitoneum from sources other than bowel perforation including pneumomediastinum, bladder perforation, and previous peritoneal lavage. This experience shows that the CT finding of pneumoperitoneum is useful, although not specific for the detection of bowel perforation in children with blunt abdominal trauma. When free air is not present, secondary signs of bowel wall thickening and unexplained peritoneal fluid suggest a bowel perforation.     

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。