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.     

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。     

CT diagnosis of renal artery injury caused by blunt abdominal trauma

Controversy exists about the sensitivity of CT in the diagnosis of occlusion of the renal artery or one of its branches after blunt abdominal trauma. We report 10 cases in which contrast-enhanced CT was used to diagnose correctly either main (seven cases) or segmental (three cases) posttraumatic renal artery occlusion. The abnormality was proved angiographically and/or surgically in all cases. CT showed the absence of a nephrogram in the devascularized portion of the kidney in all 10 cases. A pyelogram was not shown on CT in the seven patients in whom the main renal artery was occluded, but was present in the three patients who had segmental arterial lesions. Termination of enhancement within the affected artery (renal artery cutoff sign) was observed in one patient, and a thin, peripheral rim of cortical enhancement in an otherwise unenhanced renal segment (rim sign) was observed in three patients. Retroperitoneal hematoma with renal displacement was present in nine patients. Our experience suggests that the absence of a nephrogram on contrast-enhanced CT scans is a useful sign of main or segmental renal arterial occlusion in patients with blunt abdominal trauma.     

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.     

Unidentified bright objects of spleen on arterial phase CT: mimicker of splenic vascular injury in blunt abdominal trauma

PURPOSEWe have described unidentified bright objects of spleen (UBOS), a hitherto undescribed entity, as hyperdense areas on arterial phase (AP) computed tomography (CT) seen in relation to splenic lacerations and are isodense to the normal parenchyma on portal venous phase with no correlate on digital subtraction angiography (DSA). UBOS mimic splenic vascular injuries like active contrast extravasation and pseudoaneurysm and need to be differentiated from them as it would have implications on patient management. We undertook this study to identify CT features of UBOS that can differentiate them from splenic vascular injuries and to calculate their diagnostic accuracy.METHODSThis retrospective study was approved by the institutional ethical committee and the need for informed consent was waived. Patients with splenic injury who had undergone dual-phase CT and DSA were included. All the lesions that were hyperdense on AP were evaluated for their outline, their relation to the adjacent/parallel margins of a laceration (margin sign), string of beads appearance, and the presence of adjacent normal parenchyma (adjacent parenchyma sign). The Hounsfield unit (HU) of the lesion and the aorta on the AP were also noted. The diagnostic accuracy of various signs for distinguishing UBOS from splenic vascular injuries was calculated using DSA as the reference standard.RESULTSOf 48 patients, 5 were excluded due to suboptimal quality of the examination or a time difference of more than 6 hours between the CT and DSA. A total of 54 hyperdense lesions were detected on AP in 43 patients. These were classified as vascular injuries (pseudoaneurysm, n=11; active contrast extravasation, n=11) and UBOS (n=32) based on DSA. The margin sign, string of beads appearance, and ill-defined outline had high specificity (95%, 86%, and 82%, respectively) but low sensitivity (50%, 65%, and 63%, respectively). The adjacent parenchyma sign had a moderate sensitivity and specificity of 84% and 77%, respectively. ROC analysis showed that a difference of 50 HU between the aorta and the lesion had a high sensitivity and specificity of 88.9% and 90.6%, respectively, with an area under the curve of 0.90.CONCLUSIONAn attenuation difference of over 50 HU between the aorta and the lesion and the presence of normal adjacent parenchyma had the highest diagnostic accuracy, while an ill-defined outline, string of beads appearance, and margin sign had high specificity but low sensitivity for differentiating UBOS from splenic vascular injuries.

Although there is a wide variation in the computed tomography (CT) protocol for the evaluation of blunt abdominal trauma across centers, arterial phase (AP) CT is increasingly being used as part of the evaluation (1–3). AP is usually acquired as a part of whole-body (chest and abdomen) CT angiography followed by a portal venous phase (PVP) acquisition of the abdomen (4–7). AP has been shown to increase the sensitivity of CT for the detection of splenic vascular injuries like pseudoaneurysms (6–9). These appear hyperdense relative to the surrounding parenchyma on AP, leading to better detection rates on AP. However, due to poorly understood mechanisms, the splenic parenchyma shows heterogeneous enhancement in the arterial phase (10–14). This is further exaggerated in the presence of parenchymal injuries like laceration following blunt abdominal trauma leading to the appearance of hyperdense areas on AP which may masquerade as intraparenchymal pseudoaneurysms or active extravasations.We describe unidentified bright objects of spleen (UBOS) as hyperdense areas seen in relation to splenic lacerations on AP CT which are isodense to the normal parenchyma on PVP with no abnormal correlate on digital subtraction angiography (DSA). As most splenic vascular injuries are hyperdense on AP and some of them isodense on PVP, these UBOS closely mimic splenic vascular injuries (Fig. 1).Open in a separate windowFigure 1. a, bIllustration depicting the imaging features of unidentified bright objects of spleen (UBOS) and pseudoaneurysm: UBOS (a, asterisk) show ill-defined outline, normal adjacent parenchyma, string of beads appearance due to multiple adjacent lesions, the presence of lesions on adjacent/parallel margins of laceration. Also, UBOS show no communication with the arterial and is less bright than the adjacent arteries (depicting lesser HU). Pseudoaneurysm (b, asterisk) shows a well-defined lesion with no adjacent normal parenchyma in direct communication with an artery. Brown shaded area represents a laceration with intraparenchymal hematoma.The 2018 revision of the organ injury scale for splenic injuries by the American Association for Surgery in Trauma (AAST) has incorporated CT-diagnosed vascular injuries into the grading system. The grade of injury is upgraded to grade 4/grade 5 if there are associated splenic vascular injuries irrespective of the grade of parenchymal injuries (15–17). Hence, it is imperative to accurately diagnose the splenic vascular injuries on CT and to differentiate UBOS, a previously undescribed entity, from splenic vascular injuries, as it would have implications on the grading of injury and further management.There are no studies describing such an entity or its imaging features. We undertook this retrospective study to describe CT features of UBOS and to identify features that can differentiate UBOS from pseudoaneurysms or active extravasations and test their diagnostic accuracy.     

Optimizing multidetector CT for visualization of splenic vascular injury. Validation by splenic arteriography in blunt abdominal trauma patients

Nonoperative management of blunt splenic injury is the treatment of choice in hemodynamically stable patients. Detection of vascular injury by multidetector CT (MDCT) is the most significant factor predicting the need for endovascular treatment. This study evaluated the timing of the appearance of vascular lesions during angiography. Images from 20 patients embolized for pseudoaneurysms (PSA) were evaluated. Angiograms were reviewed for phase and timing of PSA. Admission MDCT was reviewed for injury grade and PSA. Initial MDCT evaluation indicated grade III and IV splenic injuries in 9 and 11 patients, respectively. PSA was seen on MDCT in 14/20 (70%) patients. Time from opacification of the aorta to vascular injury was 1.32 s for arterial phase injuries compared with 2.05 s for postcapillary injuries (P = 0.097). Angiography demonstrated 15 vascular injuries during the arterial and 5 in the venous phase. Of injuries seen during arterial phase angiography, 10/15 (66%) were identified on MDCT. Of the five injuries that exhibited postcapillary-phase findings, 4/5 (80%) demonstrated PSA (P = 0.5). Vascular lesions are a better indicator of subsequent clinical deterioration than splenic injury grade. PSAs are more frequently seen in postcapillary vascular injuries than arterial phase lesions with the current timing of MDCT. In a subset of patients in whom splenic injury grades III and IV warrant angiography, PSAs are not initially demonstrated on MDCT. Therefore, alteration of MDCT timing parameters to better correlate with arterial phase angiography may improve initial diagnosis of vascular injury.     

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.     

Bladder injury in blunt pelvic trauma

Clinical and radiologic findings in 97 patients with bladder injury secondary to blunt pelvic trauma were reviewed. Fifty-five patients had extraperitoneal bladder rupture; 35, intraperitoneal rupture; two, interstitial bladder injury; and five, combined intraperitoneal and extraperitoneal bladder rupture. Of the 61 of 97 patients with film studies available for review, two patients with surgically proved intraperitoneal rupture had false-negative cystograms. In two other cases of intraperitoneal rupture, the diagnosis was established with cystography but was not demonstrated with urography. All cases of extraperitoneal rupture were demonstrated cystographically; in 15 cases in this group, the injury was complex, with extravasation of contrast material beyond the confines of the perivesical space. In two additional patients, incomplete bladder injury termed "interstitial bladder rupture" was identified. A classification of bladder injury based on cystographic patterns of extravasation is proposed.     

钝性腹部创伤的诊断与治疗

探讨钝性腹部创伤的诊断与治疗。正确选择治疗方案,重视围手术期和合并伤的整体处理,是提高治愈率降低病死率的关键。     

闭合性腹部损伤的诊治体会

回顾分析148例腹部闭合性损伤的临床资料,对比各种诊断方法和治疗结果.认为腹部穿刺、B超检查是诊断腹部闭合性损伤的简便有效的方法,适时剖腹探查,及时手术能降低其病死率.     

CT features of blunt abdominal aortic injury: an infrequent but life-threatening event

Emergency Radiology - Blunt injury to the abdominal aorta is a rare but potentially fatal event. Despite being much less common than thoracic aorta involvement, it carries high morbidity and...     

Abdominal aortic injury in blunt abdominal trauma

Injury to the abdominal aorta secondary to blunt abdominal trauma is rare; less than 50 cases have been reported in the literature. This patient failed to demonstrate any of the classic acute signs or symptoms specific to the aortic injury, thus emphasizing the importance of a high index of suspicion in patients with the appropriate mechanism and location of injury and associated signs and symptoms.     

胰腺及肾上腺闭合性损伤的CT诊断

目的:探讨腹部闭合性外伤所致胰腺及肾上腺损伤的CT表现特征,评价CT的应用价值。方法:回顾性分析23例经手术或随访证实的闭合性腹部外伤致胰腺及肾上腺损伤的临床与CT检查资料。结果:胰腺损伤19例,其中颈体部断裂11例,体尾交界部、胰头胰体部分断裂各3例,胰腺挫伤2例,主要表现为胰腺血肿,胰腺裂隙样或条状低密度影及外伤性胰腺炎改变。肾上腺损伤4例,均位于右侧,主要CT表现肾上腺区血肿,脂肪间隙模糊,其内可见条状高密度影。合并多脏器损伤8例。结论:CT能较准确的反映胰腺及肾上腺的损伤病理解剖改变,特别是胰腺断裂等重症患者,为临床制定治疗方案和疗效观察提供可靠的依据。     

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。     

闭合性腹部外伤致胰腺损伤的CT诊断(附15例报告)

目的:评价CT对闭合性腹部外伤所致胰腺损伤的临床诊断价值。方法:回顾性分析15例经手术证实的闭合性腹部外伤所致胰腺损伤的CT征象。结果:15例闭合性腹部外伤所致胰腺损伤中,胰腺挫伤5例,胰腺完全性断裂6例,胰腺不完全性断裂1例,胰腺出血3例。胰腺内出血、水肿,胰腺增粗是胰腺挫伤的直接征象;胰腺外形不连续、平扫或增强时垂直胰腺长轴的低密度、线条状影是胰腺断裂的直接征象。胰周积液、网膜囊积血积液,肾前筋膜增厚,腹腔积液是胰腺损伤的间接征象。结论:CT检查对胰腺损伤的诊断价值较大,CT增强比平扫更能明确胰腺的断裂;CT检查对于主胰管的断裂的诊断价值有待进一步研究。     

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.     

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.