Blunt injury to mesentery and small bowel:

Intraperitoneal anatomy with the aid of pathologic fluid and gas: An imaging pictorial review

The peritoneum is a large serosal membrane enveloping the abdomen and pelvic organs and forming the peritoneal cavity. This complex relationship forms many named abdominopelvic spaces, which are frequently involved in infectious, inflammatory, neoplastic, and traumatic pathologies. The knowledge of this anatomy is essential to the radiologist to localize and describe the extent of the disease accurately. This manuscript provides a comprehensive pictorial review of the peritoneal anatomy to describe pathologic fluid and gas.

Evaluation of Bowel and Mesentery in Abdominal Trauma

Since the advent of multidetecter computed tomography (CT), radiologist sensitivity in detection of traumatic bowel and mesenteric abnormalities has significantly improved. Although several CT signs have been described to identify intestinal injury, accurate interpretation of these findings can remain challenging. Early detection of bowel and mesenteric injury is important as it alters patient management, disposition, and follow-up. This article reviews the common imaging findings of traumatic small bowel and mesenteric injury.

Can multidetector CT detect the site of gastrointestinal tract injury in trauma? - A retrospective study

PURPOSE

We aimed to assess the performance of computed tomography (CT) in localizing site of traumatic gastrointestinal tract (GIT) injury and determine the diagnostic value of CT signs in site localization.

METHODS

CT scans of 97 patients with surgically proven GIT or mesenteric injuries were retrospectively reviewed by radiologists blinded to surgical findings. Diagnosis of either GIT or mesenteric injuries was made. In patients with GIT injuries, site of injury and presence of CT signs such as focal bowel wall hyperenhancement, hypoenhancement, wall discontinuity, wall thickening, extramural air, intramural air, perivisceral infiltration, and active vascular contrast leak were evaluated.

RESULTS

Out of 97 patients, 90 had GIT injuries (70 single site injuries and 20 multiple site injuries) and seven had isolated mesenteric injury. The overall concordance between CT and operative findings for exact site localization was 67.8% (61/90), partial concordance rate was 11.1% (10/90), and discordance rate was 21.1% (19/90). For single site localization, concordance rate was 77.1% (54/70), discordance rate was 21.4% (15/70), and partial concordance rate was 1.4% (1/70). In multiple site injury, concordance rate for all sites of injury was 35% (7/20), partial concordance rate was 45% (9/20), and discordance rate was 20% (4/20). For upper GIT injuries, wall discontinuity was the most accurate sign for localization. For small bowel injury, intramural air and hyperenhancement were the most specific signs for site localization, while for large bowel injury, wall discontinuity and hypoenhancement were the most specific signs.

CONCLUSION

CT performs better in diagnosing small bowel injury compared with large bowel injury. CT can well predict the presence of multiple site injury but has limited performance in exact localization of all injury sites.

Are We Missing Traumatic Bowel and Mesenteric Injuries?

Purpose

Traumatic bowel and mesenteric injury (TBMI), although an uncommon entity, can be lethal if not detected and treated in a timely manner. The purpose of our study was to evaluate the diagnostic accuracy of 64-slice multidetector computed tomography (MDCT) for the detection of TBMI in patients at our level 1 trauma centre.

Methods

We used our hospital's trauma registry to identify patients with a diagnosis of TBMI from January 1, 2006, to June 30, 2013. Only patients who had a 64-slice MDCT scan at presentation and subsequently underwent laparotomy or laparoscopy were included in the study cohort. Using the surgical findings as the gold standard, the accuracy of prospective radiology reports was analyzed.

Results

Of the 4781 trauma patients who presented to our institution, 44 (0.92%) had surgically proven TBMI. Twenty-two of 44 were excluded as they did not have MDCT before surgery. The study cohort consisted of 14 males and 8 females with a median age of 41.5 years and a median injury severity score of 27. In total 17 of 22 had blunt trauma and 5 of 22 had penetrating injury. A correct preoperative imaging diagnosis of TBMI was made in 14 of 22 of patients. The overall sensitivity of the radiology reports was 63.6% (95% confidence interval [CI]: 41%-82%), specificity was 79.6% (95% CI: 67%-89%), PPV was 53.9% (95% CI: 33%-73%), and the NPV was 85.5% (95% CI: 73%-94%). Accuracy was calculated at 75.3%. However, only 59% (10 of 17) of patients with blunt injury had a correct preoperative diagnosis. Review of the findings demonstrated that majority of patients with missed blunt TBMI (5 of 7) demonstrated only indirect signs of injury.

Conclusion

The detection of TBMI in trauma patients on 64-slice MDCT can be improved, especially in patients presenting with blunt injury. Missed cases in this population occurred because the possibility of TBMI was not considered despite the presence of indirect imaging signs. The prospective diagnosis of TBMI remains challenging despite advances in CT technology and widespread use of 64-slice MDCT.

Unenhanced Computed Tomography to Visualize Hollow Viscera and/or Mesenteric Injury After Blunt Abdominal Trauma: A Single-Institution Experience

To identify and describe the major features of unenhanced computed tomography (CT) images of blunt hollow viscera and/or mesenteric injury (BHVI/MI) and to determine the value of unenhanced CT in the diagnosis of BHVI/MI. This retrospective study included 151 patients who underwent unenhanced CT before laparotomy for blunt abdominal trauma between January 2011 and December 2013. According to surgical observations, patients were classified as having BHVI/MI (n = 73) or not (n = 78). Sensitivity, specificity, P values, and likelihood ratios were calculated by comparing CT findings between the 2 groups. Six significant CT findings (P < 0.05) for BHVI/MI were identified and their sensitivity and specificity values determined, as follows: bowel wall thickening (39.7%, 96.2%), mesentery thickening (46.6%, 88.5%), mesenteric fat infiltration (12.3%, 98.7%), peritoneal fat infiltration (31.5%, 87.1%), parietal peritoneum thickening (30.1%, 85.9%), and intra- or retro-peritoneal air (34.2%, 96.2%). Unenhanced CT scan was useful as an initial assessment tool for BHVI/MI after blunt abdominal trauma. Six key features on CT were correlated with BHVI/MI.

Bowel and mesenteric injuries from blunt abdominal trauma: a review

The bowel and the mesentery represent the third most frequently involved structures in blunt abdominal trauma after the liver and the spleen. Clinical assessment alone in patients with suspected intestinal and/or mesenteric injury from blunt abdominal trauma is associated with unacceptable diagnostic delays. Multi-detector computed tomography, thanks to its high spatial, time and contrast resolutions, allows a prompt identification and proper classification of such conditions. The radiologist, in fact, is asked not only to identify the signs of trauma but also to provide an indication of their clinical significance, suggesting the chance of conservative treatment in the cases of mild and moderate, non-complicated or self-limiting injuries and focusing on life-threatening conditions which may benefit from immediate surgical or interventional procedures. Specific and non-specific CT signs of bowel and mesenteric injuries from blunt abdominal trauma are reviewed in this paper.

Clinical guidelines for imaging and reporting ingested foreign bodies

OBJECTIVE

The purpose of this article is to familiarize radiologists with the specific characteristics of foreign bodies, obtained from image interpretation, to guide further management. Details of object morphologic characteristics and location in the body gained through imaging form the backbone of the classification used in the treatment of ingested foreign bodies.

CONCLUSION

The characteristics of foreign bodies and predisposing bowel abnormalities affect the decision to follow ingested objects radiographically, perform additional imaging, or proceed with endoscopic or surgical removal.

Blunt hollow viscus and mesenteric injury: still underrecognized

BACKGROUND

Despite the availability of more accurate imaging modalities, specifically multidetector computed tomography (MDCT), the diagnosis of non-ischemic (NI-) and ischemic (I-) blunt hollow viscus and mesenteric injury (BHVMI) remains challenging. We hypothesized that BHVMI can be still missed with newer generations of MDCT and that patients with I-BHVMI have a poorer outcome than those with NI-BHVMI.

METHODS

We performed an eight-year retrospective review at a level 1 trauma center. Ischemic-BHVMI was defined as devascularization confirmed at laparotomy. Non-ischemic-BHVMI included perforation, laceration, and hematoma without devascularization. The sensitivity of each generation of MDCT for BHVMI was calculated. Potential predictors and outcomes of I-BHVMI were compared to the NI-BHVMI group.

RESULTS

Of 7,875 blunt trauma patients, 67 patients (0.8 %) were included in the BHVMI group; 13 patients did not have any CT findings suggestive of BHVMI (sensitivity 81 %), and 11 of them underwent surgical intervention without delay (<5 h). Newer generations of MDCT were not associated with higher sensitivity. Patients with I-BHVMI had a significantly higher rate of delayed laparotomy ≥ 12 h (23 % versus 2 %; p = 0.01) and a significantly longer length of hospital stay (median 14 versus 9 days; p = 0.02) than those with NI-BHVMI.

CONCLUSIONS

Even using an advanced imaging technique, the diagnosis of I-BHVMI can be delayed, with significant negative impact on patient outcome.

Predicting hollow viscus injury in blunt abdominal trauma with computed tomography

BACKGROUND

Evaluation of blunt abdominal trauma is controversial. Computed tomography (CT) of the abdomen is commonly used but has limitations, especially in excluding hollow viscus injury in the presence of solid organ injury. To determine whether CT reports alone could be used to direct operative treatment in abdominal trauma, this study was undertaken.

METHODS

The trauma database at Auckland City Hospital was accessed for patients who had abdominal CT and subsequent laparotomy during a five-year period. The CT scans were reevaluated by a consultant radiologist who was blinded to operative findings. The CT findings were correlated with the operative findings.

RESULTS

Between January 2002 and December 2007, 1,250 patients were evaluated for blunt abdominal injury with CT. A subset of 78 patients underwent laparotomy, and this formed the study group. The sensitivity and specificity of CT scan in predicting hollow viscus injury was 55.33 and 92.06 % respectively. The positive and negative predictive values were 61.53 and 89.23 % respectively. Presence of free fluid in CT scan was sensitive in diagnosing hollow viscus injury (90 %). Specific findings for hollow viscus injuries on CT scan were free intraperitoneal air (93 %), retroperitoneal air (100 %), oral contrast extravasation (100 %), bowel wall defect (98 %), patchy bowel enhancement (97 %), and mesenteric abnormality (94 %).

CONCLUSIONS

CT alone cannot be used as a screening tool for hollow viscus injury. The decision to operate in hollow viscus injury has to be based on mechanism of injury and clinical findings together with radiological evidence.

Multi detector computed tomography in the diagnosis of bowel injury

Bowel Injuries are uncommonly associated with traumatic abdominal injuries. However, they are associated with significant morbidity and mortality and require operative intervention unlike solid organ injuries. Hence, early diagnosis is of paramount importance. Computed tomographic (CT) scan is a well-established and highly accurate imaging modality for the detection of solid organ injury after blunt abdominal trauma. However, its role in diagnosing hollow viscus injury remains controversial. The aim of our study was to analyze the accuracy of multidetector CT (MDCT) in the diagnosis of bowel injury. Imaging features of surgically proven cases of bowel injury were identified over 8-year period (i.e., from January 2003 to December 2010) and were retrospectively analyzed. There were 32 patients with age range of 3-90 years. There was only one female. Sensitivity of various CT signs specific to bowel injury (i.e., extravasation of contrast and discontinuity of bowel wall) was 15.62, and 28.12%, respectively. While that of signs suggestive of bowel injury were pneumoperitoneum, 62.5%; gas in the vicinity, 40.62%; bowel wall hematoma, 21.87%; bowel wall thickening, 75%; ascites, 78.12%; mesenteric hematoma, 46.87%; and mesenteric stranding, 40.62%. Based on the major and minor signs, a diagnosis of bowel injury could be made in all patients except one. The minor signs showed a higher sensitivity than the major signs. Hence, we recommend that multidetector CT should be used as the modality of choice in case of patients with suspected bowel injury. We also suggest that the minor signs should be given as much importance as the major signs.

CT imaging of blunt traumatic bowel and mesenteric injuries

Delayed diagnosis of a bowel or mesenteric injury resulting in hollow viscus perforation leads to significant morbidity and mortality from hemorrhage, peritonitis, or abdominal sepsis. The timely diagnosis of bowel and mesenteric injuries requiring operative repair depends almost exclusively on their early detection by the radiologist on computed tomography examination, because the clinical signs and symptoms of these injuries are not specific and usually develop late. Therefore, the radiologist must be familiar with the often-subtle imaging findings of bowel and mesenteric injury that will allow for appropriate triage of a patient who has sustained blunt trauma to the abdomen or pelvis.

The risk of intra-abdominal injuries in pediatric patients with stable blunt abdominal trauma and negative abdominal computed tomography

OBJECTIVES

This review examines the prevalence of intra-abdominal injuries (IAI) and the negative predictive value (NPV) of an abdominal computed tomography (CT) in children who present with blunt abdominal trauma.

METHODS

MEDLINE, EMBASE, and Cochrane Library databases were searched. Studies were selected if they enrolled children with blunt abdominal trauma from the emergency department (ED) with significant mechanism of injury requiring an abdominal CT. The primary outcome measure was the rate of IAI in patients with negative initial abdominal CT. The secondary outcome measure was the number of laparotomies, angiographic embolizations, or repeat abdominal CTs in those with negative initial abdominal CTs.

RESULTS

Three studies met the inclusion criteria, comprising a total of 2,596 patients. The overall rate of IAI after a negative abdominal CT was 0.19% (95% confidence interval [CI] = 0.08% to 0.44%). The overall NPV of abdominal CT was 99.8% (95% CI = 99.6% to 99.9%). There were five patients (0.19%, 95% CI = 0.08% to 0.45%) who required additional intervention despite their initial negative CTs: one therapeutic laparotomy for bowel rupture, one diagnostic laparotomy for mesenteric hematoma and serosal tear, and three repeat abdominal CTs (one splenic and two renal injuries). None of the patients in the latter group required surgery or blood transfusion.

CONCLUSIONS

The rate of IAI after blunt abdominal trauma with negative CT in children is low. Abdominal CT has a high NPV. The review shows that it might be safe to discharge a stable child home after a negative abdominal CT.

Blunt abdominal trauma: current imaging techniques and CT findings in patients with solid organ, bowel, and mesenteric injury

Imaging plays a critical role in the evaluation of patients with blunt abdominal trauma. In most institutions, computed tomography (CT) is the modality of choice when evaluating such patients. The purpose of this review is to highlight current techniques in trauma imaging and to review CT findings associated with solid organ, bowel, mesenteric, and diaphragmatic injury. In particular, emphasis is placed on the use of multidetector CT technology (MDCT), especially 64-row detector CT. The role of various techniques, including the use of oral and intravenous contrast, as well as the potential benefit of delayed imaging, is discussed.

[Pelvic and perineal trauma. Diagnosis and interventional radiotherapy]

The integration of multislice CT (MSCT) in the imaging of emergency trauma has led to a paradigm shift in trauma management. In case of hemodynamically instable patients, initial imaging is limited to a small set of standardized radiographs. Computed tomography is the imaging modality of choice for further diagnostic work-up. Consequently it should be used at an early stage and in a less restricted manner for complete assessment of the pelvic injury and to determine therapeutic management. The MSCT allows full assessment of bone, parenchymal, and vascular injuries in a single examination in the shortest time possible. High-resolution 3D imaging provides additional options. There is increasing support for primary use of MSCT in critically ill patients due to the comprehensive imaging it allows while maintaining a fast scan time. The potential and limitations of diagnostic imaging in pelvic ring fracture and associated injuries are explained. Indications for vascular interventions in arterial bleeding are discussed.

Impact of MDCT Angiography on the Use of Catheter Angiography for the Assessment of Cervical Arterial Injury After Blunt or Penetrating Trauma

OBJECTIVE

The objective of our study was to assess the impact of the increasing use of MDCT angiography in the setting of blunt and penetrating neck trauma on the use of digital subtraction angiography (DSA) at our institution, a level 1 trauma center.

MATERIALS AND METHODS

From January 2001 to December 2003, 57 patients were referred for CT angiography or DSA of the neck after blunt or penetrating neck trauma. All CT angiograms were acquired with a 4-MDCT scanner. The patients were divided into three groups on the basis of consecutive 12-month periods (2001, 2002, and 2003), and the initial imaging technique was recorded. The results of CT and digital subtraction angiograms were compared with operative findings and with clinical course, when available.

RESULTS

In 2001, 12 patients were referred for imaging: nine patients were evaluated initially with DSA and three patients were evaluated with CT angiography and subsequently with DSA. In 2002 and 2003, 11 and 34 patients, respectively, underwent CT angiography as the initial imaging examination. During these 2 years, no patient underwent DSA as the initial diagnostic test, but five patients underwent DSA after CT angiography for the following indications: evaluation of nondiagnostic CT angiograms (n = 1), confirmation of findings when requested by the clinical service (n = 2), and catheter-guided therapy (n = 2).

CONCLUSION

CT angiography has essentially replaced DSA as the study of choice for the initial evaluation of the neck vessels in the setting of blunt or penetrating trauma at our institution. CT angiography is adequate for the initial evaluation, allows appropriate triage of patients to conventional angiography or surgery for appropriate treatment, and can guide conservative management when appropriate.

[Traumatic perforation of the sigmoid colon: role of computed tomography]

The authors report a case of a delayed traumatic perforation of the sigmoid colon, presenting three days after a motor vehicle accident. A review of the literature is presented.

Blunt Abdominal Trauma: Performance of CT without Oral Contrast Material

PURPOSE

To retrospectively evaluate multi-detector row computed tomography (CT) without oral contrast material for depiction of bowel and mesenteric injuries that require surgical repair in patients with blunt abdominal trauma.

MATERIALS AND METHODS

The investigational review board approved the study. Informed consent was waived. CT reports for October 2001 to September 2003 were reviewed and 1082 patients were identified who had undergone abdominopelvic CT with a multi-detector row scanner and without oral contrast material. Findings were divided into four categories: negative, solid organ injury with or without hemoperitoneum, free fluid only, and suspected bowel or mesenteric injury. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated by comparing CT findings with laparotomy reports and hospital course.

RESULTS

CT findings were no intraabdominal injury (n = 932), solid organ injury only (n = 102), free fluid only (n = 34), and suspected bowel or mesenteric injury (n = 14). CT findings in patients suspected of having bowel or mesenteric injury were pneumoperitoneum with other secondary findings (n = 4), mesenteric hematoma and bowel wall abnormality (n = 2), mesenteric hematoma only (n = 4), and bowel wall thickening only (n = 4). In 11 patients, bowel or mesenteric injury was proved surgically. Thus, the study included 1066 true-negative, nine true-positive, two false-negative, and five false-positive results. Based on these data, sensitivity was 82% (95% confidence interval [CI]: 52%, 95%), specificity was 99% (95% CI: 98%, 99%), positive predictive value was 64% (95% CI: 39%, 83%), and negative predictive value was 99% (95% CI: 98%, 99%) for depiction of bowel and mesenteric injuries.

CONCLUSION

Multi-detector row CT without oral contrast material is adequate for depiction of bowel and mesenteric injuries that require surgical repair. Results are comparable with previously reported data for single-detector row helical CT with oral contrast material.

Multi-detector row CT imaging of blunt abdominal trauma

CT is the imaging modality of choice to evaluate hemodynamically stable patients suffering blunt abdominal trauma. During the past five years, single-slice helical CT has been replaced by multidetector row CT (MDCT). This development has revolutionized cross-sectional imaging for blunt trauma patients. Volumetric imaging with helical CT has been a major factor supporting the nonoperative management of solid organ injury. Trauma centers in the United States are replacing single-slice helical CT scanners with state-of-the-art MDCT in suites proximate to the patient receiving area and with facilities for monitoring and maintaining physiologic support. The ability to obtain high-resolution images with MDCT during optimal contrast enhancement at unparalleled speed helps detect the presence and define the extent of injuries, and crucially, to diagnose hemorrhage and vascular injuries. This article describes our current imaging protocol with MDCT-16 (i.e., 16 detector MDCT), the spectrum of diagnostic findings seen in blunt abdominal injury, and the role of MDCT in the characterization of hemorrhage and planning injury management.