The role of computed tomography in the diagnosis and management of clinically occult post-traumatic small bowel perforation

PurposeTo evaluate the use of computed tomography [CT] in the diagnosis of occult post-traumatic small bowel perforation and to discuss the role of CT in the management of this patient group.MethodThis review includes three patients who presented with mild abdominal symptoms following minor blunt abdominal trauma. Initial radiographs and laboratory investigations were unremarkable but their symptoms failed to resolve and contrast-enhanced CT was performed for further evaluation.ResultsIn each case the CT appearances were indicative of localised small bowel perforation, with no evidence of other visceral injury. In two patients pockets of free intraperitoneal air were present closely related to the second part of the duodenum suggesting injury at this site. In the third case, a thickened proximal jejunal loop was demonstrated with free air and fluid in the adjacent mesentery consistent with a focal perforation. These CT findings were subsequently confirmed at laparotomy.ConclusionCT is an accurate diagnostic tool in the assessment of clinically and radiologically occult traumatic small bowel injury. The use of CT should be considered in patients who have unresolving abdominal symptoms even after apparently insignificant abdominal trauma.     

Pancreatic trauma: The role of computed tomography for guiding therapeutic approach

AIM: To evaluate the role of computed tomography (CT) for diagnosing traumatic injuries of the pancreas and guiding the therapeutic approach.METHODS: CT exams of 6740 patients admitted to our Emergency Department between May 2005 and January 2013 for abdominal trauma were retrospectively evaluated. Patients were identified through a search of our electronic archive system by using such terms as “pancreatic injury”, “pancreatic contusion”, “pancreatic laceration”, “peri-pancreatic fluid”, “pancreatic active bleeding”. All CT examinations were performed before and after the intravenous injection of contrast material using a 16-slice multidetector row computed tomography scanner. The data sets were retrospectively analyzed by two radiologists in consensus searching for specific signs of pancreatic injury (parenchymal fracture and laceration, focal or diffuse pancreatic enlargement/edema, pancreatic hematoma, active bleeding, fluid between splenic vein and pancreas) and non-specific signs (inflammatory changes in peri-pancreatic fat and mesentery, fluid surrounding the superior mesenteric artery, thickening of the left anterior renal fascia, pancreatic ductal dilatation, acute pseudocyst formation/peri-pancreatic fluid collection, fluid in the anterior and posterior pararenal spaces, fluid in transverse mesocolon and lesser sac, hemorrhage into peri-pancreatic fat, mesocolon and mesentery, extraperitoneal fluid, intra-peritoneal fluid).RESULTS: One hundred and thirty-six/Six thousand seven hundred and forty (2%) patients showed CT signs of pancreatic trauma. Eight/one hundred and thirty-six (6%) patients underwent surgical treatment and the pancreatic injures were confirmed in all cases. Only in 6/8 patients treated with surgical approach, pancreatic duct damage was suggested in the radiological reports and surgically confirmed in all cases. In 128/136 (94%) patients who underwent non-operative treatment CT images showed pancreatic edema in 97 patients, hematoma in 31 patients, fluid between splenic vein and pancreas in 113 patients. Non-specific CT signs of pancreatic injuries were represented by peri-pancreatic fat stranding and mesentery fluid in 89% of cases, thickening of the left anterior renal fascia in 65%, pancreatic ductal dilatation in 18%, acute pseudocyst/peri-pancreatic fluid collection in 57%, fluid in the pararenal spaces in 45%, fluid in transverse mesocolon and lesser sac in 29%, hemorrhage into peri-pancreatic fat, mesocolon and mesentery in 66%, extraperitoneal fluid in 66%, intra-peritoneal fluid in 41% cases.CONCLUSION: CT represents an accurate tool for diagnosing pancreatic trauma, provides useful information to plan therapeutic approach with a detection rate of 75% for recognizing ductal lesions.     

Evaluation of the role of chest computed tomography in the management of trauma patients

The role of chest computed tomography (CT) in the management of trauma patients is evolving. The present study reviews the chest radiographic and chest CT findings in a group of trauma patients to determine the clinical impact of findings noted exclusively on chest CT.Fifty-five trauma patients examined with chest radiography and chest CT and whose clinical charts were available for review were retrospectively identified. There were 46 men and 9 women, with a mean age of 39 years. The presence (and size) of pneumothorax, hemothorax, pulmonary contusion, and fractures was tabulated for the chest radiographs and CT scans. The presence of mediastinal widening on chest radiographs and all mediastinal findings on CT were noted. The results of aortography, when applicable, were correlated. The clinical charts were reviewed to assess the impact of CT findings on patient management.Pneumothorax (P<0.05), hemothorax (P<0.05), pulmonary contusions, and fractures were noted more frequently on chest CT than on chest radiography. However, clinical management was affected in only three (5%) of these patients. Chest CT findings related to the mediastinum affected patient management in 13 (24%) patients. CT obviated the need for aortography in 7 of 10 patients with mediastinal widening on chest radiographs. Six other patients had aortography, four for mediastinal hematoma with a normal-appearing aorta on contrast medium-enhanced CT, and two for mediastinal hematoma and aortic injury on CT.Despite detection of significantly more pneumothoraces and hemothoraces on chest CT, clinical management was affected in only a small minority (5%) of cases. CT did prove useful in evaluating the mediastinum, obviating the need for aortography in 7 of 10 patients with a widened mediastinum on chest radiography and accurately diagnosing the presence and site of aortic injury in the two patients with that diagnosis.     

Small bowel obstruction: the role of computed tomography in its diagnosis and management with reference to other imaging modalities

Small bowel obstruction is a leading cause of acute surgical admissions for abdominal pain. There is an increasing tendency for initial conservative management rather than immediate operative intervention, as a proportion of cases will resolve spontaneously. This has resulted in a growing reliance on radiological investigations to reassure the surgeon that medical therapy can be safely instituted. The onus therefore rests with radiologists to guide their surgical colleagues by correctly interpreting the plain abdominal radiograph and suggesting appropriate further investigation if warranted. Recently, computed tomography (CT) has been proposed as the test of choice to define the level and cause of acute small bowel obstruction and to identify complications such as ischaemia and perforation which will prompt surgical intervention. This review will discuss the utility of early CT in the diagnosis of acute small bowel obstruction and outline its impact on patient management.     

Splenic abnormalities: a comparative review of ultrasound, microbubble-enhanced ultrasound and computed tomography

The ultrasound appearances of abnormalities of the spleen are reviewed and images compared with computed tomography. Focal lesions, both benign and malignant, trauma, infarction and congenital abnormalities are presented. The use of microbubble ultrasound contrast media as an aid to identifying and characterizing abnormalities is discussed.     

Evaluating the role of ultrasound in chest trauma: Common complications and computed tomography comparative evaluation

Objective

to establish the role of transthoracic ultrasound as a bed-side, available, and affordable technique for imaging chest trauma patients and compared its sensitivity, specificity and accuracy for detecting chest trauma sequelae and complications to those of CT.

A standardized method for computed tomography of the orbits

Summary A standardized method for the CT exploration of the orbital region has been searched for. This method makes it possible to visualize the entire orbital region with a minimum of 4 tomographic scans, each section 6 mm thick. The reference line chosen for this exploration is parallel to the optic nerve and joins the projection of the inferior border of the orbit on the lateral view with the upper border of the ear to the scalp. After each tomographic scan the patient is moved so that the new scanning line is still parallel to the reference line but distant by 9 mm from the previous one.     

Multi-detector row computed tomography: imaging in acute aortic syndrome

Acute aortic syndromes (AAS) encompass a spectrum of emergencies. These include those non-traumatic disease entities of the aorta namely, penetrating atherosclerotic ulcer, intramural haematoma, dissection and aneurysm rupture. The various types of AAS cannot be reliably differentiated on clinical grounds alone. Acute thoracic aortic injury is usually included in this group even though clinical presentation is different, i.e., in the context of trauma, the imaging features are very similar. Differentiation of AAS from acute coronary syndrome (ACS) is important, however, it must be remembered that ACS may occur as a result of AAS. Now electrocardiogram (ECG)-gating technology is widely available, ECG-gated multi-detector row computed tomography (MDCT) is a powerful clinical tool in the acute emergency setting, which enables rapid and specific diagnosis of aortic pathology. ECG-gated MDCT significantly reduces motion artefact, avoids potential pitfalls in diagnosis and often provides diagnostic information about the coronary arteries. It should be used as a first-line imaging technique. This article examines the role of MDCT imaging and cardiac gating in the assessment of AAS and discusses the differentiation of this spectrum of aortic diseases with reference to the key imaging findings as obtained by experience in our institution.     

Hyperdense artery sign on computed tomography in acute ischemic stroke

Despite the advent and growing availability of magnetic resonance imaging, the imaging modality of choice in the acute care of stroke patients in many institutions remains computed tomography. The hyperdense artery sign is the earliest marker of acute ischemic stroke. In this short review, we discuss the pathology, incidence, clinical aspects, imaging findings, significance and future questions that need to be addressed concerning this important sign.     

Measurement of orbital volumes following trauma using low-dose computed tomography

We describe a simple CT technique for the assessment of enophthalmos and measurement of orbital volumes following trauma. The technique uses original diagnostic CT images, standard CT software and involves no additional radiation dose or scan time. The results of this technique in 66 patients with orbital trauma are presented. The incidence of post-traumatic enophthalmos was significantly raised in association with combined blow-out fractures of the floor and medial wall of the orbit and where orbital blow-out fractures occurred in conjunction with zygomatic injury. Patients without bony imjury had a traumatised orbit volume less than 1 cm³ greater than the non-traumatised side in all cases. Intra-observer reproducibility of the measurement of difference in volume between traumatised and non-traumatised orbit was ± 0.3 cm³ (1 SD). In patients with fracture, increase in orbital volume by more than 2 cm³ compared with the contralateral orbit was strongly associated with enophthalmos (sensitivity 100%, positive predictive value 69%). We conclude that routine volumetric assessment following orbital trauma provides a clinically useful, objective assessment of the risk of post-traumatic enophthalmos and that an increase in orbital volume greater than 2 cm³ is an indication for surgical repair.Correspondence to: R. W. Whitehouse     

Paediatric computed tomography radiation dose: A review of the global dilemma简

Computed tomography (CT) has earned a well-deserved role in diagnostic radiology, producing cross-sectional and three-dimensional images which permit enhanced diagnosis of many pathogenic processes. The speed, versatility, accuracy, and non-invasiveness of this procedure have resulted in a rapid increase in its use. CT imaging, however, delivers a substantially higher radiation dose than alternative imaging methodologies, particularly in children due to their smaller body dimensions. In addition, CT use in children produces an increased lifetime risk of cancer, as children’s developing organs and tissues are inherently more vulnerable to cellular damage than those of adults. Though individual risks are small, the increasing use of CT scans in children make this an important public health problem. Various organizations have recommended measures to minimize unnecessary exposures to radiation through CT scanning. These include elimination of multiple or medically unnecessary scans, development of patient-specific dosing guidelines, and use of alternative radiographic methodology wherever possible. Another important factor in excessive CT exposures, however, is a documented lack of awareness among medical practitioners of the doses involved in CT usage as well as its significant potential dangers. This review examines the effects of paediatric CT radiation, discusses the level of medical practitioner awareness of these effects, and offers recommendations on alternative diagnostic methods and practitioner education.     

Mobile computed tomography in the trauma/critical care environment: Preliminary clinical experience

This study reviews the initial clinical experience using a portable computed tomographic (CT) scanner in the trauma resuscitation unit (TRU), intensive care units (ICUs), and operating rooms (ORs) of a large trauma center. Data were collected on the first 200 patients scanned within the trauma center (including 92 in the TRU, 92 in the ICUs, and 16 in the ORs) over the first 5 months of operation. Evaluation forms were completed by interpreting radiologists, CT technicians operating the system, and nurses/clinicians involved with patients being scanned. Information sought included subjective image quality, ease of use, software and hardware limitations, accessibility to and monitoring of patients during scanning, mobility, and perceived advantages or limitations compared to fixed CT. Radiation scatter also was measured to determine the safety of the scanner for portable use.CT scans of 224 body regions performed in 200 patients included: cranium (163), cervical spine (21), abdomen/pelvis (14), chest (12), face (8), thoracic/lumbar spine (4), and temporal bone (2). Image quality was judged subjectively as excellent (107), good (99), poor (6), or artifact degraded (12). Patient transfer to the scanner was judged to be easy (63) or fair/difficult (4). Patient accessibility and monitoring during scanning was assessed as easy (61) or fair/difficult (6). Access in the smaller TRU bays was more difficult than in the ICU or OR. Cited advantages over fixed CT included decreased risk and cost of transport, quicker assessment of cranial injury on admission, and more rapid postcraniotomy assessment. Limitations cited were relatively slow scan speed, slightly poorer image quality, and technical limits on scanning multiple body regions. Radiation scatter was 25% of the ALARA (as low as reasonably achievable) target for the scanner operator. Initial clinical experience with mobile CT in the TRU, ICU, and OR of a major trauma center shows application for focused admission scanning, assessment of critically ill ICU patients, and immediate postoperative assessment after craniotomy. The system has been incorporated easily into the trauma center and has been accepted enthusiastically. Further technical improvements are anticipated to extend the range of applications in this clinical setting.     

Significance of incidental pericardial effusion on computed tomography in cardiac trauma: A report of two cases

We describe computed tomographic (CT) findings in two patients with cardiac injury who required emergency surgery. Chest CT revealed an unexpected low-density area, indicating pericardial effusion. We emphasize that, given the situation of trauma, an incidental low-density area covering more than two slices along the inferior border of the heart suggests pericardial effusion, which may be caused by cardiac injury.     

Comparison of computed tomography-enteroclysis and traditional computed tomography in the setting of suspected partial small bowel obstruction

Traditional computed tomography (CT) is sometimes limited in its ability to diagnose partial small bowel obstruction (SBO), especially if low grade. Standard enteroclysis is sensitive in diagnosing partial SBO; however, extraluminal abnormalities are not well visualized. CT-enteroclysis (CT-E) offers both crosssectional imaging and a contrast volume challenge. CT-E is compared to traditional abdominal/pelvic CT to identify any group(s) of patients who might benefit from having CT-E as the front-line examination. We performed a retrospective review of 36 patients who underwent both CT-E and traditional CT in the evaluation of suspected partial SBO. Chart review and surgical results were used as gold standards. Sensitivity, specificity, and accuracy were calculated and compared for each modality. Chart review was performed to identify the major referral categories for utilization review. Two referral categories were identified: (1) patients with a history of malignancy (N=15), and (2) patients with a benign medical or surgical history (N=21). Overall, CT-E was more sensitive (89%; 16 of 18 patients) in diagnosing partial SBO than was traditional CT (50%; 9 of 18). This was especially evident when considering only patients who presented with a history of malignancy. Of these patients, CT-E was 100% sensitive (8 of 8), whereas traditional CT was only 25% sensitive (2 of 8). The specificity of each modality was almost equivalent (100% for CT-E vs. 94% for CT). Of the patients with malignancy, CT-E was able to identify tumor involvement of the small bowel with 100% sensitivity (7 of 7), as compared with only 57% (4 of 7) for traditional CT. In patients with malignancy, CT-E was found to be superior to traditional CT in identifying partial SBO and in identifying small bowel intraluminal or intramural disease. The greater strength of CT-E is its superiority in excluding disease of the small bowel, a desired trait in the management of patients with malignancy. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or reflecting the views of the Department of the Army or of the Department of Defense.     

Posttraumatic enlargement of the spleen: A possible sign of delayed rupture

This report describes a bluntly, traumatized patient whose spleen underwent significant enlargement, as documented by serial computed tomographic scans before splenic rupture. It is proposed that posttraumatic splenic enlargement is a possible sign of impending splenic rupture.     

The halo sign and peripancreatic fluid: useful CT signs of hypovolaemic shock complex in adults

AIM: To report two new, useful computed tomography (CT) signs of the hypovolaemic shock complex (HSC) in adults admitted after blunt abdominal trauma: the halo sign (ring of fluid around a collapsed intra-hepatic inferior vena cava (IVC)), and peripancreatic retroperitoneal fluid. MATERIALS AND METHODS: CT images of 498 consecutive patients admitted after blunt abdominal trauma were reviewed, of which 27 had CT signs of the HSC. The CT images of these 27 patients were analysed. A control group of 101 patients examined using CT for suspected blunt abdominal trauma who did not have the HSC were chosen for comparison. RESULTS: The most common features involved the vascular compartment: diminished IVC diameter n = 27 a positive halo sign n = 21 diminished anteroposterior diameter of the aorta n = 13 and abnormal vascular enhancement n = 10. Peripancreatic retroperitoneal fluid in the absence of pancreatic injury, pancreatitis or pancreatic disease was observed in eight patients. Hollow visceral abnormalities included: diffuse increased mucosal enhancement of both the small and large bowel n = 19 diffuse thickening of the small bowel wall n =11 and small bowel dilatation n = 7. Solid visceral abnormalities included both decreased and or increased enhancement. Several concomitant intra- and extra-abdominal injuries were also identified. CONCLUSION: In the setting of blunt abdominal trauma, early abdominal CT can show diffuse abnormalities due to the HSC, which occasionally may alert clinicians of unsuspected shock. Recognition of these signs as distinguished from injured viscera is important in order to avoid unnecessary laparotomy. Two new signs are described: the halo sign and peripancreatic retroperitoneal fluid.     

Evaluation of personal digital assistants as an interpretation medium for computed tomography of patients with intracranial injury

The objective of the study was to assess the feasibility of using a personal digital assistant (PDA) as a medium for the interpretation of cranial CT scans of trauma patients. Twenty-one noncontrast cranial CT scans were transferred in their entirety to a PDA from the picture archiving and communications system (PACS) utilizing General Electric (GE) PathSpeed PACS Web Server interface and synchronization. All CT scans had been interpreted by board-certified radiologists prior to the study. Seven of the scans demonstrated subarachnoid hemorrhage, seven demonstrated subdural hematomas, and the remaining scans were normal. After transfer to the PDA, all images were separately reviewed in a blinded manner by a radiologist and a neurosurgeon. Images were graded for their quality and diagnostic utility in the evaluation of intracranial hemorrhage. Image quality was categorized as excellent, very good, acceptable for diagnosis, or not acceptable for diagnosis. Based on the radiologic diagnosis, recommendation for surgical management was made by the reviewing neurosurgeon. The accuracy rate for both the radiologist and the neurosurgeon in the detection of intracranial hemorrhage was 95%. There was one false negative which was attributed to error in judgment rather than poor image quality. This diagnostic error did not affect patient management. The sensitivity and specificity for detection of intracranial hemorrhage were 93% and 100%, respectively. Image quality was judged to be excellent in 90% of the cases and very good in the remaining 10%. Our results suggest that the PDA is a robust medium for interpretation of CT scans in patients with suspected hemorrhage following intracranial injury. In this setting, the PDA should be considered for teleradiology purposes.     

Timing of exposure in angiographic computed tomography

Visualization of heart chambers or the abdominal arterial phase on one of two CT-scans was achieved in 89.4% of 169 injections (91 patients) using only 30 ml of contrast medium (370 mg iodine/ml), when the start of scanning was accurately timed at predicted bolus peak concentration. Normal arrival times and numer of transit cycles to the bolus concentration maximum in the right (RV) and left ventricle (LV) after injection of a small radionuclide bolus of technetium-99 m were related to the patient's heart rate (HR) in a group of 200 patients. For the RV, mean arrival times varied significantly between 2.31 (HR: 90–109 beats per minute) and 3.46 seconds (HR: 50–59 beats per minute), mean number of transit cycles between 4.1 and 3.5. For the LV, mean arrival times varied significantly between 6.92 (HR: 90–109 beats per minute) and 11.37 seconds (HR: 50–59 beats per minute), and the mean number of transit cycles between 11.5 and 10.7. Washout from the LV lasted between an average of 9.2 (HR: 90–109 beats per minute) and 8.5 cycles (HR: 50–59 beats per minute). Contrary to actual transit times, there was no significant difference in the number of transit heart cycles for heart rates between 60 and 109 beats per minute, so that to determine the scan starting time, the patient's cycle length (60 divided by heart rate) had only to be multiplied by the corresponding normal value of transit cycles, i.e., four for the RV, 11 for the LV, and 13 for the abdominal arteries. By applying the estimated values, the result was negative on two successive scans in only 10.6% because of failure in coordination on the part of the operators or bolus transit delays (due to severe heart failure, severe lung disease, recent thoracotomy, or small veins disease). With automatic triggering of the scanner by a timer and injector and with a flush of saline after injection, results can be further improved. Radionuclide studies supported by grant of the Internal Department of the Government of the Federal Republic of Germany     

Limitations of computed tomography for diagnostic Neuroradiology

Summary The limitations of computed tomography for diagnostic Neuroradiology are pointed out. The relation of CT to the classical neuroradiological examinations are discussed.