CT of aortoenteric fistulas

We compared CT findings with endoscopic, angiographic and surgical results in ten patients suspected of having an aortoenteric fistula (AEF) because of gastrointestinal bleeding (seven) or recurrent sepsis (three). CT correctly diagnosed AEF in six patients and excluded it in the other four. CT findings of AEF consisted of perigraft fluid (PGF) (5/6) and/or gas within the bed of the graft (4/6) later than three months after graft surgery. All six patients with AEF had perigraft infections; PGF with gas was found in 50%, PGF alone in 33%, and in one patient perigraft gas alone was found. Angiography and endoscopy failed to identify AEF. Our findings indicate that CT should be the initial imaging procedure in patients with suspected AEF who do not require immediate surgical intervention.     

Aortoenteric fistula and perigraft infection: evaluation with CT

A blinded retrospective study was performed to determine the sensitivity and specificity of computed tomography (CT) in detecting perigraft infection (PGI) and aortoenteric fistula (AEF), rare but devastating complications of aortic reconstructive surgery. Two observers independently reviewed CT scans in 55 cases including AEF (n = 23); PGI (n = 12); and normal, noninfected grafts (n = 20). Each scan was assessed for ectopic gas, focal bowel wall thickening, perigraft fluid, perigraft soft tissue, pseudoaneurysm formation, disruption of the aneurysmal wrap, and increased soft tissue between the graft and surrounding wrap. Comparison of CT findings with operative results revealed that each observer correctly identified as abnormal 33 of 35 cases of PGI either with or without AEF (sensitivity, 94%) and that results were falsely positive in three cases (specificity, 85%). CT findings ranged from large amounts of perigraft soft tissue and ectopic gas to subtle findings of minimal or no abnormalities; thus, strict criteria must be applied to the interpretation of CT scans after aortic surgery. Although CT is not 100% sensitive or specific, the authors conclude that it will continue to be valuable for diagnosing PGI and AEF.     

Blunt trauma to the gastrointestinal tract and mesentery: is there a role for helical CT in the decision-making process?

The CT diagnosis of bowel and mesenteric injuries is difficult and warrants optimal technique and skilled interpretation. We retrospectively reviewed 36 consecutive patients with blunt traumatic injuries to the bowel and mesentery at our regional level I trauma center during the past 3 years. Physical examination, laboratory, Computed tomographic (CT), and intraoperative findings were compared. Surgically proven bowel injuries (13 cases) occurred in the duodenum (three cases), ileum (two cases), jejunum (two cases), colon (three cases), and stomach (three cases). CT findings considered specific of bowel rupture were observed in 5/13 patients including: extraluminal oral contrast or luminal content extravasation (four cases) and discontinuity of hollow viscus wall (one case). In the remaining 8/13 CT findings considered suggestive of bowel injury consisted of: pneumoperitoneum (six), gas bubbles close to the injured hollow viscus (three), thickened (>4-5mm) bowel wall (five), bowel wall hematoma (three), intraperitoneal fluid of unknown source (three). Mesenteric injury (23 cases) were surgically observed at the level of the mesenteric vessels (17 cases), legament of Treitz (two cases), gastro-duodenal artery (one case), transverse (one case) and sigmoid mesocolon (one case). CT finding considered specific of mesenteric laceration was active extravasation of contrast material from the mesenteric vessels (10 cases). CT findings suggestive of mesenteric injury (13 cases) consisted of: mesenteric hematoma (five) and/or high attenuation fluid collections, within the mesenteric root (eight) and folds (four). Helical CT is sensitive in the identification of bowel and mesenteric injury after blunt trauma providing a wide spectrum of findings. However, CT cannot be used as the sole indicator in cases with isolated thichened bowel wall, mesenteric hematoma, bowel hematoma, pneumoperitoneum or gas bubbles. Persistent, active extravasation of intravenous constrast medium from the mesenteric vessels, in isolation or associated with further injuries, requires immediate exploration and repair; disruption of bowel wall and extravasation of oral contrast are definite signs of bowel rupture. Close clinical observation, monitoring, and surgical expertise are mandatory for appropriate management.     

Acute massive gastrointestinal bleeding: detection and localization with arterial phase multi-detector row helical CT

PURPOSE: To prospectively evaluate accuracy of arterial phase multi-detector row helical computed tomography (CT) for detection and localization of acute massive gastrointestinal (GI) bleeding, with angiography as reference standard. MATERIALS AND METHODS: Institutional review board approved this study; written informed consent was obtained from each patient or patient's family after procedures, including radiation dose, were explained. Twenty-six consecutive patients (17 men, nine women; age range, 18-89 years) had acute massive GI bleeding (defined as requirement of transfusion of at least 4 units of blood during 24 hours in the hospital or as hypotension with systolic blood pressure <90 mm Hg) and underwent arterial phase multi-detector row CT before angiography. Scans were obtained during arterial phase to identify extravasation of contrast material with attenuation greater than 90 HU within bowel lumen; this finding was considered diagnostic for active GI bleeding. Presence of contrast medium extravasation in each anatomic location was recorded. Sensitivity, specificity, positive and negative predictive values, and accuracy of multi-detector row CT for detection of acute GI bleeding were assessed. Accuracy for localization of acute GI bleeding was assessed by comparing locations of active bleeding at both multi-detector row CT and angiography in each patient who had active bleeding. RESULTS: Arterial phase multi-detector row CT depicted extravasation of contrast material in 21 of 26 patients. Overall location-based sensitivity, specificity, accuracy, and positive and negative predictive values of multi-detector row CT for detection of GI bleeding were 90.9% (20 of 22), 99% (107 of 108), 97.6% (127 of 130), 95% (20 of 21), and 98% (107 of 109), respectively. Overall patient-based accuracy of multi-detector row CT for detection of acute GI bleeding was 88.5% (23 of 26). The location of contrast material extravasation on multi-detector row CT scans corresponded exactly to that of active bleeding on angiograms in all patients with contrast medium extravasation at both multi-detector row CT and angiography. CONCLUSION: Arterial phase multi-detector row CT is accurate for detection and localization of bleeding sites in patients with acute massive GI bleeding.     

Detection of aortoenteric fistula with helical CT

We describe a case of a patient with symptoms suggestive of secondary aortoenteric fistula (AEF). Extravasation of contrast medium from the aorta into the lumen of the small bowel was definitive evidence of AEF. The role of abdominal CT performed without oral contrast is discussed.     

Multidetector CT: detection of active hemorrhage in patients with blunt abdominal trauma

OBJECTIVE: The aim of this study was to determine the imaging findings and the prevalence of active hemorrhage on contrast-enhanced multidetector CT in patients with blunt abdominal trauma. MATERIALS AND METHODS: Contrast-enhanced multidetector CT images of 165 patients with blunt abdominal trauma were reviewed for the presence of extravasated contrast agent, a finding that represents active hemorrhage. The site and appearance of the hemorrhage were noted on multidetector CT images. These findings were compared with surgical and angiographic results or with clinical follow-up. RESULTS: On multidetector CT images, active hemorrhage was detected in 22 (13%) of 165 patients with a total of 24 bleeding sites (14 intraperitoneal sites and 10 extraperitoneal sites). Active hemorrhage was visible most frequently as a jet of extravasated contrast agent (10/24 bleeding sites [42%]). Diffuse or focal extravasation was less frequently seen (nine [37%] and five [21%] bleeding sites, respectively). CT attenuation values measured in the aorta (mean, 199 H) were significantly higher than those measured in extravasated contrast material (mean, 155 H) (p < 0.001). Sixteen (73%) of 22 patients with active bleeding on multidetector CT images underwent immediate surgical or angiographic intervention. One patient received angiographic therapy 10 hr after undergoing multidetector CT, and five patients died between 1 and 3 hr after multidetector CT examination. CONCLUSION: Active hemorrhage in patients after blunt abdominal trauma is most frequently visible as a jet of extravasated contrast agent on multidetector CT. When extravasation is detected, immediate surgical or angiographic therapy is required.     

Computerized tomography in the study of jejuno-ileal perforations. Personal case load

INTRODUCTION: The most frequent cause of pneumoperitoneum is gastroduodenal ulcer. Perforations of the small bowel are uncommon compared with perforations of the rest of the alimentary tract and radiological findings of jejunoileal perforation have not been frequently reported. The aim of our retrospective study was to assess the CT findings in 18 patients with jejunoileal perforation. MATERIAL AND METHODS: We retrospectively reviewed the CT findings in 18 patients (12 men and 6 women, age ranging 14 to 84 years, mean age 42 years) operated for jejunoileal perforation at Cardarelli Hospital, Naples. CT examination was performed in all patients after i.v. injection of contrast medium and in two cases after oral contrast medium administration. Free intraperitoneal air, extravasation of ingested contrast media and visualization of a discontinuity in the bowel wall were considered direct findings of jejunoileal perforation, while intraperitoneal free fluid, thickened bowel wall and the presence of a streaky density within the mesentery were considered indirect diagnostic findings. RESULTS: The site of perforation was the jejunum in 6 cases and the ileum in 12 cases. The following CT findings were retrospectively observed: intraperitoneal free fluid (61%), free intraperitoneal air (33%), thickened bowel wall (22.2%), presence of a streaky density within the mesentery (5.5%). Visualization of a discontinuity in the bowel wall and extravasation of ingested contrast media were never seen. We observed two findings of perforation in 7 cases, and a single finding in 8 cases. CT examination was negative in 3 cases. CONCLUSIONS: Jejunoileal perforations are difficult to identify by CT. In our series, free intraperitoneal air, as a direct finding of perforation, was observed in 33% of cases, while free intraperitoneal fluid, as an indirect diagnostic finding, was the most frequent sign.     

Role of computerized tomography in the diagnosis of peritoneo-intestinal lesions resulting from closed trauma. Experience at 2 emergency departments

INTRODUCTION: Small and large bowel mesenteric injuries from blunt abdominal trauma are rare and often difficult to diagnose. Computed Tomography 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. PURPOSE: A retrospective study of the CT examination of 24 patients, with surgically confirmed bowel and mesenteric injuries, was performed. Our goal was to evaluate the various CT signs of blunt bowel and mesenteric injury and the related frequency. MATERIAL AND METHODS: Our series includes 24 patients, 16 of them (first group) were investigated with CT at Cardarelli Hospital, Naples, while the remaining 8 (second group) at University of Bari. Patients of the first group, 11 men and 5 women, age ranging from 18 to 77 years, were submitted to a conventional abdominal CT performed after i.v. administration of contrast media. Patients of the second group, 7 men and 1 woman, age ranging from 4 to 81 years, were submitted to helical CT performed with the following parameters: 10 mm slice thickness, 5-mm contiguous intervals from the level of the diaphragm to the pubic bone, pitch 1.5. Helical CT was performed in all cases before and after i.v. administration of contrast material injected at a rate of 3.5 ml/sec. A scanning delay of 40 seconds after the beginning of contrast injection was routinely used. In all patients the following CT signs were retrospectively searched on: peritoneal or retroperitoneal fluid, mesenteric hematoma, hazy streaky changes in mesenteric fat, high-density clot (sentinel clot) adjacent to the involved bowel, pneumoperitoneum, retropneumoperitoneum, extravasation of intravenous contrast material, bowel wall thickening. RESULTS: In the first group the following CT signs were observed: mesenteric hematoma (87.5%), hazy streaky changes in mesenteric fat (56.25%), peritoneal or retroperitoneal fluid (37.5%), sentinel clot (25%), bowel wall thickening (18.75%), extravasation of intravenous contrast material (12.5%). In the second group the following CT signs were observed: peritoneal or retroperitoneal fluid (87.5%), bowel wall thickening (50%), mesenteric hematoma (37.5%), sentinel clot (25%), pneumoperitoneum (12.5%), retropneumoperitoneum (12.5%), hazy streaky changes in mesenteric fat (12.5%). DISCUSSION AND CONCLUSIONS: Bowel and mesenteric injuries from blunt trauma are infrequent and difficult to diagnose clinically, as the physical and laboratory findings may be subtle and are often overshadowed by other injuries in patients with multisystem trauma. CT represents a proven modality in the evaluation of bowel and mesenteric injuries: careful inspection and technique are required to detect often subtle findings. In our series of 24 patients with surgically confirmed bowel and mesenteric injuries, the presence of mesenteric hematoma and of peritoneal or retroperitoneal fluid were the more frequent CT signs observed. Radiologists may play a crucial role in the timely diagnosis of these injuries, allowing prompt and appropriate management of these patients.     

Incorporation versus infection of retroperitoneal aortic grafts: MR imaging features

The magnetic resonance (MR) imaging characteristics of normal aortic graft healing were compared with those of perigraft infection in 57 patients after aortic graft implantation. Thirty-three patients without postoperative complications underwent MR imaging in a 0.35-T unit 1 week after graft implantation, and 13 of those patients were reexamined 2-3 months after graft implantation. Twenty-four patients with clinically suspected perigraft infection underwent MR imaging 6 weeks to 18 years after graft implantation. Early normal postoperative changes were characterized by a perigraft collar of low to medium signal intensity on T1-weighted images and of high intensity on T2-weighted images in all 33 cases, consistent with perigraft fluid collection. In 10 of 13 patients reexamined 2-3 months postoperatively, the MR images demonstrated a collar of tissue consistent with perigraft fibrosis. In cases of clinical suspicion of retroperitoneal graft infection, MR imaging showed eccentric fluid collections of low to medium signal intensity on T1-weighted images and high intensity on T2-weighted images at more than 3 months after surgery. The MR findings were diagnostic of retroperitoneal perigraft infection in 17 of 20 patients shown to be infected at surgery. Retroperitoneal infection was correctly excluded on the basis of MR findings in four patients. Thus, MR imaging is an accurate imaging method for the diagnosis of aortic graft infection. In the early postoperative phase, resolving perigraft fluid cannot be differentiated from perigraft infection.     

Small bowel rupture after blunt trauma: Computed tomographic signs and their sensitivity

The purpose of this study is to describe the characteristic computed tomographic (CT) signs of small bowel perforation after blunt abdominal trauma and to evaluate their sensitivity. Nineteen preoperative CT scans were obtained from 16 patients with surgically proven small bowel rupture secondary to blunt abdominal trauma. Only the CT findings described in the original CT reports were used. Eleven of 19 CT scans (58 %) had findings that were unequivocal for bowel rupture (i.e., extraluminal air and/or extravasation of oral contrast medium). Seven CT scans (37 %) had findings that were suggestive of severe small bowel injury (i.e., focal small bowel wall thickening and/or free peritoneal fluid without other accompanying organ injuries). In all, 95 % of cases of small bowel rupture had either pathognomonic or suggestive CT findings. One CT scan did not demonstrate small bowel wall thickening, although a hemoperitoneum was present. CT is a sensitive method for suggesting severe small bowel injury and rupture secondary to blunt abdominal trauma.     

Active extravasation of arterial contrast agent on post-traumatic abdominal computed tomography.

OBJECTIVE: To evaluate the use of emergent dynamic intravenous contrast-enhanced computed tomography (CT) in the diagnosis of active arterial extravasation in patients admitted to hospital after blunt abdominal trauma. METHODS: Four-hundred and ninety-eight consecutive emergent contrast-enhanced computed tomographic images of the abdomen and pelvis were retrospectively reviewed. The presence of and site(s) of active arterial extravasation were recorded. Two radiologists reviewed the images and compared the site(s) of extravasated arterial contrast agent with the site(s) of active hemorrhage established at angiography (n = 9) or surgery (n = 4). RESULTS: Twenty-eight patients' computed tomographic images were identified as showing signs of extravasation of contrast agent representing active arterial bleeding. A total of 49 sources of active arterial extravasation were identified, 37 in 19 patients. A pelvic source of active arterial hemorrhage was most frequent and was typically associated with unstable pelvic fractures (n = 18). Other sources of active arterial hemorrhage included the liver (n = 3), spleen (n = 2), retroperitoneum (n = 1), kidney (n = 1), mesentery (n = 1), abdominal wall (n = 3) and lumbar region (n = 1). Only 9 of 28 patients became sufficiently hemodynamically unstable to warrant angiography. All 9 patients had a pelvic source of arterial extravasation on contrast-enhanced CT, and 7 demonstrated active bleeding requiring embolization. The contrast-enhanced computed tomographic images correctly indicated the anatomical source of bleeding in all 7 cases. CONCLUSION: In patients who have experienced blunt abdominal trauma, attention should be paid to the computed tomographic features of active arterial hemorrhage. In our series, the pelvis was the most common source of active arterial bleeding, which was typically associated with unstable pelvic fractures.     

Helical CT in acute lower gastrointestinal bleeding

The purpose of this study was to assess the usefulness of helical CT in depicting the location of acute lower gastrointestinal bleeding. A three-phase helical CT of the abdomen was performed in 24 patients referred for acute lower gastrointestinal bleeding. The diagnosis of the bleeding site was established by CT when there was at least one of the following criteria: spontaneous hyperdensity of the peribowel fat; contrast enhancement of the bowel wall; vascular extravasation of the contrast medium; thickening of the bowel wall; polyp or tumor; or vascular dilation. Diverticula alone were not enough to locate the bleeding site. The results of CT were compared with the diagnosis obtained by colonoscopy, enteroscopy, or surgery. A definite diagnosis was made in 19 patients. The bleeding site was located in the small bowel in 5 patients and the colon in 14 patients. The CT correctly located 4 small bowel hemorrhages and 11 colonic hemorrhages. Diagnosis of the primary lesion responsible for the bleeding was made in 10 patients. Our results suggest that helical CT could be a good diagnostic tool in acute lower gastrointestinal bleeding to help the physician to diagnose the bleeding site. Electronic Publication     

Brain magnetic resonance with magnetization transfer in multiple sclerosis. Lesion hyperintensity before and after intravenous gadolinium administration

PURPOSE: The possibility of detecting contrast agent extravasation (i.e., active hemorrhage) with dynamic conventional Computed Tomography (CT) in patients with abdominal trauma has already been reported in small series. We report our experience in the demonstration of contrast material extravasation using helical CT; we also investigate the diagnostic and clinical value of this finding. MATERIAL AND METHODS: January 1997 to July 1998, we examined 41 consecutive patients with upper abdominal trauma. Twelve patients (29%) had contrast material extravasation. The examinations were performed with a helical unit and volumetric acquisitions (thickness 8-10 mm, pitch 1, reconstruction interval 5-8 mm). The intravenous contrast medium (350 mgI/mL, 130-140 mL) was administered with rapid infusion (2-2.5 mL/s, 40-50 s acquisition delay from bolus starting) and using a power injector. We reviewed the CT studies and clinical records of these 12 patients. Contrast agent extravasation was considered present when this finding, not recognizable on plain scans, showed equal attenuation to or higher attenuation than the vessels within the same level. Moreover we assessed leak site, CT appearance, the direct visualization of the involved vessel, the evidence of other abdominal or extra-abdominal injuries, the CT signs of hypovolemic shock, clinical and surgical data. For comparison, we finally evaluated 50 examinations performed with a conventional CT scanner in subjects with abdominal trauma. RESULTS: Active hemorrhage involved the abdominal wall in 1 case (intercostal artery), the solid organs in 4 (splenic in 2, hepatic in 1, of the middle hepatic vein in 1), the peritoneal cavity in 3 (splenic, midcolic, and gastroduodenal artery in 1 each), the retroperitoneum in 4 (renal pedicle in 2, renal parenchyma in 1, lumbar artery in 1). In all cases the site of contrast extravasation corresponded at surgery to the site of active bleeding. The pattern was localized in 10 cases and diffuse in 2. The involved vessel could be identified in 5 cases while in the other ones the origin could be inferred from the leakage site. Associated injuries of upper abdominal organs were seen in 11 of 12 patients and extra-abdominal trauma in 6. In 4 cases there were CT features of hypovolemia. One patient died during transport to the operating room and another after surgery, while all the others survived. Contrast extravasation was identified in 9 (18%) of the patients examined with a conventional CT unit. CONCLUSIONS: Active contrast material extravasation can be recognized with conventional CT scanners, though it has been considered a rare finding. Helical CT seems to increase the detection rate and especially to boost the radiologist's confidence in this diagnosis. Though active bleeding is identified in severely-injured subjects requiring urgent intervention and may be associated with findings of hypovolemic shock, it should not be considered itself as a negative prognostic factor. Contrast extravasation is due to ongoing hemorrhage and its detection is critical for urgent treatment. Accurate anatomical location permits to choose surgical management or transcatheter embolization and thus decreases time consumption for precise bleeding site identification.     

Multidetector computed tomography imaging of aortoenteric fistula

Three case reports illustrating multidetector computed tomography (CT) imaging findings of secondary aortoenteric fistula (AEF) are described and presented in axial sections, multiplanar reformats, and 3-dimensional reconstruction. Fistulae occurred in the early and late postgrafting period and involved both end-to-end and end-to-side aortic graft anastomoses. Multidetector CT is quick and accurate in the diagnosis of bleeding AEF.     

Multidetector CT of the small bowel: evaluation after oral hyperhydration with isotonic solution

PURPOSE: The aim of our study was to assess the diagnostic capabilities of multidetector CT in the evaluation of the small bowel in different pathological conditions, with the use of oral hyperhydration with isotonic solution. MATERIALS AND METHODS: The study retrospectively evaluated 106 patients who underwent multidetector CT of the small bowel. Four groups were considered on the basis of the clinical findings: group A (48 cases), with suspected or certain chronic inflammatory disease of the small bowel; group B (16 cases), with suspected neoplastic lesion of the small bowel; group C (17 cases), patients affected by malabsorption; group D (25 cases), others: 13 cases with non-specific abdominal pain, 4 cases with occult bleeding, 8 cases affected by fever of unknown origin. Thirteen patients had previously undergone surgical intestinal resection. In all cases the CT examination was performed after the oral administration of 2000 mL polyethylene glycol electrolyte balanced solution; before the scan, N-butyl scopolamine or glucagon were administered intravenously to obtain rapid inhibition of bowel peristalsis. All multidetector CT scans were acquired at baseline and 50 seconds after the I.V. administration of 110-130 ml high-concentration non-ionic iodinated contrast medium. The images were subsequently processed on a dedicated workstation (Advantage Windows 4.0, GE Medical Systems) to obtain multiplanar reconstruction (MPR). We considered the following CT findings: fold distribution, wall thickening and stratification and contrast enhancement, extraparietal involvement and abnormalities of the abdominal organs. The CT diagnoses were compared with the clinical and laboratory findings (86 cases) and with the results of barium follow-through (55 cases), ileo-colonoscopy (45 cases) or surgery (28 cases). RESULTS: CT examination allowed the correct diagnosis in 86/106 cases (89%); 20 patients were not included in the study because of a poor (11 cases) or absent (9 cases) small bowel loop distension. The final diagnoses in the 86 patients were: Crohn's disease of the small bowel (38 cases), Crohn's disease of the duodenum (1 case), granulomatous colitis (3 cases), malabsorption (8 cases), neoplastic lesion (4 cases), post-radiation conglomeration of ileal loops (1 case), intestinal lymphangiectasia (1 case), ulceration of the last ileal loop (1 case). In 29 cases no abnormalities of the small bowel were found. Spiral CT yielded 52 true positive cases, 5 false negative cases, 2 false positive cases, and 27 true negative RESULTS: The sensitivity of the technique was 91%, specificity 93% and diagnostic accuracy 92%. CONCLUSIONS: Multidetector CT of the small bowel performed after oral hyperhydration with isosmotic solution, proved to be an accurate and thorough technique. It can be considered a safe and effective alternative to conventional radiographic studies and to small bowel spiral CT enema in patients that refuse the nasojejunal balloon catheter or the administration of methylcellulose.     

Contrast-enhanced ultrasound imaging of active bleeding associated with hepatic and splenic trauma

Purpose

The aim of this study was to evaluate contrast-enhanced ultrasound (CEUS) imaging of active bleeding from hepatic and splenic trauma.

Materials and methods

Three hundred and ninety-two patients with liver or/and spleen trauma (179 liver and 217 spleen injuries), who underwent CEUS examinations following contrast-enhanced computed tomography (CT), were enrolled in this retrospective study over a period of >4 years. CEUS detected contrast medium extravasation or pooling in 16% (63/396) of liver or spleen lesions in 61 patients, which was confirmed by contrast-enhanced CT. Special attention was paid to observing the presence, location, and characteristics of the extravasated or pooled contrast medium.

Results

The CEUS detection rate for active bleeding was not different from that of contrast-enhanced CT (p=0.333). Information from surgery, minimally invasive treatment and conservative treatment was used as reference standard, and the sensitivities of the two techniques were not different (p=0.122). Of 63 lesions in 61 patients, CEUS showed that 74.6% (47/63) (21 liver lesions and 26 spleen lesions) presented contrast medium extravasation or pooling, both in the organ and out the capsule, in 14.3% (9/63) and only outside the capsule in 11.1% (7/63). CEUS imaging of active bleeding from hepatic and splenic trauma presented various characteristics, and the sizes and shapes of the active bleeding due to contrast medium extravasation or pooling were variable.

Conclusions

CEUS can show the active bleeding associated with hepatic and splenic trauma with various imaging characteristics, thus making it possible to diagnose active bleeding using CEUS.     

CT enteroclysis in the diagnosis of obscure gastrointestinal bleeding: initial results

AIM: To evaluate the usefulness of computed tomography (CT) enteroclysis in patients with obscure gastrointestinal (GI) bleeding. MATERIALS AND METHODS: In a prospective study, CT enteroclysis was performed in 21 patients (median age 50 years; range 13-71 years) with obscure GI bleeding in which the source of the bleeding could not be detected despite the patient having undergone both upper GI endoscopic and colonoscopic examinations. The entire abdomen and pelvis was examined in the arterial and venous phases using multisection CT after distending the small intestine with 2l of 0.5% methylcellulose as a neutral enteral contrast medium and the administration of 150ml intravenous contrast medium. RESULTS: Adequate distension of the small intestine was achieved in 20 of the 21 (95.2%) patients. Potential causes of GI bleeding were identified in 10 of the 21 (47.6%) patients using CT enteroclysis. The cause of the bleeding could be detected nine of 14 (64.3%) patients with overt, obscure GI bleeding. However, for patients with occult, obscure GI bleeding, the cause of the bleeding was identified in only one of the seven (14.3%) patients. The lesions identified by CT enteroclysis included small bowel tumours (n=2), small bowel intussusceptions (n=2), intestinal tuberculosis (n=2), and vascular lesions (n=3). All vascular lesions were seen equally well in both the arterial and venous phases. CONCLUSIONS: The success rate in detection of the cause of bleeding using CT enteroclysis was 47.6% in patients with obscure GI bleeding. The diagnostic yield was higher in patients with overt, obscure GI bleeding than in those with occult obscure GI bleeding.     

Detection of prosthetic vascular complications: comparison of CT and angiography

The value of CT and angiography to detect complications of prosthetic arterial grafting was compared in 24 patients. There was a total of 27 grafts including 18 aortic or aortofemoral, five femoral-popliteal, two femoral-femoral, and two axillary-femoral reconstructions. Nineteen grafts were uninfected; eight were infected. In the absence of infection, the complications and the percentages detected by the two procedures were as follows: five graft occlusions (CT 80%, angiography 100%), six pseudoaneurysms (CT 100%, angiography 83%), three with perigraft fluid (CT 100%, angiography 0%), and one with pseudointimal hyperplasia (CT 100%, angiography 0%). Seven grafts were normal and without abnormalities on both CT and angiography. In the presence of infection the results were as follows: eight with perigraft fluid (CT 100%, angiography 0%), four with perigraft or intragraft gas (CT 100%, angiography 0%), three pseudoaneurysms (CT 100%, angiography 100%), two open groin wounds (CT 100%, angiography 0%), and two graft occlusions (CT 100%, angiography 100%). In addition, three patients with infected grafts had graft enteric fistulae. All three had fluid around the proximal anastomosis and two had gas around the graft as well. The data show that angiography is sufficient for patients with graft occlusion if there is no suspicion of infection, postoperative hemorrhage, or anastomotic pseudoaneurysm. In these cases CT has an ancillary role in detecting hemorrhage and defining pseudoaneurysms. CT is superior to angiography in patients with graft infection.     

Embolotherapy of persistent endoleaks after endovascular repair of abdominal aortic aneurysm with the ancure-endovascular technologies endograft system.

PURPOSE: Endoleak is a potential complication after endovascular repair of abdominal aortic aneurysm (AAA). It may result in continued growth of the aneurysm and potentially result in aneurysm rupture. The authors present their experience with embolotherapy in patients with persistent perigraft flow treated with the Ancure-Endovascular Technologies endograft system. MATERIALS AND METHODS: Between February 1996 and August 1998, 54 patients underwent successful repair of AAA with use of the Ancure system. All underwent operative angiography and discharge computed tomography (CT). Follow-up included CT at 6, 12, and 24 months, and CT was also performed at 3 months if an endoleak was present on the discharge CT. Persistent endoleak was defined as perigraft flow still present on the 6-month CT. Seven of 21 initial endoleaks persisted at 6 months. Six patients returned for embolization of the perigraft space and outflow vessels including lumbar arteries and the inferior mesenteric artery (IMA). RESULTS: Five of the six patients had leaks from the proximal (n = 1) or distal attachment sites (n = 4) of the Ancure system with outflow into lumbar arteries and/or the IMA; one leak was caused by retrograde IMA flow. The six patients underwent nine embolization procedures with only one minor complication. Follow-up CT showed complete resolution of endoleak and decrease in size of the aneurysm sac in all patients. CONCLUSIONS: Although endoleak is commonly seen initially with the Ancure system, persistent leak occurred in 13% of the patients in the study. Persistent flow in most patients arises from a graft attachment site combined with patent outflow vessels such as the IMA or lumbar arteries. Persistent endoleaks can be effectively and safely embolized with use of a combination of coil embolization of the perigraft space and embolization of outflow vessels. Such intervention resulted in a decrease in size of the aneurysm sac.     

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.