Pancreatic cysts: What imaging characteristics are associated with development of pancreatic ductal adenocarcinoma?

PURPOSE

To assess relationship between pancreatic cysts (PC) and pancreatic ductal adenocarcinoma (PDAC) and to compare imaging features of PC in subjects who develop PDAC and those who do not.

MATERIAL AND METHODS

This case-control IRB-approved HIPAA-compliant study included patients with PDAC (cases) and lung cancer (controls), diagnosed between 1/1/05-1/1/14. The most recent abdominal CT/MR of each patient done >6months prior to cancer diagnosis date was reviewed by radiologist blinded to case/control status. Presence of PC, number and size of largest PC, presence of main pancreatic duct (MPD) dilatation (MPD >3mm) were recorded. Simple PC was defined as lack of calcifications, septations and enhancement. Logistic regression models with binary outcome of PDAC were constructed.

RESULTS

There were 88 cases and 273 controls with mean ages of 69.6 years (±10.3) and 69.8 years (±12.0), respectively (p=0.864). PC were present in 21.6% (19/88) cases and in 9.2% (25/273) controls (p=0.002). The OR of PC for development of PDAC was 2.83, adjusting for age, sex and race (p=0.001). Mean PC size was 14.8mm (±8.7) in cases and 7.6mm (±8.0) in controls (p=0.007). PC were solitary in 6 (31.6%) of 19 cases and 21 (84.0%) of 25 controls (p=0.001). There was no significant difference in proportions of simple cysts or MPD dilatation between cases and controls. Multiple PC had 8.2 times increased odds of PDAC compared with solitary PC, adjusting for cyst size (p=0.007).

CONCLUSION

Multiple PC are associated with 8.2 times higher odds of PDAC compared with solitary PC.

Hollow organ abdominal ischemia, part II: clinical features, etiology, imaging findings and management

Acute hollow organ ischemia commonly presents with acute pain prompting radiologic evaluation and almost always requires urgent treatment. Despite different risk factors and anatomic differences, ischemia is commonly due to low flow states but can also be due to arterial and venous occlusion. Radiologic diagnosis is critical as many present with nonspecific symptoms. Contrast-enhanced computed tomography (CT) is the modality of choice. Magnetic resonance imaging (MRI) is preferred in suspected appendicitis in pregnant patients and is superior in biliary necrosis. This article provides a pictorial review of the CT/MRI features of hollow abdominal organ ischemia while highlighting key clinical features, pathogenesis, and management.

Traumatic and non-traumatic adrenal emergencies

Multiple traumatic and non-traumatic adrenal emergencies are occasionally encountered during the cross-sectional imaging of emergency department patients. Traumatic adrenal hematomas are markers of severe polytrauma, and can be easily overlooked due to multiple concomitant injuries. Patients with non-traumatic adrenal emergencies usually present to an emergency department with a non-specific clinical picture. The detection and management of adrenal emergencies is based on cross-sectional imaging. Adrenal hemorrhage, adrenal infection, or rupture of adrenal neoplasm require immediate detection to avoid dire consequences. More often however, adrenal emergencies are detected incidentally in patients being investigated for non-specific acute abdominal pain. A high index of suspicion is required for the establishment of timely diagnosis and to avert potentially life-threatening complications. We describe cross-sectional imaging findings in patients with traumatic and non-traumatic adrenal hemorrhage, adrenal infarctions, adrenal infections, and complications of adrenal masses.

Improved parenchymal liver enhancement with extended delay on Gd-EOB-DTPA-enhanced MRI in patients with parenchymal liver disease: associated clinical and imaging factors

AIM

To establish the effect of prolonged hepatobiliary phase (HBP) delay time on hepatic enhancement in patients with parenchymal liver disease (PLD).

MATERIALS AND METHODS

Gadoxetate disodium (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) examinations with HBP were obtained after 20- (HBP-20) and 30-minute (HBP-30) delays in patients with PLD. For each patient, the Model for End-Stage Liver Disease (MELD) score, total and direct bilirubin, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), prothrombin time (PT), and partial thromboplastin time (PTT) were recorded. Signal intensities of the liver, main portal vein, and spleen on pre-contrast, HBP-20, and HBP-30 were documented. Signal intensities were used to calculate liver relative enhancement (LRE), liver-spleen index (LSI), and liver-portal vein index (LPI) for HBP-20 and HBP-30. Improved hepatic enhancement was considered if two or more indices were higher on HBP-30 than HBP-20. A logistic regression model was constructed with improved hepatic enhancement as the outcome.

RESULTS

One hundred and twenty-nine patients underwent 142 MRIs. Mean LRE, LSI, and LPI each increased from HBP-20 to HBP-30 (p = 0.004, p < 0.001, and p < 0.001, respectively). Seventy-two point five percent of cases demonstrated improved hepatic enhancement. The odds ratios for improved hepatic enhancement were 0.85 for MELD score (p = 0.02) and 3.2 for the 3 T scanner (p = 0.02), adjusted for age and sex.

CONCLUSION

Increasing HBP delay to 30 minutes improves hepatic enhancement in patients with PLD, particularly if using a 3 T scanner. This effect is attenuated with higher MELD scores.

Incidental pancreatic cystic lesions: is there a relationship with the development of pancreatic adenocarcinoma and all-cause mortality?

PURPOSE

To establish the effect of incidental pancreatic cysts found by using computed tomographic (CT) and magnetic resonance (MR) imaging on the incidence of pancreatic ductal adenocarcinoma and overall mortality in patients from an inner-city urban U.S. tertiary care medical center.

MATERIALS AND METHODS

Institutional review board granted approval for the study and waived the informed consent requirement. The study population comprised cyst and no-cyst cohorts drawn from all adults who underwent abdominal CT and/or MR November 1, 2001, to November 1, 2011. Cyst cohort included patients whose CT or MR imaging showed incidental pancreatic cysts; no-cyst cohort was three-to-one frequency matched by age decade, imaging modality, and year of initial study from the pool without reported incidental pancreatic cysts. Patients with pancreatic cancer diagnosed within 5 years before initial CT or MR were excluded. Demographics, study location (outpatient, inpatient, or emergency department), dates of pancreatic adenocarcinoma and death, and modified Charlson scores within 3 months before initial CT or MR examination were extracted from the hospital database. Cox hazard models were constructed; incident pancreatic adenocarcinoma and mortality were outcome events. Adenocarcinomas diagnosed 6 months or longer after initial CT or MR examination were considered incident.

RESULTS

There were 2034 patients in cyst cohort (1326 women [65.2%]) and 6018 in no-cyst cohort (3,563 [59.2%] women); respective mean ages were 69.9 years ± 15.1(standard deviation) and 69.3 years ± 15.2, respectively (P = .129). The relationship between mortality and incidental pancreatic cysts varied by age: hazard ratios were 1.40 (95% confidence interval [ CI confidence interval ]: 1.13, 1.73) for patients younger than 65 years and 0.97 (95% CI confidence interval : 0.88, 1.07), adjusted for sex, race, imaging modality, study location, and modified Charlson scores. Incidental pancreatic cysts had a hazard ratio of 3.0 (95% CI confidence interval : 1.32, 6.89) for adenocarcinoma, adjusted for age, sex, and race.

CONCLUSION

Incidental pancreatic cysts found by using CT or MR imaging are associated with increased mortality for patients younger than 65 years and an overall increased risk of pancreatic adenocarcinoma.

Accuracy of prostate measurements on MRI with and without an endorectal coil

PURPOSE

To assess accuracy of prostate measurements with and without endorectal coil (ERC).

MATERIALS AND METHODS

Anteroposterior (AP), transverse (TX) and craniocaudal (CC) measurements were recorded from 49 prostate magnetic resonance images (MRIs) done both with and without ERC. Prostate weight was calculated as follows: AP*TX*CC*π/6. Prostate dimensions and weight were obtained from radical prostatectomy pathology report.

RESULTS

After ERC placement, AP decreased by 0.71 cm [95% confidence interval (CI) 0.80-0.61], TX and CC increased by 0.26 cm (95% CI 0.18-0.33) and 0.25 cm (95% CI 0.16-0.35), respectively. Agreement between weight on pathology and MR was excellent: intraclass correlation coefficient (ICC) without ERC=0.96, ICC with ERC=0.90.

CONCLUSION

Although ERC distorts measurements and despite a tendency to underestimate the prostate weight, absolute agreement between prostate weight on pathology and MRI is excellent, both with and without ERC.

Gallbladder torsion resulting in gangrenous cholecystitis within a parastomal hernia: findings on unenhanced CT

Gallbladder torsion is a rare cause of acute gangrenous cholecystitis; its occurrence within an abdominal hernia has not been previously reported. We present such a case occurring within a parastomal hernia and imaged with unenhanced CT.

Breast reconstruction with deep inferior epigastric artery perforator flap: 3.0-T gadolinium-enhanced MR imaging for preoperative localization of abdominal wall perforators

PURPOSE

To prospectively evaluate 3.0-T gadolinium-enhanced magnetic resonance (MR) imaging for localization of inferior epigastric artery (IEA) perforators before reconstructive breast surgery involving a deep inferior epigastric perforator (DIEP) flap.

MATERIALS AND METHODS

This study was exempt from institutional review board approval, and the requirement for informed patient consent was waived. Data were collected and stored in compliance with HIPAA regulations. Nineteen patients (mean age, 46.3 years) underwent three-dimensional gadolinium-enhanced 3.0-T MR imaging of the abdomen before undergoing DIEP flap breast reconstruction. Up to four of the largest perforators arising from the IEA on each side of the umbilicus were identified. The diameter, intramuscular course, and distance from the umbilicus of each perforator were recorded. One of the marked perforators on each side was labeled "the best" on the basis of an optimal combination of perforator features: diameter, intramuscular course, and location with respect to the flap edges. MR findings were compared with intraoperative findings. The two-tailed Student t test was used to compare the mean diameters of all perforators with the mean diameters of the perforators labeled as the best.

RESULTS

There were 30 surgical flaps, and 11 (58%) of the 19 patients underwent bilateral flap dissection. At surgery, 122 perforators were localized, and 118 (97%) of these perforators-with a mean diameter of 1.1 mm (range, 0.8-1.6 mm)-had been identified at preoperative MR imaging. Thirty perforators with a mean diameter of 1.4 mm (range, 1.0-1.6 mm) were labeled as the best at MR imaging. Thirty-three perforators were harvested intraoperatively, and all of these had been localized preoperatively. Twenty-eight (85%) of these 33 perforators were labeled as the best at MR imaging.

CONCLUSION

Gadolinium-enhanced 3.0-T MR imaging can be used to accurately localize IEA perforators and to select the optimal perforator to be harvested for DIEP flap reconstructive breast surgery.

Pelvic Pseudolesions After Inguinal Hernioplasty Using Prosthetic Mesh

PURPOSE OF STUDY

To investigate frequency and morphology of focal pelvic lesions (FPLs) in patients after open inguinal hernioplasty with a prosthetic mesh.

MATERIALS, METHODS AND PROCEDURES

Patients who had open prosthetic inguinal hernioplasties between 1999 and 2004 and subsequent pelvic computed tomography were identified. Computed tomography of each patient was evaluated by 2 observers. The presence of an FPL at the internal inguinal ring (IIR) and its shape, size, and attenuation were recorded. The findings were compared with the type of surgical mesh used for the repair.

RESULTS

There were 93 patients, 86 men, with a mean age of 62.4 years (range, 14-89 years) who underwent 96 hernioplasties, with plug or flat mesh used in 71 and 25 cases, respectively. There were 96 computed tomographies obtained between 1 and 46 months (mean, 15.4 months) after surgery. Focal pelvic lesions were identified in 69 (72%) of 96 cases. Focal pelvic lesions were found in 63 (89%) of 71 cases repaired with a plug, but in only 6 (24%) of 25 cases repaired with a flat mesh (P < 0.0001). One hundred percent of FPLs corresponded to the surgical site and were located deep to the IIR. Focal pelvic lesions were ovoid or round in 65 (94%) and 4 (6%) cases, respectively; all were well defined. Focal pelvic lesions had a mean diameter of 2.4 cm (range, 1.3-3.9 cm) and mean attenuation value of 17 Hounsfield units (range, -4 to 64 Hounsfield units).

CONCLUSIONS

A low attenuation, ovoid, or round FPL located at the IIR is a common postoperative finding in patients after open inguinal hernioplasty performed with a plug mesh.

Type II Endoleak after Endoaortic Graft Implantation: Diagnosis with Helical CT Arteriography

PURPOSE

To retrospectively assess endoleak shapes and locations within aneurysms to differentiate type II from type I and type III endoleaks.

MATERIALS AND METHODS

The institutional review board granted an exemption for this HIPAA-compliant study; patient informed consent was not required. A retrospective review of arterial phase helical computed tomographic (CT) studies and medical records was performed for 39 patients (29 men, 10 women; age range, 60-89 years; mean, 78.5 years) who had an endoleak after endoaortic graft implantation for treatment of abdominal aortic aneurysm and who subsequently underwent angiography (n = 25), surgery (n = 8), or long-term follow-up (n = 6) to classify their endoleak into a specific type. At CT, endoleak shape (tubular or nontubular) and location (central or peripheral) were recorded. An endoleak was classified as type II if it contained a peripheral tubular component (PTC) near the aortic wall, with or without an identifiable feeding vessel. Endoleaks without these features were classified as type I or III. The Fisher exact test was used to assess associations between CT findings and endoleak type.

RESULTS

There were 22 type II and 17 type I or III endoleaks. CT enabled correct identification of 22 (100%) of 22 type II endoleaks, all of which contained a PTC. Of 17 type I or III endoleaks, only two (12%) contained a PTC and were misclassified as type II endoleaks; the remaining 15 (88%) were correctly classified. Overall, CT enabled correct identification of endoleaks as type II or type I or III in 37 (95%) of 39 patients. PTCs were significantly more common (P < .001) in type II than in type I or III endoleaks, with a sensitivity, specificity, accuracy, negative predictive value, and positive predictive value of 100%, 88.2%, 94.9%, 100%, and 91.7%, respectively.

CONCLUSION

A PTC is a statistically significant predictor of type II endoleak in most patients.

Renal Medullary Carcinoma: CT and MRI Features

OBJECTIVE

We review the cross-sectional imaging findings of six cases of pathologically proven renal medullary carcinoma in patients with sickle cell trait. MRI findings were available in three of the patients. To our knowledge, only one previous report has addressed MRI features of this rare disease.

CONCLUSION

In young patients with sickle cell trait, an infiltrative renal mass with associated retroperitoneal adenopathy and caliectasis are characteristic findings of renal medullary carcinoma on CT and MRI.

Spontaneous Retroperitoneal Hemorrhage Localized by Blood Pool Scintigraphy

A healthy 17-year-old girl presented to the emergency department with a 1-day history of left upper quadrant abdominal pain associated with nausea and vomiting. Her hematocrit was 22. On physical examination, she had left upper quadrant fullness and tenderness. Initial computed tomography revealed a large, loculated, left-sided retroperitoneal hematoma. Blood pool scintigraphy with labeled red cells revealed a very large photon-deficient area with 3 areas of active bleeding in the upper margin of the cold area. An angiogram showed active extravasation from the left inferior phrenic artery. The patient was felt to have had spontaneous adrenal hemorrhage, likely within a preexisting, large adrenal cyst. Spontaneous hemorrhage into an adrenal cyst is a rare entity that can be life-threatening if not treated early in its course.

Detection of endoleaks after endovascular repair of abdominal aortic aneurysm: value of unenhanced and delayed helical CT acquisitions

PURPOSE

To assess unenhanced and delayed phase computed tomographic (CT) images combined with arterial phase images for detecting endoleaks after endovascular treatment for abdominal aortic aneurysm (AAA).

MATERIALS AND METHODS

CT scans were retrospectively evaluated for the presence of endoleaks after endovascular treatment of AAAs in 33 patients with endoleak (positive group) and 40 patients without evidence of endoleak or aneurysm enlargement (negative group). All patients underwent unenhanced and biphasic contrast material-enhanced CT. The CT scans were reviewed in the following combinations: (a) arterial phase and unenhanced scans (uniphasic/unenhanced set), (b) arterial and delayed phase scans only (biphasic set), and (c) arterial and delayed phase scans with unenhanced scans (complete set). Each set was reviewed by two radiologists blinded to the diagnosis of endoleak. Findings were recorded as positive, negative, or indeterminate for endoleak.

RESULTS

Within the positive group, endoleaks were diagnosed with the uniphasic/unenhanced, biphasic, and complete image sets in 30 (91%), 32 (97%), and 33 (100%) patients, respectively. With the uniphasic/unenhanced set, three (9%) endoleaks (seen only on delayed phase images) were missed. With the biphasic set, one (3%) endoleak was interpreted as indeterminate. Within the negative group, uniphasic/unenhanced, biphasic, and complete image sets were negative for endoleaks in 100%, 80%, and 100% of patients, respectively. With the biphasic set, results were indeterminate in 20% of cases.

CONCLUSION

A delayed CT acquisition enables detection of additional endoleaks, while an unenhanced acquisition helps eliminate indeterminate results. Thus, both acquisitions contribute to accurate diagnosis of endoleaks when combined with an arterial phase acquisition.

Diameter changes in isolated iliac artery aneurysms 1 to 6 years after endovascular graft repair

OBJECTIVE

Precise diameter changes in iliac artery aneurysms (IAAs) after endovascular graft (EVG) repair are yet to be determined. This report describes the midterm size changes in isolated IAAs 13 to 72 months after treatment with an EVG.

METHODS

From January 1993 to April 1999, 31 patients with 35 true isolated IAAs (32 common iliac and 3 hypogastric) had these lesions treated with EVGs and coil embolization of the hypogastric artery or its branches. The EVG used in this study consisted of a balloon-expandable stent attached to a polytetrafluoroethylene graft. Contrast-enhanced spiral computed tomographic scans were performed at 3- to 6-month intervals to follow the aneurysms for change in diameter and endoleaks.

RESULTS

Thirty patients had a decrease in the size of their iliac aneurysms with EVG repair. All EVGs remained patent. All patients, except for one, were followed up for 13 to 72 months (mean, 31 months). The pretreatment aneurysm size ranged from 2.5 to 11.0 cm in diameter (mean, 4.6 +/- 1.62 cm). After EVG treatment, the aneurysms ranged from 2.0 to 8.0 cm in diameter (mean, 3.8 +/- 1.36 cm). The change in aneurysm diameter ranged from 0.5 to 3.1 cm (mean, 1.1 +/- 0.62 cm) with an average change of -0.516 +/- 0.01 cm/y for the first year. Five patients died of their intercurrent medical conditions during the follow-up period. One of the patients had a new endoleak and an increase in common iliac aneurysm size 18 months after EVG treatment, despite an early contrast-enhanced computed tomographic scan that showed no endoleak. This patient's aneurysm ruptured, and a standard open surgical repair was successfully performed. Another patient had a decrease in hypogastric aneurysm size after EVG treatment and no radiographic evidence of an endoleak, but eventually the aneurysm ruptured. He was successfully treated with a standard open surgical repair.

CONCLUSIONS

EVGs can be an effective treatment for isolated IAAs. Properly treated with EVGs, IAAs decrease in size. The enlargement of an IAA, even if no endoleak can be detected, appears to be an ominous sign suggestive of an impending rupture. IAAs that enlarge should be closely evaluated for an endoleak. If an endoleak is detected, it should be eliminated if possible. If an endoleak cannot be found, open surgical repair should be considered.

Incompetent and dilated ovarian veins: a common CT finding in asymptomatic parous women

OBJECTIVE

Incompetent and dilated ovarian veins have been reported in association with pelvic congestion syndrome. We postulate that incompetent and dilated ovarian veins are often an incidental CT finding, with a low diagnostic value. To verify our hypothesis, we studied the frequency of incompetent and dilated ovarian veins seen on CT in asymptomatic women.

MATERIALS AND METHODS

We retrospectively analyzed helical CT scans and medical records of 34 consecutive female renal donors between 18 and 46 years old (mean age, 33 years). An incompetent and dilated ovarian vein was defined as a contrast-filled vein measuring 7 mm or greater, seen during the arterial phase of helical CT.

RESULTS

Incompetent and dilated ovarian veins were found in 16 (47%) of 34 asymptomatic women. All 16 women had left ovarian vein involvement; six (37.5%) had bilateral involvement. The mean diameters for the left and right (incompetent and dilated) ovarian veins were 9.1 mm and 8.8 mm, respectively (range, 7-12 mm). Of 16 women with incompetent and dilated ovarian veins, 15 (94%) were parous. Of 18 women with normal ovarian veins, nine (50%) were parous. Overall, incompetent and dilated ovarian veins were found in 15 (63%) of 24 parous women, and in one (10%) of 10 nonparous women (p < 0.05).

CONCLUSION

Incompetent and dilated ovarian veins are frequently seen on CT in asymptomatic parous women. As an isolated finding, it is unlikely to be associated with pelvic congestion syndrome.

Acute enlargement and subsequent rupture of an abdominal aortic aneurysm in a patient receiving chemotherapy for pancreatic carcinoma

We report a case of ruptured abdominal aortic aneurysm (AAA) in a patient receiving chemotherapy for pancreatic cancer. We reviewed the literature on the effects of corticosteroids and chemotherapy on aaa formation and discuss possible mechanisms for drug action to promote aneurysm expansion and rupture. If cancer and AAA coincide and curative chemotherapy is possible, a potential impact of chemotherapy on AAA expansion should be considered.

CT-guided transthoracic needle biopsy using an ipsilateral dependent position

OBJECTIVE

We postulated that the pneumothorax rate of transthoracic needle biopsy might improve with an ipsilateral dependent position of the affected side. We tried to determine the feasibility, effectiveness, and safety of CT-guided biopsy with the patient in this position.

SUBJECTS AND METHODS

CT-guided needle biopsy with the patient in an ipsilateral dependent position was performed in 23 patients with 17 lung lesions (15 posterior and two anterior) and six mediastinal lesions. Fine-needle aspiration was used in all patients, and core biopsy was also used in six patients. The technical difficulty of the procedure was classified into three grades compared with a routine transthoracic needle biopsy as follows: grade I, no more difficult; grade II, somewhat more difficult; and grade III, much more difficult.

RESULTS

Adequate samples were obtained in 22 (96%) of 23 patients. A small asymptomatic pneumothorax occurred in two patients (8.7%). Difficulty was rated grades I, II, and III in 18 (78%), two (9%), and three (13%) procedures, respectively. Four of the five grades II and III procedures were biopsies of anterior lesions. Traversing the pleura was avoided in three of six mediastinal masses.

CONCLUSION

Transthoracic needle biopsy of selected lung and mediastinal lesions using an ipsilateral dependent position is feasible, effective, and safe. The role of this technique for reducing the rate of pneumothorax as a result of the biopsy requires further investigation.

Use of spiral computerized tomography in lieu of angiography for preoperative assessment of living renal donors

PURPOSE

We evaluate whether spiral computerized tomography (CT) can be used in lieu of renal angiography for preoperative assessment of living renal donors, with special attention to multiplicity of renal vasculature.

MATERIALS AND METHODS

A total of 47 living renal donor candidates were evaluated with spiral CT and all but 2 underwent donor nephrectomy. Patients were divided into early and late groups because there was a learning curve with spiral CT. In the early group 18 donors underwent renal angiography as well as spiral CT and 10 underwent nephrectomy after spiral CT only. In the late group 5 had dual radiographic evaluation for ambiguities in spiral CT interpretation and 12 underwent nephrectomy after spiral CT only. Spiral CT was performed and interpreted blind to angiographic results, and vice versa.

RESULTS

Spiral CT identified 50 of 52 renal arteries (96%) found at surgery overall and 23 of 25 (92%) found at surgery after spiral CT only. Two accessory arteries were missed in the 10 early group donors evaluated with spiral CT only, yielding an early negative predictive value of 80%. Renal angiography identified another accessory artery missed by spiral CT in the early group. All 3 missed vessels were identified retrospectively. No arteries found at surgery were missed in the late group (negative predictive value 100%), although there were 2 false-positive results detected by spiral CT relative to renal angiography in 1 candidate renal unit. Overall accuracy to predict early renal artery division relative to surgical findings was 93% for spiral CT and 91% for renal angiography. However, early renal artery division was clinically significant for only 1 of 11 vessels found at surgery. Spiral CT demonstrated 4 anomalous venous returns and renal angiography identified none. However, spiral CT missed 2 accessory veins and identified only 1 of 2 fibromuscular dysplasia cases. Total cost for spiral CT and renal angiography was $886 and $2,905, respectively.

CONCLUSIONS

Spiral CT is a reasonably good alternative to renal angiography for living renal donor assessment but there is a profound learning curve for performance and interpretation. Renal angiography is still the gold standard with respect to the identification of arterial multiplicity and fibromuscular dysplasia, and it should be used adjunctively in cases with spiral CT ambiguity. Neither spiral CT nor renal angiography is ideal for the assessment of early renal artery division which is seldom an issue. The benefits of spiral CT over renal angiography are potentially lower morbidity, improved donor convenience and reduced cost.

Value of CT angiography for postoperative assessment of patients with iliac artery aneurysms who have received endovascular grafts

OBJECTIVE

The purpose of the study was to assess the usefulness of CT angiography for follow-up of patients with iliac artery aneurysms who have undergone endovascular treatment.

SUBJECTS AND METHODS

Twelve patients with iliac artery aneurysms (10 true aneurysms and two pseudoaneurysms) were examined with CT angiography within 1 week of receiving transfemorally placed endovascular grafts. All patients underwent follow-up CT angiography from 3 to 30 months (mean, 11 months) later. Follow-up CT angiography at 6 months or later (mean, 14 months) was also available in 10 patients. All studies were obtained after i.v. contrast administration using 3-mm collimation, 1.6-2.0 pitch, 2-mm retrospective reconstruction, and with subsequent three-dimensional rendering and multiplanar reformation. The shape and patency of the graft, perigraft thrombosis, and the size of the aneurysm were assessed.

RESULTS

All grafts remained patent and without deformity. Complete thrombosis of the aneurysm was shown by initial postoperative CT angiography in 11 patients and confirmed by follow-up studies. A single case of a perigraft leak was revealed by CT angiography and confirmed by follow-up angiography. No aneurysm showed change in size at late follow-up.

CONCLUSION

CT angiography is an accurate method for evaluating endovascular devices. CT angiography can be used as a primary technique for follow-up of patients who have undergone endovascular repair of iliac aneurysms.