Limitations of GD-EOB-DTPA-enhanced MRI: can clinical parameters predict suboptimal hepatobiliary phase?

AIM: To establish cut-off levels of the clinical parameters, which would predict suboptimal 30 minutes delayed hepatobiliary phase (HBP) with high specificity. MATERIALS AND METHODS: This retrospective study included patients with chronic liver disease who underwent hepatocellular carcinoma screening with Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) between 1 January 2011 and 30 November 2014. For each case, HBP was graded as adequate or suboptimal, based on Liver Image Reporting and Data System (LI-RADS) criteria. The following laboratory data obtained within 3 months of the MRI date was extracted: total bilirubin (TB), direct bilirubin (DB), serum glutamic oxaloacetic transaminase (SGOT), serum glutamic-pyruvic transaminase (SGPT), alkaline phosphatase (ALP), albumin, activated partial thromboplastin time (aPTT), and International normalised ratio (INR). Model For End-Stage Liver Disease (MELD) scores were calculated as 3.78×ln[TB] + 11.2×ln[INR] + 9.57×ln[creatinine] + 6.43. Receiver operating characteristic (ROC) curve analysis was used to establish cut-off values for predicting suboptimal HBP. RESULTS: Of 284 patients, 242 (85.2%) patients (91; 57.6% male) had an adequate HBP and 42 (14.8%) patients (13; 61.9% male) had suboptimal HBP, with mean ages of 58.5±9.7 years and 55±12.7 years, respectively (p=0.096). Areas under the ROC curve for predicting suboptimal HBP were 0.85 (95%CI 0.79-0.91) for the MELD score, 0.88 (95%CI 0.82-0.93) for TB, and 0.91 (95%CI 0.86-0.95) for DB. Accuracy, positive likelihood ratios and cut-off values for predicting suboptimal HBP were, respectively: 86.7% and 11.2 for the MELD score ≥16.7, 88.2% and 28.7 for TB ≥4.3 mg/dl, and 91.1% and 36.4 for DB ≥1.3 mg/dl. SGOT, SGPT, and ALP were not statistically significantly different between the groups. CONCLUSION: Cut-off levels of MELD score, DB, and TB can predict an suboptimal HBP with high accuracy. Prospective identification of patients with a high likelihood of an suboptimal HBP can help to avoid administering a more costly agent to patients who would not benefit from its unique properties.

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.

Small bowel faeces sign in patients without small bowel obstruction.

AIM: To evaluate frequency and clinical relevance of the 'small bowel faeces' sign (SBFS) on computed tomography (CT) in patients with and without small bowel obstruction (SBO) presenting with acute abdominal or acute abdominal and flank pain. METHODS: Abdominal CTs of consecutive patients presenting to the emergency department with abdominal or flank pain over a 6 month period were retrospectively reviewed by six radiologists, independently, for the presence of the SBFS. Examinations with positive SBFS were further evaluated in consensus by three radiologists, blinded to the final diagnosis. The small bowel was graded as non-dilated (<2.5 cm) and mildly (2.5-2.9 cm), moderately (3-4 cm) or severely (>4 cm) dilated. The location of SBFS and presence of distal small bowel collapse indicative of SBO was recorded. Imaging findings were subsequently correlated with the final diagnosis via chart review and compared between patients with and without SBO. RESULTS: Of 1642 CT examinations, a positive SBFS was found in 100 (6%) studies. Of 100 patients with a positive SBFS, 32 (32%) had documented SBO. The remaining 68 patients had other non-obstructive diagnoses. SBFS was located in proximal, central, distal and multisegmental bowel loops in one (3.1%), eight (25.0%), 21 (65.6%) and two (6.3%) patients with SBO, and in zero (0%), 10 (14.7%), 53 (77.9%) and five (7.4%) of patients without SBO (p<0.273). The small bowel was non-dilated and mildly, moderately or severely dilated in one (3%), five (16%), 20 (62%) and six (19%) patients with SBO, and in 61(90%), seven (10%), zero (0%) and zero (0%) patients without SBO. Normal or mildly dilated small bowel was seen in all (100%) patients without SBO, but only in six (19%) of 32 patients with SBO (p<0.0001). Moderate or severe small bowel dilatation was seen in 26 (81%) patients with SBO (p<0.0001), but it was absent in patients without SBO. Distal small bowel collapse was found in 27 (84.4%) of 32 patients with SBO, but not in patients without SBO (p<0.0001). A combination of SBFS, moderate or severe small bowel distension and distal collapse was found in 23 (71.9%) patients with SBO (p<0.0001), but was not found in patients without SBO. CONCLUSION: A SBFS is more frequent in patients presenting with acute abdominal/flank pain without bowel obstruction. When seen in association with moderate or severe small bowel dilatation, a SBFS is significantly more common in patients with SBO. When a SBFS is associated with normal or mildly dilated small bowel, the majority of patients have no bowel obstruction.

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.

Sequential phase II trials of fluorouracil and interferon beta ser with or without sargramostim in patients with advanced colorectal carcinoma.

BACKGROUND: Preclinical and early clinical trials suggested that the biologic agent interferon beta ser (IFN beta ser) may augment the anticancer activity of 5-fluorouracil (5-FU). The current studies were undertaken to explore the optimal schedule of IFN beta ser and to determine whether the hematopoietic growth factor sargramostim (granulocyte-macrophage colony-stimulating factor) could reduce the hematologic and gastrointestinal toxicities of the chemotherapy. METHODS: Three sequential, single-institution phase II trials using different regimens were initiated. Patients were required to have advanced, histologically documented colorectal carcinoma with no prior chemotherapy; to have adequate bone marrow, renal, and hepatic function; to be fully ambulatory; and to give informed consent. All patients received 5-FU, 750 mg/m2 intravenously as an infusion daily for 5 days, followed by 5-FU, 750 mg/m2, as an intravenous bolus every week beginning day 15. Patients in arm A received IFN beta ser, 9 MU subcutaneously, three times a week. Patients in arm B received IFN beta ser, 9 MU subcutaneously every day. Patients in arm C were treated exactly as in arm B but also received sargramostim, 250 micrograms subcutaneously on days they did not receive 5-FU. Beginning day 15, all patients received IFN beta ser exactly 10 minutes before receiving the 5-FU bolus. RESULTS: There were 81 patients enrolled: 19 in arm A; 40 in arm B; and 22 in arm C. Myelosuppression and diarrhea were the most common toxicities. Increasing the frequency of IFN beta ser administration in arm B resulted in a doubling of the rate of diarrhea from 11% to 22%, and the addition of sargramostim in arm C failed to reduce this. Sargramostim did reduce the incidence of grade 3 to 4 leukopenia, but this did not allow intensification of dosing or result in improved response or survival among patients in arm C. IFN-mediated fatigue was also common, occurring in 37% to 43% of patients. Patients receiving IFN beta ser on the intermittent schedule tolerated full-dose therapy longer than those on the daily schedule (10 weeks versus 5 weeks, P < 0.01). The response rates in the three arms were 21%, 35%, and 27%; there was no difference in median survival (15 months for all three arms). CONCLUSIONS: The combination of 5-FU and IFN beta ser was active in patients with advanced colorectal carcinoma, and survival with this regimen was comparable to or better than that with other modulating regimens. The intermittent schedule of IFN beta ser was better tolerated than than the daily schedule.

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.

Endoleaks after endovascular graft treatment of aortic aneurysms: classification, risk factors, and outcome.

PURPOSE: Incomplete endovascular graft exclusion of an abdominal aortic aneurysm results in an endoleak. To better understand the pathogenesis, significance, and fate of endoleaks, we analyzed our experience with endovascular aneurysm repair. METHODS: Between November 1992 and May 1997, 47 aneurysms were treated. In a phase I study, patients received either an endovascular aortoaortic graft (11) or an aortoiliac, femorofemoral graft (8). In phase II, procedures and grafts were modified to include aortofemoral, femorofemoral grafts (28) that were inserted with juxtarenal proximal stents, sutured endovascular distal anastomoses within the femoral artery, and hypogastric artery coil embolization. Endoleaks were detected by arteriogram, computed tomographic scan, or duplex ultrasound. Classification systems to describe anatomic, chronologic, and physiologic endoleak features were developed, and aortic characteristics were correlated with endoleak incidence. RESULTS: Endoleaks were discovered in 11 phase I patients (58%) and only six phase II patients (21%; p < 0.05). Aneurysm neck lengths 2 cm or less increased the incidence of endoleaks (p < 0.05). Although not significant, aneurysms with patent side branches or severe neck calcification had a higher rate of endoleaks than those without these features (47% vs 29% and 57% vs 33%, respectively), and patients with iliac artery occlusive disease had a lower rate of endoleaks than those without occlusive disease (18% vs 42%). Endoleak classifications revealed that most endoleaks were immediate, without outflow, and persistent (71% each), proximal (59%), and had aortic inflow (88%). One patient with a persistent endoleak had aneurysm rupture and died. CONCLUSIONS: Endoleaks complicate a significant number of endovascular abdominal aortic aneurysm repairs and may permit aneurysm growth and rupture. The type of graft used, the technique of graft insertion, and aortic anatomic features all affect the rate of endoleaks. Anatomic, chronologic, and physiologic classifications can facilitate endoleak reporting and improve understanding of their pathogenesis, significance, and fate.

Imaging of the vascular system for endovascular grafting and other procedures.

Success of endovascular therapy largely depends on accurate imaging before, during, and after the procedure. The vascular system can be evaluated noninvasively with computed tomography (CT), magnetic resonance (MR) imaging, and duplex ultrasound (US), or invasively with angiography and intravascular ultrasonography (IVUS). Noninvasive methods are preferred for both preprocedure screening and postprocedure follow-up, whereas invasive imaging modalities constitute an essential part of the endovascular procedure. Invasive techniques are also used in preprocedural or postprocedural evaluation when noninvasive methods are unable to obtain important diagnostic information, or when the confirmation of noninvasive imaging findings is desired. Specific roles of these modalities for endovascular treatment of aortoiliac aneurysms are discussed.

Evolution of the infected abdominal aortic aneurysm: CT observation of early aortitis.

Infected aortic aneurysm is an uncommon, life-threatening disease. Early surgical treatment is crucial to survival. An early diagnosis could be made on CT in suspected cases, although CT features of infectious aortitis overlap with retroperitoneal fibrosis, hemorrhage, and lymphadenopathy. We report the case of an infected abdominal aortic aneurysm and describe the additional potentially useful CT finding of early infectious aortitis, which helps localize the abnormality to the aortic wall.

Cystic adrenal lesions: CT features.

PURPOSE: To define computed tomographic (CT) features of cystic adrenal lesions that differentiate them from similar-appearing adenoma. MATERIALS AND METHODS: CT scans of 13 cystic adrenal lesions (four endothelial cysts, three benign pseudocysts, one nonspecific benign cyst, one carcinoma, one pheochromocytoma, and three stable lesions with no histologic diagnosis) were analyzed retrospectively. Reports in the literature of 26 benign adrenal cysts were also reviewed. RESULTS: Mean lesion diameter was 6.2 cm, and six lesions were less than 5.0 cm. Mean attenuation values was 21 HU, and in eight cases it was less than 15 HU. Partial adrenal involvement was noted in six cases. Ten lesions contained wall or septal calcification. Wall thickness was 3 mm or less in nine and exceeded 6 mm in three lesions; one of the latter was cystic carcinoma. Wall enhancement (but no intralesional enhancement) was found in two of six lesions. Of 37 reviewed benign cysts, 19 had mural and seven had central calcification, 28 were unilocular, and seven had high attenuation value. Wall thickness was 3 mm or less in 31 lesions. CONCLUSION: CT findings of a nonenhancing mass with or without wall calcification allow differentiation of adrenal cyst from adenoma. A small adrenal cyst with near-water attenuation and a thin (< or = 3-mm) wall is likely to be benign.