George R. Oliveira

Identifying, Characterizing, and Classifying Congenital Anomalies of the Coronary Arteries

The clinical manifestations of coronary artery anomalies vary in severity, with some anomalies causing severe symptoms and cardiovascular sequelae and others being benign. Cardiovascular computed tomography (CT) has emerged as the standard of reference for identification and characterization of coronary artery anomalies. Therefore, it is important for the reader of cardiovascular CT images to be thoroughly familiar with the spectrum of coronary artery anomalies. Hemodynamically significant anomalies include atresia, origin from the pulmonary artery, interarterial course, and congenital fistula. Non-hemodynamically significant anomalies include duplication; high origin; a prepulmonic, transseptal, or retroaortic course; shepherds crook right coronary artery; and systemic termination. In general, coronary arteries with an interarterial course are associated with an increased risk of sudden cardiac death. Coronary artery anomalies that result in shunting, including congenital fistula and origin from the pulmonary artery, are also commonly symptomatic and may cause steal of blood from the myocardium. Radiologists should be familiar with each specific variant and its specific constellation of potential implications.

90Y-Ibritumomab tiuxetan, fludarabine, and TBI-based nonmyeloablative allogeneic transplantation conditioning for patients with persistent high-risk B-cell lymphoma

Nonmyeloablative allogeneic transplantation (NMAT) infrequently cures active chemoresistant, bulky, or aggressive B-cell lymphoma (B-cell non-Hodgkin lymphoma [B-NHL]). We hypothesized that ⁹⁰Y-ibritumomab tiuxetan-based NMAT would facilitate early cytoreduction in such patients promoting improved long-term disease control by the allogeneic graft. Forty high-risk B-NHL patients with persistent disease received 0.4 mCi/kg (maximum, 32 mCi/kg) ⁹⁰Y-ibritumomab tiuxetan, fludarabine, and 2 Gy total body irradiation and matched-related (15) or unrelated (25) transplantation. Baseline features included: median age, 58 years (range, 29-69 years); median prior regimens, 6 (range, 3-12); chemosensitive disease, 6 (15%); bulk > 5 cm, 17 (range, 5.2-18.6 cm, 43%); diffuse large B-cell lymphoma, 14 (35%); and comorbidity score > zero, 34 (85%). Early responses were observed in 24 (60%, 14 complete remission/complete remission unconfirmed, 10 partial response) patients, including 17 of 29 (59%) with chemotherapy-resistant disease and 10 (59%) with bulk > 5 cm. The estimated 30-month survival, progression-free survival, and nonrelapse mortality were 54.1%, 31.1%, and 15.9%, respectively. Early response, baseline platelet counts over 25 000/μL, indolent histology, and related donors were associated with improved survival. The addition of ⁹⁰Y-ibritumomab tiuxetan to NMAT is safe and yields early responses and prolonged disease control in some of the highest-risk B-NHL patients. This trial was registered at www.clinicaltrials.gov as #NCT00119392.

Renovascular imaging in the NSF Era.

The detection of the association between nephrogenic systemic fibrosis (NSF), a rare but potentially life‐threatening disease only encountered in patients with severely impaired renal function, and the previous administration of some Gd‐chelates has cast a shadow on the administration of Gd‐chelates in patients with chronic renal failure. So far, contrast‐enhanced MR‐angiography (MRA) was considered the best diagnostic modality in patients with suspected renal disease. This review explores the most appropriate use of renal MRA with a focus on newly developed nonenhanced MRA techniques. Nonenhanced MRA techniques mainly based on SSFP with ECG‐gating allow for acceptable spatial resolution to visualize at least the proximal parts of the renal arteries. In addition functional renal imaging techniques and their current clinical role are critically appreciated. J. Magn. Reson. Imaging 2009;30:1323–1334.

Venous compression syndromes: clinical features, imaging findings and management

Extrinsic venous compression is caused by compression of the veins in tight anatomic spaces by adjacent structures, and is seen in a number of locations. Venous compression syndromes, including Paget-Schroetter syndrome, Nutcracker syndrome, May-Thurner syndrome and popliteal venous compression will be discussed. These syndromes are usually seen in young, otherwise healthy individuals, and can lead to significant overall morbidity. Aside from clinical findings and physical examination, diagnosis can be made with ultrasound, CT, or MR conventional venography. Symptoms and haemodynamic significance of the compression determine the ideal treatment method.

Large vessel involvement by IgG4-related disease.

Objectives: IgG4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory condition that can affect multiple organs and lead to tumefactive, tissue-destructive lesions. Reports have described inflammatory aortitis and periaortitis, the latter in the setting of retroperitoneal fibrosis (RPF), but have not distinguished adequately between these 2 manifestations. The frequency, radiologic features, and response of vascular complications to B cell depletion remain poorly defined. We describe the clinical features, radiology findings, and treatment response in a cohort of 36 patients with IgG4-RD affecting large blood vessels. Methods: Clinical records of all patients diagnosed with IgG4-RD in our center were reviewed. All radiologic studies were reviewed. We distinguished between primary large blood vessel inflammation and secondary vascular involvement. Primary involvement was defined as inflammation in the blood vessel wall as a principal focus of disease. Secondary vascular involvement was defined as disease caused by the effects of adjacent inflammation on the blood vessel wall. Results: Of the 160 IgG4-RD patients in this cohort, 36 (22.5%) had large-vessel involvement. The mean age at disease onset of the patients with large-vessel IgG4-RD was 54.6 years. Twenty-eight patients (78%) were male and 8 (22%) were female. Thirteen patients (36%) had primary IgG4-related vasculitis and aortitis with aneurysm formation comprised the most common manifestation. This affected 5.6% of the entire IgG4-RD cohort and was observed in the thoracic aorta in 8 patients, the abdominal aorta in 4, and both the thoracic and abdominal aorta in 3. Three of these aneurysms were complicated by aortic dissection or contained perforation. Periaortitis secondary to RPF accounted for 27 of 29 patients (93%) of secondary vascular involvement by IgG4-RD. Only 5 patients demonstrated evidence of both primary and secondary blood vessel involvement. Of those treated with rituximab, a majority responded positively. Conclusions: IgG4-RD is a distinctive, unique, and treatable cause of large-vessel vasculitis. It can also involve blood vessels secondary to perivascular tumefactive lesions. The most common manifestation of IgG4-related vasculitis is aortitis with aneurysm formation. The most common secondary vascular manifestation is periaortitis with relative sparing of the aortic wall. Both primary vasculitis and secondary vascular involvement respond well to B cell depletion therapy.

May-Thurner syndrome: can it be diagnosed by a single MR venography study?

PURPOSE We aimed to evaluate the longitudinal stability of left common iliac vein (LCIV) compression by the right common iliac artery on magnetic resonance venography (MRV). MATERIALS AND METHODS This retrospective study included 214 patients diagnosed with May-Thurner syndrome by MRV. We identified a subset of patients who underwent contrast-enhanced cross-sectional imaging of the pelvis six months before or anytime after the MRV and did not undergo any interventional venous procedures between the two studies; 36 patients met these criteria. The degree of venous compression was calculated in both the index and comparison study. RESULTS On the index MRV, the mean compression of the LCIV was 62%. However, on the comparison study in the same patients, the mean compression was 39%. The mean change in degree of compression between the two studies was 23% (P < 0.0001), ranging from a 12% increase to 69% decrease in degree of compression on the comparison study. CONCLUSION The compressed LCIV on a single MRV study was not stable over time and thus may be insufficient to diagnose May-Thurner syndrome.

A phase I study of pulse high-dose vorinostat (V) plus rituximab (R), ifosphamide, carboplatin, and etoposide (ICE) in patients with relapsed lymphoma.

Given the poor outcomes of relapsed aggressive lymphomas and preclinical data suggesting that ≥2·5 μmol/l concentrations of vorinostat synergize with both etoposide and platinums, we hypothesized that pulse high‐dose vorinostat could safely augment the anti‐tumour activity of (R)ICE [(rituximab), ifosphamide, carboplatin, etoposide] chemotherapy. We conducted a phase I dose escalation study using a schedule with oral vorinostat ranging from 400 mg/d to 700 mg bid for 5 d in combination with the standard (R)ICE regimen (days 3, 4 and 5). Twenty‐nine patients [median age 56 years, median 2 prior therapies, 14 chemoresistant (of 27 evaluable), 2 prior transplants] were enrolled and treated. The maximally tolerated vorinostat dose was defined as 500 mg twice daily × 5 d. Common dose limiting toxicities included infection (n = 2), hypokalaemia (n = 2), and transaminitis (n = 2). Grade 3 related gastrointestinal toxicity was seen in 9 patients. The median vorinostat concentration on day 3 was 4·5 μmol/l (range 4·2–6·0 μmol/l) and in vitro data confirmed the augmented antitumour and histone acetylation activity at these levels. Responses were observed in 19 of 27 evaluable patients (70%) including 8 complete response/unconfirmed complete response. High‐dose vorinostat can be delivered safely with (R)ICE, achieves potentially synergistic drug levels, and warrants further study, although adequate gastrointestinal prophylaxis is warranted.

Prospective Comparison of Reduced-Iodine-Dose Virtual Monochromatic Imaging Dataset From Dual-Energy CT Angiography With Standard-Iodine-Dose Single-Energy CT Angiography for Abdominal Aortic Aneurysm

OBJECTIVE The purpose of this study was to compare the image quality of reduced-iodine-dose single-source dual-energy CT angiography (CTA) with that of standard-iodine-dose single-energy CTA in examinations of patients with abdominal aortic aneurysm and to assess the effect of the concentration of iodinated contrast medium on intravascular enhancement and image quality of reduced-iodine-dose CTA. SUBJECTS AND METHODS In a prospective randomized clinical trial, 66 consecutively registered patients with abdominal aortic aneurysm who had previously undergone single-energy CTA (30-37 g I) underwent follow-up CTA at a reduced dose (21-27 g I) of iodinated contrast medium of either 270 mg I/mL (n = 33) or 320 mg I/mL (n = 33). Two readers independently evaluated virtual monochromatic imaging datasets (40-140 keV) and single-energy CTA images for image quality and noise and their preference for optimal energy virtual monochromatic imaging dataset. A value of p < 0.05 was considered statistically significant. RESULTS All 66 dual-energy CTA examinations were rated diagnostic with mean image quality and image noise scores of 4.8 and 4.5 for reader 1 and 3.8 and 3.4 for reader 2 compared with single-energy CTA results of 4.5 and 4.2 for reader 1 and 4.5 and 4.1 for reader 2. Low-energy virtual monochromatic images (40-60 keV) from reduced-iodine-dose (28%) dual-energy CTA had significantly higher intravascular aortic attenuation (26-185%) and contrast-to-noise ratio (CNR) (20-25%) than standard-iodine-dose single-energy CTA images (p < 0.0001). No significant difference was found between patients who received 270 and those who received 320 mg I/mL with respect to intravascular aortic attenuation (p = 0.6331) or CNR (p = 0.9775). CONCLUSION Low-energy virtual monochromatic imaging datasets from reduced-iodine (24 g I) single-source dual-energy CTA of the abdomen provide up to 185% higher attenuation and 25% higher CNR than standard-iodine-dose (33.3 g I) single-energy CTA while offering a wide range of energy settings irrespective of the concentration of IV contrast medium used.

An easily missed diagnosis: flank pain and nutcracker syndrome

A 27-year-old woman presented to her primary care doctors office with left flank pain. CT of the abdomen showed an isolated left renal vein thrombus. The clot was initially attributed to her oral contraceptive use; however, closer inspection of CT images revealed nutcracker phenomenon (compression of the renal vein between the superior mesenteric artery and abdominal aorta). Intravascular ultrasound imaging confirmed the diagnosis. Nutcracker syndrome is a rare condition, which if left untreated may cause damage to the left kidney. Although under diagnosed, there are several treatment options available ranging from simple surveillance to surgical resolution.

Critical limb ischemia: an update for interventional radiologists.

Critical limb ischemia (CLI) is a growing epidemic with bleak patient outcomes. A variety of treatment modalities have been adopted to address CLI based on comorbidities, life expectancy, and the nature of the arterial disease. With advances in technology and treatment strategies, the clinical outcomes of CLI patients have significantly improved over recent years. However, despite progress, patency rates of both surgical and endovascular interventions, limb-salvage and amputation rates are still dismal. We review the epidemiology, treatment strategies, imaging modalities, and the microcirculation aspect of CLI.