Ugur Bozlar

Normal renal arterial anatomy assessed by multidetector CT angiography: Are there differences between men and women?

The purpose of this study was to determine renal arterial anatomy and gender differences in adults without renovascular disease using multidetector computed tomography angiography (MDCTA). MDCTA datasets of 399 patients were retrospectively reviewed. Measurements of the aortorenal diameters, the angulation of the renal ostia and pedicles as well as the distance between the origins of the renal arteries were measured. Differences in measurements between genders were tested for statistical significance using analysis of variance (ANOVA) and Pearsons Chi‐Square tests. A total of 798 renal arteries were available for analysis in 207 female (mean age = 52.91 years) and 192 male patients (mean age = 53.04 years). Female patients were found to have smaller aortae (at the level of the right renal ostium) and bilateral renal arteries than males (mean aortic diameter M/F = 18.33/15.89 mm, mean right renal artery ostial diameter M/F = 5.06/4.59 mm, mean left ostial renal diameter M/F = 5.14/4.66 mm) (p < .001). There was no statistical significance for the renal ostia level in relation to the vertebrae and the majority of renal arteries originated at the L1 and L2 levels. The longitudinal distance between right and left renal artery ostia ranged from 0 to 32 mm (mean = 4,6 mm, median = 5mm). The mean anteroposterior orientation of the right renal ostia was M/F = 29.45°/28.20°, and M/F = −7.96°/−11.14° for left renal artery ostia. The mean anteroposterior orientation of the right renal pedicle was M/F = 41.37°/44.34° and M/F = 42.31°/43.95° for the left pedicle. There are some differences in normal renal arterial anatomy between genders. Normal renal arterial information is useful not only for planning and performing of endovascular and laparoscopic urologic procedures, but also for medical device development. Clin. Anat. 22:236–242, 2009.

The prevalence of extracardiac findings by multidetector computed tomography before atrial fibrillation ablation

BACKGROUND AND OBJECTIVESnThe study was designed to determine the prevalence of extracardiac findings discovered during multidetector computed tomography (CT) (MDCT) examinations before atrial fibrillation ablation. Multidetector CT has become a valuable tool in detailing left atrial anatomy before catheter ablation. The incidence of extracardiac findings has been reported for electron beam CT calcium scoring and coronary MDCT, but no data exist for the prevalence of extracardiac findings discovered before atrial fibrillation ablation with MDCT.nnnMETHODS AND RESULTSnClinical reports from MDCT examinations before atrial fibrillation ablation and interpretations by 2 radiologists blinded to the clinical reports were reviewed for significant additional extracardiac findings and recommendations for follow-up. In 149 patients who underwent MDCT, the mean age was 55.9 +/- 11.0 years, 75% were men, and 47% had a history of smoking. Extracardiac findings were identified in 69% of patients with clinical, 90% of reader 1, and 97% of reader 2 interpretations (kappa = 0.086). Follow-up was recommended in 30% of clinical, 50% of reader 1, and 38% of reader 2 interpretations (kappa = 0.408). Pulmonary nodules were the most common additional finding and reason for suggested follow-up for all interpreters.nnnCONCLUSIONSnThe prevalence of extracardiac abnormalities detected by MDCT is considerable. Significant variability in their identification exists between interpreters, but there is good agreement about the need for further follow-up. It is important that those who interpret these examinations are adequately trained in the identification and interpretation of both cardiac and extracardiac findings.

Three-Dimensional Rotational Angiography of the Inferior Vena Cava as an Adjunct to Inferior Vena Cava Filter Retrieval

The objective of this study was to explore the role of three-dimensional (3-D) rotational angiography (RA) of the inferior vena cava (IVC; 3-D CV) before filter retrieval and its impact on treatment planning compared with standard anteroposterior cavography (sCV). Thirty patients underwent sCV and 3-D CV before IVC filter retrieval. Parameters assessed were: projection of filter arms or legs beyond the caval lumen, thrombus burden within the filter and IVC, and orientation of the filter within IVC. Skin and effective radiation doses were calculated. Statistical analysis was performed using paired Student t test and nonparametric McNemar’s test. Standard anteroposterior cavography detected 49 filter arms or legs projecting beyond the caval lumen in 25 patients. Three-dimensional CV demonstrated 89 filter arms or legs projecting beyond the caval lumen in 28 patients. Twenty-two patients had additional filter arms or legs projecting beyond the caval lumen detected on 3-D CV that were not detected on sCV (pxa0<xa00.001). Filter apex tilt detection differed significantly (pxa0<xa00.001) between sCV and 3-D CV, with 3-D CV being more accurate. The filter apex abutted the IVC wall in 10 patients (33%) on 3-D CV, but this was diagnosed in only 3 patients (10%) with sCV. Thrombus was detected in 8 patients (27%), 1 thrombus of which was seen only on 3-D CV, and treatment was changed in this patient because of thrombus size. Mean effective radiation doses for 3-D CV were approximately two times higher than for sCV (1.68 vs. 0.86xa0mSv), whereas skin doses were three times lower (12.87 vs. 35.86xa0mGy). Compared with sCV, performing 3-D CV before optional IVC filter retrieval has the potential to improve assessment of filter arms or legs projecting beyond the caval lumen, filter orientation, and thrombus burden.

Initial Clinical Experience with Biopolymer-coated Detachable Coils (HydroCoil) in Peripheral Embolization Procedures

PURPOSEnTo evaluate the technical and clinical success of HydroCoils in patients who underwent peripheral embolization procedures.nnnMATERIALS AND METHODSnBetween July 2006 and June 2007, 12 peripheral embolization procedures with HydroCoils in 11 patients (six male patients and five female patients; age range, 4-74 years; mean age, 46 y) were available for this retrospective review. The indications for embolization were hemorrhage (n = 4), aneurysm (n = 1), recurrent pulmonary arteriovenous malformation (n = 1), and protection before radioembolization and chemoembolization (n = 5). HydroCoil-10, -14, and -18 systems were used. Procedural and postprocedural follow-up imaging were reviewed by two interventional radiologists. Digital subtraction angiography (DSA) images were used to evaluate embolization success and vessel diameter. DSA and computed tomography (CT) angiography were used for follow-up, which included evaluation for recanalization and migration of coils. Chart review was also performed.nnnRESULTSnAll procedures were successful in occluding the target vessels (100%), which ranged from 1.2 mm to 8.2 mm in diameter (median, 2.2 mm). Immediate clinical success was achieved in all procedures (100%). Follow-up imaging was available in seven cases (four CT angiography and three DSA) at 2-108 days (mean, 42 d). No recanalization or migration of coils was found. There were no procedure-related complications, no clinical evidence of nontarget embolization, and no recurrence of presenting symptoms.nnnCONCLUSIONSnThe use of HydroCoils in peripheral arterial embolization procedures is effective and safe. They are viable alternatives to standard coils, particularly in tortuous, small target vessels or in cases in which controlled release is desirable.

Imaging diagnosis of acute pulmonary embolism

Pulmonary embolism represents a major public healthcare problem and it also imposes frequent clinical diagnostic issues. Despite the availability of the D-dimer tests, imaging remains the mainstay for its diagnosis. Computed tomography pulmonary angiography (CTPA) is now the most widely used diagnostic test and its utility has been well validated in a large number of trials. Nuclear medicine techniques, which are also well established, are now used significantly less frequently. Magnetic resonance pulmonary angiography is developing as an alternative to CTPA in patients who have contraindications to iodinated contrast media. Catheter pulmonary angiography remains the gold standard, although it is being used increasingly less frequently. In this article, we review the current knowledge on the imaging diagnosis of acute pulmonary embolism with special emphasis on the noninvasive techniques.

MR diagnosis of a pulmonary embolism: comparison of P792 and Gd-DOTA for first-pass perfusion MRI and contrast-enhanced 3D MRA in a rabbit model.

Objective To compare P792 (gadomelitol, a rapid clearance blood pool MR contrast agent) with gadolinium-tetraazacyclododecanetetraacetic acid (Gd-DOTA), a standard extracellular agent, for their suitability to diagnose a pulmonary embolism (PE) during a first-pass perfusion MRI and 3D contrast-enhanced (CE) MR angiography (MRA). Materials and Methods A perfusion MRI or CE-MRA was performed in a rabbit PE model following the intravenous injection of a single dose of contrast agent. The time course of the pulmonary vascular and parenchymal enhancement was assessed by measuring the signal in the aorta, pulmonary artery, and lung parenchyma as a function of time to determine whether there is a significant difference between the techniques. CE-MRA studies were evaluated by their ability to depict the pulmonary vasculature and following defects between 3 seconds and 15 minutes after a triple dose intravenous injection of the contrast agents. Results The P792 and Gd-DOTA were equivalent in their ability to demonstrate PE as perfusion defects on first pass imaging. The signal from P792 was significantly higher in vasculature than that from Gd-DOTA between the first and the tenth minutes after injection. The results suggest that a CE-MRA PE could be reliably diagnosed up to 15 minutes after injection. Conclusion P792 is superior to Gd-DOTA for the MR diagnosis of PE.

Catheter-directed thrombolysis of acute lower extremity arterial thrombosis in a patient with heparin-induced thrombocytopenia

Heparin‐induced thrombocytopenia (HIT) is an underdiagnosed problem, and the optimal treatment of arterial thrombosis in patients with HIT remains controversial. There are many angiographic procedures which require heparin as an adjunctive agent; however, some of the heparin‐related complications and their management remains unclear. We are presenting a 77‐year‐old male patient with HIT, who developed acute lower extremity limb threatening ischemia due to arterial thrombosis. In our case, the patient has been successfully treated with percutaneous catheter‐directed thrombolysis with tissue plasminogen activator and a direct thrombin inhibitor argatroban.

Pulmonary blood volume imaging with dual-energy computed tomography: spectrum of findings.

Dual-energy (DE) pulmonary blood volume (PBV) computed tomography (CT) has recently become available on clinical CT systems. The underlying physical principle of DECT is the fact that the photoelectric effect is strongly dependent on the CT energies resulting in different degrees of x-ray attenuation for different materials at different energy levels. DECT thus enables the characterization and quantification of iodine within tissues via imaging at different x-ray energies and analysis of attenuation differences. Technical approaches to DECT include dual-source scanners acquiring two scans with different energy levels simultaneously, and single-source CT scanners using sandwich detectors or rapid voltage switching. DE PBV CT enables the creation of iodine maps of the pulmonary parenchyma. Experience to date shows that these studies can provide additional physiological information in patients with acute or chronic pulmonary embolism beyond the pure morphological assessment a standard CT pulmonary angiography (CTPA) provides. It appears also to be promising for the evaluation of patients with obstructive airways disease. This article reviews the physics and technical aspects of DE PBV CT as well as the appearance of normal and abnormal lung tissue on these studies. Special consideration is given to pitfalls and artefacts.

Outback catheter-assisted simultaneous antegrade and retrograde access for subintimal recanalization of peripheral arterial occlusion

Subintimal recanalization techniques have been shown to be beneficial in selected patients with severe peripheral vascular disease with tissue loss or rest pain and limited surgical options. In this report, we use an Outback catheter in order to gain access to the subintimal channel from the true lumen during percutaneous intentional extraluminal recanalization using the subintimal arterial flossing with antegrade-retrograde intervention (SAFARI) technique. To the best of our knowledge, this is the first report where the Outback catheter was used in antegrade fashion in order to gain access to the subintimal space from the true lumen using the SAFARI technique.

Comparison of three-dimensional rotational angiography and digital subtraction angiography for the evaluation of the liver transplants

PURPOSEnThe objective of this study is to define the role of three-dimensional (3D) rotational angiography (RA) in the evaluation of transplant hepatic arteries and compare it with digital subtraction angiography (DSA).nnnMATERIALS AND METHODSnThe patency of the arteries and anastomoses, confidence in the ability to make a therapeutic decision, and the value of the study for the definition of the optimal projection for an intervention were graded on a scale from 0 to 10.nnnRESULTSnForty-three vascular segments in five patients were available for analysis. Complete concordance between 3D RA and DSA was present in 92.9% of the major (extrahepatic) segments. Three-dimensional RA demonstrated two major hepatic segments that were not visualized on DSA. There was no difference in diagnostic confidence, but 3D RA was considered superior for planning the optimal projection for intervention (10+/-0 vs. 6.4+/-1.8).nnnCONCLUSIONnThree-dimensional RA DSA allows a more complete depiction of the hepatic allograft arterial system than DSA with comparable accuracy. Three-dimensional RA provides similar degrees of confidence in the ability to make a treatment decision, and its appropriate implementation could help reduce overall contrast and radiation dose.