Polysplenia syndrome and sickle cell trait: extensive deep venous thrombosis from venous stasis and hypercoagulability.

Deep venous thrombosis is a hitherto under-recognized complication occurring in patients with polysplenia syndrome, despite the high prevalence of venous anomalies such as interrupted inferior vena cava (IVC) with azygos/hemiazygos continuation. Here we report the first case of concurrent polysplenia (as evidenced by interrupted IVC with azygos/hemiazygos continuation, multiple left-sided spleens, bowel malrotation with inverted mesenteric veins, preduodenal portal vein, and pancreatic hypoplasia/partial agenesis of the dorsal pancreas) and sickle cell trait, complicated by extensive deep venous thrombosis refractory to medical and interventional radiologic management.

Recent Innovations in Renal Vascular Imaging.

Noninvasive imaging of the vascular renal system is a common request in diagnostic radiology. Typical indications include suspected renovascular hypertension, vasculitis, neoplasm, vascular malformation, and structural diseases of the kidney. Profound knowledge of the renal anatomy, including vascular supply and variants, is mandatory for radiologists and allows for optimized protocolling and interpretation of imaging studies. Besides renal ultrasound, computed tomography and MR imaging are commonly requested cross-sectional studies for renal and renal vascular imaging. This article discusses basic renal vascular anatomy, common imaging findings, and current and potential future imaging protocols for various renovascular pathologic conditions.

Bilateral Common Iliac Artery Endofibrosis in a Recreational Cyclist: Case Report and Review of the Literature.

External iliac artery endofibrosis is a rare medical condition typically encountered in young endurance athletes, mainly cyclists. Iliac endofibrosis usually develops in the external iliac artery and is rarely seen in the common iliac or in common femoral arteries. We describe a unique case of a patient who was not a professional or high-endurance cyclist. The lesions in our case appeared to be bilateral in the common iliac arteries and were not limited to the external iliac artery as most commonly described. We present an overview of the literature regarding this medical condition.

Delayed Myocardial Enhancement in Cardiac Magnetic Resonance Imaging.

Delayed myocardial enhancement MRI is a highly valuable but non-specific imaging technique that is ancillary in the diagnosis of a variety of diseases including myocardial viability, cardiomyopathy, myocarditis and other infiltrative myocardial processes. The lack of specificity stems from the wide variety of differential diagnoses that may present with overlapping patterns of delayed enhancement. Many of these differential diagnoses have been presented and discussed in this article.

Patients' Perceptions of Radiation Exposure Associated With Mammography.

OBJECTIVE: Radiation associated with breast imaging is a sensitive issue, particularly for women who undergo mammography as a screening measure to detect breast cancer. Misinformation and misunderstanding regarding the risks associated with ionizing radiation have created heightened public concern and fear, which may result in avoidance of diagnostic procedures. The objectives of this study were to ascertain patients' knowledge and opinion of ionizing radiation as a whole and specifically in mammography, as well as to determine common misunderstandings and points of view that may affect women's decisions about whether to have a mammogram. MATERIALS AND METHODS: Over a 9-month period, a total of 1725 patients presenting for a mammogram completed a 25-point questionnaire focused on the following: general knowledge of radiation dose in common imaging modalities, the amount of radiation associated with a mammogram relative to five radiation benchmarks, and patients' opinions of the involvement of radiation in their health care. RESULTS: Although 65% of the women receiving a mammogram responded that they had been informed of the risks and benefits of the examination, 60% overestimated the radiation in a mammogram. CONCLUSION: Efforts should be made to accurately inform women of the risks and benefits of mammography, specifically highlighting the low dose of mammographic ionizing radiation and providing objective facts to ensure that they are making an informed decision regarding screening.

Reliability and reproducibility of quantitative assessment of left ventricular function and volumes with 3-slice segmentation of cine steady-state free precession short axis images.

OBJECTIVES: Quantitative assessment of left ventricular (LV) functional parameters in cardiac MR requires time-consuming contour tracing across multiple short axis images. This study assesses global LV functional parameters using 3-slice segmentation on steady state free precision (SSFP) cine short axis images and compares the results with conventional multi-slice segmentation of LV. METHODS: Data were collected from 61 patients who underwent cardiac MRI for various clinical indications. Semi-automated cardiac MR software was used to trace LV contours both at multiple slices from base to apex as well as just 3 slices (base, mid, and apical) by two readers. Left ventricular ejection fraction (LVEF), LV volumes, and LV mass were calculated using both methods. RESULTS: Bland-Altman plot revealed narrow limits of agreement (-4.4% to 5.1%) between LVEF obtained by the two methods. Bland-Altman analysis showed slightly wider limits of agreement between end-diastolic volumes (-5.0 to 12.0%; -3.9 to 8.5 ml/m(2)), end-systolic volumes (-10.9 to 14.7%; -4.1 to 6.5 ml/m(2)), and LV mass (-5.2 to 12.7%; -4.8 to 10.2g/m(2)) obtained by the two methods. There was a small mean difference between LV volumes and LV mass obtained using multi-slice and 3-slice segmentation. No statistically significant difference existed between the LV parameters obtained by the two readers using 3-slice segmentation (p>0.05). Multi-slice assessment required approximately 15 min per study while 3-slice assessment required less than 5 min. CONCLUSIONS: 3-slice segmentation of the left ventricle at basal, mid, and apical levels on cine SSFP short axis images can provide rapid and reliable assessment of LVEF with good reproducibility. The 3-slice method also provides a reasonable estimate of the LV volumes and LV mass.

Investigation of DNA Damage Dose-Response Kinetics after Ionizing Radiation Schemes Similar to CT Protocols.

Although there has been extensive research done on the biological response to doses of ionizing radiation relevant to radiodiagnostic procedures, very few studies have examined radiation schemes similar to those frequently utilized in CT exams. Instead of a single exposure, CT exams are often made up of a series of scans separated on the order of minutes. DNA damage dose-response kinetics after radiation doses and schemes similar to CT protocols were established in both cultured (ESW-WT3) and whole blood lymphocytes and compared to higher dose exposures. Both the kinetics and extent of H2AX phosphorylation were found to be dose dependent. Damage induction and detection showed a clear dose response, albeit different, at all time points and differences in the DNA repair kinetics of ESW-WT3 and whole blood lymphocytes were characterized. Moreover, using a modified split-dose in vitro experiment, we show that phosphorylation of H2AX is significantly reduced after exposure to CT doses fractionated over a few minutes compared to the same total dose delivered as a single exposure. Because the split-dose exposures investigated here are more similar to those experienced during a CT examination, it is essential to understand why and how these differences occur. This work provides compelling evidence supporting differential biological responses not only between high and low doses, but also between single and multiple exposures to low doses of ionizing radiation.

Prevalence of coronary artery disease evaluated by coronary CT angiography in women with mammographically detected breast arterial calcifications.

To assess the correlation between breast arterial calcifications (BAC) on digital mammography and the extent of coronary artery disease (CAD) diagnosed with dual source coronary computed tomography angiography (CTA) in a population of women both symptomatic and asymptomatic for coronary artery disease. 100 consecutive women (aged 34 - 86 years) who underwent both coronary CTA and digital mammography were included in the study. Health records were reviewed to determine the presence of cardiovascular risk factors such as hypertension, hyperlipidemia, diabetes mellitus, and smoking. Digital mammograms were reviewed for the presence and degree of BAC, graded in terms of severity and extent. Coronary CTAs were reviewed for CAD, graded based on the extent of calcified and non-calcified plaque, and the degree of major vessel stenosis. A four point grading scale was used for both coronary CTA and mammography. The overall prevalence of positive BAC and CAD in the studied population were 12% and 29%, respectively. Ten of the 12 patients with moderate or advanced BAC on mammography demonstrated moderate to severe CAD as determined by coronary CTA. For all women, the positive predictive value of BAC for CAD was 0.83 and the negative predictive value was 0.78. The presence of BAC on mammography appears to correlate with CAD as determined by coronary CTA (Spearman's rank correlation coefficient = 0.48, p<.000001). Using logistic regression, the inclusion of BAC as a feature in CAD predication significantly increased classification results (p=0.04).

Computed tomography angiography of lower extremities in the emergency room for evaluation of patients with gunshot wounds.

OBJECTIVE: To assess the role of CT angiography in the evaluation of patients with lower extremity gunshot wounds in the emergency room. MATERIALS AND METHODS: Eighty patients (73 male, 7 female, mean age 26 years) underwent CT angiography for the evaluation of lower extremity gunshot injuries. Imaging was conducted on the basis of standardized protocols utilizing 16-slice and 64-slice multidetector systems and images were qualitatively graded and assessed for various forms of arterial injury. RESULTS: CT angiography findings indicative of arterial injury were observed in 24 patients (30%) and a total of 43 arterial injuries were noted; the most common form was focal narrowing/spasm (n = 16, 37.2%); the most common artery involved was the superficial femoral artery (n = 12, 50%). In qualitative assessment of images based on a 4-point grading system, both readers considered CT angiography diagnostically excellent (grade 4) in most cases. Surgical findings were consistent with CT angiography and follow-up of patients' medical records showed no arterial injuries in patients with normal findings on initial imaging. CONCLUSION: Our findings demonstrate that CT angiography is an effective imaging modality for evaluation of lower extremity gunshot wounds and could help limit more invasive procedures such as catheter angiography to a select group of patients. KEY POINTS: • CT angiography efficiently evaluates lower extremity gunshot wounds. • CT angiography provides image quality sufficiently reliable for assessment of gunshot injuries. • CT angiography could help limit invasive procedures to select patients.

Successful patient recruitment in CT imaging clinical trials: what factors influence patient participation?

RATIONALE AND OBJECTIVES: Analyze factors that influence participation in research studies that use coronary computed tomography (CT) imaging. MATERIALS AND METHODS: A 12-point survey using a questionnaire was conducted on 80 subjects, of whom 40 agreed to participate in a cardiovascular CT imaging research study (enrolling subjects) and 40 declined participation (non-enrolling subjects). Potential factors that motivated the acceptance or refusal of enrollment were evaluated using a 5-point Likert scale. The following aspects were addressed: (1) additional health information, (2) free imaging, (3) altruistic benefit to society, (4) monetary compensation, (5) radiation exposure, (6) role as an experimental subject, (7) possible loss of confidentiality, (8) contrast or investigational drug use, (9) premedication use, (10) blood draw or intravenous placement, (11) time commitment, and (12) personal medical opinion. Response distributions were obtained for each question and compared between enrolling and non-enrolling groups. RESULTS: Enrolling subjects gave significantly higher ratings than non-enrolling subjects for the following factors: additional health information (P < .001), free imaging (P < .001), and the altruistic benefit to society (P < .001). For non-enrolling subjects, concern for possible drug use or contrast injection (P < .001), concern for possible premedication (P < .001), and personal availability or time commitment (P < .001) were all given significantly higher ratings. Concern for radiation exposure (P = .002) and personal medical opinion (P < .001) received significantly high ratings among both groups but did not differ between groups. CONCLUSIONS: Several influential concerns and benefits were identified from potential research subjects. Knowledge of what influences patient participation in studies involving CT imaging may allow researchers to effectively address concerns and highlight the potential benefits related to participation.

The quadricuspid aortic valve.

The quadricuspid aortic valve is a very rare congenital defect that may be an isolated entity or associated with a multitude of cardiovascular abnormalities. Isolated cases usually manifest late in life with the complication of aortic regurgitation, which can be delayed by early valve replacement. We present a case of quadricuspid aortic valve associated with truncus arteriosus, ventricular septal defect, and interrupted aortic arch.

Enhancement of liver parenchyma after injection of hepatocyte-specific MRI contrast media: a comparison of gadoxetic acid and gadobenate dimeglumine.

PURPOSE: To compare enhancement of liver parenchyma in MR imaging after injection of hepatocyte-specific contrast media. MATERIALS AND METHODS: Patients (n = 295) with known/suspected focal liver lesions randomly received 0.025 mmol gadoxetic acid/kg body weight or 0.05 mmol gadobenate dimeglumine/kg body weight by means of bolus injection. MR imaging was performed before and immediately after injection, and in the delayed phase at approved time points (20 min after injection of gadoxetic acid and 40 min after injection of gadobenate dimeglumine). The relative liver enhancement for the overall population and a cirrhotic subgroup was compared in T1-weighted GRE sequences. An independent radiologist performed signal intensity measurements. Enhancement ratios were compared using confidence intervals (CIs). RESULTS: The relative liver enhancement in the overall population was superior with gadoxetic acid (57.24%) versus gadobenate dimeglumine (32.77%) in the delayed-imaging phase. The enhancement ratio between the contrast media was statistically significant at 1.75 (95% CI: 1.46-2.13). In the delayed phase, the enhancement of cirrhotic liver with gadoxetic acid (57.00%) was comparable to that in the overall population. Enhancement with gadobenate dimeglumine was inferior in cirrhotic liver parenchyma (26.85%). CONCLUSION: In the delayed, hepatocyte-specific phase, liver enhancement after injection of gadoxetic acid was superior to that obtained with gadobenate dimeglumine.

Cardiovascular magnetic resonance and PET-CT of left atrial paraganglioma.

Cardiac paragangliomas are among the rarest primary cardiac tumors. We present a case of left atrial paraganglioma in a patient who presented with symptoms and signs of catecholamine excess in which cardiovascular magnetic resonance in multiple orientations and PET-CT played an important role in the diagnosis and tissue characterization.

Image quality and diagnostic accuracy of unenhanced SSFP MR angiography compared with conventional contrast-enhanced MR angiography for the assessment of thoracic aortic diseases.

OBJECTIVES: The purpose of this study was to determine the image quality and diagnostic accuracy of three-dimensional (3D) unenhanced steady state free precession (SSFP) magnetic resonance angiography (MRA) for the evaluation of thoracic aortic diseases. METHODS: Fifty consecutive patients with known or suspected thoracic aortic disease underwent free-breathing ECG-gated unenhanced SSFP MRA with non-selective radiofrequency excitation and contrast-enhanced (CE) MRA of the thorax at 1.5 T. Two readers independently evaluated the two datasets for image quality in the aortic root, ascending aorta, aortic arch, descending aorta, and origins of supra-aortic arteries, and for abnormal findings. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were determined for both datasets. Sensitivity, specificity, and diagnostic accuracy of unenhanced SSFP MRA for the diagnosis of aortic abnormalities were determined. RESULTS: Abnormal aortic findings, including aneurysm (n = 47), coarctation (n = 14), dissection (n = 12), aortic graft (n = 6), intramural hematoma (n = 11), mural thrombus in the aortic arch (n = 1), and penetrating aortic ulcer (n = 9), were confidently detected on both datasets. Sensitivity, specificity, and diagnostic accuracy of SSFP MRA for the detection of aortic disease were 100% with CE-MRA serving as a reference standard. Image quality of the aortic root was significantly higher on SSFP MRA (P < 0.001) with no significant difference for other aortic segments (P > 0.05). SNR and CNR values were higher for all segments on SSFP MRA (P < 0.01). CONCLUSION: Our results suggest that free-breathing navigator-gated 3D SSFP MRA with non-selective radiofrequency excitation is a promising technique that provides high image quality and diagnostic accuracy for the assessment of thoracic aortic disease without the need for intravenous contrast material.

Three-dimensional imaging of pulmonary veins by a novel steady-state free-precession magnetic resonance angiography technique without the use of intravenous contrast agent: initial experience.

PURPOSE: To evaluate the feasibility of 3-dimensional (3D) steady-state free-precession (SSFP) magnetic resonance angiography (MRA) using nonselective radiofrequency excitation for imaging of pulmonary veins (PVs) without intravenous gadolinium chelate and to correlate the results with conventional contrast-enhanced MRA (CE-MRA). MATERIAL AND METHODS: Forty consecutive patients with history of atrial fibrillation underwent free-breathing respiratory navigator-gated electrocardiogram-triggered SSFP MRA without contrast administration and conventional high-resolution 3D CE-MRA of the thorax at 1.5 T. Two readers assessed both datasets for vascular definition (from 0, not visualized, to 3, excellent definition), artifacts, and ostial diameters. Statistical analysis was performed using Wilcoxon, paired t test, and kappa coefficient. RESULTS: On SSFP MRA, readers 1 and 2 graded 96.4% (160/166) and 97% (161/166) of the segments as having diagnostic visibility and sharpness, respectively (k = 0.82). On CE-MRA datasets, all segments were graded as having diagnostic visibility and sharpness by both readers (k = 0.86). No significant difference existed for visibility and sharpness of pulmonary venous segments between the datasets for each reader (P[r] > 0.05). Reader 1 (2) identified 27 (28) and 35 (32) motion artifacts on SSFP and CE-MRA datasets, respectively. No significant difference was found to exist between ostial diameters on CE-MRA and SSFP datasets (P > 0.05). CONCLUSION: Our study shows that 3D depiction of PVs without intravenous contrast is feasible with nonslice-selective SSFP MRA. This novel MRA technique may be used in certain patients with atrial fibrillation to assess the number and size of PV ostia draining to the left atrium prior to radiofrequency ablation.