Quantification of urinary stone volume: attenuation threshold-based CT method--a technical note.

Purpose: To compare two threshold-based computed tomographic (CT) methods for the quantification of urinary stone volume; to assess their accuracy and precision at varying tube voltages, tube currents, and section thicknesses in a phantom; and to determine interobserver agreement with each of these methods in a pilot clinical study.

Materials And Methods: After institutional review board approval, written informed consent was waived. The study was HIPAA compliant.

Reduced exposure using asymmetric cone beam processing for wide area detector cardiac CT.

The purpose of this study was to estimate dose reduction after implementation of asymmetrical cone beam processing using exposure differences measured in a water phantom and a small cohort of clinical coronary CTA patients. Two separate 320 × 0.5 mm detector row scans of a water phantom used identical cardiac acquisition parameters before and after software modifications from symmetric to asymmetric cone beam acquisition and processing.

Surgical planning for composite tissue allotransplantation of the face using 320-detector row computed tomography.

We report initial surgical planning computed tomographic protocols for composite tissue allotransplantation of the face. This complex procedure replaces missing facial structures with anatomically identical tissues, restoring form and function. Achieved results are superior to those accomplished with conventional techniques.

Immobilized contrast-enhanced MRI: Gadolinium-based long-term MR contrast enhancement of the vein graft vessel wall.

An implantable MR contrast agent that can be covalently immobilized on tissue during surgery has been developed. The rationale is that a durable increase in tissue contrast using an implantable contrast agent can enhance postsurgical tissue differentiation using MRI. For small-vessel (e.

Contrast opacification using a reduced volume of iodinated contrast material and low peak kilovoltage in pulmonary CT angiography: Objective and subjective evaluation.

Objective: The purpose of our study was to evaluate whether a reduced volume of iodinated contrast material for pulmonary CT angiography (CTA) using a low peak kilovoltage (kVp) technique yields equivalent opacification in all vessels.

Materials And Methods: Four hundred fifty-two consecutive pulmonary CTA patients (265 women and 187 men; age range, 18-91 years; mean age, 56.2 years) were retrospectively evaluated.

CT angiography: current technology and clinical use.

Since 1958, catheter angiography has assumed the role of gold standard for vascular imaging, despite the invasive nature of the procedure. Less invasive techniques for vascular imaging, such as computed tomographic angiography (CTA), have been developed and have matured in conjunction with developments in catheter arteriography. In a few cases, such as imaging, the aorta and the pulmonary arteries, CTA has supplanted catheter angiography as the gold standard.

Immobilization of iron oxide magnetic nanoparticles for enhancement of vessel wall magnetic resonance imaging--an ex vivo feasibility study.

Emerging data supports a role for negative wall remodeling in the failure of vascular interventions such as vein grafts, yet clinicians/researchers currently lack the ability to temporally/efficiently investigate adventitial surface topography/total vascular wall anatomy in vivo. We established a strategy of immobilizing commercially available iron oxide magnetic nanoparticles (Fe-NPs) onto the surface of human vein conduits to facilitate high-throughput total vascular wall demarcation with magnetic resonance (MR). Binding of activated Fe-NPs to amine groups on the surface of the veins induced a thin layer of negative contrast that differentiated the adventitia from surrounding saline signal in all MR images, enabling delineation of total wall anatomy; this was not possible in simultaneously imaged unlabeled control veins.

Catheter directed lysis and thrombectomy of submassive pulmonary embolism.

Acute pulmonary embolism (PE) is a common and potentially highly morbid disease. However, there are a broad range of clinical presentations, varying from asymptomatic to life-threatening hemodynamic compromise. Accordingly, the aggressiveness of treatment for acute PE must be adjusted to the acuity of the presentation and patient-specific comorbidities.

Cost-effective diagnostic cardiovascular imaging: when does it provide good value for the money?

To summarize the results of all original cost-utility analyses (CUAs) in diagnostic cardiovascular imaging (CVI) and characterize those technologies by estimates of their cost-effectiveness. We systematically searched the literature for original CVI CUAs published between 2000 and 2008. Studies were classified according to several variables including anatomy of interest (e.

CT coronary angiography: 256-slice and 320-detector row scanners.

Multidetector computed tomography (MDCT) has rapidly evolved from 4-detector row systems in 1998 to 256-slice and 320-detector row CT systems. With smaller detector element size and faster gantry rotation speed, spatial and temporal resolution of the 64-detector MDCT scanners have made coronary artery imaging a reliable clinical test. Wide-area coverage MDCT, such as the 256-slice and 320-detector row MDCT scanners, has enabled volumetric imaging of the entire heart free of stair-step artifacts at a single time point within one cardiac cycle.

Multi-contrast high spatial resolution black blood inner volume three-dimensional fast spin echo MR imaging in peripheral vein bypass grafts.

The purpose of this study is to primarily evaluate the lumen area and secondarily evaluate wall area measurements of in vivo lower extremity peripheral vein bypass grafts patients using high spatial resolution, limited field of view, cardiac gated, black blood inner volume three-dimensional fast spin echo MRI. Fifteen LE-PVBG patients prospectively underwent ultrasound followed by T1-weighted and T2-weighted magnetic resonance (MR) imaging. Lumen and vessel wall areas were measured by direct planimetry.

Imaging presentation of venous thrombosis in patients with cancer.

Objective: The purpose of this article is to review the imaging of venous thrombosis in patients with cancer.

Conclusion: Multiple imaging techniques have the capacity to display thrombosis accurately. The optimal choice is dictated by the location and duration of symptoms and by the availability of imaging techniques.

Iodinated contrast opacification gradients in normal coronary arteries imaged with prospectively ECG-gated single heart beat 320-detector row computed tomography.

Background: To define and evaluate coronary contrast opacification gradients using prospectively ECG-gated single heart beat 320-detector row coronary angiography (CTA).

Methods And Results: Thirty-six patients with normal coronary arteries determined by 320 x 0.5-mm detector row coronary CTA were retrospectively evaluated with customized image postprocessing software to measure Hounsfield Units at 1-mm intervals orthogonal to the artery center line.

Imaging features of intramural hematoma of the aorta.

Intramural hematoma (IMH) is defined as localized hemorrhage within the aortic wall and is included in the acute aortic syndrome spectrum with aortic dissection and penetrating aortic ulcer. The mortality from IMH is similar to classic aortic dissection (21%). 16% of patients with IMH will evolve to classic aortic dissection over time.

New advances in cardiac computed tomography.

Purpose Of Review: Applications of computed tomography (CT) for cardiac imaging have evolved rapidly with the introduction of new hardware. These advances require a technology update, particularly as the new scanners have novel, unique features. This review focuses on post-64 generation CT scanner capabilities and novel clinical research applications enabled by these technologies.

Venous thrombosis in an outpatient oncologic center: distribution, type, and comorbidities.

Purpose: To examine outpatient oncologic patients with venous thrombosis (VT) and correlate ultrasound findings with clinical characteristics and outcome.

Materials And Methods: A retrospective study of 76 patients who had upper- and lower-extremity ultrasound examinations positive for VT formed the population, drawn from a total of 509 patients who presented over a 24-month period for non-invasive imaging. Clinical indication, demographics, sonographic findings, comorbidities, and development of pulmonary embolism in these patients were recorded.