Use of a 3D-Printed Abdominal Compression Device to Facilitate CT Fluoroscopy-Guided Percutaneous Interventions.

Objective: The purpose of this article is to describe a handheld external compression device used to facilitate CT fluoroscopy-guided percutaneous interventions in the abdomen.

Conclusion: The device was designed with computer-aided design software to modify an existing gastrointestinal fluoroscopy compression device and was constructed by 3D printing. This abdominal compression device facilitates access to interventional targets, and its use minimizes radiation exposure of radiologists.

Bending percutaneous drainage catheters to facilitate CT-guided insertion using curved trocar technique.

Purpose: To assess the safety and efficacy of placing thoraco-abdominal drainage catheters under CT-guidance using a curved trocar technique.

Methods: A retrospective study of 182 CT/CT-fluoroscopy-guided thoraco-abdominal catheter drainages was conducted; half were performed by residents or fellows under the supervision of one radiologist (Group 1) and the other half under the supervision of 10 other radiologists (Group 2). Group 1 procedures employed a curved catheter assembly placed using trocar technique (n = 44) or straight catheters placed with Seldinger technique (n = 47).

Measured Head CT/CTA Skin Dose and Intensive Care Unit Patient Cumulative Exposure.

Background And Purpose: Estimates of cumulative CT/CTA radiation dose based on volumetric CT dose index have raised concern that neurological intensive care unit patient exposures may reach thresholds for deterministic skin injury. Because the accuracy of volumetric CT dose index for this purpose in unknown, we set out to directly measure head CT and CTA peak skin dose, assess the relationship of volumetric CT dose index to measured peak skin dose, and determine whether multiple CT/CTA exposures in typical patients in the neurological intensive care unit produce cumulative doses approaching or exceeding single-dose deterministic thresholds for skin injury.

Materials And Methods: In a prospective study from 2011-2013, nanoDot optical stimulated luminescence dosimeters were used to measure head CT/CTA peak skin dose in 52 patients (28 female, 24 male; mean age, 63 years) divided equally between 2 CT scanners.

Radiation dose during CT-guided percutaneous cryoablation of renal tumors: Effect of a dose reduction protocol.

Purpose: To estimate and compare the radiation dose using a standard protocol and that of a dose reduction protocol in patients undergoing CT-guided percutaneous cryoablation of renal tumors.

Materials And Methods: An IRB-approved, HIPAA-compliant retrospective study of 97 CT-guided cryoablation procedures to treat a solitary renal tumor in each of 97 patients (64 M, 33 F; range 31-84 yrs) was performed. Fifty patients were treated using a standard dose protocol (kVp=120, mean mAs=180, monitoring scans every 3 min during freezes), and an additional 47 patients were treated using a dose reduction protocol (kVp=100, mean mAs=100, monitoring scans less frequently than every 3 min during freezes).

Recurrent CT, cumulative radiation exposure, and associated radiation-induced cancer risks from CT of adults.

Purpose: To estimate cumulative radiation exposure and lifetime attributable risk (LAR) of radiation-induced cancer from computed tomographic (CT) scanning of adult patients at a tertiary care academic medical center.

Materials And Methods: This HIPAA-compliant study was approved by the institutional review board with waiver of informed consent. The cohort comprised 31,462 patients who underwent diagnostic CT in 2007 and had undergone 190,712 CT examinations over the prior 22 years.

Musculoskeletal biopsies using computed tomography fluoroscopy.

Objective: To determine the diagnostic yield, accuracy, and safety of computed tomography (CT) fluoroscopy guidance for musculoskeletal biopsies.

Materials And Methods: A retrospective analysis of musculoskeletal biopsies performed with CT fluoroscopy guidance over a 2-year period was made. Data collected were biopsy sites, CT fluoroscopic times, and biopsy results.

Patient radiation dose at CT urography and conventional urography.

Purpose: To measure and compare patient radiation dose from computed tomographic (CT) urography and conventional urography and to compare these doses with dose estimates determined from phantom measurements.

Materials And Methods: Patient skin doses were determined by placing a thermoluminescent dosimeter (TLD) strip (six TLD chips) on the abdomen of eight patients examined with CT urography and 11 patients examined with conventional urography. CT urography group consisted of two women and six men (mean age, 55.

Safety of ERCP during pregnancy.

Objectives: There are few data in the literature regarding the indications, therapy, and safety of endoscopic management of pancreatico-biliary disorders during pregnancy. We report the largest single center experience with ERCP in pregnancy.

Methods: We reviewed 15 patients that underwent ERCP during pregnancy.

Multi-detector row CT urography: comparison of strategies for depicting the normal urinary collecting system.

Purpose: To evaluate several protocols for depiction of the urinary collecting system with multi-detector row computed tomographic (CT) urography.

Materials And Methods: Fifty-one patients with hematuria or a suspicious renal mass underwent CT urography, during which thinly collimated (1-mm) pyelographic phase scanning was performed 8-10 minutes after contrast medium administration. Patients were examined while prone only (n = 17) and while both prone and supine (n = 17) after a 250-mL infusion of normal saline.

Skin and thyroid dosimetry in cervical spine screening: two methods for evaluation and a comparison between a helical CT and radiographic trauma series.

Objective: The first objective of this study was to test the hypothesis that estimates of radiation dose from an ionization chamber correspond to thermoluminescent dosimeter measurements in patients with suspected cervical spine injury. The second objective was to compare the radiation dose of a protocol using helical CT of the entire cervical spine with that of a protocol using radiography alone.

Subjects And Methods: Thermoluminescent dosimeter measurements of radiation dose to the skin over the thyroid were made in two patient groups: six patients evaluated with CT of the cervical spine and six patients evaluated with radiography.

Patient and personnel exposure during CT fluoroscopy-guided interventional procedures.

Purpose: To estimate patient dose and personnel exposure from phantom measurements during computed tomographic (CT) fluoroscopy, to use the estimates to provide users with dose information, and to recommend methods to reduce exposure.

Materials And Methods: Surface dose was estimated on a CT dosimetric phantom by using thermoluminescent dosimetric (TLD) and CT pencil chamber measurements. Scatter exposure was estimated from scattered radiation measured at distances of 10 cm to 1 m from the phantom.

CT fluoroscopy-guided abdominal interventions: techniques, results, and radiation exposure.

Purpose: To evaluate the benefits of computed tomographic (CT) fluoroscopy-guided interventions and assess radiation exposures incurred with CT fluoroscopy.

Materials And Methods: A 6-month period of use of CT fluoroscopy to guide abdominal biopsy procedures and catheter drainage was analyzed. Efficacy measures and needle placement and procedure room times were compared with those of the preceding 6 months during which conventional CT was used.

Comparison of polytomography and computed tomography for fracture assessment.

Objective: To compare polytomography (PT) and computed tomography (CT) for visualizing fractures and arthrodeses, with and without metal hardware, to determine whether CT could adequately replace PT.

Design And Patients: An ex vivo bovine model containing fractures in three planes, reduced with metal hardware, was created to compare fractures using PT and CT. The radiation dose at the skin surface was calculated for both examinations.

Flattening of the contrast-detail curve for large lesions on liver CT images.

This study evaluated the relative roles of physical and perceptual factors in flattening the contrast-detail (CD) curve on liver CT scans. To estimate the role of physical factors, the theoretical CD curve for a calculated theoretical observer (i.e.

Contrast-detail curves for liver CT.

Contrast-detail curves were constructed for liver computed tomographic (CT) images using an objective method. Stimuli were created by superimposing disks at specified locations on sets of 92 normal liver CT images. Bright and dark disks of 9 sizes and 36 possible image contrasts were used.

Evaluation of video gray-scale display.

Setting up and maintaining video display monitors properly will help to reduce display variation and improve overall presentation of the radiological image. Display monitor gray-scale characteristics were examined using the SMPTE test pattern. This test pattern may be used as a standard for adjusting brightness and contrast.

Visualization and detection-localization on computed tomographic images.

These studies investigated observers' ability to detect and locate highly visible liver lesions on computed tomographic (CT) images, manipulating both the lesion's location and polarity (brighter or darker than liver background). Visibility of a lesion is not sufficient to guarantee accurate localization. With clinical images, possible confusions between a lesion and coexisting normal structures (like blood vessels) is a serious constraint on observer performance.

Size discrimination in computed tomographic images. Effects of feature contrast and display window.

Studies show that features on computed tomographic (CT) images in clinical formats become less detectable when the images are produced with wider CT display windows. We studied the effects of feature contrast and the display window on observer performance in higher-order tasks that involved discriminating small size differences between features on CT images. The features to be discriminated were pairs of disks (9.