Heart Transplantation: Indications, Surgical Techniques, and Complications.

Heart transplantation has been increasingly performed for patients with end-stage heart failure most commonly related to ischemic and non-ischemic cardiomyopathies. The major complications are procedure-related complications, infection, acute rejection, cardiac allograft vasculopathy, and malignancy. Radiologists have an important role in the evaluation of transplant candidates and early detection of postoperative complications.

Split-Bolus, Single-Acquisition, Dual-Phase Abdominopelvic CT Angiography for the Evaluation of Lung Transplant Candidates: Image Quality and Resource Utilization.

The purpose of this study was to assess the image quality and resource utilization of single-injection, split-bolus, dual-enhancement abdominopelvic CT angiography (hereafter referred to as dual-enhancement CTA) performed for combined vascular and solid organ assessment compared with those of single-injection, single-enhancement abdominopelvic CT angiography (hereafter referred to as single-enhancement CTA) for vascular assessment in combination with additional examinations (CT, MRI, and US) performed to assess for malignancy in lung transplant candidates. We retrospectively reviewed 100 patients who underwent abdominopelvic CTA examinations before lung transplant. Cohort A ( = 50) underwent dual-enhancement CTA and cohort B ( = 50) underwent single-enhancement CTA.

Point Organ Radiation Dose in Abdominal CT: Effect of Patient Off-Centering in an Experimental Human Cadaver Study.

To determine the effect of patient off-centering on point organ radiation dose measurements in a human cadaver scanned with routine abdominal CT protocol. A human cadaver (88 years, body-mass-index 20 kg/m2) was scanned with routine abdominal CT protocol on 128-slice dual source MDCT (Definition Flash, Siemens). A total of 18 scans were performed using two scan protocols (a) 120 kV-200 mAs fixed-mA (CTDIvol 14 mGy) (b) 120 kV-125 ref mAs (7 mGy) with automatic exposure control (AEC, CareDose 4D) at three different positions (a) gantry isocenter, (b) upward off-centering and (c) downward off-centering.

Assessment of sub-milli-sievert abdominal computed tomography with iterative reconstruction techniques of different vendors.

Aim: To assess diagnostic image quality of reduced dose (RD) abdominal computed tomography (CT) with 9 iterative reconstruction techniques (IRTs) from 4 different vendors to the standard of care (SD) CT.

Methods: In an Institutional Review Board approved study, 66 patients (mean age 60 ± 13 years, 44 men, and 22 women) undergoing routine abdomen CT on multi-detector CT (MDCT) scanners from vendors A, B, and C (≥ 64 row CT scanners) (22 patients each) gave written informed consent for acquisition of an additional RD CT series. Sinogram data of RD CT was reconstructed with two vendor-specific and a vendor-neutral IRTs (A-1, A-2, A-3; B-1, B-2, B-3; and C-1, C-2, C-3) and SD CT series with filtered back projection.

Comparison of Measured and Estimated CT Organ Doses for Modulated and Fixed Tube Current:: A Human Cadaver Study.

Rationale And Objectives: The aim of this study was to compare the directly measured and the estimated computed tomography (CT) organ doses obtained from commercial radiation dose-tracking (RDT) software for CT performed with modulated tube current or automatic exposure control (AEC) technique and fixed tube current (mAs).

Materials And Methods: With the institutional review board (IRB) approval, the ionization chambers were surgically implanted in a human cadaver (88 years old, male, 68 kg) in six locations such as liver, stomach, colon, left kidney, small intestine, and urinary bladder. The cadaver was scanned with routine abdomen pelvis protocol on a 128-slice, dual-source multidetector computed tomography (MDCT) scanner using both AEC and fixed mAs.

Quantification of interstitial fluid on whole body CT: comparison with whole body autopsy.

Purpose: Interstitial fluid accumulation can occur in pleural, pericardial, and peritoneal spaces, and subcutaneous tissue planes. The purpose of the study was to assess if whole body CT examination in a postmortem setting could help determine the presence and severity of third space fluid accumulation in the body.

Materials And Methods: Our study included 41 human cadavers (mean age 61 years, 25 males and 16 females) who had whole-body postmortem CT prior to autopsy.

Ultralow-Dose Abdominal Computed Tomography: Comparison of 2 Iterative Reconstruction Techniques in a Prospective Clinical Study.

Purpose: To assess lesion detection and image quality of ultralow-dose (ULD) abdominal computed tomography (CT) reconstructed with filtered back projection (FBP) and 2 iterative reconstruction techniques: hybrid-based iDose, and image-based SafeCT.

Materials And Methods: In this institutional review board-approved ongoing prospective clinical study, 41 adult patients provided written informed consent for an additional ULD abdominal CT examination immediately after standard dose (SD) CT exam on a 256-slice multidetector computed tomography (iCT, Philips-Healthcare). The SD examination (size-specific dose estimate, 10 ± 3 mGy) was performed at 120 kV with automatic exposure control, and reconstructed with FBP.

CT radiation dose and iterative reconstruction techniques.

1. CT radiation dose optimization is one of the major concerns for the scientific community. 2.

Improving Concordance of MRI and PET/CT Interpretations With Retrospectively Coregistered MRI and PET/CT Data Sets.

This study evaluates if retrospective software-fused magnetic resonance imaging/positron emission tomography (MRI/PET) images can improve concordance of MRI and PET/computed tomography (CT) findings in the pelvis and improve overall lesion detection and characterization, as compared with independent side-by-side interpretation of MRI and PET data sets. Institutional review board approval was obtained for this retrospective study. Our institution's electronic medical record system was examined for pelvic MRI scans and whole-body (18)F-fluorodeoxyglucose-PET/CT scans performed within a 2-month interval between January 2007 and June 2011.

Assessment of Filtered Back Projection, Adaptive Statistical, and Model-Based Iterative Reconstruction for Reduced Dose Abdominal Computed Tomography.

Purpose: To compare standard of care and reduced dose (RD) abdominal computed tomography (CT) images reconstructed with filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR), model-based iterative reconstruction (MBIR) techniques.

Materials And Methods: In an Institutional Review Board-approved, prospective clinical study, 28 patients (mean age 59 ± 13 years ), undergoing clinically indicated routine abdominal CT on a 64-channel multi-detector CT scanner, gave written informed consent for acquisition of an additional RD (<1 milli-Sievert) abdomen CT series. Sinogram data of RD series were reconstructed with FBP, ASIR, and MBIR and compared with FBP images of standard dose abdomen CT.

CT and MRI of aortic coarctation: pre- and postsurgical findings.

OBJECTIVE. The purpose of this article is to summarize the roles of CT and MRI in the diagnosis and follow-up of patients with aortic coarctation. CONCLUSION.

Simplifying size-specific radiation dose estimates in pediatric CT.

Objective: Size-specific dose estimates (SSDEs) require manual measurement of torso diameters for individual patients--anteroposterior (hereafter, D(AP)), lateral (hereafter, D(LAT)), and effective (hereafter, D(E))--which can be tedious in clinical settings. We aimed to determine whether body weight can be used as a surrogate for measuring diameter in children.

Materials And Methods: D(AP) and D(LAT) were measured in 522 consecutive CT examinations (chest, 187 and abdomen-pelvis, 335) performed in 483 (± SD) children (13 ± 7 years).

Ultra-low dose abdominal MDCT: using a knowledge-based Iterative Model Reconstruction technique for substantial dose reduction in a prospective clinical study.

Purpose: To assess lesion detection and image quality parameters of a knowledge-based Iterative Model Reconstruction (IMR) in reduced dose (RD) abdominal CT examinations.

Materials And Methods: This IRB-approved prospective study included 82 abdominal CT examinations performed for 41 consecutive patients (mean age, 62 ± 12 years; F:M 28:13) who underwent a RD CT (SSDE, 1.5 mGy ± 0.

Dose reduction in pediatric abdominal CT: use of iterative reconstruction techniques across different CT platforms.

Dose reduction in children undergoing CT scanning is an important priority for the radiology community and public at large. Drawbacks of radiation reduction are increased image noise and artifacts, which can affect image interpretation. Iterative reconstruction techniques have been developed to reduce noise and artifacts from reduced-dose CT examinations, although reconstruction algorithm, magnitude of dose reduction and effects on image quality vary.

Submillisievert chest CT with filtered back projection and iterative reconstruction techniques.

Objective: The purpose of this study was to compare submillisievert chest CT images reconstructed with filtered back projection (FBP), SafeCT, adaptive statistical iterative reconstruction (ASIR), and model-based iterative reconstruction (MBIR) with standard of care FBP images.

Subjects And Methods: Fifty patients (33 men and 17 women; mean age [± SD], 62 ± 10 years) undergoing routine chest CT gave written informed consent for acquisition of an additional submillisievert chest CT series with reduced tube current but identical scanning length as standard of care chest CT. Sinogram data of the submillisievert series were reconstructed with FBP, SafeCT, ASIR, and MBIR and compared with FBP images at standard-dose chest CT (n = 8 × 50 = 400 series).

In vitro dose measurements in a human cadaver with abdomen/pelvis CT scans.

Purpose: To present a study of radiation dose measurements with a human cadaver scanned on a clinical CT scanner.

Methods: Multiple point dose measurements were obtained with high-accuracy Thimble ionization chambers placed inside the stomach, liver, paravertebral gutter, ascending colon, left kidney, and urinary bladder of a human cadaver (183 cm in height and 67.5 kg in weight) whose abdomen/pelvis region was scanned repeatedly with a multidetector row CT.

Ultra low-dose chest CT using filtered back projection: comparison of 80-, 100- and 120 kVp protocols in a prospective randomized study.

Purpose: To assess lesion detection and diagnostic image quality of filtered back projection (FBP) reconstruction technique in ultra low-dose chest CT examinations.

Methods And Materials: In this IRB-approved ongoing prospective clinical study, 116 CT-image-series at four different radiation-doses were performed for 29 patients (age, 57-87 years; F:M - 15:12; BMI 16-32 kg/m(2)). All patients provided written-informed-consent for the acquisitions of additional ultra low-dose (ULD) series on a 256-slice MDCT (iCT, Philips Healthcare).

What is the minimal radiation dose that can be used for detecting pleural effusion?

Objective: The objective of our study was to assess the effect of radiation dose reduction on the detection of pleural effusions, thickening, and calcifications.

Materials And Methods: Forty-five human cadavers (mean age at death, 60 ± 17 [SD] years; male-female ratio, 29:16; mean body mass index, 29 ± 5.7 [SD] kg/m(2)) were scanned at seven different dose levels (CT Dose Index volume [CTDIvol] = 20, 12, 10, 6, 4, 2, and 0.

Dose reduction for chest CT: comparison of two iterative reconstruction techniques.

Background: Lowering radiation dose in computed tomography (CT) scan results in low quality noisy images. Iterative reconstruction techniques are used currently to lower image noise and improve the quality of images.

Purpose: To evaluate lesion detection and diagnostic acceptability of chest CT images acquired at CTDIvol of 1.

Giant osteosarcoma of chest wall requiring resection and pneumonectomy.

We present the case of a 13-year-old girl who had a large swelling in her left breast with a history of weight loss, low-grade fever, and cold sweats. Computed tomography showed a large mass encroaching on the mediastinum and heart, with erosion of the adjacent ribs. Resection of the mass along with a pneumonectomy were performed.

Role of compressive sensing technique in dose reduction for chest computed tomography: a prospective blinded clinical study.

Purpose: The purpose of this study was to assess pulmonary lesion detection, diagnostic confidence, and noise reduction in sparse-sampled (SpS) computed tomographic (CT) data of submillisievert (SubmSv) chest CT reconstructed with iterative reconstruction technique (IRT).

Materials And Methods: This Human Insurance Portability and Accountability-compliant, institutional review board-approved prospective study was performed using SpS-SubmSv IRT chest CT in 10 non-obese patients (body-mass index, 21-35 kg/m; age range, 26-90 years). Written informed consent was obtained.

Computed tomography (CT) of the chest at less than 1 mSv: an ongoing prospective clinical trial of chest CT at submillisievert radiation doses with iterative model image reconstruction and iDose4 technique.

Purpose: To assess lesion detection and diagnostic confidence of computed tomography (CT) of the chest performed at less than 1 mSv with 2 iterative reconstruction (IR) techniques.

Materials And Methods: Ten patients gave written informed consent for the acquisitions of images at submillisievert dose (0.9 mSv), in addition to clinical standard-dose (SD) chest CT (2.