Publications by authors named "Sameer Tipnis"

Background And Purpose: The first-generation photon-counting detector CT was recently introduced into clinical practice and represents a promising innovation in high-resolution CT imaging. The purpose of this study was to assess the image quality of ultra-high-resolution photon-counting detector CT compared with energy-integrating detector CT and to explore different reconstruction kernel sharpness levels for the evaluation of intracranial aneurysms.

Materials And Methods: Ten patients with intracranial saccular aneurysms who had previously undergone conventional energy-integrating detector CT were prospectively enrolled.

View Article and Find Full Text PDF

Purpose: Photon-counting-detector computed tomography (PCD-CT) offers enhanced noise reduction, spatial resolution, and image quality in comparison to energy-integrated-detectors CT (EID-CT). These hypothesized improvements were compared using PCD-CT ultra-high (UHR) and standard-resolution (SR) scan-modes.

Methods: Phantom scans were obtained with both EID-CT and PCD-CT (UHR, SR) on an adult body-phantom.

View Article and Find Full Text PDF

The Modified Barium Swallow Study (MBSS) is a videofluoroscopic examination of the anatomy and physiology involved in swallowing. Like other fluoroscopic examinations, the MBSS uses ionizing radiation with related radiation risks. Thus, the procedures and protocols related to MBSSs must balance the benefit of the diagnostic information gained with the risk of radiation exposure.

View Article and Find Full Text PDF

Lu-DOTATATE has gained wide clinical acceptance for the treatment of advanced gastroenteropancreatic neuroendocrine tumors; however, little is known regarding its accumulation in ascites. As such, clinical staff performing paracenteses shortly after a treatment dose may be concerned about their potential radiation exposure or the risk of contamination. In this report, therapeutic paracenteses were performed on a patient with metastatic intestinal carcinoid complicated by recurrent chylous ascites at various time intervals after a standard 7.

View Article and Find Full Text PDF

Modified Barium Swallow Studies (MBSSs) are important tests to aid the diagnosis of swallowing impairment and guide treatment planning. Since MBSSs use ionizing radiation, it is important to understand the radiation exposure associated with the exam. This study reports the average radiation dose in routine clinical MBSSs, to aid the evidence-based decision-making of clinical providers and patients.

View Article and Find Full Text PDF

Purpose Of Review: The modified barium swallow study (MBSS) is an X-ray examination of swallowing used to detect the presence and type impairment, aspiration risk, and to develop intervention plans. In this review, we will cover the use of ionizing radiation in MBSSs and review recent literature concerning radiation exposure and cancer risks to patients undergoing MBSSs. Lastly, we will discuss the clinical implications of these findings.

View Article and Find Full Text PDF

Purpose Clinicians are trained to rely on radiation exposure time as an indicator of patient radiation exposure in Videofluoroscopic Swallowing Studies (VFSSs). However, it has been shown in other medical uses of fluoroscopy that dose area product (DAP), the amount of radiation delivered to the patient, is a better indicator of overall patient radiation exposure than radiation exposure time. This study sought to understand the relationship of DAP in VFSSs with radiation exposure time and projection used (lateral vs.

View Article and Find Full Text PDF

Modified Barium Swallow Studies (MBSSs) are a fluoroscopic exam that exposes patients to ionizing radiation. Even though radiation exposure from MBSSs is relatively small, it is necessary to understand the excess cancer risk to the patient, in order to ensure a high benefit-to-risk ratio from the exam. This investigation was aimed at estimating the excess radiation risks during MBSSs.

View Article and Find Full Text PDF

Our goal was to define a pediatric head CT protocol able to provide images of diagnostic quality, using the least amount of radiation, in children <10 years of age, while using a filtered back projection reconstruction algorithm. Image quality of 119 pediatric head CTs was assessed using a 5-point scoring system. Exams with scores ≥2.

View Article and Find Full Text PDF

This study sought to obtain factors to convert entrance air kerma into thyroid doses for patients undergoing modified barium swallow studies. A commercial software package (PCXMC 2.0.

View Article and Find Full Text PDF

This study presents an investigation of adult effective dose (E) per unit Kerma-Area Product (KAP) in Modified Barium Swallow Study (MBSS) examinations. PC program for X-ray Monte Carlo (version 2.0.

View Article and Find Full Text PDF

Utilization of a radiology resident-specific quality improvement (QI) program and curriculum based on the Accreditation Council for Graduate Medical Education (ACGME) milestones can enable a program's assessment of the systems-based practice component and prepare residents for QI implementation post graduation. This article outlines the development process, curriculum, QI committee formation, and resident QI project requirements of one institution's designated radiology resident QI program. A method of mapping the curriculum to the ACGME milestones and assessment of resident competence by postgraduate year level is provided.

View Article and Find Full Text PDF

The purpose of this study was to quantify how changing the amount of radiation used to perform routine head CT examinations (CTDIvol) affects visibility of key anatomical structures. Eight routine noncontrast head CT exams were selected from six CT scanners, each of which had a different CTDIvol setting (60 to 75 mGy). All exams were normal and two slices were selected for evaluation, one at the level of basal ganglia and the other at the fourth ventricle.

View Article and Find Full Text PDF

The aim of this study was to investigate how effective dose and size-specific dose estimate (SSDE) change with patient age (size) for routine head and abdominal/pelvic CT examinations. Heads and abdomens of patients were modelled as a mass-equivalent cylinder of water corresponding to the patient 'effective diameter'. Head CT scans were performed at CTDIvol(S) of 40 mGy, and abdominal CT scans were performed at CTDIvol(L) of 10 mGy.

View Article and Find Full Text PDF

Objective: The purpose of this study was to estimate absorbed thyroid dose and consequent cancer risks in adult patients undergoing neck CT examinations.

Materials And Methods: We used data from neck CT examinations of 68 consecutive adult patients to calculate the thyroid dose and estimate the corresponding cancer risk. Age and sex were recorded along with the volume CT dose index (CTDIvol) that was used to perform the examination.

View Article and Find Full Text PDF

Objective: To estimate thyroid doses and cancer risk for paediatric patients undergoing neck computed tomography (CT).

Methods: We used average CTDI(vol) (mGy) values from 75 paediatric neck CT examinations to estimate thyroid dose in a mathematical anthropomorphic phantom (ImPACT Patient CT Dosimetry Calculator). Patient dose was estimated by modelling the neck as mass equivalent water cylinder.

View Article and Find Full Text PDF

Our primary objective in this study was to determine the preferred strength setting for the sinogram-affirmed iterative reconstruction algorithm (SAFIRE) in abdominal computed tomography (CT) imaging. Sixteen consecutive clinical CT scans of the abdomen were reconstructed by use of traditional filtered back projection (FBP) and 5 SAFIRE strengths: S1-S5. Six readers of differing experience were asked to rank the images on preference for overall diagnostic quality.

View Article and Find Full Text PDF

Objective: The aim of this study was to directly compare the preference between low-dose sinogram-affirmed iterative reconstruction (SAFIRE) and routine filtered back projection (FBP) abdominopelvic computed tomography (CT).

Methods: A retrospective review identified 41 subjects who had undergone 2 different CT examinations at different times (a CT with reduced radiation dose SAFIRE and also a CT with routine-dose FBP). Radiation dose, patient size, and image noise were recorded.

View Article and Find Full Text PDF

The aim of the study was to investigate how differences in patient anatomy and CT technical factors in neck CT impact on thyroid doses and the corresponding carcinogenic risks. The CTDIvol and dose-length product used in 11 consecutive neck CT studies, as well as data on automatic exposure control (AEC) tube current variation(s) from the image DICOM header, were recorded. For each CT image that included the thyroid, the mass equivalent water cylinder was estimated based on the patient cross-sectional area and average relative attenuation coefficient (Hounsfield unit, HU).

View Article and Find Full Text PDF

Unlabelled: RATIONALE AND OBJECTS: We describe a new web-based physics course for radiology residents preparing for the Exam of the Future (EOF).

Materials And Methods: A course was developed with a total of 12 web-based modules. Six modules were focused on "imaging" and six on "radiation.

View Article and Find Full Text PDF

The purpose of this study was to investigate how the choice of the scanned region affects organ doses in CT. ImPACT CT Patient Dosimetry Calculator (version 1.0) was used to compute absorbed doses to eight organs of interest in medical radiation dosimetry.

View Article and Find Full Text PDF

We present a method of estimating effective doses in cardiac CT that accounts for selected techniques (kV mAs(-1)), anatomical location of the scan and patient size. A CT dosimetry spreadsheet (ImPACT CT Patient Dosimetry Calculator) was used to estimate effective doses (E) using ICRP 103 weighting factors for a 70 kg patient undergoing cardiac CT examinations. Using dose length product (DLP) for the same scans, we obtained values of E/DLP for three CT scanners used in cardiac imaging from two vendors.

View Article and Find Full Text PDF

To investigate the relationship between radiographic techniques (i.e. kilovolt and milliampere-second) and the corresponding volume computed tomography dose index (CTDI(vol)).

View Article and Find Full Text PDF

Objective: The purpose of this article is to develop a method for estimating embryo doses in CT.

Materials And Methods: Absorbed doses to the uterus (embryo) of a 70-kg woman were estimated using the ImPACT CT Patient Dosimetry Calculator. For a particular CT scan length, relative uterus doses and normalized plateau uterus doses were determined for a range of commercial CT scanners.

View Article and Find Full Text PDF