Artificial intelligence and the medical physics profession - A Swedish perspective.

Background: There is a continuous and dynamic discussion on artificial intelligence (AI) in present-day society. AI is expected to impact on healthcare processes and could contribute to a more sustainable use of resources allocated to healthcare in the future. The aim for this work was to establish a foundation for a Swedish perspective on the potential effect of AI on the medical physics profession.

Age-specific and gender-specific radiation risks in paediatric angiography and interventional cardiology: conversion coefficients and risk reference values.

Objectives: To estimate risk for exposure-induced cancer death (REID), organ-specific risks of exposure-induced cancer death (REID) and associated conversion coefficients (CC=REID/kerma-area product (KAP), CC=REID/KAP) in paediatric cardiac catheterizations using data from radiation dose structured reports (RDSR). A novel risk surveillance tool consisting of age-specific and gender-specific risk reference values (RRVs) related to population cancer risk is suggested.

Methods: The PCXMC v.

Calculating organ and effective doses in paediatric interventional cardiac radiology based on DICOM structured reports - Is detailed examination data critical to dose estimates?

Purpose: To estimate effective dose (E), equivalent organ doses (H) and associated conversion coefficients (CC = E/KAP, CC = H/KAP; KAP = Kerma-area product) in paediatric cardiac interventions, using detailed exposure data from radiation dose structured reports (RDSR). These "RDSR dose estimations" have been compared with estimations performed using the approach currently implemented in the clinic that is based on a simplified assumptions method (SAM).

Methods: The Monte Carlo system PCXMC, incorporated into a previously developed framework, was used to calculate E and H for 202 children.

Assessment of the occupational eye lens dose for clinical staff in interventional radiology, cardiology and neuroradiology.

In accordance with recommendations by the International Commission on Radiological Protection, the current European Basic Safety Standards has adopted a reduced occupational eye lens dose limit of 20 mSv yr. The radiation safety implications of this dose limit is of concern for clinical staff that work with relatively high dose x-ray angiography and interventional radiology. Presented in this work is a thorough assessment of the occupational eye lens dose based on clinical measurements with active personal dosimeters worn by staff during various types of procedures in interventional radiology, cardiology and neuroradiology.

Practical approaches to approximating MTF and NPS in CT with an example application to task-based observer studies.

Purpose: To investigate two methods of approximating the Modulation Transfer Function (MTF) and Noise Power Spectrum (NPS) in computed tomography (CT) for a range of scan parameters, from limited image acquisitions.

Methods: The two methods consist of 1) using a linear systems approach to approximate the NPS for different filtered backprojection (FBP) kernels with a filter function derived from the kernel ratio of determined MTFs and 2) using an empirical fitted model to approximate the MTF and NPS. In both cases a scaling function accounts for variations in mAs and kV.

A framework for organ dose estimation in x-ray angiography and interventional radiology based on dose-related data in DICOM structured reports.

Although interventional x-ray angiography (XA) procedures involve relatively high radiation doses that can lead to deterministic tissue reactions in addition to stochastic effects, convenient and accurate estimation of absorbed organ doses has traditionally been out of reach. This has mainly been due to the absence of practical means to access dose-related data that describe the physical context of the numerous exposures during an XA procedure. The present work provides a comprehensive and general framework for the determination of absorbed organ dose, based on non-proprietary access to dose-related data by utilizing widely available DICOM radiation dose structured reports.

Quality control of CT systems by automated monitoring of key performance indicators: a two-year study.

The purpose of this study was to develop a method of performing routine periodical quality controls (QC) of CT systems by automatically analyzing key performance indicators (KPIs), obtainable from images of manufacturers' quality assurance (QA) phantoms. A KPI pertains to a measurable or determinable QC parameter that is influenced by other underlying fundamental QC parameters. The established KPIs are based on relationships between existing QC parameters used in the annual testing program of CT scanners at the Karolinska University Hospital in Stockholm, Sweden.

On the feasibility of utilizing active personal dosimeters worn on the chest to estimate occupational eye lens dose in x-ray angiography.

The International Commission on Radiological Protection (ICRP) has recommended that the occupational dose limit to the eye lens be substantially reduced. To ensure compliance with these recommendations, monitoring of the occupational eye lens dose is essential in certain hospital work environments. For assessment of the eye lens dose it is recommended to use a supplementary dosimeter placed at a position adjacent to the eye(s).

Influence of phantom thickness and material on the backscatter factors for diagnostic x-ray beam dosimetry.

Most of the existing backscatter factors for the dosimetry of clinical diagnostic x-ray beams have been calculated for 15 cm thick phantoms; these data are used for skin dose determinations which in general ignore the influence of phantom material and thickness. The former should strictly be required whenever dosimetry measurements are made on phantom materials different from those used for the backscatter factor calculations. The phantom or patient thickness is of special importance when skin dose determinations are made for infants or paediatric patients.

Backscatter factors and mass energy-absorption coefficient ratios for diagnostic radiology dosimetry.

Backscatter factors, B, and mass energy-absorption coefficient ratios, (μ(en)/ρ)(w, air), for the determination of the surface dose in diagnostic radiology were calculated using Monte Carlo simulations. The main purpose was to extend the range of available data to qualities used in modern x-ray techniques, particularly for interventional radiology. A comprehensive database for mono-energetic photons between 4 and 150 keV and different field sizes was created for a 15 cm thick water phantom.

Polyp detection with MDCT: a phantom-based evaluation of the impact of dose and spatial resolution.

Objective: The objective of our study was to evaluate the impact of dose and spatial resolution on the detection of colonic polyps using a 4-MDCT scanner.

Materials And Methods: Twenty-four latex phantoms that simulate the large bowel and contain artificial polyps of different sizes and shapes were constructed. The polyps were divided into three size groups (diameter, 0-2, 2-5, and 5-10 mm) and were classified into four shape groups: pedunculated; broad-based; ulcerated or depressed; and sessile or flat.

Effects of geometric distortion in 0.2T MRI on radiotherapy treatment planning of prostate cancer.

Background And Purpose: To evaluate the impact of two different methods of geometric distortion correction of MR images from a Siemens Magnetom Open Viva 0.2T resistive MR unit on the process of external beam radiotherapy treatment planning for prostate cancer.

Patients And Methods: A method for correction of system related and object induced distortions and one for correction of purely system related distortions have been evaluated.

Interobserver comparison of CT and MRI-based prostate apex definition. Clinical relevance for conformal radiotherapy treatment planning.

Background: CT is widely used for conformal radiotherapy treatment planning of prostate carcinoma. Its limitations are especially at the prostatic apex which cannot be separated from the urogenital diaphragm. The aim of this study was to compare the localization of the prostatic apex in CT and axial MRI to the sagittal MRI in an interobserver analysis.