Use of Multiphase CT Protocols in 18 Countries: Appropriateness and Radiation Doses.

PURPOSE: To assess the frequency, appropriateness, and radiation doses associated with multiphase computed tomography (CT) protocols for routine chest and abdomen-pelvis examinations in 18 countries. MATERIALS AND METHODS: In collaboration with the International Atomic Energy Agency, multi-institutional data on clinical indications, number of scan phases, scan parameters, and radiation dose descriptors (CT dose-index volume; dose-length product [DLP]) were collected for routine chest (n = 1706 patients) and abdomen-pelvis (n = 426 patients) CT from 18 institutions in Asia, Africa, and Europe. Two radiologists scored the need for each phase based on clinical indications (1 = not indicated, 2 = probably indicated, 3 = indicated). We surveyed 11 institutions for their practice regarding single-phase and multiphase CT examinations. Data were analyzed with the Student t test. RESULTS: Most institutions use multiphase protocols for routine chest (10/18 institutions) and routine abdomen-pelvis (10/11 institutions that supplied data for abdomen-pelvis) CT examinations. Most institutions (10/11) do not modify scan parameters between different scan phases. Respective total DLP for 1-, 2-, and 3-phase routine chest CT was 272, 518, and 820 mGy·cm, respectively. Corresponding values for 1- to 5-phase routine abdomen-pelvis CT were 400, 726, 1218, 1214, and 1458 mGy cm, respectively. For multiphase CT protocols, there were no differences in scan parameters and radiation doses between different phases for either chest or abdomen-pelvis CT (P = 0.40-0.99). Multiphase CT examinations were unnecessary in 100% of routine chest CT and in 63% of routine abdomen-pelvis CT examinations. CONCLUSIONS: Multiphase scan protocols for the routine chest and abdomen-pelvis CT examinations are unnecessary, and their use increases radiation dose.

Suboptimal Chest Radiography and Artificial Intelligence: The Problem and the Solution.

Chest radiographs (CXR) are the most performed imaging tests and rank high among the radiographic exams with suboptimal quality and high rejection rates. Suboptimal CXRs can cause delays in patient care and pitfalls in radiographic interpretation, given their ubiquitous use in the diagnosis and management of acute and chronic ailments. Suboptimal CXRs can also compound and lead to high inter-radiologist variations in CXR interpretation. While advances in radiography with transitions to computerized and digital radiography have reduced the prevalence of suboptimal exams, the problem persists. Advances in machine learning and artificial intelligence (AI), particularly in the radiographic acquisition, triage, and interpretation of CXRs, could offer a plausible solution for suboptimal CXRs. We review the literature on suboptimal CXRs and the potential use of AI to help reduce the prevalence of suboptimal CXRs.

A systematic review of conversion factors between kerma-area product and effective/organ dose for cardiac interventional fluoroscopy procedures performed in adult and paediatric patients.

The aim of this systematic review is to undertake a critical appraisal of the evidence in the published literature concerning the conversion factors between kerma-area product (PKA) and effective/organ dose (DCED_PKA, DCHT_PKA) for cardiac interventional fluoroscopy procedures performed in adults and paediatric patients and to propose reference conversion factors to help standardize dose calculations. A search strategy utilizing MeSH headings in three databases identified 59 (adult) and 37 (paediatric) papers deemed eligible for the review. Exclusion criteria were adopted to select data only from publications which established DCED_PKAin patients using the ICRP 103 tissue weighting factors. A time restriction from January 2007 was introduced in the search to capture the evolving trends of utilization of fluoroscopy-guided intervention technologies only in recent years. The suggested DCED_PKAand DCHT_PKAwere synthesized by calculating the weighted averages of the values reported by the authors with weights corresponding to the study sample size. Eighteen studies for both adult (9) and paediatric (9) patients matching the search terms fulfilled the inclusion criteria. The suggested value for DCED_PKAin adult patients amounts to 0.24 mSv Gy-1cm-2. The suggested values for DCHT_PKAranged from a minimum of 0.15 mSv Gy-1cm-2for the female breast to a maximum of 0.97 mSv Gy-1cm-2for the lungs. The suggested values for DCED_PKAin paediatric patients ranged from 3.45 mSv Gy-1cm-2for the new-born to 0.49 mSv Gy-1cm-2in the 15 years age class. The suggested values for DCHT_PKAranged from a minimum of 0.33 mSv Gy-1cm-2for bone marrow in the 15 years age class to a maximum of 11.49 mSv Gy-1cm-2for the heart in the new-born. To conclude, values of DCED_PKA/DCHT_PKAwere provided for calculating effective/organ doses in cardiac interventional procedures. They can be useful for standardizing dose calculations, hence for comparison of the radiation detriment from different imaging procedures and in the framework of epidemiologic studies.

National reference levels of CT procedures dedicated for treatment planning in radiation oncology.

OBJECTIVE: To present results of the first national survey on reference levels of CT imaging performed for the treatment planning purposes in radiation oncology in Croatia. METHODS: Data for CT protocols of five anatomical regions including head, head and neck, pelvis, breast, and thorax were collected at eight radiation oncology departments in Croatia. Data included volume CT dose index (CTDIvol), dose-length product (DLP), scan length and set of acquisition and reconstruction parameters. Data on a total of 600 patients were collected. Median values of scan length, DLP and CTDIvol were calculated for each acquisition protocol. Third quartiles of the median CTDIvol and DLP values were proposed as the national radiotherapy planning reference levels (RPRL). RESULTS: The largest CoV were assessed for RT Breast (63.8% for CTDIvol), RT Thorax (79.7% for DLP) and RT H&N (21.2% for scan length). RT Head had the lowest CoV for CTDIvol (1,9%) and DLP (17,2%), while RT Breast had the lowest coefficient of variation for scan length (12.8%). Proposed national RPRLs are: for RT Head CTDIvol16cm = 62 mGy and DLP16cm = 1738 mGy.cm; for RT H&N CTDIvol16cm = 35 mGy and DLP16cm = 1444 mGy.cm; for RT Breast CTDIvol32cm = 16 mGy and DLP32cm = 731 mGy.cm; for RT Thorax CTDIvol32cm = 17 mGy and DLP32cm = 865 mGy.cm; for RT Pelvis CTDIvol32cm = 20 mGy and DLP32cm = 1133 mGy.cm. CONCLUSIONS: Results of this study show variations in CT imaging for treatment planning practice at the national level which call for optimization of procedures.

Optimization of paranasal sinus CT procedure: Ultra-low dose CT as a roadmap for pre-functional endoscopic sinus surgery.

OBJECTIVE: To assess image quality and radiation dose associated with ultra-low dose CT protocol for patients with benign paranasal sinus diseases undergoing functional endoscopic surgery (FESS). METHODS: We scanned the head portion of Alderson RANDO phantom on a second generation, dual-source, multidetector-row CT scanner (Siemens Definition Flash) using standard-dose and five low-dose protocols. Two radiologists assessed the image quality for each protocol to determine best ultra-low-dose protocols for imaging patients with benign paranasal sinus diseases undergoing FESS. The ultra-low-dose CT protocols were then used for scanning. Thereafter, 40 adult patients (age range 18-54 years, M:F 23:17) were scanned with the four low dose scanning protocols (10 patients per protocol). On both transverse and coronal reformatted CT images, two radiologists assessed visibility of key anatomic landmarks for FESS on a 2-point scale (1 = clear and complete visualization; 2 = suboptimal visualization). Data were analyzed with descriptive statistics and Cohen's kappa coefficient for interobserver agreement. RESULTS: In phantom study, the lowest dose scan protocol (CTDIvol 2.1 mGy, 70 kV, 75 mAs) was unacceptable due to poor image quality. For patient studies, both radiologists gave acceptable image quality scores for ultra-low-dose scan protocol with axial scan mode, automatic tube potential selection and tube current modulation (CTDIvol 2.2 mGy; DLP 22.9 mGy.cm) with up to 60% lower dose compared to prior standard-dose CT (CTDIvol 5.3 mGy; DLP 73.5 mGy.cm). CONCLUSIONS: Ultra-low-dose CT protocol provides sufficient image quality for scanning patients undergoing functional endoscopic surgery for benign paranasal sinus diseases.

National survey to set diagnostic reference levels in nuclear medicine single photon emission imaging in Croatia.

PURPOSE: In order to introduce the concept of diagnostic reference levels (DRLs) in the national nuclear medicine practice a survey was proposed and completed through all nuclear medicine departments in Croatia. An additional aim was to increase the awareness of importance and full implementation of a comprehensive quality program that includes devices used in the nuclear medicine chain. METHODS: Data were collected for more than 30 nuclear medicine single photon emission procedures. National DRLs (NDRLs) as administered activity and also as administered activity per unit mass were calculated in accordance to International Commission on Radiological Protection (ICRP) recommendations. Additionally, effective doses were estimated using conversion factors published by the ICRP. RESULTS: NDRLs for nuclear medicine single photon emission procedures were proposed. For procedures performed in only one department typical values were presented as reference. Effective doses related to applied radiopharmaceuticals were calculated to estimate radiation risk related to respective nuclear medicine procedure in more detail. CONCLUSION: This work presents results of the first national survey on DRLs of nuclear medicine single photon emission procedures and proposes reliable NDRLs that represent an actual status of nuclear medicine practice in Croatia. Results have motivated departments to introduce and set their own typical values to be used, as one of the tools, for further optimization process. One of the drawbacks of the DRL concept in nuclear medicine is the lack of the image quality parameters involved. For this reason, a quantity that considers both radiation protection and image quality should be introduced.

IMPLEMENTATION OF QUALITY ASSURANCE PROGRAM IN RADIOGRAPHY-2-YEAR EXPERIENCE OF COLLABORATION WITH PUBLIC HEALTH INSTITUTIONS IN WEST REGION OF CROATIA.

Quality Assurance program on using ionizing radiation is mandatory in all EU member states but this is still not implemented in most facilities in Croatia mostly because of a lack of medical physicists in diagnostic radiology. Since public health institutions in Croatia do not employ medical physicists in diagnostic radiology, collaboration between these institutions in west region of Croatia with Clinical Hospital Center Rijeka (CHC) was initiated during the year 2015. Physicists from CHC Rijeka performed periodical Quality Control (QC) tests and were included in optimization process. Results of QC tests during the period of 2 years showed a lot of improvements-equipment is maintained more frequently, some old units were replaced with new ones and all institutions acquired QC equipment so radiographers could perform daily and monthly QC tests. All these activities showed that medical physics support in radiology departments is necessary and can improve clinical practice.