Assessment of the viability of integrating virtual reality programs in practical tests for the Korean Radiological Technologists Licensing Examination: a survey study

PURPOSE: The objective of this study was to assess the feasibility of incorporating virtual reality/augmented reality (VR/AR) programs into practical tests administered as part of the Korean Radiological Technologists Licensing Examination (KRTLE). This evaluation is grounded in a comprehensive survey that targeted enrolled students in departments of radiology across the nation. METHODS: In total, 682 students from radiology departments across the nation were participants in the survey. An online survey platform was used, and the questionnaire was structured into 5 distinct sections and 27 questions. A frequency analysis for each section of the survey was conducted using IBM SPSS ver. 27.0. RESULTS: Direct or indirect exposure to VR/AR content was reported by 67.7% of all respondents. Furthermore, 55.4% of the respondents expressed that VR/AR could be integrated into their classes, which signified a widespread acknowledgment of VR among the students. With regards to the integration of a VR/AR or mixed reality program into the practical tests for purposes of the KRTLE, a substantial amount of the respondents (57.3%) exhibited a positive inclination and recommended its introduction. CONCLUSION: The application of VR/AR programs within practical tests of the KRTLE will be used as an alternative for evaluating clinical examination procedures and validating job skills.

Updated National Diagnostic Reference Levels and Achievable Doses for CT Protocols: A National Survey of Korean Hospitals.

Background: In 2021, the Korean government proposed a new CT diagnostic reference level. This study performed a nationwide survey and developed new DRLs and AD for 13 common CT examinations. We compared other countries' DRLs for CT examinations. Methods: This study investigated the CTDIvol and DLP of the 12 types of CT protocols for adults and brain CT protocol for pediatrics. A total of 7829 CT examinations were performed using 225 scanners. We defined the DRLs values in the distribution of radiation exposure levels to determine the nationwide patient dose and distribution status of the dose. Results: This study showed that the new Korean national CT DRLs are slightly higher or similar to those of previous surveys and are similar or lower than those of other countries. In some protocols, although the DLP value increased, the CTDIvol decreased; therefore, it can be concluded that the patient's dose in CT examinations was well managed. Conclusions: The new CT DRLs were slightly higher than or similar to that of the previous survey and were evaluated to be similar or lower than CT DRLs of other countries. These DRLs will be used for radiation optimization and effective dose calculation for an individual.

Radiation safety behavior model for the radiological science departments of Universities in Korea.

OBJECTIVES: This study was to employ the major variables relating to radiation safety that were derived using the Haddon Matrix to develop a radiation safety behavior model based on social cognitive theory that can be applied to improve the radiation safety behaviors of professors and students in radiological science departments. METHODS: The safety levels of students and professor in radiological science departments were analyzed in order to design a radiation safety behavior management model based on the Haddon Matrix and social cognitive theory, which can be used to enhance radiation safety strategically. The survey was administered on April 23, 2015, to professor and students of 45 universities around South Korea with established radiological science departments, and the investigation lasted for 30 days. RESULTS: When multiple linear regression analysis was conducted taking the radiation safety behaviors of the students in the radiological science departments as the dependent variables, it was found that these behaviors were affected by self-efficacy, knowledge of the materials, and attitudes towards the materials, in order of greatest to least influence. CONCLUSION: Since the general view on radiation safety management in universities is also changing to a maximalist attitude, the level of safety management must be increased accordingly.

The Optimal Energy Level of Virtual Monochromatic Images From Spectral CT for Reducing Beam-Hardening Artifacts Due to Contrast Media in the Thorax.

OBJECTIVE: The purpose of this study is to determine the optimal energy level of virtual monochromatic images from spectral CT compared with conventional polychromatic images for reducing beam-hardening artifacts caused by contrast media in the thorax. MATERIALS AND METHODS: A total of 101 consecutive patients who underwent chest CT with contrast enhancement were retrospectively included in this study. The same contrast media and injection protocols were applied to the whole study population. Virtual monochromatic image datasets ranging from 70 to 200 keV and conventional polychromatic images were obtained. Readers' subjective image quality scores were recorded for conventional polychromatic and virtual monochromatic images obtained at 70, 100, 130, and 200 keV. Image noise, CT attenuation difference, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) were also obtained in each algorithm. Comparisons of parameters between algorithms were performed. RESULTS: The best subjective image quality score and significantly lower image noise were observed for 130-keV virtual monochromatic images compared with conventional polychromatic images (all p < 0.001). Also, CT attenuation differences were significantly lower for both 100- and 130-keV virtual monochromatic images than for conventional polychromatic images (all p < 0.001). Meanwhile, the lowest differences in CT attenuation were observed for 100-keV virtual monochromatic images compared with conventional polychromatic images. However, there were no significant differences in CT attenuation between 100- and 130-keV virtual monochromatic images. SNR was similar between 130-keV virtual monochromatic images and conventional polychromatic images, although both SNR and CNR decreased as the energy level increased. CONCLUSION: Virtual monochromatic imaging reduced beam-hardening artifacts and improved image quality, and optimal evaluation of chest CT was best achieved at 100 and 130 keV.

Radiation dose reduction from low-kilovoltage liver computed tomography using multidetector row computed tomography.

The primary goal of this study was to ascertain the reduction in radiation dose when conducting low-kilovoltage liver computed tomography (CT) examinations using multidetector row CT (MDCT). Fifty patients under follow-up who were diagnosed with liver cancer were examined using a 16-slice MDCT scanner and volume CT dose index (CTDI(vol)) measured according to the methods of examination, which were based on a three-phase CT scan conducted in the previous year and a four-phase CT scan was done a year later. Scanning parameters were 120 kVp-140 mA s, 120 kVp-120 mA s and 80 kVp-280 mA s. The CTDI(vol) was decreased to ∼47% at 80 kVp -280 mA s. The results indicate that low-kilovoltage liver CT is a useful means of reducing radiation doses.

The development of a diagnostic reference level on patient dose for head computed tomographyangiography examinations in Korea.

The primary goal of this study was to analyse the state of patient doses in the field for head computed tomography angiography (HCTA) examinations in the Republic of Korea. All survey data, including CT application and patient dose details, were obtained from the general hospitals registered in the Korean Hospital Association. The systematic analysis of patient dose data would allow target value to be established for the weighted CT dose index (CTDIw), volume-weighted CTDI (CTDIvol) and a dose-length product (DLP), which might be used to set diagnostic reference levels. The survey on patients' dose showed that the 75th percentiles in the distribution of CTDIw, CTDIvol and DLP were 34.09, 26.7 and 1816 mGy for the HCTA examinations, respectively.

Spontaneously healed asymptomatic pulmonary tuberculosis: prevalence of airflow obstruction, and correlation between high-resolution CT findings and pulmonary function tests.

RATIONALE AND OBJECTIVES: We investigated the relationships between spontaneously healed asymptomatic pulmonary tuberculosis (SHAPTB), airflow obstruction (AFO), and high-resolution computed tomography (HRCT) findings. MATERIALS AND METHODS: We selected 82 participants with SHAPTB diagnosed by interferon-γ release assay and 8044 with normal chest radiographs (CXR). We applied a CT scoring system for the extent of tuberculous sequelae to correlate the HRCT findings with pulmonary function test. We compared the AFO prevalence between subjects with and without SHAPTB. RESULTS: The subjects with SHAPTB diagnosed by interferon-γ release assay had a significantly higher prevalence of AFO (13.4% [11/82]) than those with normal CXR (7.4% [595/8044]). The important HRCT findings that correlated with AFO were the number of lung segments with TB sequelae and the CT score for emphysema. CONCLUSION: The subjects with SHAPTB had a higher AFO prevalence than those with normal CXR, and the important HRCT findings correlated with AFO were the extent of tuberculous sequelae and emphysema.

Comparative analysis of radiation dose and image quality between thyroid shielding and unshielding during CT examination of the neck.

OBJECTIVE: The purpose of this study is to evaluate the feasibility of thyroid shielding by measuring radiation dose, CT attenuation, and noise of superficial neck structures during CT examination. SUBJECTS AND METHODS: We divided 84 patients without abnormalities seen on CT into two groups depending on whether shielding with a cotton spacer was applied over the thyroid. On CT images, we measured the CT attenuation and noises in the strap and sternocleidomastoid (SCM) muscles. The superficial radiation dose was measured using a head CT dose phantom containing ionization chambers located at the 3, 6, 9, and 12 o'clock positions. RESULTS: With thyroid shielding, the CT attenuation was significantly increased (shielded strap and SCM muscles, 117.6 ± 19.2 HU and 113.7 ± 31.8 HU, respectively; unshielded strap and SCM muscles, 84.1 ± 12.2 HU and 78.4 ± 10.1 HU, respectively; p < 0.05), whereas noise was unaffected (shielded strap and SCM muscles, 7.2 ± 4.2 HU and 10.8 ± 4.9 HU, respectively; unshielded strap and SCM muscles, 8.6 ± 4.9 HU and 10.7 ± 6.6 HU, respectively; p > 0.05). On the phantom study, the shield significantly reduced the superficial unshielded dose at the 12 o'clock position only (27.5% reduction; p < 0.01). CONCLUSION: Below the shielded surface, thyroid shielding significantly reduced the superficial radiation dose of the neck without a remarkable noise increase while increasing CT attenuation.

Optimal multidetector row CT parameters for evaluations of the breast: a phantom and specimen study.

RATIONALE AND OBJECTIVES: The use of breast computed tomography (CT) has been limited by radiation hazard and image quality. The objective of this study was to compare radiation doses and image quality for different 64-channel multidetector row CT (MDCT) parameters, and to potentially provide optimal CT parameters for breast imaging. MATERIALS AND METHODS: For assessment of radiation doses, CT dose index (CTDI(100)) values were obtained at various x-ray tube voltages (80, 120, 140 kVp) and currents (30, 50, 100, 150, 200 mAs) using a standard CT body dose phantom. To evaluate image quality, four fresh mastectomy specimens were scanned and three radiologists graded images for overall image quality, glandular tissue-fat conspicuity, and Cooper's ligament sharpness. Statistically, linear regression analyses and multiple comparisons were used for investigation of the relationship between radiation dose, image qualities, and CT parameters. RESULTS: CTDI(100) values of < or =6 mGy were obtained at 80 kVp and any mAs, 120 kVp and 30 or 50 mAs, and 140 kVp and 30 or 50 mAs. Image quality at 80 kVp and 200 mAs, 120 kV and 50, 100, 150, or 200 mAs, and 140 kVp and all mAs values tested were significantly superior to those at 80 kVp and 30, 50, 100, or 150 mAs and 120 kV and 30 mAs (P < .05). CONCLUSIONS: Based on our results, 80 kVp and 200 mAs, 120 kVp and 50 mAs, 140 kVp and 30 mAs, or 140 kVp and 50 mAs can be used for breast MDCT scanning to reduce radiation dose and preserve image quality and 140 kVp at 30 mAs is the optimal setting.

Improved imaging of the cervico-thoracic junction in computed tomography.

PURPOSE: To reduce beam hardening artifacts caused by the shoulder joint, we explored new and unique methods to improve the quality of images, such as varying the injection site and changing the position of patients (swimmers position). MATERIALS AND METHODS: Fifth-four patients underwent neck CT examinations performed in routine and swimmers position and with a 64-slice MDCT scanner in spiral scanning. To examine the difference due to the injection sites of contrast material, subjects were divided into right- and left-side groups. For the evaluation of images, we carried out a subjective and objective assessment based on radiologists' ratings and noise measurement. RESULTS: Images of the lower neck in the swimmers position exhibited less hardening and streak artifacts. The subjective and objective evaluations showed that the swimmers position received higher rating by radiologists and had lower noise level than that of routine position. The swimmers position was the most effective for the diagnosis of the cervico-thoracic junction area. As for the injection site, we obtained better images by an injection of contrast material in the right arm than in the left. CONCLUSION: CT examination of the lower neck in the swimmers position may improve the quality of image and the effectiveness of diagnosis. The injection of a contrast material to the right side rather than the left side reduced foreign body artifacts.

Patient dose measurements in diagnostic radiology procedures in Korea.

This study is the first nationwide investigation aimed at estimating the patient dose for radiographic examinations in Korea including gastrointestinal studies, computed tomography and mammography. The survey data from 161 hospitals and the dose data from 32 hospitals were analysed. The third quartile entrance surface dose, dose area product (DAP), weighted CT dose index (CTDIw) and mean glandular dose (MGD) were reported. All the estimated doses were less than the stated International Atomic Energy Agency (IAEA) reference levels for radiographic examinations. However, DAPs for the fluoroscopic examinations had higher dose values than the IAEA reference levels. In addition, the CTDIw and MGD were lower than the IAEA reference levels.

Low-dose multidetector dynamic CT in the breast: preliminary study.

This study investigated the feasibility of using low-dose multidetector dynamic computed tomography (CT) scan for imaging breast. We measured the radiation dose using a phantom at low- and standard-dose CT. To compare the image quality at low- and standard-dose CT, we evaluated normal breasts in 57 cases. In 44 cases with breast cancer, we assessed the staging and time-enhancement curves of breast cancer. In conclusion, the low-dose multidetector dynamic CT scan is feasible for the evaluation of the breast, with reduced radiation dose and with similar image quality when compared with standard-dose CT scan. In breast cancers, low-dose dynamic CT could be used for the staging of breast cancer before surgery.