Clinical Imaging Sciences

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    Development and evaluation of a soft-copy mammographic viewing protocol to improve radiological reporting
    (University of the Free State, 2012-10-02) Meyer, Carin; Rae, W. I. D.; Herbst, C. P.
    English: INTRODCUTION: Switching from screen-film mammography to digital mammography entails a lot more for the reporting radiologists, than switching from a light box to a computer monitor. Soft-copy viewing of the digitally processed image demands different skills and thus knowledge from the radiologist. The image processing option on digital mammography units is vendor dependant and the optimal processing options have not yet been established. The main aim of this study was to develop and evaluate a soft-copy viewing protocol for mammography through participative learning to improve radiological reporting. METHODS A phantom-based method was used to identify a smaller set of processing options to be evaluated for image quality assessment on clinical images. Three (3) radiologists were trained in the new modality with specific emphasis on how to address the challenges of soft-copy viewing. The viewing protocol was developed through participative learning. The radiologists scored the image quality on thirty six (36) medio-lateral oblique images processed with four (4) different image processing options (MUSICA2, MUSICA2 Invert, Unprocessed, and Unprocessed Invert). An image quality score was calculated to find the best processing option for the anatomical structures overall, anatomical structures individually, masses, calcifications, noise, and the early detection of breast cancer. A viewing protocol was recommended based on the findings. The effect of the viewing protocol was assessed by comparing diagnostic accuracy of the radiologists before and after the viewing protocol. They reported on eighty (80) mammograms using the breast imaging and reporting data system (BI-RADS) of the American College of Radiology. Sensitivity, specificity, positive predictive value (PPV) and BI-RADS category 3 were calculated and compared. RESULTS The phantom-based method found Unprocessed Invert, MUSICA2, MUSICA2 Invert, and Unprocessed to provide the best image quality. These processing options were therefore identified for image quality assessment on clinical images. For the anatomical structures overall, MUSICA2 provided significantly superior image quality compared to Unprocessed (p<0.0001) and Unprocessed Invert (p<0.0001). MUSICA2 Invert also provided significantly superior image quality compared to Unprocessed (p<0.0001) and Unprocessed Invert (p=0.0003) for that. The only significant difference between MUSICA2 and MUSICA2 Invert was found for skin outline for which MUSICA2 Invert showed superiority (p=0.0563). The image quality of vessels in dense parenchyma was found be significantly inferior to that of all other anatomical structures with all processing options, even with the processed images (p<0.0001). For calcifications MUSICA2 provided significantly superior image quality compared to Unprocessed and its Invert (p=0.0066 and p=0.0001 respectively). However, no significant difference was found between any of the processing options for masses (p>0.05). Noise was significantly less visible for Unprocessed compared to MUSICA2 (p = 0.016) although it was still acceptable to all three radiologists in 97.2% of cases with MUSICA2. For the early detection of breast cancer, MUSICA2 was found to be significantly superior to Unprocessed (p=0.0003) and Unprocessed Invert (p=0.0005). The recommended default processing option for the viewing protocol was MUSICA2 Invert. After the development of the viewing protocol, sensitivity increased for two of the radiologists [from 90% to 95% (p=0.6752)], and from 90% to 97.5% (p =0.3589) respectively]; specificity increased for two of the radiologists [from 61.5% to 72.5% (p=0.2999), and from 70% to 85% (p=0.1082) respectively]; PPV increased for all three radiologists [from 71.7% to 77.6% (p=0.6198), from 75% to 86.4% (p=0.1699), and from 83.7% to 84.8% (p=0.8907) respectively]. The percentage BI-RADS category 3 cases decreased for two of the radiologists [from 15% to 12.5% (p=0.6461) and from 28.8% to 22.5% (p=0.2810) respectively]. CONCLUSIONS Although not significant, the study found improvement in diagnostic accuracy after the development of the viewing protocol. Training of radiologists in the new modality and knowledge of the effect of image processing on image quality is regarded as important. The development of the viewing protocol through participative learning of the radiologist provided evidence to the radiologists that they could confidently use the proposed viewing protocol in clinical practice.
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    Diagnostic quality of neonatal radiograph images after 50% radiation-dose reduction on a computed radiography system
    (University of the Free State, 2013-12) Naude, Frans S. J.; Herbst, C. P.
    Background X-rays are frequently performed in the neonatal intensive care unit (NICU) setting, leading to a high radiation burden on patients. Neonates are more radiosensitive than adults, therefore all imaging should be done with the smallest possible dose. The European Commission guidelines suggest a 60-65 kV setting and maximum entrance skin kerma dose of 80 μGy, but no guidance is provided regarding the tube current (mAs) setting. Consequently, there is large variation in the mAs at different institutions. Objective To determine whether image quality would be compromised by utilising exposure parameter settings of 55 kV and 1,6 mAs, which delivers a radiation exposure of approximately 24 μGy using a computed radiography system in the NICU. This mAs setting can be used as a guideline, thereby preventing unnecessary radiation exposure. This will result in a significantly lower entrance skin kerma than the suggested European Committee guideline. Materials and methods A prospective study was performed and 60 NICU chest X-ray image sets were collected. These contained standard-dose images of 3,2mAs and lower dose images of 1,6mAs, acquired on the same day on a computed radiography system. The kV remained unchanged at 55kV. Randomised image sets were evaluated by five consultants regarding general image quality and some specific aspects thereof. Results. Generally, the routine-dose images had a better appearance. However, the image quality was considered acceptable for all the lower-dose exposures. Conclusion Computed radiography systems allow the use of lower radiation exposure without loss of diagnostic image detail. The radiation-dose burden could be significantly reduced in the NICU by using lower-dose settings. NICU institutions should consider to using 1,6 mAs and 55 kV as reference guidelines for the maximum setting for CR-system for all babies in NICU. This study suggests that the current EC radiation dose guideline of 80 μGy for neonates can be reduced by 66% without meaningful loss of diagnostic image quality.
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    Cost analysis of violence-related medical imaging in a Free State Tertiary Trauma Unit
    (University of the Free State, 2019-01) Steyn, Tiaan Pieter; Gebremariam, F. A.
    Background: Violence is a leading public health problem worldwide. Beyond the pain and suffering, violence has a significant economic impact on a country’s health, policing, and judicial services. Due to the lack of current and comprehensive data in South Africa, local violence-related economic impact studies are largely estimations. Violence-related imaging expenditure, as a component of a public hospital’s expenditure, is yet to be determined. Objectives: To measure the violence-related patient burden on Pelonomi Tertiary Hospital’s (PTH) trauma and radiology services, determine the imaging-component cost of violence-related injuries and calculate the financial burden violence has on the hospital’s expenditures. Method: From the PTH’s Trauma Unit patient registry, 1 380 patients with violence-related injuries were consecutively sampled for six months ending 31 December 2017. Imaging investigations were documented and categorised according to the South African National Department of Health’s (SANDOH) 2017 Uniform Patient Fee Schedule (UPFS). Descriptive analysis and cost calculations were performed using the 2017 UPFS tariff schedule and hospital-specific health efficiency indicators i.e. Patient Day Equivalent (PDE) and Expenditure per Patient Day Equivalent (ExPDE). Results: Violence-related injuries accounted for 50.64% of all trauma department visits and received a total of 5 475 imaging investigations. Violence-related imaging investigations represented 14.81% of all investigations performed by the radiology department in the study period. Overall violence-related admission costs amounted to R35 410 241.85 (8.33% of the hospital’s total expenditure) of which 20.08% (R7 108 845.00) was attributed to imaging investigations. Conclusion: Violence-related admissions had a high patient and financial burden on PTH. The pinnacle of health care cost saving is violence prevention; however, the cost-conscious radiologist could assist with cost saving if responsible and ethical imaging practices are followed.
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    Tunnelled haemodialysis catheters in central Free State: epidemiology and complications
    (University of the Free State, 2020-01) Fox, John Edward; Loggenberg, E.
    Background: End stage renal disease (ESRD) is a disease with profound impact on the patient, health system and economy. Tunnelled haemodialysis catheters (TDC) are amongst the most common dialysis methods. It has been established internationally that certain demographic descriptors and aetiologies carry an increased risk of complications. There is a dearth of epidemiological profiling of ESRD patients with TDC in South Africa. Objective: To establish the epidemiological profile of patients who received TDC and to establish the complication rate, with the goal of demonstrating associations between the epidemiological profiles and complications. Method: This was a retrospective study of all patients who received TDC in an Academic Hospital Interventional Radiological Suite over a period of 60 months between 01 March 2011 and 29 February 2016. Results: A total of 179 patients received 231 catheters. The majority of patients were male (58.7%) and 35.8% of the patients resided in Mangaung. The leading aetiologies of ESRD included hypertensive nephropathy (43.6%), primary glomerular disease (17.3%) and HIV associated nephropathy (6.1%). Procedural complications occurred in 7/224 (3.1%) insertions, whilst 37/185 (20.0%) developed catheter related infection and 54/185 (29.2%) developed dysfunctional catheters. There were no deaths due to catheter related complications. Conclusion: Our patients’ demographic profile, ESRD aetiology, complication rate for procedural complications and catheter related infections are roughly on par with international studies, however, the catheter dysfunction rate is higher than in the aforementioned studies. This possibly reflects the difficulty of accessing specialist care for our patients, the majority of whom reside outside the Mangaung district. Further studies with larger patient numbers are required to demonstrate statistically relevant associations.
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    Cost awareness of radiological studies amongst doctors at Universitas Academic Hospital, Bloemfontein
    (University of the Free State, 2020-07) Mrwetyana, Khanyisa Nothemba; Janse van Rensburg, Jacques; Joubert, Gina
    Background: South Africa has high healthcare expenses, implementing cost-consciousness would translate to a reduction in costs which will reduce government spending on healthcare. Objectives: To determine cost awareness of radiological studies amongst doctors. To assess whether there are differences in cost estimation accuracy according to the level of training and speciality amongst doctors working at Universitas Hospital. To determine whether the participants have undergone any prior education or training related to cost awareness of radiological studies and if there is a desire to learn about the cost of radiological imaging. Methods: This study was a cross-sectional survey by means of an anonymous questionnaire. The study was conducted in six clinical departments at Universitas Academic Hospital. The questionnaire was aimed at determining cost awareness of five radiological studies amongst doctors. Doctors were given six different cost ranges to choose from for each imaging study with only one correct option. The costs were based on South Africans National Department of Health’s 2019 Uniform Patients Fee Schedule (UPFS). Questionnaires were distributed in person by principal investigator. Results: 195 questionnaires were distributed and 131 (67.2%) returned. There was an overall low cost estimation accuracy, with 45.2% of the participants getting none of the costs correctly. None of the participants estimated all five costs correctly. There was no significant difference in cost estimation accuracy according to the level of training or speciality. The majority of participants (88.6%) would like to learn about the cost of imaging. Only 2.3% of the participants have received prior education or training related to cost awareness of radiological studies. Conclusion: Doctors were consistently inaccurate in estimating the cost of the radiological studies. As doctors are largely responsible for health care expenditure, the result of this research suggest that educating doctors about the cost of radiological imaging can have a positive effect on healthcare expenditure.
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    Diagnostic accuracy and reliability of smartphone captured radiologic images communicated via WhatsApp®
    (University of the Free State, 2021-02) Ntja, Unathi; Janse van Rensburg, Jacques; Joubert, Gina
    Background: Sending radiographic images as instant messages have become a common means of communication between physicians, aiding in triaging and transfer decision-making in emergencies. While the use of technology is increasing, this is not the case for the underserved or rural areas of South Africa with no picture archiving and communications system (PACS) or advanced hardware in place. In these areas, however, the medical population tends to have nearly universal access to smartphones and would benefit from the ability to share images quickly and easily with trained radiologists. South African data on diagnostic reliability of smartphone radiology images is lacking. Objectives: The objective of the study was to determine the accuracy and reliability of diagnoses made on radiologic images with a smartphone compared to radiologic images on PACS. Method: This was a cross-sectional study. Radiographs from 1 June 2018 to 1 July 2019 were selected from the PACS system at a tertiary hospital in the east-central South Africa. The images were displayed on a PACS computer screen and captured by the researcher using a smartphone. Five radiology registrars received the images via WhatsApp® and reviewed them on their phones. After three weeks, the registrars viewed the images in random order on a PACS station. McNemar’s test was used to compare the diagnostic accuracy of smartphone and PACS. Kappa values were calculated for agreement. Reliability was assessed by analyzing the results of different registrars and diagnoses separately. Results: One hundred and thirty-five X-rays, representative of common emergency conditions, were selected. For all registrars, the PACS accuracy was generally higher than the smartphone accuracy. The Kappa values all indicated fair to moderate agreement between smartphone and PACS diagnosis. Conclusion: Capturing radiographic images using at least a 12-megapixel smartphone and sharing them via WhatsApp® is a reliable method that can be used with a high degree of confidence in emergencies to aid clinical decision making. This method of viewing medical imaging is however not a substitution for images viewed on PACS.