Diagnostic reference levels in low- and middle-income countries: early "ALARAm" bells?

Colon histology slide classification with deep-learning framework using individual and fused features

Cancer occurrence rates are gradually rising in the population, which reasons a heavy diagnostic burden globally. The rate of colorectal (bowel) cancer (CC) is gradually rising, and is currently listed as the third most common cancer globally. Therefore, early screening and treatments with a recommended clinical protocol are necessary to trat cancer. The proposed research aim of this paper to develop a Deep-Learning Framework (DLF) to classify the colon histology slides into normal/cancer classes using deep-learning-based features. The stages of the framework include the following: (ⅰ) Image collection, resizing, and pre-processing; (ⅱ) Deep-Features (DF) extraction with a chosen scheme; (ⅲ) Binary classification with a 5-fold cross-validation; and (ⅳ) Verification of the clinical significance. This work classifies the considered image database using the follwing: (ⅰ) Individual DF, (ⅱ) Fused DF, and (ⅲ) Ensemble DF. The achieved results are separately verified using binary classifiers. The proposed work considered 4000 (2000 normal and 2000 cancer) histology slides for the examination. The result of this research confirms that the fused DF helps to achieve a detection accuracy of 99% with the K-Nearest Neighbor (KNN) classifier. In contrast, the individual and ensemble DF provide classification accuracies of 93.25 and 97.25%, respectively.

Typical Diagnostic Reference Levels of Common Indications for Computed Tomography Scans Among Adult Patients in Uganda: a Cross-sectional Study

Background

Medical exposure to ionizing radiation has increased due to an increase in the number of computerized tomography (CT) scan examinations performed. The International Commission on Radiological Protection (ICRP) recommends indication-based diagnostic reference levels (IB-DRLs) as an effective tool that aids in optimizing CT scan radiation doses. In many low-income settings, there is a lack of IB-DRLs to support optimization of radiation doses.

Objective

To establish typical DRLs for common CT scan indications among adult patients in Kampala, Uganda.

Methodology

A cross sectional study design was employed involving 337 participants enrolled from three hospitals using systematic sampling. The participants were adults who had been referred for a CT scan. The typical DRL of each indication was determined as the median value of the pooled distribution of CTDIvol (mGy) data and the median value of the pooled distribution of total DLP (tDLP)(mGy.cm) data from three hospitals. Comparison was made to anatomical, and indication based DRLs from other studies.

Results

54.3% of the participants were male. The following were typical DRLs for: acute stroke (30.17mGy and 653mGy.cm); head trauma (32.04mGy and 878mGy.cm); interstitial lung diseases/ high resolution chest CT scan (4.66mGy and 161mGy.cm); pulmonary embolism (5.03mGy and 273mGy.cm); abdominopelvic lesion (6.93mGy and 838mGy.cm) and urinary calculi (7.61mGy and 975mGy.cm). Indication based total Dose Length Product (tDLP) DRLs was lower than tDLP DRLs of a whole anatomical region by 36.4% on average. Most of the developed typical IB-DLP DRLs were lower or comparable to values from studies in Ghana and Egypt in all indications besides urinary calculi while they were higher than values in a French study in all indications besides acute stroke and head trauma.

Conclusion

Typical IB-DRLs is a good clinical practice tool for optimization of CT doses and therefore recommended for use to manage CT radiation dose. The developed IB-DRLs varied from international values due to differences in selection of CT scan parameters and standardization of CT imaging protocols may narrow the variation. This study can serve as baseline for establishment of national indication-based CT DRLs in Uganda.

An audit of patient radiation doses in interventional radiology at a South African hospital

Background

Interventional radiology (IR) is becoming more relevant in patient care and is associated with increased patient radiation exposure and radiation-induced adverse effects. Diagnostic reference levels (DRLs) are crucial for radiation control. There is a paucity of published DRLs for IR in South Africa and sub-Saharan Africa.

Objectives

This study aimed to determine local DRLs for fluoroscopically-guided IR procedures and compare the achieved DRLs with published local and international DRLs.

Method

Retrospective, descriptive, single-centre study. Kerma air product (KAP), reference point air kerma (K_a,r) and fluoroscopy time (FT) were collected for patients (12 years and older) who underwent IR procedures at a university hospital from 01 January 2019 to 31 December 2019. The 75th percentile of the distribution of each dose parameter (KAP, K_a,r and FT) per procedure was calculated and taken as the local diagnostic reference levels (LDRL). The established LDRLs were compared to published DRLs.

Results

A total of 564 cases were evaluated. The 13 most frequent procedures (with 15 or more cases) represented 86.1% (487/564). Percutaneous transhepatic biliary drainage was the most common procedure (n = 146, 25.9%). Diagnostic cerebral angiogram DRLs exceeded the published DRL data ranges for all parameters (DRL 209.3), and interventional cerebral angiogram exceeded published ranges (DRL 275). Uterine artery embolisation (UAE) exceeded these ranges for KAP and K_a,r. (KAP-954.9 Gy/cm², K_a,r-2640.8 mGy).

Conclusion

The LDRLs for diagnostic cerebral angiogram, interventional cerebral angiogram and UAE exceeded published international DRL ranges. These procedures require radiation optimisation as recommended by the International Commission on Radiological Protection (ICRP).

Contribution

In addition to informing radiation protection practices at the level of the institution, the established LDRLs contribute towards Regional and National DRLs.

[Imaging after trauma in clinics and practice for children and adolescents : Part 1 of the results of a nationwide online survey of the Pediatric Traumatology Section of the German Trauma Society]

BACKGROUND

The indication for radiography should strictly follow the ALARA (as low as reasonably achievable) principle in pediatric and adolescent trauma patients. The effect of radiation on the growing sensitive tissue of these patients should not be disregarded.

QUESTION

The Pediatric Traumatology Section (SKT) of the German Trauma Society (DGU) wanted to clarify how the principle is followed in trauma care.

METHODS

An online survey was open for 10 weeks. Target groups were trauma surgeons, pediatric surgeons, general surgeons, and orthopedic surgeons.

RESULTS

From Nov. 15, 2019, to Feb. 29, 2020, 788 physicians participated: branch office 20.56%, MVZ 4.31%, hospital 75.13%; resident 16.62%, senior 38.07%, chief 22.59%. By specialist qualification, the distribution was: 38.34% surgery, 33.16% trauma surgery, 36.66% special trauma surgery, 70.34% orthopedics and trauma surgery, 18.78% pediatric surgery. Frequency of contact with fractures in the above age group was reported as 37% < 10/month, 27% < 20/M, 36% > 20/M. About 52% always request radiographs in 2 planes after acute trauma. X-ray of the opposite side for unclear findings was rejected by 70%. 23% use sonography regularly in fracture diagnosis. In polytrauma children and adolescents, whole-body CT is never used in 18%, rarely in 50%, and standard in 14%.

DISCUSSION

The analysis shows that there is no uniform radiological management of children and adolescents with fractures among the respondents.

CONCLUSION

Comparing the results of the survey with the consensus findings of the SKT recently published in this journal, persuasion is still needed to change the use of radiography in primary diagnosis.

[Intraoperative imaging of children and adolescents, for selected fractures and in follow-up after conservative and operative treatment : Part 2 of the results of a nationwide online survey of the Pediatric Traumatology Section of the German Trauma Society]

The indication for radiographic examinations in pediatric and adolescent trauma patients should follow ALARA (as low as reasonably achievable). Because of the effect of radiation on the growing sensitive tissues of these young patients, a strict indication should always be given for radiation use and during controls after fracture repair.

METHODS

An online survey by the Pediatric Traumatology Section (SKT) of the German Trauma Society (DGU) from Nov. 15, 2019, to Feb. 29, 2020, targeting trauma, pediatric, and general surgeons and orthopedic surgeons.

RESULTS

Participants: 788. Intraoperative applications: Collimation 50% always, postprocessing for magnification 40%, pulsed x-ray 47%, and 89% no continuous fluoroscopy; 63% osteosynthesis never directly on image intensifier. Radiographic controls after implant removal never used by 24%. After operated supracondylar humerus fracture, controls are performed up to 6 times. After distal radius greenstick fracture, 40% refrain from further X-ray controls, after conservatively treated clavicular shaft fracture, 55% refrain from further controls, others X-ray several times. After nondisplaced conservatively treated tibial shaft fracture, 63% recommend radiographic control after 1 week in two planes, 24% after 2 weeks, 37% after 4 weeks, and 32% after 6 weeks.

DISCUSSION

The analysis shows that there is no uniform radiological management of children and adolescents with fractures among the respondents. For some indications for the use of radiography, the benefit does not seem evident. The ALARA principle does not seem to be consistently followed.

CONCLUSION

Comparing the documented results of the survey with the consensus results of the SKT, differences are apparent.

A low-resource digital infrastructure to streamline viewing and interpretation of radiographic images: A case study of Uganda's hospital-wide environment

Picture Archiving and Communication Systems (PACS) are said to improve patient quality of care through timely access to radiological images by clinicians. However, they are costly to be considered for hospital wide environment in low income countries. Ordinary core i3 computer systems (PCs) can provide an affordable and faster alternative solution for PACS workstations. This comparative study assessed the diagnostic accuracy, image quality of ordinary PC systems versus PACS workstations and patient turnaround time (PTAT). Forty images were randomly obtained and viewed by four raters from both PACS and PC. The findings showed modest agreement among raters (kappa 0.644 for PACS and 0.5164 PC) with acceptable diagnostic accuracy for PC (AUC = 0.7990), 97.5% reproduction of images on PC and significant reduction in PTAT after a switch to PC (4.8 min), p < 0.001, suggesting that PC display can improve quality of health care services through timely access to radiographic images.

An audit of published South African diagnostic reference level data

Diagnostic reference levels (DRLs) are accepted as a dose optimisation tool for patients undergoing x-ray imaging and are required by South African (SA) legislation for 26 fluoroscopically guided procedures (FGPs). The aim of this paper is to collate all published SA data on DRLs in preparation for a project to establish national DRLs. Systematic searches were conducted of various applicable databases. All research that proposed DRLs for any imaging procedure in South Africa was included. Twenty-one works met inclusion criteria, the earliest from 2001. Two-thirds of all work reported on FGPs and five studies documented computed tomography DRLs. Three publications focussed exclusively on paediatric imaging DRLs. No studies on mammography or dental radiography were found. For clinical procedures with more than one proposed DRL, the range of proposed DRL varied by up to a factor of five. The highest proposed DRL is 373.1 Gy cm²for endovascular aneurysm/aortic repair procedures. Data were collected in six public hospitals and two private hospital groups. Thirty-six authors contributed to the manuscripts, but only six studies had an inter-disciplinary authorship. This is the first paper to provide a comprehensive review of SA DRL data and thereby advances international radiation protection initiatives. The data suggests there is room for more interdisciplinary work and that there must be rigorous standardization of reported parameters and data collection. This audit also highlights the need for standardized terminology, particularly for FGPs.

Diagnostic reference levels for fluoroscopically guided procedures in a South African tertiary hospital

BACKGROUND

The burgeoning usage and complexity of fluoroscopically guided procedures (FGPs) contribute to extended examination times and increased risk of adverse radiation effects. Diagnostic reference levels (DRLs) play a pivotal role in dose optimization. There are limited DRL data for FGPs in low- and middle-income countries (LMICs).

PURPOSE

To determine local DRLs (LDRLs) for common FGPs in the South African (SA) context and compare these with published international data.

MATERIAL AND METHODS

A three-year, retrospective study of the 15 most frequently performed FGPs at a SA institution. For each procedure, the 50th and 75th percentiles of kerma area product (KAP), reference point air kerma (K_a,r), and fluoroscopy time data were derived. Published international FGP DRL data were collated and compared with the 75th percentiles of local institutional dosage parameters.

RESULTS

The commonest FGPs were aorto-bifemoral diagnostic angiography (n = 590), aorto-bifemoral interventional angiography (n = 287), nephrostomy (n = 265), and bronchial arterial embolization (BAE) (n = 208). Selective abdominal vessel interventional angiography (KAP = 170 Gy . cm²; K_a,r = 877 mGy) recorded the highest LDRL dosages; BAE was the longest procedure (LDRL = 38 min). Nephrostomies achieved the lowest LDRLs across all parameters (KAP = 10 Gy . cm²; K_a,r = 63 mGy, fluoroscopy time = 4.3 min). All Tygerberg Hospital LDRLs with comprehensive comparable data were within or below published ranges.

CONCLUSION

This study advances international radiation protection initiatives, addresses the paucity of LMIC DRL data, demonstrates broad alignment of Tygerberg Hospital FGP practice with international norms and highlights areas for optimization of institutional practice.

[X-ray diagnostics of fractures in childhood and adolescence-Consensus report of the scientific working group of the pediatric traumatology section of the German Society for Trauma Surgery (DGU)]

Seit Jahrzehnten ist die Projektionsradiographie Standard in der Diagnostik von Frakturen und Verletzungen auch bei Patienten im Kindes- und Jugendalter. Bei jeder Untersuchung mit Röntgenstrahlen sollen aber auch individuell Nutzen und Risiko gegeneinander abgewogen werden. Die Sektion Kindertraumatologie der DGU hat zu verschiedenen Aspekten der Bildgebung zu Diagnostik und Verlaufsbeurteilung, zu Einstellungsmöglichkeiten der intraoperativen Bildgebung, zum Röntgen der Gegenseite, zu Polytrauma und CT, zu postoperativen radiologischen Kontrollen und dem Einsatz der Sonographie ein Konsenspapier erarbeitet.

Review of the current status of radiation protection in diagnostic radiology in Africa

The aim of this paper is to review the available published studies from African countries on patient doses and medical radiation protection and identify strengths, weaknesses, and challenges. Papers on radiation doses to patients published until 2016 pertaining to studies in African countries were reviewed. Radiography, interventional radiology, computed tomography (CT), and mammography modalities were covered. In radiography, the entrance surface air kerma values were below the established diagnostic reference levels (DRLs) provided by the International Atomic Energy Agency, European Commission, and National Council on Radiation Protection and Measurements. Patient and staff doses in interventional procedures were not on the higher side when compared with other published reports from developed countries. The dose length product values in CT in many situations were higher than established DRLs. In mammography, the variations of clinical image quality and dose to standard breast between African countries and other countries were insignificant. In conclusion, like in any continent, not all countries in Africa are active, but some have produced good results. The potential for optimization of radiation protection using simple and inexpensive techniques has been demonstrated. The lack of medical physicists is one of the important challenges.