SA Journal of Radiology最新文献

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.

Dynamic contrast-enhanced (DCE) lymphangiography is a novel imaging technique with a potential role in suspected cases of lymphatic leaks. A 15-year-old male with a post operative chylous leak and an 8-year-old male who developed chylous ascites secondary to disseminated tuberculosis are presented. Both children underwent MR lymphangiography.

Contribution: The role of DCE-MR lymphangiography in cases of chylous ascites to help guide appropriate management.

Background: Digital subtraction angiography (DSA) is invasive, costly and unavailable in many South African hospitals; however, it remains the gold standard for imaging intracranial aneurysms. CT angiography (CTA) is a non-invasive and readily available screening tool prior to DSA.

Objectives: This study aimed to evaluate the diagnostic performance of CTA in detecting ruptured intracranial aneurysms using DSA as the reference standard and to determine the effect of aneurysm size and location on CTA sensitivity.

Method: A retrospective analysis of CTA and DSA data from reports of patients suspected to have aneurysmal subarachnoid haemorrhage (SAH) at Chris Hani Baragwanath Academic Hospital between January 2017 and June 2020.

Results: Conventional DSA detected aneurysms in 94 out of 115 patients; while of these, CTA detected 75 and missed 19. The CTA sensitivity, specificity and accuracy was 80%, 43% and 73%, respectively. The CTA sensitivity for aneurysms < 3 mm and 3 mm - 5 mm in size was 30% and 81.5%, respectively (p = 0.024). Sensitivity of CTA for posterior communicating artery (PComm) aneurysms was 56% and lower than other major anterior circulation locations (83% - 91%) (p = 0.045).

Conclusion: The CTA diagnostic efficiency was lower than previously reported, with even lower sensitivity for aneurysms < 3 mm and for those arising from the PComm. Thus, CTA should remain a screening tool prior to DSA in all local patients suspected to have aneurysmal SAH.

Contribution: Larger, prospective studies are required to accurately define the role of CTA in diagnosing intracranial aneurysms in a developing country with limited resources.

Background: Incidentally detected unruptured intracranial aneurysms have a prevalence of 3% with some predisposed to rupture and others remaining static. Diagnostic knowledge of previous aneurysmal subarachnoid haemorrhage (ASAH) in the chronic phase could identify patients requiring treatment.

Objectives: To assess the sensitivity of susceptibility weighted imaging (SWI) in the detection of ASAH at 3 months post ictus and determine any influencing effects.

Method: A retrospective chart analysis of 46 patients with ASAH who underwent post-embolisation SWI imaging at 3 months. The SWI and available initial CT brain scans or CT reports were evaluated and correlated with patient demographics and clinical severity.

Results: Susceptibility weighted imaging indicated a sensitivity of 95.7% in the detection of ASAH at 3 months. Increased number of haemosiderin zones on SWI correlated with older patient age (p = 0.0003). Clinical severity (World Federation Neurosurgical Societies Score) showed a tendency towards a statistically relevant relationship (p = 0.07). No statistically significant relationship was identified between the number of haemosiderin zones and initial CT modified Fisher score (p = 0.34) or the causative aneurysm location (p = 0.37).

Conclusion: Susceptibility weighted imaging is sensitive in the detection of ASAH at 3 months, increasing in sensitivity with patient age and higher initial clinical severity.

Contribution: In patients presenting in the subacute to chronic phase with a clinically suspicious history of previous aneurysm rupture but without convincing CT or spectrophotometry evidence, SWI can detect previous rupture. This can identify patients who could benefit from endovascular treatment and those who can safely undergo follow-up imaging.

The floor of the mouth is an important anatomical region of the oral cavity where primary benign and malignant disease processes can originate or secondary pathologies can extend into adjacent spaces. Knowledge of the anatomy is crucial for accurate localisation of pathology and understanding the spread of disease. The sublingual space is the dominant component of the floor of the mouth, bounded inferiorly by the mylohyoid muscle that separates it from the submandibular space. Imaging is immensely important to characterise and map the extent of disease, considering the fact that the bulk of the disease may be submucosal and not visible on clinical inspection.

Contribution: The floor of the mouth is a complex anatomical region for radiological evaluation. The purpose of this pictorial review is to present an understanding of the relevant anatomy and to demonstrate the role and appropriate application of different imaging modalities. This article highlights the imaging spectrum of a wide range of various benign conditions including normal variants and a variety of malignant lesions at different tumour stages, with an aim to establish the correct diagnosis, avoid misinterpretation and help in treatment planning.

Background: The blue-light hazard is a well-documented entity addressing the detrimental health effects of high-energy visible light photons in the range of 305 nm - 450 nm. Radiologists spend long hours in front of multiple light-emitting diode (LED)-based diagnostic monitors emitting blue light, predisposing them to potentially higher blue-light dosages than other health professionals.

Objectives: The authors aimed to quantify the blue light that radiology registrars are exposed to in daily viewing of diagnostic monitors and compared this with international occupational safety standards.

Method: A limited cross-sectional observational study was conducted. Four radiology registrars at two academic hospitals in Bloemfontein from 01 October 2021 to 30 November 2021 participated. Diagnostic monitor viewing times on a standard workday were determined. Different image modalities obtained from 01 June 2019 to 30 November 2019 were assessed, and blue-light radiance was determined using a spectroscope and image analysis software. Blue-light radiance values were compared with international safety standards.

Results: Radiology registrars spent on average 380 min in front of a diagnostic display unit daily. Blue-light radiance from diagnostic monitors was elevated in higher-intensity images such as chest radiographs and lower for darker images like MRI brain studies. The total blue-light radiance from diagnostic display units was more than 10 000 times below the recommended threshold value for blue-light exposure.

Conclusion: Blue-light radiance from diagnostic displays measured well below the recommended values for occupational safety. Hence, blue-light exposure from diagnostic monitors does not significantly add to the occupational health burden of radiologists.

Contribution: Despite spending long hours in front of diagnostic monitors, radiologists' exposure to effective blue-light radiance from monitors was far below hazardous values. This suggests that blue-light exposure from diagnostic monitors does not increase the occupational health burden of radiologists.

Isosexual precocious puberty with ovarian masses in long-standing juvenile hypothyroidism is well described in the literature as Van Wyk Grumbach syndrome (VWGS). The present case reports this rare entity in a 4-year-old girl who was referred for imaging to evaluate the cause of non-traumatic bleeding per vagina. Antecedent history, clinical features and thyroid function tests were consistent with long-standing juvenile hypothyroidism with documented clinical response to thyroxine replacement therapy.

Contribution: Typical clinical and radiological features of the syndrome are reported, which helps in the early diagnosis and management, henceforth avoiding the associated complications.

Congenital anatomical variations of the terminal aorta are rare. Given the increasing number of endovascular and laparoscopic procedures, such variations are likely to assume greater clinical significance. A 15-year-old male sustained a pelvic vascular injury following a stab to the left gluteus. Computed tomographic angiography and digital subtraction angiography demonstrated a left superior gluteal artery pseudoaneurysm and absence of the common iliac arteries consistent with congenital quadrifurcation of the terminal aorta. The patient was subsequently treated with endovascular coil embolisation with a good angiographic and clinical outcome.

Contribution: Terminal aortic variants are rare and given the increasing number of interventional endovascular procedures performed in the aorta, an awareness of the potential anatomical configurations of the distal aortic branches is of increasing relevance. The authors describe the imaging findings of one such anatomical variant.

Background: Worldwide, intracranial aneurysms are associated with a high mortality rate. While endovascular management has proven to be the choice of treatment in selected patients, patient demographics and aneurysm characteristics differ between study populations.

Objectives: This study aimed to investigate the profile of patients with intracranial aneurysms who underwent endovascular management in the Interventional Neuroradiology Unit at Chris Hani Baragwanath Academic Hospital. Patient demographics, risk factors, indications, aneurysm characteristics and intra-operative complications were studied.

Method: This was a 3-year retrospective study of all adult patients between 01 January 2018 and 31 January 2021. The Chi-square test was used to compare categorical variables.

Results: A total of 77 patients were included in this study. The mean age of the patients was 47 ± 11.6 with a male-to-female ratio of 1:1.8. Hypertension was the most reported risk factor in 27% of patients. There was no statistical correlation between the gender groups according to presentation, multiplicity, aneurysmal size dimensions and locations. According to the presentation, there was statistical significance in ruptured intracranial aneurysms (p = 0.020), neck size dimensions less than 4 mm (p = 0.010), and aneurysms located in the internal cerebral artery (ICA) circulation (p = 0.001).

Conclusion: The study findings support known parameters including females and anterior circulation aneurysm preponderance, and the low complication risk of endovascular management. Interestingly, intracranial aneurysms presented with rupture at smaller size dimensions.

Contribution: This study provides valuable insights into intracranial aneurysm characteristics and endovascular management efficacy in a resource-limited setting.