SA Journal of Radiology最新文献

Heterotaxy syndrome, also known as situs ambiguous, is a spectrum of pathology due to loss of the normal right-to-left asymmetry of the thoraco-abdominal organs. This report describes the case of a 39-year-old female, previously well, who presented with bowel obstruction. CT showed features of left isomerism, with malrotation and volvulus.

Contribution: Heterotaxy syndrome consists of cardiac and non-cardiac manifestations. Imaging studies play a crucial role in the individualised management of the patient.

Leptomeningeal dissemination is a rare manifestation of pilocytic astrocytoma. It may occur with higher-grade tumours like medulloblastoma, ependymoma and high-grade glioma, but is extremely rare with low-grade glioma. There has been a growing number of reported cases documenting leptomeningeal dissemination of pilocytic astrocytoma in the medical literature.

Contribution: Description of a World Health Organization (WHO) Grade I suprasellar pilocytic astrocytoma with leptomeningeal dissemination in the brain and spinal cord which showed progression of the leptomeningeal nodules without tumour upgrading on long-term follow-up.

Vein of Galen aneurysmal malformation (VGAM) is a rare congenital malformation characterised by arteriovenous fistulas between primitive choroidal arteries and the median prosencephalic vein, the embryonic precursor to the vein of Galen. Endovascular techniques have changed the management of these patients with improved prognosis. An eight-month-old with VGAM managed by endovascular embolisation using ethylene vinyl alcohol copolymer (EVOH) developed a chemical abscess - a rare complication. It was managed conservatively and showed promising clinical outcome.

Contribution: Chemical abscesses following EVOH embolisation are scarce - with imaging differentials, which include brain abscess and onyx granuloma. Knowledge and successful identification of this entity are essential as its management as prognoses differ. Chemical abscess is managed conservatively and has a good prognosis.

Background: Diagnostic reference levels (DRLs) are an important metric in identifying abnormally high radiation doses in diagnostic examinations. National DRLs for CT colonography do not currently exist in South Africa, but there are efforts to collect data for a national DRL project.

Objectives: This study investigated radiation doses for CT colonography in adult patients at a large tertiary hospital in South Africa with the aim of setting local DRLs.

Method: Patient data from two CT scanners (Philips Ingenuity and Siemens Somatom go.Top) in the period March 2020 - March 2023 were obtained from the hospital's picture archiving and communication system (PACS) (n = 115). Analysis involved determining the median computed tomography dose index-volume (CTDI_vol) and dose-length product (DLP) values. The findings were compared with DRLs established internationally.

Results: Ingenuity median CTDI_vol was 20 mGy and DLP was 2169 mGy*cm; Somatom median CTDI_vol was 6 mGy and DLP was 557 mGy*cm. Ingenuity exceeded the United Kingdom's (UK) recommended DRLs by 82% and 214%, respectively. Somatom median CTDI_vol and DLP were 45% and 19% lower than UK NDRLs.

Conclusion: Somatom's tin filter and other dose reduction features provided significant dose reduction. These data were used to set DRLs for CT colonography at the hospital; CTDI_vol: 6 mGy and DLP: 557 mGy*cm.

Contribution: In addition to informing radiation protection practices at the level of the institution, the established local DRLs contribute towards implementing regional and national DRLs.

Rosai Dorfman disease is a rare but benign and self-limiting disorder. A case of Rosai Dorfman disease in a 16-year-old female with classic radiological and pathological findings is presented. T2W hypointense signal of the soft tissue masses was a distinguishing MRI feature.

Contribution: Rosai Dorfman disease is often overlooked in the differentials of lymphadenopathy and soft tissue masses on account of its rarity. This case report comprehensively discusses the imaging approach to this rare disorder.

The glenoid labrum deepens the glenoid fossa and allows for the attachment of the long head of the biceps tendon and the glenohumeral ligaments, contributing to the stability of the glenohumeral joint. The superior labrum is a common site of labral injury, especially in athletic activities involving overhead activity. The acronym SLAP (superior labrum anterior to posterior or anteroposterior) lesion was introduced by Snyder and colleagues in 1990 to describe superior labral tears. The article will review the optimal technique to image the glenoid labrum, covering normal labral anatomy with special emphasis on the anatomic variants of the labrum that can be mistaken for SLAP tears by means of colour illustrations, magnetic resonance imaging and correlative arthroscopy images.

Contribution: The illustrated review functions as a crucial radiological guide for both radiologists and orthopaedic surgeons. The combination of illustrations, MR and correlative arthroscopic images enhances the comprehension of normal labral anatomy and its variants. The review underscores the significance of understanding anatomic variations that may be misinterpreted as pathology. This understanding is vital in guiding orthopaedic management for patients, ensuring appropriate treatment strategies.

Frequent imaging manifestations of pulmonary tuberculosis are airspace or interstitial nodules with or without tree-in-bud nodules, consolidation, cavitation, ground glass opacity, miliary nodules, lymphadenopathy and pleural effusion. It is unusual to encounter cystic changes in patients with pulmonary tuberculosis, and these findings should be differentiated from other cystic lung diseases. This case series describes five cases of cystic lung disease in children with tuberculosis (TB) with illustrative chest radiography and CT findings.

Contribution: The manuscript highlights the need to consider tuberculosis as a possible cause of acquired cystic lung disease in appropriate clinical settings, particularly in endemic regions.

Calcinosis circumscripta involving the breasts usually hints at an underlying systemic cause, most commonly connective tissue disorders such as scleroderma or dermatomyositis. Localised scleroderma, also known as morphoea, is not usually associated with the systemic anomalies affecting the lungs and gastrointestinal system, but does manifest as calcified dermal and subdermal sclerotic plaques. Histological confirmation with skin biopsy is diagnostic.

Contribution: Recognition of the atypical, bizarre, linear dystrophic calcifications on mammography should direct appropriate systemic investigations.

Tubulocystic anomalies of the mesonephric duct (MND) are a rare group of related entities with a perplexing clinical presentation. Ultrasound is a useful screening investigation, which can help identify a dysplastic kidney or point to renal agenesis and identify cystic or tubulocystic changes in the structures derived from the ureteric bud or MND. Further evaluation with MRI can help in characterisation and direct management. The presence of a dysplastic kidney or absence of a kidney should prompt further evaluation for associated ureteric abnormalities such as ectopic insertion or ureterocoele, which could lead to a diagnosis of tubulocystic anomaly of the MND.

Contribution: The authors describe two cases, briefly outline the diagnostic approach and summarise the literature on management. Reporting radiologists should be aware of these entities.

Background: An MRI is potentially hazardous for patients with retained ferromagnetic bullets. Recent studies have aimed to develop dual-energy computed tomography (DECT) as a screening tool for recognising highly ferromagnetic bullets. Inconsistent findings have been ascribed to inherent CT technology differences. Previous research demonstrated significant Hounsfield unit (HU) measurement variation among single-source CT machines.

Objectives: This study investigated the theoretical dual-energy index (DEI) variation between DECT machines when evaluating the potential ferromagnetic properties within the same sample of ex vivo bullets and metal phantoms.

Method: An experimental ex vivo study was conducted on eight metal phantoms and 10 unused bullets individually positioned in the same Perspex head phantom and scanned on two DECT machines. Two senior radiology registrars independently recorded the HU readings, and DEI values were calculated. Statistical analysis was performed using non-parametric methods for paired data, namely the Signed Rank Test. The DEI values based on mean HU readings between the DECT machines were compared.

Results: Inter- and intra-reader agreement was not statistically significant. The metal phantoms had poor interscanner agreement, with an overlap of the ferromagnetic and non-ferromagnetic ranges. The bullets had good interscanner agreement, with a similar ferromagnetic to non-ferromagnetic relationship.

Conclusion: The use of DEI values negates the previous assumption that significant interscanner variability exists among different DECT technologies while assessing highly attenuative ex vivo bullets.

Contribution: This investigation demonstrated that even though HU readings may be variable, the implementation of the DEI equation translates this into comparable values with good interscanner agreement.