The Great Contrast Shortage of 2022-Lessons learnt in Australia.

INTRODUCTION: Computed tomography (CT) imaging is one of the most commonly used diagnostic tools. Iodine-based contrast media (IBCM) are frequently administered intravenously to improve soft tissue contrast in a wide range of CT scans. Supply chain disruptions triggered by the SARS-CoV-19 pandemic led to a global shortage of IBCM in mid-2022. The purpose of this study was to explore the impact of this shortage on the delivery of healthcare in Western Australia. METHODS: We performed a single-centre retrospective analysis of the provision of CT studies, comparing historical patterns to the shortage period. We focussed our attention on the total number of CT scans (noncontrast CT [NCCT] and contrast-enhanced CT [CECT]) and also specifically CT pulmonary angiogram (CTPA) and CT neck angiogram with or without inclusion of circle of Willis (CTNA) examinations. We also examined whether a decrease was compensated by increasing frequency of alternate examinations such as ventilation/perfusion (V/Q) scans, carotid Doppler ultrasound studies and Magnetic Resonance Angiograms (MRAs). RESULTS: Since 2012, there has been an approximate linear increase in the frequency of CT examinations. During the period of contrast shortage, there was an abrupt drop-off by approximately 50% in the CECT, CTPA and CTNA groups compared with the preceding 6 weeks (49%, 55% and 44%, respectively, with P < 0.001 in all cases). During the contrast shortage, the frequency of V/Q scans increased fivefold (from 13 to 65; P < 0.001). However, the provision of carotid Doppler ultrasound studies and MRAs remained approximately stable in frequency across recent time intervals. CONCLUSION: Our findings demonstrate that the IBCM shortage crisis had a very significant impact on the delivery of healthcare. While V/Q scans could (partially) substitute for CTPA studies in suspected pulmonary emboli, there appeared to be no valid alternative for CTNA studies in stroke calls. The unexpected and critical shortage of IBCM forced healthcare professionals to conserve resources, prioritise indications, triage patients based on risk, explore alternate imaging strategies and prepare for similar events recurring in the future.

The emerging association between bronchiectasis and systemic sclerosis: assessing prevalence and potential causality.

BACKGROUND: Bronchiectasis has been observed in association with systemic sclerosis (SSc). Theorised aetiology includes aspiration related to oesophageal dysmotility, immunosuppressant medication use and the direct effect of collagen deposition on airway calibre. AIMS: To detail bronchiectasis prevalence in an SSc population who have had a high-resolution computed tomography (HRCT) of the thorax. We assessed whether oesophageal dysmotility, demographic variables, SSc duration or subclass were associated with bronchiectasis. METHODS: Participants in the Australian Scleroderma Cohort Study (ASCS) with a HRCT were included. The ASCS provided demographic and clinical data. HRCT studies were reviewed for bronchiectasis, oesophageal dilatation and interstitial lung disease (ILD). Traction bronchiectasis associated with ILD was recorded as a separate entity to bronchiectasis. Oesophageal dysmotility was defined by symptoms and/or oesophageal dilatation. RESULTS: Of the 256 participants, 16.4% (n = 42) had bronchiectasis. Logistic regression analysis revealed no significant association between bronchiectasis and oesophageal dysmotility (observed in 95.7%), any demographic variable, SSc duration or subclass. A negative association between bronchiectasis and ILD was observed (P = 0.009; odds ratio 0.322; 95% confidence intervals 0.137-0.756). CONCLUSION: Those with SSc appear to have an increased risk for bronchiectasis. Since bronchiectasis was not more frequent in participants with a longer duration of SSc, we hypothesise that its development is not related to immunosuppression alone. Oesophageal dysmotility was almost universal in our population such that its effect on bronchiectasis development could not be concluded. A negative association between bronchiectasis and ILD reflects that bronchiectasis occurring alongside ILD was recorded as a separate entity.

Low volume contrast CTPA in patients with renal dysfunction.

INTRODUCTION: The study aims to evaluate a method for and technical feasibility of performing CT pulmonary angiography (CTPA) with just 30 mL of contrast. METHODS: Twenty-four patients with renal dysfunction suspected of having pulmonary embolus underwent CTPA using 30 mL of contrast. A modified acquisition protocol was employed where sequential monitoring of the central superior vena cava (SVC) was performed following injection of contrast. Scanning was triggered at the first visualised arrival of contrast within the SVC. Hounsfield unit (HU) measurements were performed at the main pulmonary artery to the subsegmental branches to determine the adequacy of each study. RESULTS: The level of pulmonary arterial enhancement achieved was high, averaging 247 HU across all measured arteries. Average enhancement within more peripheral lobar, segmental and subsegmental arteries was also greater than 200. Only one study was considered non-diagnostic. CONCLUSION: Low-volume CTPA is technically feasible and provides excellent enhancement of the pulmonary arterial tree.