Adjustments of iodinated contrast media using lean body weight for abdominopelvic computed tomography: A systematic review and meta-analysis.

PURPOSE: This systematic review aimed to compare the effect of contrast media (CM) dose adjustment based on lean body weight (LBW) method versus other calculation protocols for abdominopelvic CT examinations. METHOD: Studies published from 2002 onwards were systematically searched in June 2024 across Medline, Embase, CINAHL, Cochrane CENTRAL, Web of Science, Google Scholar and four other grey literature sources, with no language limit. Randomised controlled trials (RCT) and quasi-RCT of abdominopelvic or abdominal CT examinations in adults with contrast media injection for oncological and acute diseases were included. The comparators were other contrast dose calculation methods such as total body weight (TBW), fixed volume (FV), body surface area (BSA), and blood volume. The main outcomes considered were liver and aortic enhancement. Titles, abstracts and full texts were independently screened by two reviewers. RESULTS: Eight studies were included from a total of 2029 articles identified. Liver parenchyma and aorta contrast enhancement did not significantly differ between LBW and TBW protocols (p = 0.07, p = 0.06, respectively). However, the meta-analysis revealed significantly lower contrast volume injected with LBW protocol when compared to TBW protocol (p = 0.003). No statistical differences were found for contrast enhancement and contrast volume between LBW and the other strategies. CONCLUSION: Calculation of the CM dosage based on LBW allows a reduction in the injected volume for abdominopelvic CT examination, ensuring the same image quality in terms of contrast enhancement.

Gated cardiac CT in infants: What can we expect from deep learning image reconstruction algorithm?

BACKGROUND: ECG-gated cardiac CT is now widely used in infants with congenital heart disease (CHD). Deep Learning Image Reconstruction (DLIR) could improve image quality while minimizing the radiation dose. OBJECTIVES: To define the potential dose reduction using DLIR with an anthropomorphic phantom. METHOD: An anthropomorphic pediatric phantom was scanned with an ECG-gated cardiac CT at four dose levels. Images were reconstructed with an iterative and a deep-learning reconstruction algorithm (ASIR-V and DLIR). Detectability of high-contrast vessels were computed using a mathematical observer. Discrimination between two vessels was assessed by measuring the CT spatial resolution. The potential dose reduction while keeping a similar level of image quality was assessed. RESULTS: DLIR-H enhances detectability by 2.4% and discrimination performances by 20.9% in comparison with ASIR-V 50. To maintain a similar level of detection, the dose could be reduced by 64% using high-strength DLIR in comparison with ASIR-V50. CONCLUSION: DLIR offers the potential for a substantial dose reduction while preserving image quality compared to ASIR-V.

Plain radiography has a role to play in current clinical practice in Western Switzerland.

AIM: The aim of the study was to investigate the current role of conventional radiography examinations in Western Switzerland and the main clinical indications required to justify the use of this imaging examination. METHODS: Ethical approval was obtained from Vaud Ethics committee (Ref 2020-00311). An online questionnaire was specifically designed and implemented on the data collection tool LimeSurvey composed of two parts: a) to characterise the participants' profile and their institutions and b) 169 projections for the different anatomical area (upper and lower limbs, pelvis, skull, spine, thorax, abdomen) were presented to collect data about the frequency and main clinical indications. Statistical analysis was performed using the software IBM SPSS® (Statistical Package for the Social Sciences) version 26. RESULTS: Radiographers from 60% (26/43) of the invited institutions participated in this survey, mainly from Vaud region. The upper and lower limbs were the most commonly examined by using conventional radiography mainly for trauma and degenerative disorders. The thorax was also an anatomical area commonly explored by X-rays, so were the spine (cervical and lumbar lateral). The skull radiographs were rarely performed in clinical practice and some of the projections were not being used, namely Hirtz, Tangential Nose Bones, Worms and Caldwell's views. CONCLUSIONS: Plain radiography is being used in clinical practice mainly for appendicular skeleton studies and for trauma and degenerative pathologies. Adaptations in radiographers' education and training and other healthcare professionals are needed to provide the judicious use of data that radiographs can give to better manage the patients' imaging pathway.

The combination of non-contrast abbreviated MRI and alpha foetoprotein has high performance for hepatocellular carcinoma screening.

OBJECTIVES: This study aimed to compare two abbreviated MRI (AMRI) protocols to complete MRI for HCC detection: non-contrast (NC)-AMRI without/with alpha foetoprotein (AFP) and dynamic contrast-enhanced (Dyn)-AMRI. METHODS: This retrospective single-center study included 351 patients (M/F: 264/87, mean age: 57y) with chronic liver disease, who underwent MRI for HCC surveillance between 2014 and 2020. Two reconstructed AMRI sets were obtained based on complete MRI: NC-AMRI (T2-weighted imaging (WI) + diffusion-WI) and Dyn-AMRI (T2-WI + dynamic T1-WI) and were assessed by 2 radiologists who reported all suspicious lesions, using LI-RADS/adapted LI-RADS classification. The reference standard was based on all available patient data. Inter-reader agreement was assessed and MRI diagnostic performance was compared to the reference standard. RESULTS: The reference standard demonstrated 83/351 HCC-positive patients (prevalence: 23.6%, median size: 22 mm, and positive MRIs: 83/631). Inter-reader agreement was substantial for all sets. Sensitivities of Dyn-AMRI and complete MRI (both 92.8%) were similar, higher than NC-AMRI (72.3%, p < 0.001). Specificities were not different between sets. NC-AMRI + AFP (92.8%) had similar sensitivity to Dyn-AMRI and complete MRI. In patients with small size HCCs (≤ 2 cm), sensitivities of Dyn-AMRI (85.3%) and complete MRI (88.2%) remained similar (p = 0.564), also outperforming NC-AMRI (52.9%, p < 0.05). NC-AMRI + AFP had similar sensitivity (88.2%) to Dyn-AMRI and complete MRI (p = 0.706 and p = 1, respectively). CONCLUSIONS: Dyn-AMRI has similar diagnostic performance to complete MRI for HCC detection, while both outperform NC-AMRI, especially for small size HCCs. NC-AMRI + AFP demonstrates similar sensitivity to Dyn-AMRI and complete MRI. CLINICAL RELEVANCE STATEMENT: Due to the low sensitivity of ultrasound for hepatocellular screening, new screening methods are needed. Abbreviated MRI (AMRI) is a candidate, especially non-contrast AMRI with serum alpha foetoprotein as the acquisition time is low, without the need for contrast medium injection. KEY POINTS: • Dynamic contrast-enhanced abbreviated MRI using extracellular gadolinium-based contrast agent and complete MRI have similar diagnostic performance for hepatocellular carcinoma detection in an at-risk population. • Non-contrast abbreviated MRI with alpha foetoprotein has similar diagnostic performance to dynamic contrast-enhanced abbreviated MRI and complete MRI, including when considering small size hepatocellular carcinoma ≤ 2 cm. • Non-contrast abbreviated MRI and dynamic contrast-enhanced abbreviated MRI can be performed in 7 and 10 min, excluding patient setup time.