British Journal of Radiology最新文献

Objectives: Assessment of patient dose is a critical quality assurance check towards ensuring it is kept as low as reasonably practicable. One metric used to evaluate this is Entrance Surface Dose (ESD)- the summed magnitudes of the incident radiation and Compton scatter resulting from photon interactions within tissue. ESD can be directly measured using a dosemeter that is sensitive to backscattered radiation. However, the increasing use of solid-state detectors such as the tin backed RaySafe X2 R/F detector, means that ESD cannot be directly measured. The IAEA Technical Report No.457, recommends using backscatter factors (BSF) as calculated by Petoussi-Henss et al in1998 via Monte Carlo methods when measuring ESD using such dosemeters. This research seeks to practically determine a reliable method of calculating the BSF using a PMMA patient-equivalent phantom.

Methods: A comparison between the solid-state detector and an ionisation chamber capable of detecting backscatter was conducted. Special attention was given to BSF variation with both radiation field size and beam quality by varying additional copper and aluminium filtration to mimic the behaviour of patient-dose reducing techniques on modern fluoroscopy systems.

Results: Results have shown significant correspondence with those of Petoussi-Henss et al using the simulated water and ICRU tissue equivalent phantoms.

Conclusions: Given the results consistency, BSFs from this study have been proposed for use when measuring ESD using the RaySafe solid state detector with a PMMA patient-equivalent phantom for quality assurance purposes.

Advances in knowledge: This research provides the opportunity to obtain more accurate patient dose data during quality assurance testing with modern solid-state dosemeters.

Adrenal infections are considered clinically important but often go unrecognized, with a significant number of cases only diagnosed post-mortem. The limited evidence regarding imaging findings in the literature emphasizes the need to detect and diagnose these infections early in disease course to improve patient outcomes. A range of microorganisms, including fungi, viruses, parasites, and bacteria, can directly or indirectly affect the morphology and function of the adrenal glands. When evaluating a patient with adrenal infection, several immunological and hormonal factors should be considered, such as the status of the hypothalamic-pituitary-adreno cortical axis and the serum cortisol level. Moreover, certain microorganisms specifically target one of the zones of the adrenal glands or vascular supply, resulting in distinct imaging manifestations. The purpose of this article is to describe the fundamental clinical features and imaging manifestations associated with adrenal infections, enabling radiologists to make informed interpretations and contribute to accurate diagnostic assessments.

Objectives: To evaluate the diagnostic accuracy of 18F-FDG PET or PET/CT in detecting histological transformation (HT) of indolent lymphomas.

Methods: A systematic search of articles up to July 2024 was performed in Embase and Medline. Eligible studies included adults with histologically proven indolent lymphoma, 18F-FDG PET or PET/CT as the index test, and sufficient data to assess diagnostic performance. Summary receiver operating characteristic curves were plotted using a bivariate model to estimate diagnostic accuracy with area under the curve (AUC).

Results: Fifteen studies with 1,307 participants were included. Ten studies assessed PET ability to detect Richter's transformation, and 5 studies focussed on HT in follicular lymphoma and other subtypes. A meta-analysis of the former showed pooled sensitivity of 0.90 (95% CI, 0.84-0.93) and specificity of 0.54 (95% CI, 0.28-0.77) when using a SUVmax threshold of around 5. AUC was 0.89. Pooled sensitivity was 0.74 (95% CI, 0.54-0.87) and specificity was 0.84 (95% CI, 0.67-0.93) when using a SUVmax threshold of around 10. AUC was 0.84. For detecting HT in follicular lymphoma, thresholds were found higher than those for Richter's transformation.

Conclusions: 18F-FDG PET or PET/CT demonstrates good diagnostic accuracy to detect Richter's transformation, best when employing SUVmax ≥ 5. SUVmax thresholds may be limited in discriminating follicular lymphoma from HT, and alternatives should be sought.

Advances in knowledge: If biopsy is feasible, SUVmax ≥ 5 can guide biopsy in patients with clinically suspicious Richter's transformation. If biopsy is infeasible, SUVmax ≥ 10 can better identify HT and guide patient management.

With a focus on imaging, this narrative review describes why biomarker research rarely culminates in anything clinically useful. We explain the difference between diagnostic and prognostic biomarkers and the different phases of their research. We describe what factors need consideration when designing research studies to generate evidence sufficient to translate a potential imaging biomarker into clinical practice. We emphasise the need to balance the number of biomarkers investigated with the number of available patient events, so that studies are not overwhelmed by false-positive results. We explain the need for rigorous evaluation, so that clinicians can be convinced the biomarker will work in their practice and benefit their patients. In particular, we explain why novel biomarkers should be evaluated alongside factors already known to be clinically useful, so that their incremental benefit, if any, can be determined.

Solitary plasmacytoma and multiple myeloma are plasma cell dyscrasias that typically present as bone tumour(s) due to abnormal and unregulated proliferation of plasma cells in the skeletal marrow. Both can manifest as soft tissue lesions within the head and neck region, and they may pose a diagnostic challenge given their relative rarity. This review aims to highlight the key multimodality imaging features of plasma cell neoplasms with an emphasis on extraosseous/extramedullary presentations in the anatomically complex head and neck region, as well as the relevant anatomy of various head and neck subsites and the main differential diagnoses that the radiologist should consider. Familiarity with these entities is crucial and will help the radiologist facilitate the timely diagnosis of plasma cell neoplasia using the arsenal of increasingly available and sensitive imaging techniques.

Lymphedema is a common complication of cancer treatment, leading to significant morbidity. Early and accurate diagnosis through the combined expertise of radiology and nuclear medicine is crucial for preventing lymphedema progression and improving patient outcomes. Imaging techniques such as lymphoscintigraphy, duplex ultrasound, MRI, and CT as well as newer modalities including near-infrared lymphangiography can diagnose and assess lymphedema severity. Bioimpedance spectroscopy (BIS) provides a non-invasive tool for early detection by measuring extracellular fluid changes, aiding in identifying lymphedema at its earliest stages. Pretreatment baseline measurements and prospective surveillance models (PSMs) are essential for tracking limb volume changes and mobility, enhancing early intervention outcomes. Recognizing the strengths and limitations of each imaging modality allows radiologists and nuclear medicine physicians to synergistically optimize lymphedema diagnosis and management. Effective management relies on multidisciplinary collaboration and includes conservative and surgical options tailored to disease severity. Advanced imaging modalities are pivotal for planning and monitoring interventional strategies. This review explores the development and management of secondary lymphedema in oncological patients, focusing chiefly on imaging and treatment strategies. It also briefly highlights the evolving role of artificial intelligence and machine learning in enhancing imaging precision and treatment outcomes.

Objectives: The objective of this study was to investigate the association of radiological sarcopenia and frailty with postoperative outcomes in adult patients undergoing oncological surgery.

Methods: Data were derived from the PICNIC study, consisting of two consecutive series of patients undergoing surgical cancer treatment. Radiological sarcopenia was assessed based on CT imaging. Presence of low muscle mass and/or low muscle density were determined based on lowest quartile gender specific cut-off values. Frailty was defined by a score of ≥ 4 on the Groningen Frailty Index. Postoperative overall survival was analysed with Kaplan-Meier curves and Logrank testing. Multivariable Cox regression analyses adjusted for age and gender were performed to calculate adjusted hazard ratios (HR).

Results: A total of 372 patients were included. Median age was 69 (28-86) years, 77 patients (23.5%) were frail and radiological sarcopenia was present in 134 patients (41.0%). Combined radiological sarcopenia and frailty was present in 35 patients (10.7%). One year (65.6% versus 87.0%) and three-year survival (31.4% versus 66.8%) were significantly worse in patients with combined radiological sarcopenia and frailty. The combined presence of radiological sarcopenia and frailty was associated with significantly decreased overall survival (HRadjusted : 2.06, 95-CI : 1.39-3.05, P < 0.001).

Conclusion: Co-occurrence of radiological sarcopenia and frailty is strongly related to impaired survival in surgical cancer patients.

Advantages in knowledge: Combined presence of radiological sarcopenia and frailty is associated with decreased postoperative survival, strongly exceeding the effects of both risk factors separately. The use of radiological sarcopenia in addition to frailty screening can further optimize preoperative risk stratification.

A multitude of drugs are used for the treatment of various types of cancers. They consist of conventional cytotoxic agents and newer targeted agents. Both types of agents produce a variety of side effects by their effect on normal cells of the body. Regardless of whether they produce any symptoms or not, a proportion of these side effects can be visualised on imaging and their identification is crucial for guiding further management. While some of the adverse effects are mild and tolerable, many others require dose reduction and even withdrawal of the drug. A few of these manifestations may resemble tumour progression or recurrence on imaging. Therefore, appropriate knowledge regarding the imaging manifestations of the adverse effects caused by the chemotherapeutic agents used for various types of cancers is an integral part of onco-radiology practice. In this review, the common adverse effects of various anti-cancer drugs have been described based on the type of malignancy in which they occur, rather than based on the organ affected. This would allow the radiologist to look for common side effects while reading the scan of a patient with a specific cancer.

Objectives: To develop and validate the myocardial extracellular volume (ECV) obtained from non-electrocardiography (ECG)-gated delayed CT images acquired 4 minutes post-contrast infusion (4-min-nonECG-ECV) compared with the ECV obtained from ECG-gated delayed CT images acquired 10 min post-contrast infusion (Conv-ECV).

Methods: We retrospectively analysed 29 patients (males: 21) after a comprehensive CT protocol of both 4-min-nonECG-ECV and Conv-ECV on a dual-layer CT scanner. The mean volume of contrast medium administered: 90 ± 11.8 mL, the average heart rate during the CT examinations: 74.2 ± 18.2 bpm. Two independent observers calculated the respective 4-min-nonECG-ECV and Conv-ECV. We determined the correlation between the ECV obtained by the two methods and conducted a Bland-Altman analysis to identify systematic errors and determine the limits of agreement (LOA) between the 4-min-nonECG-ECV and Conv-ECV values.

Results: The respective median ECV values for observer 1 were 27.3 for 4-min-nonECG-ECV and 26.5 for Conv-ECV; for observer 2, they were 27.8 and 27.1. The correlation between the methods was 0.97 for both observers (p < 0.01). The Bland-Altman plots for observers 1 and 2 demonstrated a minor bias (-0.2% and -0.5%, respectively), with the 95% LOA ranges at - 4.4%-4.0% and -5.0%-4.0%, respectively.

Conclusion: The 4-min-nonECG-ECV provided ECV values comparable to those obtained by Conv-ECV.

Advances in knowledge: Myocardial ECV quantification is feasible using a non-gated, 4-minute delayed dual-energy CT scan with an already established CT acquisition method. This approach achieves ECV accuracy comparable to that of the conventional CT-ECV calculation method (gated 10-minute delayed imaging) while enhancing clinical efficacy and diagnostic throughput.

Objective: Gallbladder polyps (GBPs) are commonly detected with trans-abdominal ultrasound (TAUS). Gallbladder cancer (GBC) is associated with GBPs but the risk of malignancy is low. International guidelines recommend ultrasound surveillance (USS) in selected cases of GBPs <10mm, with cholecystectomy advised if polyp size increases. USS (including potential surgeries) is resource intense. We evaluated the costs and potential cost-effectiveness of USS in a theoretical UK patient cohort with GBPs.

Methods: A health economic model mapped expected management pathways over 2-years for 1,000 GBP patients with and without USS, stratified by initial size of GBP (<6mm and 6-9mm). We estimated USS resource and costs under alternate thresholds for surgery. Clinical data were extracted from a large-scale cohort study. TAUS and surgery costs were based on NHS tariffs. GBC costs were estimated from the literature. Outcomes included USS costs, expected numbers of GBC and incremental cost for each case of GBC avoided.

Results: The 2-year additional cohort costs of USS (n=number of additional surgeries) were estimated between £213,441 (n = 50) and £750,045 (n = 253) in GBPs <6mm, and between £420,275 (n = 165) and £531,297 (n = 207) in GBPs 6-9mm, balanced against avoidance of 1.3 (<6mm) and 8.7 (6-9mm) cases of GBC. Model findings were robust to plausible changes in inputs.

Conclusions: Using published data, we demonstrated that, in patients with GBPs <10mm, the costs of USS to avoid GBC outweigh potential GBC cost offsets, and would result in high rates of cholecystectomy. Additional evidence is needed to establish the formal cost-effectiveness of GBP USS in the UK.