British Journal of Radiology最新文献

Objectives: To measure fat mass (FM) and fat-free mass (FFM) in the limbs and abdomen using whole-body DXA and compare them with whole-body CT, emphasizing precise regional comparisons to demonstrate the correlation between the methods.

Methods: Fifty-eight healthy adults (aged 20-69) who underwent both whole-body DXA and whole-body CT were included in this study. The CT scans included the entire body except the head, and image segmentation was employed for body composition analysis. Total limb FM, FFM, segmental abdominal FM, and visceral adipose tissue (VAT) were measured from both DXA and CT.

Results: The DXA-derived total limb FM and segmental abdominal FM were significantly lower than the CT-derived FM, whereas the DXA-derived total limb FFM was higher than the CT-derived FFM (p < 0.001). Despite these differences, very strong positive correlations were observed between DXA and CT for total limb FM (r = 0.951), total limb FFM (r = 0.992), and segmental abdominal FM (r = 0.984) (p < 0.001). The correlation for VAT was also strong (r = 0.861) (p < 0.001).

Conclusions: Our study demonstrated very strong correlation in direct regional comparisons between whole-body DXA and CT, supporting the reliability of DXA for analysing FM and FFM in the limbs and abdomen.

Advances in knowledge: We compared FM and FFM in the limbs and abdomen between whole-body DXA and CT through a region-by-region comparison, demonstrating a more direct correlation between the two methods.

Quantitative computed tomography (CT) enables the measurement of biophysical processes characterized by morphology, composition, flow and/or motion to aid in clinical diagnosis and intervention. Since its initial application for determining bone mineral density for skeletal fragility assessment, quantitative CT has continued to evolve alongside CT's technological advancements. A key challenge facing quantitative CT is the lack of standardization pertinent to image acquisition, reconstruction and image analysis. With the introduction of spectral CT involving dual-energy approaches and photon-counting detectors (PCD), we are now able to obtain detailed information regarding mass densities of endogenous and exogeneous materials. Further, energy-resolved CT yields spectral image types (e.g. virtual monoenergetic image) that are, in principle, independent of tube potential and patient size. This paves the way for workflow standardization and to improve the consistency and reproducibility of CT-derived measurements. In this article, we review clinical applications of quantitative CT, discuss key challenges associated with quantitative CT and its adoption into routine practice, and outline the unique benefits ushered by new CT technologies such as PCD-CT towards improving quantitative imaging.

The U.S. Supreme Court Dobbs decision has significantly impacted reproductive healthcare in the USA. While obstetricians are most directly affected, radiologists, radiation oncologists, and medical imaging professionals are also involved in the care of pregnant patients, and these legislative changes can alter our practices. In this commentary, we describe examples of how this reproductive legal landscape has changed the practice of interventional radiology in states affected by abortion bans, discuss some of the radiologist lead advocacy efforts for the preservation of reproductive healthcare, and review the Society of Radiologists in Ultrasound's first trimester ultrasound consensus statement clarifying and standardizing medical terminology frequently used in radiologist reports. The radiology community has a responsibility to advocate for the preservation of reproductive health and the patient-physician relationship.

Objectives: Trauma in the Elderly is associated with high mortality. Elderly people who have suffered low impact trauma, such as fall from standing (FFS) are believed still to be at high risk of injury. Whole-body trauma CT (WBCT) is increasingly used to image such people, to prevent missing injuries which are not detected clinically. This study aims to assess the utility of WBCT in assessing elderly people who have suffered FFS.

Methods: Over a two-year period in a single health board, data was collected retrospectively for all patients that underwent WBCT. Data was collected on the mechanism, pattern of injury and outcomes including 30-day mortality using clinical records. Comparison was made between pre-CT clinical suspicion and injury found on WBCT to identify discrepancies.

Results: In total 460 patients were included in this study. Compared with FFS, fall from more than standing was associated with higher adjusted odds of having an injury out with zone of clinical suspicion (AOR 2.80 95%CI 1.23-7.28 p = 0.021). There was no significant difference in 30-day mortality between patients who had an injury on WBCT and those without.

Conclusions: FFS is associated with a reduced risk of injury out with areas of clinical concern when compared with fall from greater than standing. As such, a targeted approach to CT scanning in these patients could be considered.

Advances in knowledge: This study challenges the current prevailing dogma for the requirement of WBCT in elderly people who suffer FFS, providing evidence that such people have a low risk of injuries out with areas of clinical suspicion.

Objectives: To assess quantitative and qualitative image characteristics in phantoms and patients using a simultaneous ultra-high resolution (UHR) and multi-energy (ME) dual-source cardiac scan mode in a photon counting detector (PCD) CT scanner.

Methods: UHR-ME cardiac scans were performed to determine the spatial resolution and multi-energy performance. UHR reconstructions were completed to measure transverse and axial spatial resolution in terms of modulation transfer function (MTF) and slice sensitivity profile (SSP). Virtual monoenergetic images (VMIs), virtual non-contrast (VNC) images, and iodine concentration images were created using moderately sharp reconstruction kernels to assess ME performance. With IRB approval, coronary CT angiograms were acquired in 19 patients using the UHR-ME mode, from which iodine contrast-to-noise ratio (CNR) was measured. Various ME post-processing tasks were performed to show the utility of the spectral capabilities.

Results: VMIs showed a mean CT number error of 5.9%, while iodine accuracy was 0.75 mg/cc (root-mean-square-error). Spatial resolution matched well with a standard UHR mode. Patient images showed a trend of higher CNR at lower keV, while higher keV images showed decreased calcium blooming. ME techniques to separate iodine and calcium were used successfully.

Conclusions: The combination of UHR-ME cardiac mode retains UHR image quality while providing flexibility for ME post-processing.

Advances in knowledge: Cardiac UHR-ME scanning offers simultaneous ultra-high-resolution and ME imaging without loss of spatial or temporal resolution or quantitative accuracy.

Objectives: To investigate the impacts of a deep learning-based iterative reconstruction algorithm on image quality and measuring accuracy of bone mineral density (BMD) in low dose chest CT.

Methods: Phantom and patient studies were separately conducted in this study. The same low dose protocol was used for phantoms and patients. All images were reconstructed with filter back projection, hybrid iterative reconstruction (KARL, level of 3,5,7), and deep learning-based iterative reconstruction (AIIR, low, medium and high-strength). The noise power spectrum (NPS) and the task-based transfer function (TTF) were evaluated using phantom. The accuracy and the relative error (RE) of BMD were evaluated using a European spine phantom. The subjective evaluation was performed by two experienced radiologists. BMD was measured using QCT. Image noise, signal-to-noise ratio, contrast-to-noise ratio, BMD values and subjective scores were compared with Wilcoxon signed-rank test. The Cohen's kappa test was used to evaluate the inter-reader and inter-group agreement.

Results: AIIR reduced noise and improved resolution in phantom images significantly. There were no significant differences among BMD values in all groups of images (all p > 0.05). RE of BMD measured with AIIR images were smaller. In objective evaluation, all strengths of AIIR achieved less image noise, higher SNR and CNR (all p < 0.05). AIIR-H showed the lowest noise, highest SNR and CNR (p < 0.05). The increase of AIIR algorithm strengths did not affect BMD values significantly (all p > 0.05).

Conclusion: The deep learning-based iterative reconstruction did not affect the accuracy of BMD measurement with Low-dose chest CT, while reducing image noise and improving spatial resolution.

Advances in knowledge: The BMD values could be measured accurately in low-dose chest CT with deep learning-based iterative reconstruction, while reducing image noise and improving spatial resolution.

To fully exploit the prospects presented by the increasing focus on biological approaches for enhancing radiotherapy outcomes, improvements in repeatability and translatability of radiobiological and preclinical studies are required. This requires the development and adoption of appropriate dosimetric standards and reproducible approaches to increase confidence in the studies, enabling inter-laboratory validation and facilitating clinical translation. An IPEM Working-Party reviewed the current status and challenges associated with dosimetry of medium-energy X-rays and make recommendations with the aim to optimize the potential clinical significance of radiobiological preclinical investigations. The paper discusses the currently available resources with technical recommendations for performing dosimetry in medium-energy X-rays, along with the consequences of lack of standardization and implications of dose inhomogeneity. It is clear that there is still a gap in understanding the needs for standardisation of dosimetric aspects of preclinical and radiobiological studies. It is recommended that these radiobiology studies should be conducted in partnership with medical/radiation physicists. This collaboration ensures the correct utilization of suitable dosimetry systems, thus guaranteeing accuracy and consistency of dose delivery. Appropriate calibration and traceability to national/international standards laboratory, along with regular quality assurance of radiation devices are paramount to reproducibility. Additionally, it is critical that experimental details and associated dosimetry are sufficiently reported to ensure accurate replication that enables reanalysis including evaluation of dose distributions. Increasing awareness among the researchers and the funding bodies was identified as a crucial step to improve translatability and appropriate resources are budgeted to increase the value for money of research proposals. Advances in knowledge: The proposed recommendations will serve as a vital resource for researchers, encouraging uniformity in experimental design and improving the translatability of preclinical research to clinical settings.

Objectives: This technical report describes a method for template selection in atlas-based segmentation (ABS) for breast cancer that uses breast volume and nipple position.

Methods: Fifty patients who underwent postoperative radiotherapy (RT) after breast-conserving surgery were included. An experienced radiation oncologist manually segmented the bilateral breasts and recorded parameters including breast volume and nipple position. Nipple position was defined as the vertical distance from the midsternal skin to the nipple base on axial computed tomography. A radiation technologist subjectively selected eight patients as templates and generated an ABS using each template for the remaining 49 cases (392 template-case pairs, 784 breast pairs). The Dice similarity coefficient (DSC) was used to assess the agreement between ABS and manual segmentation. Both breasts were evaluated simultaneously without consideration of the differences between the ipsilateral and contralateral operated sides. The Mann-Whitney U-test and Kruskal-Wallis test were used to compare DSC values among groups based on breast parameters.

Results: Breast volume (P < 0.001) and nipple position (P < 0.001) were significant parameters for template selection in the 784 breast pairs. Selecting templates with breast volumes that were half to double those of the test case while maintaining the dorsal nipple position relative to the test case resulted in a median DSC of 0.88.

Conclusions: Breast volume and nipple position are valuable parameters that can improve template selection in ABS for breast cancer.

Advances in knowledge: We developed a new nipple position measure to enhance ABS in breast cancer RT planning.

Objectives: To evaluate the evolution and current diagnostic capabilities of medical imaging in cancer of unknown primary (CUP) and explore promising technologies for enhancing diagnostic precision.

Methods: A comprehensive literature search was conducted across MEDLINE, Embase, and Scopus in March 2023 (updated in August 2024) to identify original articles focusing on CUP imaging. Two reviewers independently selected articles and extracted data. Quality assessment was performed using QUADAS-2 and Radiomics Quality Score. Given the variability in study designs, imaging techniques, and reported outcomes, a narrative synthesis was performed. Subgroup analyses compared detection rates across modalities.

Results: From 4760 de-duplicated search results, 140 original articles were included. Early CUP imaging relied on two-dimensional modalities with notable diagnostic limitations. Modern three-dimensional modalities have risen in prominence, though mammography and ultrasound remain in CUP guidelines. Implementing CT and MRI significantly improved primary tumor detection and disease characterization. CT is fundamental for CUP evaluation, and MRI offers superior soft tissue resolution, effective for detecting occult breast cancer, head and neck primaries, and suspected abdominopelvic neoplasms. FDG-PET/CT showed varying primary detection capabilities, adding value in identifying lesions/metastases missed by other modalities, essential for confirming locoregional treatment strategies. Emerging technologies for CUP imaging include whole-body MRI, FAPI-PET/CT, and AI/radiomics.

Conclusions: Advancements in imaging have improved the diagnostic workup for CUP. Innovative approaches show potential for further improvement in diagnostic accuracy.

Advances in knowledge: This study provides a comprehensive overview of CUP imaging and introduces emerging modalities that could boost diagnostic accuracy.