Acta radiologica open最新文献

⁶⁸Gallium-PSMA positron emission tomography/computer tomography has been utilized recently for the diagnosis and staging of prostate cancer. PSMA is a transmembrane protein that is expressed not only in the prostate gland but also in other tissues. While some pitfalls have been addressed, there are still uncertainties. Herein, we report a 79-year-old male with prostate cancer who underwent a PSMA scan after coronary artery bypass graft surgery, revealing disease progression and PSMA-avid foci at the surgical stitch sites. This report discusses the immunohistochemical and molecular imaging mechanisms underlying PSMA expression in surgical scar tissues, providing critical insights for optimizing radiologic reporting in such situations.

Background: Low-dose CT (LDCT) chest protocols have widespread clinical applications for many indications; as a result, there is a need for protocol assessment prior to standardization. Dalhousie University and Oslo Metropolitan University have a formally established cooperative relationship.

Purpose: The purpose is to assess radiation dose and image quality for LDCT chest protocols in seven different hospital locations in Norway and Canada.

Material and methods: Retrospective dosimetry data, volumetric CT dose index (CTDI_vol), and dose length product (DLP) from 240 average-sized patients as well as CT protocol parameters were included in the survey. Effective dose (ED) and size-specific dose estimate (SSDE) were calculated for each examination. For a quantitative image quality analysis, noise, CT number, and signal-to-noise ratio (SNR) were determined for three regions in the chest. The contrast-to-noise ratio (CNR) was calculated for lung parenchyma in comparison to the subcutaneous fat. Differences in dose and image quality were evaluated by a single-factor ANOVA test. A two-sample t-test was performed to determine differences in means between individual scanners.

Results: The ANOVA test revealed significant differences (p < .05) in dose values for all scanners, including identical scanner models. Statistically significant differences (p < .05) were determined in mean values of the SNR distributions between the scanners in all three measured regions in the chest, as well as the CNR values.

Conclusion: The observed variations in dose and image quality measurements, even within the same hospitals and between identical scanner models, indicate a potential for protocol optimization in the involved hospitals in both countries.

The purpose of this report was to evaluate the usefulness of hyperdense whirl sign on unenhanced computed tomography (CT) for diagnosing gallbladder torsion. The CT scans of seven patients with gallbladder torsion were independently reviewed by two board-certified radiologists for locating the high-density core with twisting between the gallbladder neck and liver bed, termed hyperdense whirl sign. The sign was observed in six cases. The detection of a hyperdense whirl sign on unenhanced CT appears useful for diagnosing gallbladder torsion.

Background: The growing role of artificial intelligence (AI) in healthcare, particularly radiology, requires its unbiased and fair development and implementation, starting with the constitution of the scientific community.

Purpose: To examine the gender and country distribution among academic editors in leading computer science and AI journals.

Material and methods: This cross-sectional study analyzed the gender and country distribution among editors-in-chief, senior, and associate editors in all 75 Q1 computer science and AI journals in the Clarivate Journal Citations Report and SCImago Journal Ranking 2022. Gender was determined using an open-source algorithm (Gender Guesser™), selecting the gender with the highest calibrated probability.

Result: Among 4,948 editorial board members, women were underrepresented in all positions (editors-in-chief/senior editors/associate editors: 14%/18%/17%). The proportion of women correlated positively with the SCImago Journal Rank indicator (ρ = 0.329; p = .004). The U.S., the U.K., and China comprised 50% of editors, while Australia, Finland, Estonia, Denmark, the Netherlands, the U.K., Switzerland, and Slovenia had the highest women editor representation per million women population.

Conclusion: Our results highlight gender and geographic disparities on leading computer science and AI journal editorial boards, with women being underrepresented in all positions and a disproportional relationship between the Global North and South.

Background: Early detection of post-traumatic cartilage damage in the ankle joint in magnetic resonance images can be difficult due to disturbances to structures usually appearing over time.

Purpose: To study the articular cartilage of unilateral Weber type-B/SER-type ankle fractures shortly post-trauma using T2 relaxation time.

Material and methods: Fifty one fractured ankles were gathered from consecutively screened patients, compiled initially for RCT studies, and treated at Oulu University Hospital and classified as stable (n = 28) and unstable fractures (n = 23) based on external-rotation stress test: medial clear space of ≥5 mm was interpreted as unstable. A control group of healthy young individuals (n = 19) was also gathered. All ankles were imaged on average 9 (range: 1 to 25) days after injury on a 3.0T MRI unit for T2 relaxation time assessment, and the cartilage was divided into sub-regions for comparison.

Results: Control group displayed significantly higher T2 values in tibial cartilage compared to stable (six out of nine regions, p-values = .003-.043) and unstable (six out of nine regions, p-values = .001-.037) ankle fractures. No differences were detected in talar cartilage. Also, no differences were observed between stable and unstable fractures in tibial or talar cartilage.

Conclusions: Lower T2 relaxation times of tibial cartilage in fractured ankles suggest intact extra cellular matrix (ECM) of the cartilage. Severity of the ankle fracture, measured by ankle stability, does not seem to increase ECM degradation immediately after trauma.

Background: Management of the distal radius fracture (DRF) is to some extent based on radiographic characterization of fracture displacement. It remains unclear, however, if the measurements used to quantify displacement are accurate.

Purpose: To quantify accuracy of two radiographic measurements: dorsal/volar tilt and fracture compression, measured indirectly as ulnar variance (UV), using radiostereometric analyses (RSA) as reference standard.

Material and methods: Twenty-one fresh frozen non-fractured human cadaveric forearms (right = 11, left = 10) were thawed and eligible for inclusion. The forearms were mounted on a custom made platform that allowed for controlled forearm rotation, and they underwent two rounds of imaging (both rounds consisted of RSA and radiographs). In round one, the non-fractured forearms were radiographed. In round two, artificial DRF´s with compression and dorsal angulation were created and imaging procedures repeated. Change in tilt and UV between the non-fractured and later fractured forearms was defined as fracture-induced deformity. Deformity was measured radiographically and additionally calculated using RSA. Bland Altman analyses were used to estimate agreement between radiographically measured, and RSA calculated, fracture-induced deformity.

Results: Our results indicated that radiographs underestimate the amount of fracture-induced deformity. Mean measured differences (bias) in dorsal tilt deformity between radiographs and RSA were -2.5° for both observers. The corresponding values for UV were -1.4 mm and -1.5 mm.

Conclusion: Quantifying fracture-induced deformity on radiographs underestimated the actual deformity when compared to RSA calculated deformity. These findings suggest that clinicians, at least in part, base fracture management and potentially corrective surgery on inaccurate measurements.

Background: Dual-energy computed tomography (DECT) is an advanced imaging method that enables reconstruction of virtual non-contrast (VNC) images from a contrast-enhanced acquisition. This has the potential to reduce radiation exposure by eliminating the need for a true non-contrast (TNC) phase.

Purpose: The purpose is to evaluate the feasibility of VNC images in the neck region.

Materials and methods: A total of 100 patients underwent a DECT scan as part of diagnostic workup of primary hyperparathyroidism. VNC images were reconstructed from 30 s (arterial) and 50 s (venous) post-contrast scans. Regions of interest (ROIs) were placed in thyroid tissue, lymph node, carotid artery, jugular vein, fat, and sternocleidomastoid muscle. Mean densities of all anatomical structures were compared between VNC and TNC images.

Results: For all anatomical structures except the thyroid gland, the difference in mean density between TNC and VNC images was less than 15 HU. The mean difference in density between TNC and VNC images of the thyroid was 53.2 HU (95% CI 46.8; 59.6, p = <0.001).

Conclusion: This study demonstrated an acceptable agreement in density between true non-contrast and virtual non-contrast images for most anatomical structures in the neck region. Therefore, VNC images may have the potential to replace TNC images in the neck. However, due to significant differences in CT density of thyroid tissue, true non-contrast imaging cannot be directly substituted by virtual non-contrast imaging when examining the thyroid and its surrounding tissue.

We present a case of the T2-FLAIR mismatch sign in glioblastoma, isocitrate dehydrogenase (IDH)-wild type. The T2-FLAIR mismatch sign is known as a highly specific imaging finding of astrocytoma, IDH-mutant. Meanwhile, IDH-wildtype diffuse astrocytic gliomas with telomerase reverse transcriptase (TERT) promoter mutation in adults are defined as glioblastoma in the 2021 World Health Organization Classification of Tumors of the Central Nervous System, fifth edition (2021 WHO classification), which underscores the importance of molecular information in central nervous system tumors. This indicates even glioblastoma, IDH-wild type may be masquerading as lower-grade glioma in histology. The reasons for the discrepancy between tumors with less aggressive histology and poor prognosis caused by telomerase reverse transcriptase promoter mutation of IDH-wildtype diffuse glioma remain unclear. However, glioblastoma, IDH-wildtype should be considered as a potential differential diagnosis even in patients with the T2-FLAIR mismatch sign in diffuse gliomas.

Background: Rapid diagnosis and risk stratification are important to reduce the risk of adverse clinical events and mortality in acute pulmonary embolism (PE). Although clot burden has not been consistently shown to correlate with disease outcomes, proximally located PE is generally perceived as more severe.

Purpose: To explore the ability of the Mean Bilateral Proximal Extension of the Clot (MBPEC) score to predict mortality and adverse outcome.

Methods: This was a single center retrospective cohort study. 1743 patients with computed tomography pulmonary arteriography (CTPA) verified PE diagnosed between 2005 and 2020 were included. Patients with active malignancy were excluded. The PE clot burden was assessed with MBPEC score: The most proximal extension of PE was scored in each lung from 1 = sub-segmental to 4 = central. The MBPEC score is the score from each lung divided by two and rounded up to nearest integer.

Results: We found inconsistent associations between higher and lower MBPEC scores versus mortality. The all-cause 30-day mortality of 3.9% (95% CI: 3.0-4.9). The PE-related mortality was 2.4% (95% CI: 1.7-3.3). Patients with MBPEC score 1 had higher all-cause mortality compared to patients with MBPEC score 4: Crude Hazard Ratio (cHR) was 2.02 (95% CI: 1.09-3.72). PE-related mortality was lower in patients with MBPEC score 3 compared to score 4: cHR 0.22 (95% CI: 0.05-0.93). Patients with MBPEC score 4 did more often receive systemic thrombolysis compared to patients with MBPEC score 1-3: 3.2% vs. 0.6% (p < .001). Patients with MBPEC score 4 where more often admitted to the intensive care unit: 13% vs. 4.7% (p < .001).

Conclusion: We found no consistent association between the MBPEC score and mortality. Our results therefore indicate that peripheral PE does not necessarily entail a lower morality risk than proximal PE.