Purpose To identify the risk factors for liver abscess in patients undergoing CT-guided interstitial brachytherapy, and the effectiveness of intensified antibiotic prophylaxis regimen in patients with assumed high-risk. Methods All patients who underwent CT-guided high-dose-rate interstitial brachytherapy of liver lesions between July 2017 and June 2022 at a single center were retrospectively evaluated. Patients with a follow-up shorter than 1 month were excluded. No routine periinterventional antibiotic prophylaxis was used. Patients with assumed risk factors (enterobiliary manipulations, biliary dilatation, central large tumor) were prescribed with 10-day ciprofloxacin and metronidazol, followed by ciprofloxacin for a week every month. Risk factors were identified using multivariable logistic regression and LASSO. Results 560 patients with 862 interstitial brachytherapy sessions were included. Of 55 patients with risk factors, 42 received antibiotic prophylaxis and 13 did not. The rate of liver abscess was 1.04% (9 of 862 procedures) per procedure and 1.6% (9 of 560 patients) per patient. The rate of hepatic abscess was 0.39% in patients without risk factors. Multivariable analysis and LASSO showed a significant correlation between liver abscess and the presence of biliodigestive anastomosis (p < 0.001) and biliary stent (p < 0.001). The rate of liver abscess in patients with enterobiliary manipulations was 23% (3 of 13) without antibiotic prophylaxis and 11.7% (4 of 34) under antibiotic prophylaxis (p = 0.376). Conclusion The risk of liver abscess after CT-guided interstitial brachytherapy is extremely low in patients without risk factors. Biliodigestive anastomosis is a risk factor for liver abscess, and intensified antibiotic prophylaxis shows a trend to decrease liver abscess risk.
INTRODUCTION:The flexor carpi radialis tendon (FCR tendon) is an important anatomical structure of the wrist, frequently implicated in radial-sided pain. FCR tendon disorders include tenosynovitis, tendinopathy, partial or complete tears, and compressive syndromes such as trapezial tunnel syndrome. Knowledge of anatomical variants, pathophysiology, and imaging techniques is essential for accurate diagnosis and management. METHODOLOGY:This educational narrative review is based on a structured, non-systematic review of the literature, supplemented by representative imaging findings from clinical practice. It focuses on the anatomy, variants, pathology, multimodality imaging findings, and post-therapeutic evaluation of the flexor carpi radialis tendon. RESULTS:The FCR tendon exhibits notable anatomical complexity, including variants that may influence clinical presentation and surgical planning. Multimodality imaging has been used to characterize tendinopathy, tenosynovitis, partial or complete tears, synovial sheath cysts, calcifications, and associated scaphotrapeziotrapezoid joint abnormalities. Surgical procedures involving the FCR tendon-including trapezial tunnel decompression, tenodesis, tendon transfers, and ligament reconstruction-require imaging follow-up to assess tendon integrity, postoperative changes, and potential complications. Dynamic ultrasound and MRI are particularly useful in routine clinical practice for evaluating these conditions. CONCLUSION:This educational narrative review highlights practical imaging insights derived from the literature and illustrated by representative clinical cases. Multimodality imaging plays an important role in the diagnosis and post-therapeutic evaluation of FCR tendon disorders and contributes to patient management in routine clinical practice.
PURPOSE:Portable ultra-low-field (ULF) magnetic resonance imaging (MRI) is usually judged by how closely it approaches high-field performance. This opinion paper argues that, in many resource-constrained settings, the question is miscast, and sets out how the technology should instead be evaluated. METHOD:Drawing on recent systematic reviews and meta-analyses of portable ULF-MRI and on more than fifteen years of neuroradiology practice in Nigeria, the paper examines whether pooled diagnostic-accuracy estimates transfer to settings where the portable scanner may be the only imaging device available. RESULTS:Diagnostic accuracy and clinical utility are not the same thing. Pooled estimates were derived almost entirely where conventional MRI or computed tomography was immediately available; transferring them assumes comparable case-mix and workflow (spectrum and implementation effects) and, critically, overlooks that without a fallback, the consequences of false-negative, indeterminate and non-diagnostic examinations are far graver. A pooled acute-ischaemic-stroke sensitivity near 73% is a manageable adjunct with backup but means roughly one in four infarcts is missed and left uncorrected without it. Four arguments follow: accuracy estimates may be optimistic and are insufficient for unsupported pathways; interpretation capacity and medicolegal responsibility are decisive but underestimated constraints, alongside cost, power and connectivity; quantitative normative morphometry rests on non-African reference data; and low-field practice in Africa is a decades-old continuity. CONCLUSIONS:Portable ULF-MRI should be evaluated as an access technology on the terms its setting imposes, using a minimum outcome set - including non-diagnostic and indeterminate rates, downstream consequences, and cost per completed diagnostic pathway - not sensitivity alone.
Objectives To evaluate whether adding dual-layer spectral CT (DLCT) to conventional CT (CCT) improves diagnostic accuracy for acute bowel ischemia (ABI). Materials and Methods This retrospective single-center study included 387 consecutive patients (61 ± 15 years; 42% female) who underwent biphasic abdominal DLCT for clinically suspected ABI. After testing interobserver agreement with an enriched sample of 25 scans (ĸ:0.41–0.68), the scans were divided into four batches and independently evaluated by four radiologists. Each scan was evaluated twice: first using CCT, then with added iodine density and 40 keV monoenergetic (monoE40) reconstructions. The presence of ABI was rated in accordance with our clinical practice on a five-point Likert scale. The reference standard was a composite of surgery, pathology, endoscopy, endovascular intervention, and/or clinical follow-up data. Diagnostic accuracy was calculated with 95% confidence intervals. Results Fifty-five patients (14%) had ABI, of whom 65% with surgical and/or pathological proof. The most common etiologies were arterial occlusion (44%) and non-occlusive mesenteric ischemia (33%). For CCT, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 65% (95% CI 51–78), 93% (90–96), 61% (50–71), 94% (92–96), and 89% (86–92), respectively. Adding DLCT reconstructions did not improve sensitivity (65%), but had a limited improvement in the positive predictive value (61% to 67%) for monoE40 reconstruction (p = 0.046). Conclusion Qualitative assessment of additional DLCT reconstructions (iodine density and monoE40) alongside CCT did not improve sensitivity for ABI diagnosis, but a small overall improvement in positive predictive value was observed for monoE40
BACKGROUND:Noninvasive imaging is essential for long-term surveillance of flow diverter-treated intracranial aneurysms. We evaluate the image quality and feasibility of photon-counting detector CT (PCD-CT) in a real-world, non-contemporaneous follow-up setting, comparing it with intraoperative baseline DSA and flat-panel detector CT (VasoCT). METHODS:This retrospective cohort study included 30 patients (32 aneurysms) followed with PCD-CT (median: 6.5 months) after flow diverter treatment. Three neurointerventionalists, blinded to clinical data, assessed stent lumen visibility and diagnostic confidence using a 5-point Likert scale. Quantitative metrics included signal-to-noise ratio, contrast-to-noise ratio, relative metal artifact width, and radiation doses. A mixed linear model identified predictors of image quality. RESULTS:PCD-CT stent lumen visibility (4.6 ± 0.7) was significantly higher than baseline DSA (3.0 ± 0.5, P < 0.001) and VasoCT (3.1 ± 1.2, P < 0.001). Diagnostic confidence scores were significantly higher for DSA (5.0 ± 0.0) and PCD-CT (4.8 ± 0.6) than for VasoCT (3.4 ± 1.0, both P < 0.001), while PCD-CT was slightly but significantly lower than DSA (P = 0.031). Inter-observer agreement was excellent (ICC ≥ 0.945). PCD-CT effective dose (0.79 ± 0.07 mSv) was higher than localized DSA (0.13 ± 0.02 mSv) and VasoCT (0.55 ± 0.08 mSv) due to whole-brain coverage. Mixed model identified PCD-CT as the strongest positive predictor for lumen visibility (β = 1.65, P < 0.001), and this advantage remained robust across different aneurysm morphologies and the predominant stent designs evaluated in this cohort. CONCLUSION:PCD-CT provides superior stent lumen visualization compared to baseline imaging, while maintaining a sub-millisievert radiation dose. It represents a promising non-invasive surveillance tool, though prospective validation of its diagnostic accuracy for in-stent stenosis is required.
OBJECTIVE:To characterize quantitative imaging features of the infrapatellar fat pad (IPFP) using intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and DWI-derived virtual magnetic resonance elastography (vMRE) in adults with knee pain and to evaluate their associations with cartilage lesions and patient-reported outcomes. METHODS:Adults with early knee osteoarthritis (EKOA; n = 55) and individuals without EKOA (n = 38) were prospectively enrolled. International Knee Documentation Committee (IKDC) scores were recorded. Between-group comparisons were adjusted for age and BMI. Within the EKOA group, multivariable linear regression and exploratory parallel path analysis were performed. RESULTS:After adjustment, the EKOA group had higher D and lower μdiff than the non-EKOA group (adjusted P = 0.022 and 0.002, respectively), whereas D*, f, and IPFP volume did not differ significantly. Within the EKOA group, higher D was independently associated with lower IKDC scores (B = - 24.45; 95 % CI, -37.57 to - 11.33; P < 0.001), whereas higher μdiff was associated with higher IKDC scores (B = 4.06; 95 % CI, 2.49-5.63; P < 0.001). Exploratory path analysis identified a significant μdiff-related indirect association and a significant total indirect association through D and μdiff, while the D-related indirect association and direct association were not significant. CONCLUSION:IVIM-DWI and DWI-derived vMRE identified quantitative differences in IPFP D and μdiff between the groups. These cross-sectional findings support further longitudinal validation of quantitative IPFP MRI parameters as candidate imaging biomarkers for EKOA.
OBJECTIVES:This study aimed to compare image quality and diagnostic performance between artificial intelligence-assisted compressed sensing (ACS) images reconstructed using deep learning reconstruction (ACS-DLR) and conventional parallel imaging (PI) images in rectal cancer MRI. METHODS:107 patients with biopsy-proven rectal cancer were included. MRI included conventional PI and ACS acquisitions, with the ACS raw data reconstructed at three deep learning reconstruction strength levels (ACS-L, ACS-M, and ACS-H). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were compared across four image sets using the Friedman test. Subjective image quality was assessed using a 5-point Likert scale for overall image quality, noise, artefact, and edge sharpness. Interobserver agreement for objective metrics was measured by ICC, and for subjective metrics by Cohen's kappa. Diagnostic performance was evaluated using postoperative histopathology, including T stage, N stage, extramural venous invasion (EMVI), and mesorectal fascia (MRF) involvement. RESULTS:ACS reduced acquisition time by 50 % (from 3 min 20 s to 1 min 40 s). Lesion SNR did not differ significantly among the four image sets (P > 0.05), but ACS-H showed the highest muscle SNR. CNR showed significant differences in selected pairwise comparisons. ACS-H achieved the highest subjective scores for overall image quality, noise reduction, and lesion edge sharpness. In the surgical subcohort, ACS-H improved T staging accuracy (P = 0.010; P = 0.018), MRF involvement assessment (P = 0.004; P = 0.012), and EMVI sensitivity (P = 0.039; P = 0.041). N staging accuracy was not significantly different (P = 0.521; P = 0.841). CONCLUSION:ACS reduced acquisition time, while ACS-DLR improved subjective image quality. ACS-H improved T-stage and MRF assessment and increased EMVI sensitivity, whereas N-stage accuracy did not improve significantly.
Introduction Recent study results of our group demonstrated that [18F]PSMA-1007 (PSMA) PET/CT outperforms PSA response in predicting overall survival in metastatic castration-resistant prostate cancer (mCRPC) patients. However, its health economic implications for guiding treatment decisions remained unclear. This post-hoc analysis explores the potential impact of PSMA PET/CT on treatment decisions and patient-level costs, highlighting its relevance for future health economic evaluations. Methods Time from therapy initiation to therapy discontinuation and the reasons for discontinuation were studied. A swimmer plot visualised individual patient timelines and censored events. Hospital-perspective cost estimates were determined per patient. Results Among 60 patients, 53 discontinued therapy: 28 due to disease progression, 7 due to toxicity, and 18 after completing chemotherapy cycles. Seven patients remained on-treatment at the time of analysis. Costs varied by treatment duration and medication: monthly hospital costs were €1,826 for abiraterone, €3,652 for enzalutamide and €3,190 for chemotherapy. The cost of PSMA PET/CT was estimated at €1,286 and requires contextual evaluation within rapidly changing treatment pathways. Discussion PSMA PET/CT helps inform treatment decisions, but its cost is considerable relative to the cost of conventional therapy. Whether the use of PSMA PET/CT translates into avoidance of ineffective therapy or in therapy-related cost savings should be studied in formal cost-effectiveness analysis. Cost savings are less evident where conventional treatment costs are low compared with novel (but costly) targeted therapy options. Standardised imaging protocols, multicentre data and population registries are essential to strengthen the evidence base and enable future health economic evaluation.
PURPOSE:To evaluate the feasibility of CT feature tracking (CT-FT) for assessing left atrial (LA) and left ventricular (LV) strain in atrial fibrillation (AF) patients, using 3T cardiac magnetic resonance (CMR) as the reference standard. METHODS:In this prospective single-center study, 30 patients were included in the final analysis. All participants underwent both coronary CT angiography (CCTA) and CMR examinations within 3 days before radiofrequency ablation. LA and LV strain parameters were measured using CT-FT, including LA reservoir strain (LASr), LV global longitudinal strain (LVGLS), LV global circumferential strain (LVGCS), and LV global radial strain (LVGRS). Conventional parameters, including LV end-diastolic volume, end-systolic volume, ejection fraction, and LA maximum volume, minimum volume, and emptying fraction, were also evaluated. CCTA-derived parameters werecompared withthe CMR using paired t test, Pearson or Spearman correlation coefficients, and Bland-Altman analysis. The reproducibility of CCTA measurements, including intraobserver and interobserver variability, was assessed using intraclass correlation coefficients (ICCs). RESULTS:CCTA yielded slightly lower values for strain parameters (LVGLS: 11.54 % vs 13.52 %; LVGCS: 11.65 % vs 13.44 %; LVGRS: 16.61 % vs 20.73 %; LASr: 18.04 % vs 19.85 %; all p < 0.05), yet correlations with CMR were excellent (r = 0.85-0.96, all p < 0.001). The conventional parameters showed no statistically significant differences between CCTA and CMR measurements (all p > 0.05), with excellent correlations (r = 0.93-0.99, p < 0.001). CCTA measurements exhibited high intraobserver and interobserver reproducibility (ICC > 0.75 for all). CONCLUSION:CT-FT showed strong correlations with CMR and good reproducibility for assessing LV and LA strain in patients with AF, supporting its feasibility as a complementary method for comprehensive cardiac functional assessment.
Objectives To evaluate the accuracy and reliability of automated Gaussian Mixture Modelling (GMM) and K-means clustering for intramuscular fat (IMF) quantification on T2-weighted (T2W) and intermediate-weighted (IW) shoulder MRI, using two-point Dixon as the reference standard. Materials & Methods This retrospective study collected MRI datasets of patients who underwent both two-point Dixon with T2W and/or IW shoulder MRI. GMM and K-means were applied to quantify IMF of the supraspinatus, subscapularis, infraspinatus, teres minor, and deltoid. Accuracy and reliability relative to Dixon were evaluated using Bland-Altman analysis and intraclass correlation coefficients (ICC2,1). Raw IMF values from GMM, K-means and Dixon were compared using repeated-measures ANOVA with post-hoc Dunnett’s test (∝=0.05). Results Eighty patients (mean age, 58 years ± 15 [standard deviation]; 41 males) were evaluated. On T2W MRI, GMM outperformed K-means with a maximum mean bias of −3.07% and excellent reliability for supraspinatus, subscapularis, infraspinatus and deltoid (ICC2,1 ≥ 0.90). K-means produced poor to moderate reliability. On IW MRI, GMM mean bias did not exceed −2.81% and showed excellent reliability for infraspinatus (ICC2,1 = 0.92) with good reliability for other muscles. K-means showed higher bias (−4.36%) and lower reliability (ICC2,1 ≤ 0.81) than GMM. GMM was the only model that did not significantly differ from Dixon IMF values on T2W (p ≥ 0.074) and IW (p ≥ 0.243) MRI. Conclusion IMF quantification using GMM thresholding achieves better agreement with Dixon IMF values than K-Means on T2W and IW MRI.
PURPOSE:To determine how participant-level outcome missingness and center-level endpoint absence influence estimates of the incremental prognostic value of infarct volume in public stroke magnetic resonance imaging datasets. METHODS:We analyzed two public cohorts separately. In the Stroke Outcome Optimization Project (SOOP), 948 of 1106 S records had a valid acute lesion mask and core predictors; 620 had discharge modified Rankin Scale (mRS). Models containing age, sex, and admission National Institutes of Health Stroke Scale, with or without log lesion volume, underwent repeated nested cross-validation and inverse-probability weighting. In ISLES'24, models developed in center 1 (n = 87) were evaluated in center 2 (n = 39) for 3-month mRS and compared with pooled random cross-validation. The primary measure was the ranked probability score (RPS) difference. RESULTS:In SOOP, observed outcomes were associated with larger lesions than missing outcomes (median, 15.08 vs 3.68 mL; standardized mean difference for log volume, 0.486). Adding volume improved RPS by 0.0609 (95 % confidence interval [CI], 0.0314-0.0893); the weighted improvement was 0.0538 (95 % CI, 0.0267-0.0799). In ISLES'24, discharge mRS was absent from center 2. For 3-month mRS, the center-held-out RPS improvement was 0.0488 (95 % CI, -0.1228 to 0.2473), compared with 0.1351 in pooled random validation. Both models overpredicted disability in center 2. CONCLUSIONS:Outcome ascertainment and validation design changed the apparent prognostic contribution of infarct volume. Endpoint-by-center auditing should precede interpretation of multicenter imaging performance.
