Lung nodules are a common radiological finding that can be caused by a variety of reasons, ranging from benign granulomas and scarring to the early stages of primary lung malignancies and metastases

Background/Objectives: Accurate visualization of peroneal perforator vessels prior to autologous transplantation of osteomyocutaneous fibular flap is essential for surgical success. Our aim was to improve and simplify pre-surgical diagnostics of peroneal perforators using a dedicated dual-energy Computed Tomography Angiography (CTA) protocol and semiautomatic Vessel Unfolding Reconstruction algorithm (VUR). Methods: CTA of both lower legs was performed in 22 patients using dual-energy acquisitions from a third-generation dual-source CT scanner and a high iodine flux (7 mL/s, 350 mg/mL). Low-energy virtual monoenergetic reconstructions (40 keV) were automatically reconstructed from the scanner and used for centerline labeling of the peroneal arteries and their perforators on a post-processing console using a dedicated vascular workflow. Separate segmentation and curved multiplanar reconstructions (MPRs) of each identified peroneal perforator vessel were regarded as the gold standard. Traditional visualization techniques of the entire volume like thin-slice maximum intensity projections (MIPs) or the volume rendering technique (VRT) were compared to a new VUR algorithm that aimed to adjust the visualization plane to the course of the vessels. The identified numbers and lengths of the perforator arteries were compared between curved MPRs, thin-slice MIPs in oblique coronal orientation, posterior-view VRT and coronal VUR of each lower leg. Results: The VUR algorithm was feasible in all patients and the same quantity of peroneal perforator vessels could be detected in comparison to the gold standard. The mean number of perforator vessels per lower leg was 2.6. Mean perforator length in VUR was slightly shorter by 1.6% and did not significantly differ from curved MPRs (p = 0.54), whereas length values from oblique coronal MIP and VRT reconstructions were significantly shorter (both p < 0.001). Conclusions: The combination of virtual monoenergetic reconstructions and the VUR algorithm enables comprehensive and precise depiction of small peroneal perforator vessels prior to autologous fibular flap transplantation, representing a diagnostic tool comparable to traditional visualization methods.

Background: Childhood cancer survivors have a high risk of chronic multi-organ disease that does not plateau over time. To date, there is a lack of sensitive diagnostic techniques that allow early detection of tissue damage before clinical symptoms occur, particularly regarding pulmonary function. Free-breathing phase-resolved functional lung (PREFUL) low-field magnetic resonance imaging (LF-MRI) may enable visualization and quantification of functional and structural lung damage without the need of specific contrast agents. Methods: In this single-center, cross-sectional diagnostic study, we performed LF-MRI in a cohort of n = 27 children and adolescents (age range: 5 to 17 years) after treatment for acute lymphoblastic leukemia (ALL; n = 21) and Hodgkin’s disease (HD; n = 6) to determine the frequency of morphologic and functional lung parenchymal changes. Results: Here, we show that despite the absence of clinical symptoms, significant time-dependent pulmonary ventilation and perfusion defects are detected. A negative correlation between the time after the end of therapy and defect-free lung tissue in the cohort of patients treated for ALL (Spearman-coefficient = − 0.69, p = 0.0005) is observed. Conclusions: Our results suggest an increase in pulmonary ventilation and perfusion defects preceding the increase in chronic disease that has already been reported in this patient population. Further research is needed to determine whether the functional abnormalities described in this study are an early morphological correlate of developing organ damage that may become clinically evident over time. PREFUL MRI may be an effective and highly sensitive tool for early detection of these changes in lung function, allowing longitudinal studies for risk stratification and potential future treatment adaptation.

Background and purpose: Deep-learning (DL) based MRI denoising techniques promise improved image quality and shorter examination times. This advancement is particularly beneficial for 0.55T MRI, where the inherently lower signal-to-noise (SNR) ratio can compromise image quality. Sufficient SNR is crucial for the reliable detection of vestibular schwannoma (VS). The objective of this study is to evaluate the VS conspicuity and acquisition time (TA) of 0.55T MRI examinations with contrast agents using a DL-denoising algorithm. Materials and methods: From January 2024 to October 2024, we retrospectively included 30 patients with VS (9 women). We acquired a clinical reference protocol of the cerebellopontine angle containing a T1w fat-saturated (fs) axial (number of signal averages [NSA] 4) and a T1w Spectral Attenuated Inversion Recovery (SPAIR) coronal (NSA 2) sequence after contrast agent (CA) application without advanced DL-based denoising (w/o DL). We reconstructed the T1w fs CA sequence axial and the T1w SPAIR CA coronal with full DL-denoising mode without change of NSA, and secondly with 1 NSA for T1w fs CA axial and T1w SPAIR coronal (DL&1NSA). Each sequence was rated on a 5-point Likert scale (1: insufficient, 3: moderate, clinically sufficient; 5: perfect) for: overall image quality; VS conspicuity, and artifacts. Secondly, we analyzed the reliability of the size measurements. Two radiologists specializing in head and neck imaging performed the reading and measurements. The Wilcoxon Signed-Rank Test was used for non-parametric statistical comparison. Results: The DL&4NSA axial/coronal study sequence achieved the highest overall IQ (median 4.9). The image quality (IQ) for DL&1NSA was higher (M: 4.0) than for the reference sequence (w/o DL; median 4.0 versus 3.5, each p < 0.01). Similarly, the VS conspicuity was best for DL&4NSA (M: 4.9), decreased for DL&1NSA (M: 4.1), and was lower but still sufficient for w/o DL (M: 3.7, each p < 0.01). The TA for the axial and coronal post-contrast sequences was 8:59 minutes for DL&4NSA and w/o DL and decreased to 3:24 minutes with DL&1NSA. Conclusions: This study underlines that advanced DL-based denoising techniques can reduce the examination time by more than half while simultaneously improving image quality.

Background: Lung surveillance in cystic fibrosis (CF) relies on chest radiography (CR) despite cumulative radiation. Low-field MRI may be a radiation-free alternative for children and young adults. Methods: We prospectively compared 0.55 T MRI and CR in 28 same-day examinations of 22 people with CF (mean age 13 ± 5 years). Three raters scored the disease with the MRI CF score and a modified Chrispin–Norman score, expanded from two to three zones per hemithorax to match the six MRI lobes. Analyses used per-examination values averaged across the raters (Wilcoxon tests, intraclass correlation coefficients, ICC). Results: MRI yielded higher global scores (median 8.2 vs. 6.7, p = 0.002) and higher centrilobular opacity scores (p = 0.005, adjusted p = 0.03). Air trapping was also higher on MRI (p = 0.025) but not after correction for multiple comparisons (adjusted p = 0.12). The other categories did not differ. Both correlated inversely with FEV1 (p < 0.001), without a significant modality-by-FEV1 interaction (p = 0.08). Interobserver agreement was higher for MRI (ICC = 0.93) than CR (0.82), difference 0.12 (95% bootstrap CI 0.06 to 0.18). The findings held in a per-participant sensitivity analysis. Conclusions: 0.55 T MRI is a feasible, radiation-free alternative to CR in CF, yielding higher modality-specific scores and more consistent interobserver agreement. Because the instruments were only category-mapped and no CT reference was available, higher scores do not establish superior lesion detection.