European Radiology最新文献

Background

Amidst the global rise of metabolic dysfunction-associated steatotic liver disease (MASLD), driven by increasing obesity rates, there is a pressing need for precise, non-invasive diagnostic tools. Our research aims to validate MRI Proton Density Fat Fraction (MRI-PDFF) utility, compared to liver biopsy, in grading hepatic steatosis in MASLD.

Methods

A systematic search was conducted across Embase, PubMed/Medline, Scopus, and Web of Science until January 13, 2024, selecting studies that compare MRI-PDFF with liver biopsy for hepatic steatosis grading, defined as grades 0 (< 5% steatosis), 1 (5–33% steatosis), 2 (34–66% steatosis), and 3 (> 66% steatosis).

Results

Twenty-two studies with 2844 patients were included. The analysis showed high accuracy of MRI-PDFF with AUCs of 0.97 (95% CI = 0.96–0.98) for grade 0 vs ≥ 1, 0.91 (95% CI = 0.88–0.93) for ≤ 1 vs ≥ 2, and 0.91 (95% CI = 0.88–0.93) for ≤ 2 vs 3, diagnostic odds ratio (DOR) from 98.74 (95% CI = 58.61–166.33) to 23.36 (95% CI = 13.76–39.68), sensitivity and specificity from 0.93 (95% CI = 0.88–0.96) to 0.76 (95% CI = 0.63–0.85) and 0.93 (95% CI = 0.88–0.96) to 0.89 (95% CI = 0.84–0.93), respectively. Likelihood ratio (LR) + ranged from 13.3 (95% CI = 7.4–24.0) to 7.2 (95% CI = 4.9–10.5), and LR − from 0.08 (95% CI = 0.05–0.13) to 0.27 (95% CI = 0.17–0.42). The proposed MRI-PDFF threshold of 5.7% for liver fat content emerges as a potential cut-off for the discrimination between grade 0 vs ≥ 1 (p = 0.075).

Conclusion

MRI-PDFF is a precise non-invasive technique for diagnosing and grading hepatic steatosis, warranting further studies to establish its diagnostic thresholds.

Clinical relevance statement

This study underscores the high diagnostic accuracy of MRI-PDFF for distinguishing between various grades of hepatic steatosis for early detection and management of MASLD, though further research is necessary for broader application.

Key Points

• MRI-PDFF offers precision in diagnosing and monitoring hepatic steatosis.

• The diagnostic accuracy of MRI-PDFF decreases as the grade of hepatic steatosis advances.

• A 5.7% MRI-PDFF threshold differentiates steatotic from non-steatotic livers.

Graphical Abstract

Objectives

This study examines clustering based on shape radiomic features and tumor volume to identify IDH-wildtype glioma phenotypes and assess their impact on overall survival (OS).

Materials and methods

This retrospective study included 436 consecutive patients diagnosed with IDH-wt glioma who underwent preoperative MR imaging. Alongside the total tumor volume, nine distinct shape radiomic features were extracted using the PyRadiomics framework. Different imaging phenotypes were identified using partition around medoids (PAM) clustering on the training dataset (348/436). The prognostic efficacy of these phenotypes in predicting OS was evaluated on the test dataset (88/436). External validation was performed using the public UCSF glioma dataset (n = 397). A decision-tree algorithm was employed to determine the relevance of features associated with cluster affiliation.

Results

PAM clustering identified two clusters in the training dataset: Cluster 1 (n = 233) had a higher proportion of patients with higher sphericity and elongation, while Cluster 2 (n = 115) had a higher proportion of patients with higher maximum 3D diameter, surface area, axis lengths, and tumor volume (p < 0.001 for each). OS differed significantly between clusters: Cluster 1 showed a median OS of 23.8 compared to 11.4 months of Cluster 2 in the holdout test dataset (p = 0.002). Multivariate Cox regression showed improved performance with cluster affiliation over clinical data alone (C index 0.67 vs 0.59, p = 0.003). Cluster-based models outperformed the models with tumor volume alone (evidence ratio: 5.16–5.37).

Conclusion

Data-driven clustering reveals imaging phenotypes, highlighting the improved prognostic power of combining shape-radiomics with tumor volume, thereby outperforming predictions based on tumor volume alone in high-grade glioma survival outcomes.

Clinical relevance statement

Shape-radiomics and volume-based cluster analyses of preoperative MRI scans can reveal imaging phenotypes that improve the prediction of OS in patients with IDH-wild type gliomas, outperforming currently known models based on tumor size alone or clinical parameters.

Key Points

• Shape radiomics and tumor volume clustering in IDH-wildtype gliomas are investigated for enhanced prognostic accuracy.

• Two distinct phenotypic clusters were identified with different median OSs.

• Integrating shape radiomics and volume-based clustering enhances OS prediction in IDH-wildtype glioma patients.

Objectives

To describe and categorize splenic cystic-appearing lesions (S-CAL) with B-mode and contrast-enhanced ultrasound (CEUS).

Materials and methods

This retrospective study investigated S-CALs in 111 patients between 2003 and 2023 in an interdisciplinary ultrasound center with B-mode ultrasound, color Doppler sonography (CDS), and CEUS. S-CAL was characterized by echogenicity, diameter, and shape, as well as additional features like septation, calcification, or wall thickening, and CDS/CEUS were used to identify perfusion. Histological examination or imaging follow-up was necessary to determine the nature of S-CAL. Moreover, ‘S-CAL with risk’ was defined, necessitating further procedures. Four types (0–III) of S-CALs were defined based on ultrasound parameters. Fisher’s exact test was used to compare non-parametric data.

Results

S-CAL of 111 patients (58 female, 53 men—average age: 58.6 years) was examined. Final diagnoses were: splenic cyst (n = 64, 57.7%); splenic abscess (n = 10, 9.0%); intrasplenic pseudoaneurysm (n = 10, 9.0%); splenic metastasis (n = 10, 9.0%); splenic infarction (n = 6, 5.4%); splenic hematoma (n = 4, 3.6%); other (n = 7, 6.3%). S-CAL groupings were type 0 (n = 11, 9.9%), type I (n = 33, 29.7%), type II (n = 24, 21.6%), and type III (n = 43, 38.7%). ‘S-CAL with risk’ was diagnosed in n = 41 (36.9%). Malignant S-CAL was only seen in type II (n = 2, 8.2%) and type III (n = 9, 20.9%) (p < 0.001). ‘S-CALs with risk’ were found more frequently in type 0 (n = 11, 100%), type II (n = 16, 66.7%) and type III (n = 13, 30.2%) than in type I (n = 1, 3%) (p < 0.001).

Conclusion

B-mode ultrasound, CDS, and CEUS are useful to further characterize and follow-up S-CAL and identify ‘S-CAL with risk’, requiring further procedures.

Clinical relevance statement

Ultrasound imaging is valuable for the detection, categorization, and monitoring of cystic-appearing lesions of the spleen, as well as for the identification of those with risk.

Key Points

• An S-CAL may introduce uncertainty in clinical practice as imaging-based risk stratification is missing.

• B-mode and CEUS, along with the clinical context and follow-up, assist in characterizing and identifying ‘S-CAL with risk’.

• S-CALs encompass various lesions, including simple cysts, metastases, abscesses, and intrasplenic pseudoaneurysms.

Fibrotic lung diseases (FLDs) represent a subgroup of interstitial lung diseases (ILDs), which can progress over time and carry a poor prognosis. Imaging has increased diagnostic discrimination in the evaluation of FLDs. International guidelines have stated the role of radiologists in the diagnosis and management of FLDs, in the context of the interdisciplinary discussion. Chest computed tomography (CT) with high-resolution technique is recommended to correctly recognise signs, patterns, and distribution of individual FLDs. Radiologists may be the first to recognise the presence of previously unknown interstitial lung abnormalities (ILAs) in various settings. A systematic approach to CT images may lead to a non-invasive diagnosis of FLDs. Careful comparison of serial CT exams is crucial in determining either disease progression or supervening complications. This 'Essentials' aims to provide radiologists a concise and practical approach to FLDs, focusing on CT technical requirements, pattern recognition, and assessment of disease progression and complications. Hot topics such as ILAs and progressive pulmonary fibrosis (PPF) are also discussed. KEY POINTS: Chest CT with high-resolution technique is the recommended imaging modality to diagnose pulmonary fibrosis. CT pattern recognition is central for an accurate diagnosis of fibrotic lung diseases (FLDs) by interdisciplinary discussion. Radiologists are to evaluate disease behaviour by accurately comparing serial CT scans.

Objectives: The unprecedented surge in energy costs in Europe, coupled with the significant energy consumption of MRI scanners in radiology departments, necessitates exploring strategies to optimize energy usage without compromising efficiency or image quality. This study investigates MR energy consumption and identifies strategies for improving energy efficiency, focusing on musculoskeletal MRI. We assess the potential savings achievable through (1) optimizing protocols, (2) incorporating deep learning (DL) accelerated acquisitions, and (3) optimizing the cooling system.

Materials and methods: Energy consumption measurements were performed on two MRI scanners (1.5-T Aera, 1.5-T Sola) in practices in Munich, Germany, between December 2022 and March 2023. Three levels of energy reduction measures were implemented and compared to the baseline. Wilcoxon signed-rank test with Bonferroni correction was conducted to evaluate the impact of sequence scan times and energy consumption.

Results: Our findings showed significant energy savings by optimizing protocol settings and implementing DL technologies. Across all body regions, the average reduction in energy consumption was 72% with DL and 31% with economic protocols, accompanied by time reductions of 71% (DL) and 18% (economic protocols) compared to baseline. Optimizing the cooling system during the non-scanning time showed a 30% lower energy consumption.

Conclusion: Implementing energy-saving strategies, including economic protocols, DL accelerated sequences, and optimized magnet cooling, can significantly reduce energy consumption in MRI scanners. Radiology departments and practices should consider adopting these strategies to improve energy efficiency and reduce costs.

Clinical relevance statement: MRI scanner energy consumption can be substantially reduced by incorporating protocol optimization, DL accelerated acquisition, and optimized magnetic cooling into daily practice, thereby cutting costs and environmental impact.

Key points: Optimization of protocol settings reduced energy consumption by 31% and imaging time by 18%. DL technologies led to a 72% reduction in energy consumption of and a 71% reduction in time, compared to the standard MRI protocol. During non-scanning times, activating Eco power mode (EPM) resulted in a 30% reduction in energy consumption, saving 4881 € ($5287) per scanner annually.

Purpose: This study aims to comprehensively evaluate the quality of radiomics research by examining unique papers from reviews using the radiomics quality score (RQS).

Methods: A literature search was conducted in PubMed (last search date: April 14, 2024). Systematic or non-systematic reviews using the RQS to evaluate radiomic studies were potentially included. Exclusion was applied at two levels: first, at the review level, and second, at the study level (i.e., for the individual articles previously evaluated within the reviews). Score-wise and item-wise analyses were performed, along with trend, multivariable, and subgroup analyses based on baseline study characteristics and validation methods.

Results: A total of 1574 unique papers (published online between 1999 and 2023) from 89 reviews were included in the final analysis. The median RQS percentage was 31% with an IQR of 25% (25th-75th percentiles, 14-39%). A positive correlation between median RQS percentage and publication year (2014-2023) was found, with Kendall's tau coefficient of 0.908 (p < 0.001), suggesting an improvement in quality over time. The quality of radiomics publications significantly varied according to different subfields of radiology (p < 0.001). Around one-third of the publications (32%) lacked a separate validation set. Papers with internal validation (54%) dominated those with external validation (14%). Higher-quality validation practices were significantly associated with better RQS percentage scores, independent of the validation's effect on the final score. Item-wise analysis revealed significant shortcomings in several areas.

Conclusion: Radiomics research quality is low but improving according to RQS. Significant variation exists across radiology subfields. Critical areas were identified for targeted improvement.

Clinical relevance statement: Our study shows that the quality of radiomics research is generally low but improving over time, with item-wise analysis highlighting critical areas needing improvement. It also reveals that the quality of radiomics research differs across subfields and validation methods.

Key points: Overall quality of radiomics research remains low and highly variable, although a significant positive trend suggests an improvement in quality over time. Considerable variations exist in the quality of radiomics publications across different subfields of radiology and validation types. The item-wise analysis highlights several critical areas requiring attention, emphasizing the need for targeted improvements.

For every patient, the MR safety evaluation should include the assessment of risks in three key areas, each corresponding to a specific hazard posed by the electromagnetic fields generated by the MR scanner: ferromagnetic attraction and displacement by the static field; stimulation, acoustic noise, and device interaction by the gradient fields; and bulk and focal heating by the radiofrequency field. MR safety guidelines and procedures are typically designed around the "average" patient: adult, responsive, and of typical habitus. For this type of patient, we can safely expect that a detailed history can identify metallic objects inside and outside the body, verbal contact during the scan can detect signs of discomfort from heating or acoustic noise, and safety calculations performed by the scanner can prevent hyperthermia. However, for some less common patient categories, these assumptions do not hold. For instance, patients with larger habitus, febrile patients, or pregnant people are more subject to bulk heating and require more conservative MR protocols, while at the same time presenting challenges during positioning and preparation. Other vulnerable categories are infants, children, and patients unable to communicate, who might require screening for ferromagnetic objects with other imaging modalities or dedicated equipment. This paper will provide guidance to implement appropriate safety margins in the workflow and scanning protocols in various vulnerable patient categories that are sometimes overlooked in basic MR safety guidance documents. CLINICAL RELEVANCE STATEMENT: Special care in the implementation of MR safety procedures is of paramount importance in the handling of patients. While most institutions have streamlined operations in place, some vulnerable patient categories require specific considerations to obtain images of optimal quality while minimizing the risks derived by exposure to the MR environment. KEY POINTS: Patients unable to effectively communicate need to be carefully screened for foreign objects. Core temperature management is important in specific patient categories. There are no hard quantitative criteria that make a patient fall into a specific vulnerable category. Protocols and procedures need to be adaptable.

Objectives: Portal hypertension resulting from non-cirrhotic extrahepatic portal vein obstruction (EHPVO) in children has been primarily managed with the Meso-Rex bypass, but only a few patients have a viable Rex recessus, required by surgery. This study reports a preliminary series of patients who underwent interventional radiology attempts at portal vein recanalization (PVR), with a focus on technical aspects and safety.

Methods: A retrospective review of consecutive patients with severe portal hypertension due to non-cirrhotic EHPVO at a single institution from 2022, who underwent percutaneous attempts at PVR, was performed. Technical and clinical data including fluoroscopy time, radiation exposure, technical and clinical success, complications and follow-up were recorded.

Results: Eleven patients (6 males and 5 females; median age 7 years, range 1-14) underwent 15 percutaneous transhepatic (n = 1), transplenic (n = 11), or simultaneous transhepatic/transplenic (n = 3) procedures. Rex recessus was patent in 4/11 (36%). Fluoroscopy resulted in a high median total dose area product (DAP) of 123 Gycm² (range 17-788 Gycm²) per procedure. PVR was achieved in 5/11 patients (45%), 3/5 with obliterated Rex recessus. Two adverse events of grade 2 and grade 3 occurred without sequelae. After angioplasty, 4/5 patients required stenting to obtain sustained patency, as demonstrated by colour-Doppler ultrasound in all PVR after a median follow-up of 6 months (range 6-14).

Conclusion: Our preliminary experience suggests that 45% of children with non-cirrhotic EHPVO can restore portal flow even with obliterated Rex recessus. In non-cirrhotic EHPVO, PVR may be an option, if a Meso-Rex bypass is not feasible, although the radiation exposure deserves attention.

Clinical relevance statement: Innovative percutaneous procedures may have the potential to be an alternative option to the traditional surgical approach in the management of non-cirrhotic EHPVO and its complications in children not eligible for Meso-Rex bypass surgery.

Key points: Non-cirrhotic portal hypertension in children has been traditionally managed by surgery with Meso-Rex bypass creation. Percutaneous PVR may restore the patency of the native portal system even when the Rex recessus is obliterated and surgery has been excluded. Interventional radiological techniques may offer a minimally invasive solution in complex cases of EHPVO in children when Meso-Rex bypass is not feasible.

Objectives: To develop an MRI-based score that enables individualized predictions of the survival benefit of wide over narrow resection margins.

Materials and methods: This single-center retrospective study (December 2011 to May 2022) included consecutive patients who underwent curative-intent resection for single Barcelona Clinic Liver Cancer (BCLC) 0/A HCC and preoperative contrast-enhanced MRI. In patients with narrow resection margins, preoperative demographic, laboratory, and MRI variables independently associated with early recurrence-free survival (RFS) were identified using Cox regression analyses, which were employed to develop a predictive score (named "MARGIN"). Survival outcomes were compared between wide and narrow resection margins in a propensity-score matched cohort for the score-stratified low- and high-risk groups, respectively.

Results: Four hundred nineteen patients (median age, 54 years; 361 men) were included, 282 (67.3%) undergoing narrow resection margins. In patients with narrow resection margins, age, alpha-fetoprotein (AFP) > 400 ng/mL, protein induced by vitamin K absence or antagonist-II (PIVKA-II) > 200 mAU/mL, radiological involvement of liver capsule, and infiltrative appearance were associated with early RFS (p values, 0.002-0.04) and formed the MARGIN score with a testing dataset C-index of 0.75 (95% CI: 0.65-0.84). In the matched cohort, wide resection margin was associated with improved early RFS rate for the high-risk group (MARGIN score ≥ - 1.3; 71.1% vs 41.0%; p = 0.02), but not for the low-risk group (MARGIN score < - 1.3; 79.7% vs 76.1%; p = 0.36).

Conclusion: In patients with single BCLC 0/A HCC, the MARGIN score may serve as promising decision-making to indicate the need for wide resection margins.

Clinical relevance statement: The MARGIN score has the potential to identify patients who would benefit more from wide resection margins than narrow resection margins, improving the postoperative survival of patients with single BCLC 0/A hepatocellular carcinoma (HCC).

Key points: Age, AFP, PIVKA-II, radiological involvement of liver capsule, and infiltrative appearance were associated with early RFS and formed the MARGIN score. The MARGIN score achieved a testing dataset C-index of 0.75. Wide resection margins were associated with improved early RFS for the high-risk group, but not for the low-risk group.

Objective: Novel pericardial adipose tissue imaging biomarkers are currently under investigation for cardiovascular risk stratification. However, a specific compartment of the epicardial adipose tissue (EAT), lipomatous hypertrophy of the interatrial septum (LHIS), is included in the pericardial fat volume (PCFV) quantification software. Our aim was to evaluate LHIS by computed tomography angiography (CTA), to elaborate differences to other pericardial adipose tissue components (EAT) and paracardial adipose tissue (PAT), and to compare CT with [¹⁸F]FDG-PET.

Materials and methods: Of 6983 patients screened who underwent coronary CTA for clinical indications, 190 patients with LHIS were finally included (age 62.8 years ± 9.6, 31.6% females, BMI 28.5 kg/cm² ± 4.7) in our retrospective cohort study. CT images were quantified for LHIS, EAT, and PAT density (HU), and total PCFV, with and without LHIS, was calculated. CT was compared with [¹⁸F]FDG-PET if available.

Results: CT-density of LHIS was higher (- 22.4 HU ± 22.8) than all other pericardial adipose tissue components: EAT right and left (97.4 HU ± 13 and - 95.1 HU ± 13) PAT right and left (- 107.5 HU ± 13.4 and - 106.3 HU ± 14.5) and PCFV density -83.3 HU ± 5.6 (p < 0.001). There was a mild association between LHIS and PAT right (Beta 0.338, p = 0.006, 95% CI: 0.098-577) and PAT left (Beta 0.249, p = 0.030; 95% CI: 0.024-0.474) but not EAT right (p = 0.325) and left (p = 0.351), and not with total PCFV density (p = 0.164). The segmented LHIS volume comprised 3.01% of the total PCFV, and 4.3% (range, 2.16-11.7%) in those with LHIS > 9 mm. [¹⁸F]FDG-PET: LHIS was tracer uptake positive in 83.3% (37.5%: mild and 45.8%: minimal) of 24 patients.

Conclusions: LHIS is a distinct compartment of PCFV with higher density suggesting brown fat and has no consistent association with EAT, but rather with PAT.

Clinical relevance statement: LHIS should be recognized as a distinct compartment of the EAT, when using EAT for cardiovascular risk stratification.

Key points: LHIS is currently included in EAT quantification software. LHIS density is relatively high, it is not associated with EAT, and has a high [¹⁸F]FDG-PET positive rate suggesting brown fat. LHIS is a distinct compartment of the EAT, and it may act differently as an imaging biomarker for cardiovascular risk stratification.