European Radiology最新文献

Objective: To evaluate radiation dose and image quality of a double-low CCTA protocol reconstructed utilizing high-strength deep learning image reconstructions (DLIR-H) compared to standard adaptive statistical iterative reconstruction (ASiR-V) protocol in non-obese patients.

Materials and methods: From June to October 2022, consecutive patients, undergoing clinically indicated CCTA, with BMI < 30 kg/m² were prospectively included and randomly assigned into three groups: group A (100 kVp, ASiR-V 50%, iodine delivery rate [IDR] = 1.8 g/s), group B (80 kVp, DLIR-H, IDR = 1.4 g/s), and group C (80 kVp, DLIR-H, IDR = 1.2 g/s). High-concentration contrast medium was administered. Image quality analysis was evaluated by two radiologists. Radiation and contrast dose, and objective and subjective image quality were compared across the three groups.

Results: The final population consisted of 255 patients (64 ± 10 years, 161 men), 85 per group. Group B yielded 42% radiation dose reduction (2.36 ± 0.9 mSv) compared to group A (4.07 ± 1.2 mSv; p < 0.001) and achieved a higher signal-to-noise ratio (30.5 ± 11.5), contrast-to-noise-ratio (27.8 ± 11), and subjective image quality (Likert scale score: 4, interquartile range: 3-4) compared to group A and group C (all p ≤ 0.001). Contrast medium dose in group C (44.8 ± 4.4 mL) was lower than group A (57.7 ± 6.2 mL) and B (50.4 ± 4.3 mL), all the comparisons were statistically different (all p < 0.001).

Conclusion: DLIR-H combined with 80-kVp CCTA with an IDR 1.4 significantly reduces radiation and contrast medium exposure while improving image quality compared to conventional 100-kVp with 1.8 IDR protocol in non-obese patients.

Clinical relevance statement: Low radiation and low contrast medium dose coronary CT angiography protocol is feasible with high-strength deep learning reconstruction and high-concentration contrast medium without compromising image quality.

Key points: Minimizing the radiation and contrast medium dose while maintaining CT image quality is highly desirable. High-strength deep learning iterative reconstruction protocol yielded 42% radiation dose reduction compared to conventional protocol. "Double-low" coronary CTA is feasible with high-strength deep learning reconstruction without compromising image quality in non-obese patients.

Objective

To evaluate how intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) histogram analysis contribute to assessing complete response (CR) to neoadjuvant therapy (NAT) in locally advanced rectal cancer (LARC).

Material and methods

In this prospective study, participants with LARC, who underwent NAT and subsequent surgery, with adequate MR image quality, were enrolled from November 2021 to March 2023. Conventional MRI (T2WI and DWI), IVIM, and DKI were performed before NAT (pre-NAT) and within two weeks before surgery (post-NAT). Image evaluation was independently performed by two experienced radiologists. Pathological complete response (pCR) was used as the reference standard. An IVIM–DKI-added model (a combination of IVIM and DKI histogram parameters with T2WI and DWI) was constructed. Receiver operating characteristic (ROC) curves were generated to evaluate the diagnostic performance of conventional MRI and the IVIM–DKI-added model.

Results

A total of 59 participants (median age: 58.00 years [IQR: 52.00, 62.00]; 38 [64%] men) were evaluated, including 21 pCR and 38 non-pCR cases. The histogram parameters of DKI, including skewness of kurtosis post-NAT (post-K_Skewness) and root mean squared of change ratio of diffusivity (Δ%D_{DKI-root mean squared}), were entered into the IVIM–DKI-added model. The area under the ROC curve (AUC) of the IVIM–DKI-added model for assessing CR to NAT was significantly higher than that of conventional MRI (0.855 [95% CI: 0.749–0.960] vs 0.685 [95% CI: 0.565–0.806], p < 0.001).

Conclusion

IVIM and DKI provide added value in the evaluation of CR to NAT in LARC.

Key Points

Question The current conventional imaging evaluation system lacks adequacy for assessing CR to NAT in LARC.

Findings Significantly improved diagnostic performance was observed with the histogram analysis of IVIM and DKI in conjunction with conventional MRI.

Clinical relevance IVIM and DKI provide significant value in evaluating CR to NAT in LARC, which bears significant implications for reducing surgical complications and facilitating organ preservation.

Objective: To evaluate multisite effects on fetal brain MRI. Specifically, to identify crucial acquisition factors affecting fetal brain structural measurements and developmental patterns, while assessing the effectiveness of existing harmonization methods in mitigating site effects.

Materials and methods: Between May 2017 and March 2022, T2-weighted fast spin-echo sequences in-utero MRI were performed on healthy fetuses from retrospectively recruited pregnant volunteers on four different scanners at four sites. A generalized additive model (GAM) was used to quantitatively assess site effects, including field strength (FS), manufacturer (M), in-plane resolution (R), and slice thickness (ST), on subcortical volume and cortical morphological measurements, including cortical thickness, curvature, and sulcal depth. Growth models were selected to elucidate the developmental trajectories of these morphological measurements. Welch's test was performed to evaluate the influence of site effects on developmental trajectories. The comBat-GAM harmonization method was applied to mitigate site-related biases.

Results: The final analytic sample consisted of 340 MRI scans from 218 fetuses (mean GA, 30.1 weeks ± 4.4 [range, 21.7-40 weeks]). GAM results showed that lower FS and lower spatial resolution led to overestimations in selected brain regions of subcortical volumes and cortical morphological measurements. Only the peak cortical thickness in developmental trajectories was significantly influenced by the effects of FS and R. Notably, ComBat-GAM harmonization effectively removed site effects while preserving developmental patterns.

Conclusion: Our findings pinpointed the key acquisition factors in in-utero fetal brain MRI and underscored the necessity of data harmonization when pooling multisite data for fetal brain morphology investigations.

Key points: Question How do specific site MRI acquisition factors affect fetal brain imaging? Finding Lower FS and spatial resolution overestimated subcortical volumes and cortical measurements. Cortical thickness in developmental trajectories was influenced by FS and in-plane resolution. Clinical relevance This study provides important guidelines for the fetal MRI community when scanning fetal brains and underscores the necessity of data harmonization of cross-center fetal studies.

Objectives

This study aimed to evaluate the prognostic value of left atrial (LA) strain in patients with apical hypertrophic cardiomyopathy (ApHCM), as assessed by cardiac magnetic resonance (CMR) imaging.

Methods

Four hundred and five consecutive patients with ApHCM who underwent CMR examination were retrospectively included. The study endpoint included all-cause death, heart transplant, aborted sudden cardiac death, hospitalization for heart failure, stroke, and new-onset atrial fibrillation (AF).

Results

After a median follow-up of 97 months, 75 patients (18.5%) reached the endpoint. Patients were divided into two groups based on the median LA reservoir strain of 29.4%. The group with lower LA reservoir strain had thicker maximum wall thickness, greater late gadolinium enhancement extent, and smaller end-diastolic volume index, stroke volume index, and cardiac index (all p < 0.02). For LA parameters, this subgroup showed greater diameter and volume index and worse ejection fraction, reservoir, conduit, and booster strain (all p < 0.001). In the multivariable model, age (HR 1.88, 95% CI: 1.06–3.31, p = 0.030), baseline AF (HR 2.95, 95% CI: 1.64–5.28, p < 0.001), LA volume index (LAVi) (HR 2.07, 95% CI: 1.21–3.55, p = 0.008) and LA reservoir strain (HR 2.82, 95% CI: 1.51–5.26, p = 0.001) were all associated with the outcome. Adding LAVi and LA reservoir strain in turn to the multivariable model (age and baseline AF) resulted in significant improvements in model performance (p < 0.001).

Conclusion

In ApHCM patients, LA reservoir strain is independently associated with cardiovascular risk events and has an incremental prognostic value.

Clinical relevance statement

Left atrial reservoir strain measured by cardiac magnetic resonance is highly correlated with the prognosis of apical hypertrophic cardiomyopathy and has potential incremental value in the prognosis of major adverse cardiac events.

Key Points

• Left atrial (LA) strain parameters may be useful for risk stratification and treatment of apical hypertrophic cardiomyopathy (ApHCM).

• Apical hypertrophic cardiomyopathy (ApHCM) is independently associated with LA morphology and function.

• Cardiac MR examination, especially its feature-tracking technology, provides the possibility to prognosticate ApHCM at an early stage.

Graphical Abstract

Objectives

The current understanding of survival prediction of lung transplant (LTx) patients with systemic sclerosis (SSc) is limited. This study aims to identify novel image features from preoperative chest CT scans associated with post-LTx survival in SSc patients and integrate them into comprehensive prediction models.

Materials and methods

We conducted a retrospective study based on a cohort of SSc patients with demographic information, clinical data, and preoperative chest CT scans who underwent LTx between 2004 and 2020. This cohort consists of 102 patients (mean age, 50 years ± 10, 61% (62/102) females). Five CT-derived body composition features (bone, skeletal muscle, visceral, subcutaneous, and intramuscular adipose tissues) and three CT-derived cardiopulmonary features (heart, arteries, and veins) were automatically computed using 3-D convolutional neural networks. Cox regression was used to identify post-LTx survival factors, generate composite prediction models, and stratify patients based on mortality risk. Model performance was assessed using the area under the receiver operating characteristics curve (ROC-AUC).

Results

Muscle mass ratio, bone density, artery–vein volume ratio, muscle volume, and heart volume ratio computed from CT images were significantly associated with post-LTx survival. Models using only CT-derived features outperformed all state-of-the-art clinical models in predicting post-LTx survival. The addition of CT-derived features improved the performance of traditional models at 1-year, 3-year, and 5-year survival prediction with maximum AUC scores of 0.77 (0.67–0.86), 0.85 (0.77–0.93), and 0.90 (95% CI: 0.83–0.97), respectively.

Conclusion

The integration of CT-derived features with demographic and clinical features can significantly improve t post-LTx survival prediction and identify high-risk SSc patients.

Key Points

Question What CT features can predict post-lung-transplant survival for SSc patients?

Finding CT body composition features such as muscle mass, bone density, and cardiopulmonary volumes significantly predict survival.

Clinical relevance Our individualized risk assessment tool can better guide clinicians in choosing and managing patients requiring lung transplant for systemic sclerosis.

Graphical Abstract

Objectives

To compare immune response evaluation criteria in solid tumors (iRECIST) and response evaluation criteria in solid tumors (RECIST) 1.1 for response assessment of immune checkpoint inhibitor (ICI) therapy in a real-world setting in patients with melanoma and non-small cell lung cancer (NSCLC).

Methods

Two-hundred fifty-two patients with melanoma and NSCLC who received CTLA-4 inhibitor ipilimumab or PD-1 inhibitors nivolumab or pembrolizumab and who underwent staging CT of the chest and abdomen were retrospectively included. Treatment response evaluation according to the RECIST 1.1 and iRECIST guidelines was performed for all patients. Response patterns, as well as overall response rate (ORR), disease control rate (DCR), and time to progression (TTP), were compared between RECIST 1.1 and iRECIST.

Results

Out of 143 patients with progressive disease (PD) according to RECIST 1.1, 48 (33.6%) did not attain confirmation of progression (iCPD) as per iRECIST and six patients who were treated beyond RECIST 1.1 progression reached PD at a later point in time in iRECIST, resulting in a significant difference in TTP between iRECIST and RECIST 1.1 (618.3 ± 626.9 days vs. 538.1 ± 617.9 days, respectively (p < 0.05)). The number of non-responders as per RECIST 1.1 was 79, whereas it was 60 when using iRECIST. ORR was 28.5% for RECIST 1.1 and 34.1% for iRECIST, and corresponding DCR of 67.4% for RECIST 1.1 and 74.6% for iRECIST.

Conclusion

iRECIST was more suitable than RECIST 1.1 for capturing atypical response patterns to ICI therapy in patients with melanoma and NSCLC, resulting in differences in the assessment of treatment response.

Clinical relevance statement

Compared to RECIST 1.1, iRECIST may improve patient care and treatment decisions for patients with NSCLC or melanoma who are treated with immune checkpoint inhibitors in clinical routine.

Key Points

• RECIST 1.1 may incorrectly assess atypical treatment patterns to immune checkpoint inhibitors.

• iRECIST better captured atypical response patterns compared to RECIST 1.1.

• iRECIST was more suitable for assessing response to immune checkpoint inhibitors in non-small cell lung carcinoma and melanoma.

Abstract

The goal of this paper is to provide a useful desktop reference for the imaging of suspected child abuse with clear, age-specific pathways for appropriate evidence-based imaging and follow-up.

We aim to provide a road map for the imaging evaluation and follow-up of this important and vulnerable cohort of patients presenting with signs and symptoms concerning for inflicted injury. As the imaging recommendations differ for children of different ages, we provide a flowchart of the appropriate imaging pathway for infants, toddlers, and older children, which allows ease of selection of which children should undergo skeletal survey, non-contrast computed tomography (CT) brain with 3-dimensional (D) reformats, and magnetic resonance imaging (MRI) of the brain and whole spine. For ease of review, we include a table of the common intracranial and spinal patterns of injury in abusive head trauma. We summarise search patterns, areas of review, and key findings to include in the report.

To exclude skeletal injury, infants and children under 2 years of age should undergo a full skeletal survey in accordance with national guidelines, with a limited follow-up skeletal survey performed 11–14 days later. For children over 2 years of age, the need for skeletal imaging should be decided on a case-by-case basis.

All infants should undergo a non-contrast-enhanced CT brain with 3-D reformats. If this is normal with no abnormal neurology, then no further neuroimaging is required. If this is abnormal, then they should proceed to MRI brain and whole spine within 2–5 days. Children older than 1 year of age who have abnormal neurology and/or findings on skeletal survey that are suggestive of inflicted injury should undergo non-contrast CT brain with 3-D reformats and, depending on the findings, may also require MRI of the brain and whole spine.

We hope that this will be a helpful contribution to the radiology literature, particularly for the general radiologist with low volumes of paediatrics in their practice, supporting them with managing these important cases when they arise in daily practice.

Key Points

• The choice of initial imaging (skeletal survey and/or brain CT) depends on the age of the child in whom abuse is suspected.

• A follow-up skeletal survey is mandatory 11–14 days after the initial survey.

• If an MRI of the brain is performed, then an MRI of the whole spine should be performed concurrently.

Objectives

The purpose of this study was to investigate the relevance of focal liver lesions (FLL) size for lesion detection comparing navigator triggering (TRIG) to free breathing (FB) liver Diffusion-weighted magnetic resonance imaging (DWI).

Materials and method

Patients with known or suspected FLL were prospectively (registry number 276_19 B) included from October to December 2019 in this study, out of which 32 had liver lesions. Echo planar spin-echo DWI data both with TRIG and FB were with approximately constant acquisition times acquired at 1.5 T. Lesions were segmented in the b = 800 s/mm² images in both the TRIG and FB images. The lesion size, location (liver segment), liver lesion visibility, as well as contrast-to-noise ratio (CNR) were recorded. The CNR was assessed with the Wilcoxon–Mann–Whitney test and the number of visible lesions with the Fisher test.

Results

Data from 43 patients (22 female) were analyzed. The mean patient age was 58 ± 14 years. A total of 885 FLL (N_total) were segmented. Among these, 811 lesions (N_both) were detected with TRIG and FB, 65 lesions exclusively with TRIG (N_{TRIG_Only}), and nine exclusively in FB (N_{FB_Only}). The largest additional lesion in TRIG/FB had a diameter of 10.4 mm/7.6 mm. The number of additional lesions detected with TRIG decreased with size. Among all lesions ≤ 4.7 mm, the relative number of additional lesions was 15.6%. Additional lesions were found in all liver segments with TRIG. In the left liver lobe, the relative proportion was 9.2%, and in the right liver lobe 5.4%. CNR and visibility were significantly higher in TRIG than in FB (p < 0.001). In relation to size, the difference is significant in terms of visibility and CNR for lesion diameters ≤ 8 mm.

Conclusion

Respiration triggering can improve the detection of small liver lesions with diameters up to approx. 1 cm in the whole liver.

Key Points

Question Can respiration triggering (TRIG) improve the detection of small FLL compared to FB diffusion-weighted imaging?

Findings Among 885 segmented FLL, TRIG was superior to FB for lesions smaller than 8 mm and had improved CNR and visibility.

Clinical relevance Diffusion-weighted magnetic resonance imaging is used for the detection of focal liver lesions and image quality is influenced by breathing motion. Navigator triggering becomes more important for smaller lesions, and seems recommendable for the detection of small focal liver lesions.

Objectives

There is still a debate regarding the prognostic implication of lymphovascular invasion (LVI) in stage I lung adenocarcinoma. Ground-glass opacity (GGO) on CT is known to correlate with a less invasive or lepidic component in adenocarcinoma, which may influence the strength of prognostic factors. This study aimed to explore the prognostic value of LVI in stage I lung adenocarcinoma based on the presence of GGO.

Materials and methods

Stage I lung adenocarcinoma patients receiving lobectomy between 2010 and 2019 were retrospectively categorized as GGO-positive or GGO-negative (solid adenocarcinoma) on CT. Multivariable Cox regression analyses were performed for disease-free survival (DFS) and overall survival (OS) to evaluate the prognostic significance of pathologic LVI based on the presence of GGO.

Results

Of 924 patients included (mean age, 62.5 ± 9.2 years; 505 women), 525 (56.8%) exhibited GGO-positive adenocarcinoma and 116 (12.6%) were diagnosed with LVI. LVI was significantly more frequent in solid than GGO-positive adenocarcinoma (20.1% vs. 6.9%, p < 0.001). Multivariable analysis identified LVI and visceral pleural invasion (VPI) as significant prognostic factors for shorter DFS among solid adenocarcinoma patients (LVI, hazard ratio (HR): 1.89, p = 0.004; VPI, HR: 1.65, p = 0.003) but not GGO-positive patients (p = 0.76 and p = 0.87). In contrast, LVI was not a significant prognostic factor for OS in either group (p > 0.05).

Conclusion

In stage I lung adenocarcinoma, pathologic LVI was associated with DFS only in patients with solid lung adenocarcinoma.

Clinical relevance statement

Lymphovascular invasion (LVI) significantly affects disease-free survival in solid-stage I lung adenocarcinoma patients, but not those with ground-glass opacity (GGO) adenocarcinoma. Risk stratification considering both GGO on CT and LVI may identify patients benefiting from increased surveillance.

Key Points

• The presence of ground-glass opacity portends different prognoses for lung adenocarcinoma.

• In stage I lung adenocarcinoma, lymphovascular invasion (LVI) was significantly more frequent in solid adenocarcinomas than in ground-glass opacity (GGO)-positive adenocarcinomas.

• LVI was not associated with overall survival in patients with either solid adenocarcinomas or GGO adenocarcinomas.