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Objectives: To evaluate the identification of tumor deposits (TDs) and the prognostic significance of an MRI tumor regression grade for TDs in patients with rectal cancer treated with neoadjuvant chemoradiotherapy (nCRT)., Methods: Ninety-one patients with cT3 or cT4 rectal cancer who underwent surgery following nCRT between August 2014 and June 2020 were retrospectively analyzed. Changes in pre-nCRT MRI-detected TDs (mrTDs) were described as mrTD regression grade. The diagnostic performance of post-nCRT MRI-detected TDs (ymrTDs) was compared with histopathological reference standard. The correlation between ymrTDs, mrTD regression grade, and disease-free survival (DFS) was assessed., Results: The sensitivity and specificity of ymrTDs were 88.00% and 89.39%, respectively. The area under the receiver operating characteristic curve was 0.887 (95% confidence interval [CI]: 0.803-0.944). The 3-year DFS of patients with positive ymrTDs was significantly lower than of the negative group (44.83% vs 82.73%, p < 0.001). The 3-year DFS was 33.33% for patients with poor regression of mrTDs following nCRT and 55.56% for those with moderate regression, compared to 69.23% in good responders and 83.97% in patients without mrTDs (p < 0.001). On multivariable Cox regression, mrTD regression grade was the only independent MRI factor associated with DFS (p = 0.042)., Conclusions: Diagnostic performance of ymrTDs was moderate. The mrTD regression grade was independently correlated with DFS, which may have a prognostic implication for treatment and follow-up., Clinical Relevance Statement: Patients with poor regression of MRI-detected tumor deposits may benefit from more aggressive treatments, such as chemoradiation therapy plus induction or consolidation chemotherapy., Key Points: • MRI provides a preoperative and noninvasive way to visualize tumor deposits (TDs) after neoadjuvant chemoradiotherapy (nCRT). • Post-nCRT MRI-detected TDs are a poor prognostic marker in cT3 and cT4 rectal cancer patients. • The regression of MRI-detected TDs after nCRT is associated with an improved disease-free survival., (© 2023. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: To determine association of gross tumour volume (GTV) of resectable oesophageal squamous cell carcinoma (SCC) measured on T 2 -weighted imaging (T 2 WI), contrast-enhanced T 1 -weighted imaging (CE-T 1 WI) and diffusion-weighted imaging (DWI) with T category and lymphatic metastasis (LM)., Methods: Sixty oesophageal SCC patients underwent fat-suppressed T 2 WI, CE-T 1 WI and DWI with b values of 0, 500 and 800 s/mm 2 . GTV was measured on three sequences. Statistical analyses were performed to determine association of GTV with T category and LM., Results: Spearman's rank correlation analysis showed positive association of GTV with T category and LM (all p values < 0.01). Differences in GTV were found between T1 and T2 or T3 categories shown by Kruskal-Wallis H and one-way ANOVA tests, and between T1/T2 and T3 and between tumours with and without LM by Mann-Whitney U tests (all p values < 0.05). Receiver operating characteristic analyses showed cut-off GTVs of 5.795, 5.276 and 10.11 cm 3 on CE-T 1 WI could better differentiate T1 from T2 categories, T1 from T3, and T1-2 from T3 than those of 7.066, 7.045 and 8.504 cm 3 on T 2 WI, of 5.793, 6.609 and 6.989 cm 3 on DWI with b value of 500 s/mm 2 , and of 4.156, 4.519 and 4.985 cm 3 with b value of 800 s/mm 2 , respectively. Cut-off of 10.462 cm 3 on DWI with b value of 500 s/mm 2 could better identify LM than of 12.38, 8.793 and 9.600 cm 3 on T 2 WI, CE-T 1 WI and DWI with b value of 800 s/mm 2 , respectively., Conclusions: GTVs on T 2 WI, CE-T 1 WI and DWI are associated with T category of and LM of oesophageal SCC., Key Points: • GTV is associated with T category and lymphatic metastasis of oesophageal SCC • GTV measured on contrast-enhanced T 1 -weighted imaging better identifies T category • GTV measured on DWI with b value of 500 s/mm 2 better identifies lymphatic metastasis.

Objectives: To investigate functional cerebral abnormalities in patients with amyotrophic lateral sclerosis (ALS) using functional magnetic resonance imaging (fMRI) during action observation., Methods: Thirty patients with ALS and 30 matched healthy controls underwent fMRI with an experimental paradigm while observing a video of repetitive flexion-extension of the fingers at three frequency levels or three complexity levels, alternated with periods of a static hand. A parametric analysis was applied to determine the effects of each of the two factors., Results: Action observation activated similar neural networks as the research on execution of action in the ALS patients and healthy subjects in several brain regions related to the mirror-neuron system (MNS). In the ALS patients, in particular, the dorsal lateral premotor cortex (dPMC), inferior parietal gyrus (IPG), and SMA, were more activated compared with the activation in the controls. Increased activation within the primary motor cortex (M1), dPMC, inferior frontal gyrus (IFG), and superior parietal gyrus (SPG) mainly correlated with hand movement frequency/complexity in the videos in the patients compared with controls., Conclusions: The findings indicated an ongoing compensatory process occurring within the higher order motor-processing system of ALS patients, likely to overcome the loss of function., Key Points: • Action observation activated similar core nodes of MNS in ALS and controls. • Increased activation within M1, dPMC, IFG and SPG mainly correlated with hand movement frequency/complexity. • Differences in patients and controls may be due to compensatory processes in ALS.

Purpose: The present study aims to investigate structural and functional connectivity (SC and FC) in cerebello-cerebral circuit in idiopathic generalized epilepsy (IGE).Methods: Diffusion tensor imaging and resting-state imaging data were collected from 57 patients with IGE and 66 controls in the present study. First, we performed bidirectional probabilistic fiber tracking between cerebellum and cerebral cortex, consisting of cerebellar efferent and afferent fibers. Then, strength of structural connectivity (SCS), fractional anisotropy (FA), mean diffusivity (MD), and radial diffusivity (RD) were extracted and compared between groups. Finally, cerebellar FC with cerebral cortex was evaluated with seeding at dentate nucleus. Between-group comparisons were performed using t tests with a significant level setting at p < 0.05 with threshold-free cluster enhancement correction.Results: The patients with IGE showed decreased SCS in cerebellar efferent fibers to sensorimotor cortex in anterior corona radiate and increased SCS in efferent fibers to occipital cortex in posterior corona radiata. The SCS in cerebellar afferent fibers in corticospinal tract from frontal and in retrolenticular part of the internal capsule from occipital cortices were increased in IGE, and SCS in afferent fibers in posterior limb of internal capsule from parietal cortex was decreased. Decreased FA and increased MD and RD were observed in cerebello-cerebral tracts. Besides, decreased cerebellar FC with putamen and motor cortex was observed in IGE.Conclusion: The patients with IGE demonstrated distinct alterations in efferent and afferent pathways between cerebellum and different cerebral cortices, which might be the pathological anatomical basis for cerebellar modulation effect on epileptic activities and contribute to motor deficits.Key Points: • IGE showed decreased SCS in cerebellar efferent fibers to the sensorimotor cortex and increased SCS in efferent fibers to the occipital cortex. • Patients demonstrated increased SCS in cerebellar afferent fibers from the frontal and the occipital cortex and decreased SCS in afferent fibers from parietal cortex. • Decreased FC between motor-related regions and dentate nucleus was observed in IGE. [ABSTRACT FROM AUTHOR]

Objectives: To explore the sensitivity of potential DTI-based biomarkers in detecting microstructural changes for whole-brain white matter in early stage amyotrophic lateral sclerosis (ALS), analyze the relationship between the DTI indices and disease status, and further clarify potential brain regions for disease monitoring and clinical assessment.Methods: Thirty-three non-demented ALS patients and 32 age- and gender-matched subjects participated in this study. DTI data were acquired via 3.0T MRI scanner. Maps of diffusion-related indices including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were obtained. Tract-based spatial statistics (TBSS) were used to investigate whole-brain white matter changes of each index. Correlation analyses between both brain-wide and volume-of-interest (VOI)-wide white matter alterations and clinical factors including ALSFRS-R scores, disease duration, and progression rate were performed.Results: Compared to healthy subjects, ALS patients showed significantly increased RD, MD and reduced FA, mainly along the corticospinal tract (CST) and the body of corpus callosum (CC). Increases in RD were broader than decreases in FA, in CST of both hemispheres. Meanwhile, involvement of several extra-motor regions was also revealed by RD. Significant positive correlation between ALSFRS-R scores and FA, negative correlation between ALSFRS-R and RD were found in left CST.Conclusions: RD may be the most sensitive biomarker for the detection of early demyelination of white matter. Both RD and FA may serve as objective biomarkers for disease severity assessment. CST may be the most affected brain region in non-demented ALS.Key Points: • Changes in RD were broader than those in FA in bilateral CST. • Involvement of extra-motor regions was uncovered by RD. • FA and RD in CST were related to ALSFRS-R scores. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the potential of various metrics derived from mono-exponential model (MEM), bi-exponential model (BEM) and stretched exponential model (SEM)-based diffusion-weighted imaging (DWI) in diagnosing and differentiating the pathological subtypes and grades of uterine cervical carcinoma.Methods: 71 newly diagnosed patients with cervical carcinoma (50 cases of squamous cell carcinoma [SCC] and 21 cases of adenocarcinoma [AC]) and 32 healthy volunteers received DWI with multiple b values. The apparent diffusion coefficient (ADC), pure molecular diffusion (D), pseudo-diffusion coefficient (D*), perfusion fraction (f), water molecular diffusion heterogeneity index (alpha), and distributed diffusion coefficient (DDC) were calculated and compared between tumour and normal cervix, among different pathological subtypes and grades.Results: All of the parameters were significantly lower in cervical carcinoma than normal cervical stroma except alpha. SCC showed lower ADC, D, f and DDC values and higher D* value than AC; D and DDC values of SCC and ADC and D values of AC were lower in the poorly differentiated group than those in the well-moderately differentiated group.Conclusion: Compared with MEM, diffusion parameters from BEM and SEM may offer additional information in cervical carcinoma diagnosis, predicting pathological tumour subtypes and grades, while f and D showed promising significance.Key Points: • DWI-derived parameters by different models are related but provide diversified information. • Commonly used ADC by MEM of DWI overestimates the tissue water diffusivity. • DWI processed by BEM could separate blood perfusion from true diffusion effects. • The derived diffusion-related and perfusion-related parameters by BEM are superior to ADC. [ABSTRACT FROM AUTHOR]