Phase-sensitive fat suppression steady-state free procession sequence with phase correction

Robust and fast fat suppression is a challenge in balanced steady-state free precession （SSFP） magnetic resonance imaging. Although single-acquisition phase-sensitive SSFP can provide fat-suppressed images in short scan time, phase errors, especially spatially-dependent phase shift, caused by a variety of factors may result in misplacement of fat and water voxels. In this paper, a novel phase correction algorithm was used to calibrate those phase errors during image reconstruction. This algorithm corrects phase by region growing, employing both the magnitude and the phase information of image pixels. Phantom and in vivo imagings were performed to validate the technique. As a result, excellent fat-suppressed images were acquired by using single-acquisition phase-sensitive SSFP with phase correction.

Advancing gastrointestinal stromal tumor management: The role of imagomics features in precision risk assessment

BACKGROUND Gastrointestinal stromal tumors(GISTs)vary widely in prognosis,and traditional pathological assessments often lack precision in risk stratification.Advanced imaging techniques,especially magnetic resonance imaging(MRI),offer potential improvements.This study investigates how MRI imagomics can enhance risk assessment and support personalized treatment for GIST patients.AIM To assess the effectiveness of MRI imagomics in improving GIST risk stratification,addressing the limitations of traditional pathological assessments.METHODS Analyzed clinical and MRI data from 132 GIST patients,categorizing them by tumor specifics and dividing into risk groups.Employed dimension reduction for optimal imagomics feature selection from diffusion-weighted imaging(DWI),T1-weighted imaging(T1WI),and contrast enhanced T1WI with fat saturation(CET1WI)fat suppress(fs)sequences.RESULTS Age,lesion diameter,and mitotic figures significantly correlated with GIST risk,with DWI sequence features like sphericity and regional entropy showing high predictive accuracy.The combined T1WI and CE-T1WI fs model had the best predictive efficacy.In the test group,the DWI sequence model demonstrated an area under the curve(AUC)value of 0.960 with a sensitivity of 80.0%and a specificity of 100.0%.On the other hand,the combined performance of the T1WI and CE-T1WI fs models in the test group was the most robust,exhibiting an AUC value of 0.834,a sensitivity of 70.4%,and a specificity of 85.2%.CONCLUSION MRI imagomics,particularly DWI and combined T1WI/CE-T1WI fs models,significantly enhance GIST risk stratification,supporting precise preoperative patient assessment and personalized treatment plans.The clinical implications are profound,enabling more accurate surgical strategy formulation and optimized treatment selection,thereby improving patient outcomes.Future research should focus on multicenter studies to validate these findings,integrate advanced imaging technologies like PET/MRI,and incorporate genetic factors to achieve a more comprehensive risk assessment.

Age-related Marrow Conversion and Developing Epiphysis in the Proximal Femur: Evaluation with STIR MR Imaging

In order to observe the feature of age-related marrow conversion and maturation of epiphyseal cartilage and analyze the distribution of red and yellow marrow in the proximal femur at STIR MR imaging, STIR and T1 weighted MR imaging of the proximal femur in 52 subjects, aged 4 months to 25 years old, were retrospectively analyzed for the distribution and appearance of red and yellow marrow. The subjects with no known bone marrow abnormalities were divided into 6 age groups. The signal intensity of the marrow in the proximal epiphysis, proximal metaphysis, proximal diaphysis, distal diaphysis and greater trochanter was compared with the signal intensity and homogeneity of surrounding muscle and fat and graded by two observers. The results showed that the conversion of hematopoietic marrow in the proximal femur followed a well-defined sequence, occurring first in the proximal epiphysis, followed by the distal diaphysis, and then greater trochanter and metaphysis. STIR in combination with T1-weighted imaging could display clearly the origin of ossification center and the course of conversion from red to yellow marrow in proximal epiphysis and greater trochanter. STIR imaging showed that the marrow conversion in proximal metaphysic began below epiphyseal plate and intertrochanter. The site of red yellow was distributed in weight-bearing axis by 20 years of age. The marrow conversion of diaphysis was from distal end to proximal end, and the consequence of conversion was that distal diaphysis contained yellow marrow but proximal diaphysis partly red marrow connected with the red marrow of metaphysic. The epiphyseal cartilage had different characters of signal-intensity with age in STIR sequence. The distribution of red marrow in STIR imaging was more close to that of anatomy than T1-weighted imaging. It was concluded that STIR could dynamically display the feature of morrow conversion and the development of epiphyseal cartilage and accurately reveal the age-related distribution of red and yellow marrow on STIR imaging in the proximal femur.