Magnetic resonance scoring system for assessment of adnexal masses: added value of diffusion-weighted imaging including apparent diffusion coefficient map.

OBJECTIVES: To validate prospectively the ADNEX magnetic resonance (MR) scoring system to assess adnexal masses and to evaluate a new, modified ADNEX MR scoring system that incorporates diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) mapping. METHODS: Between January 2015 and September 2018, 323 consecutive women with adnexal masses diagnosed on transvaginal ultrasound (TVS) underwent standardized MR imaging (MRI) including diffusion and dynamic contrast-enhanced sequences. Of these, 131 underwent subsequent surgery. For interpretation of the MRI examinations, we applied the five-category ADNEX MR scoring system, along with a modified scoring system including DWI with ADC mapping. For both scoring systems, a score was given for all adnexal masses. Histological diagnosis was considered as the gold standard and lesions were classified as benign or malignant. The difference between the predictive values for diagnosing malignancy of the classical and modified scoring systems was assessed on the basis of the areas under the receiver-operating-characteristics (AUC) curves. The sensitivity and specificity for diagnosing malignancy of each score were also calculated. RESULTS: Among the 131 women with adnexal mass(es) diagnosed on TVS who underwent MRI and subsequent surgery, the surgery revealed 161 adnexal masses in 126 women; five women had no mass. Histological examination confirmed 161 adnexal masses, of which all had been detected on MRI: 32 malignant tumors, 15 borderline tumors, which were classified as part of the malignant group (n = 47), and 114 benign lesions. The AUC for prediction of a malignant lesion was 0.938 (95% CI, 0.902-0.975) using the classical ADNEX MR scoring system and 0.974 (95% CI, 0.953-0.996) using the modified scoring system. Pairwise comparison of these AUCs revealed a significant difference (P = 0.0032). The sensitivity and specificity for diagnosing malignancy with an ADNEX MR score of 4 or more were 95.5% and 86.6%, respectively, using the classic scoring system, and 95.7% and 93.3%, respectively, using the modified scoring system. CONCLUSION: DWI with ADC mapping could be integrated into the ADNEX MR scoring system to improve specificity, thereby potentially optimizing clinical management by avoiding unnecessary surgery. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Gender differences in language and motor-related fibers in a population of healthy preterm neonates at term-equivalent age: a diffusion tensor and probabilistic tractography study.

BACKGROUND AND PURPOSE: Sex differences in white matter structure are controversial. In this MR imaging study, we aimed to investigate possible sex differences in language and motor-related tracts in healthy preterm neonates by using DTI and probabilistic tractography. MATERIALS AND METHODS: Thirty-eight preterm neonates (19 boys and 19 girls, age-matched), healthy at term-equivalent age and at 12 months were included. TBV was measured individually. Probabilistic tractography provided tract volumes, relative tract volumes (volume normalized to TBV), FA, MD, and λ(⊥) in the SLF, in the TRs, and in the CSTs. Data were compared by using independent t tests, and Bonferroni corrections were performed to adjust for multiple comparisons. RESULTS: We showed that healthy preterm boys had larger TBV than girls. However, girls had statistically significantly larger relative tract volumes than boys bilaterally in the parieto-temporal SLF, and in the left CST. Moreover, in the left parieto-temporal SLF, a trend toward lower MD and λ(⊥) was observed in females. CONCLUSIONS: Structural sex differences were found in preterm neonates at term-equivalent age in both sides of the parieto-temporal SLF and in the left CST. Further studies are necessary to investigate whether these structural differences are related to later sex differences in language skills and handedness or to the effect of prematurity.

Maturation of thalamic radiations between 34 and 41 weeks' gestation: a combined voxel-based study and probabilistic tractography with diffusion tensor imaging.

BACKGROUND AND PURPOSE: This study aimed to investigate brain maturation along gestational age with diffusion tensor imaging in healthy preterm and term neonates. Therefore, a voxel-based study of fractional anisotropy (FA) and mean diffusivity (D(av)) was performed to reveal the brain regions experiencing microstructural changes with age. With tractography, the authors intended to identify which fiber tracts were included in these significant voxels. MATERIALS AND METHODS: There were 22 healthy preterm and 6 healthy term infants who underwent MR imaging between 34 and 41 weeks of gestation. A statistical parametric approach was used to evidence the effect of age on regional distribution of FA and D(av) values. The fiber tracts suspected to be included in the significant clusters of voxels were identified with neuroanatomy and tractography atlases, reconstructed with probabilistic tractography, and superimposed on the parametric maps. RESULTS: Parametric analysis showed that FA increases with age in the subcortical projections from the frontal (motor and premotor areas) and parietal cortices, the centrum semiovale, the anterior and posterior arms of the internal capsules, the optic radiations, the corpus callosum, and the thalami (P < .05, corrected). Superimposition of the parametric maps on tractography showed that the corticospinal tract (CST); the callosal radiations (CR); and the superior, anterior, and posterior thalamic radiations were included in the significant voxels. No statistically significant results were found for D(av) maps. CONCLUSIONS: These results highlight that, besides the already-evidenced FA increase in the CST and CR, the thalami and the thalamic radiations experience microstructural changes in the early development of the human brain.

Stereotactic comparison among cerebral blood volume, methionine uptake, and histopathology in brain glioma.

BACKGROUND AND PURPOSE: Vascularity, metabolism, and histologic grade are related in gliomas but the exact determinants of these relationships are not fully defined. We used image coregistration and stereotactic biopsies to regionally compare cerebral blood volume (CBV) and (11)C-methionine (MET) uptake measurements in brain gliomas and to assess their relationship by histopathologic examination. MATERIALS AND METHODS: Fourteen patients with brain gliomas underwent MR imaging, including dynamic susceptibility contrast-enhanced MR and positron-emission tomography (PET) using MET acquired in identical stereotactic conditions before biopsy. MR-based CBV maps were calculated and both CBV maps and PET images were coregistered to anatomic images. Sixty-five biopsy samples were obtained on trajectories targeted toward high MET uptake area. The following histopathologic features were semiquantified in each sample: mitotic activity, endothelial proliferation, cellular pleomorphism, and tumor necrosis. CBV and MET uptake values were measured in the biopsy area and normalized to contralateral white matter. CBV ratios were compared with MET uptake ratios, and both measurements were compared with histologic features of each sample. RESULTS: CBV ratios ranged from 0.08 to 10.24 (median = 1.73), and MET uptake ratios ranged from 0.30 to 4.91 (median = 1.67). There was a positive correlation between CBV ratios and MET uptake ratios (r = 0.65, P < .001). Both CBV and MET uptake ratios were found to be significantly related to endothelial proliferation and mitotic activity (P < .01). CONCLUSION: Within glial tumors, there is a local relationship between CBV and MET uptake measurements. Both provide indices of focal malignant activity.

Fat attenuation using a dual steady-state balanced-SSFP sequence with periodically variable flip angles.

A refocused-SSFP sequence based on balanced-FFE (TrueFisp, Fiesta) that attenuates fat signal is presented. The sequence uses periodically variable flip angles and produces a dual steady state of the signal, which is obtained after a dual transient phase if an appropriate preparation is used. The off-resonance profile of the steady-state signal exhibits large stopbands that can be employed for fat suppression. Numerical simulations were performed to investigate the signal behavior and the off-resonance properties of the sequence. Experimental results obtained with a Philips Gyroscan Intera 1.5T MR scanner demonstrated fat attenuation in phantoms and abdominal images in volunteers.

Functional MRI activation of somatosensory and motor cortices in a hand-grafted patient with early clinical sensorimotor recovery.

The aim of this study was to investigate somatosensory and motor cortical activity with functional MRI (fMRI) in a hand-grafted patient with early clinical recovery. The patient had motor fMRI examinations before transplantation, and motor and passive tactile stimulations after surgery. His normal hand and a normal group were studied for comparison. A patient with complete brachial plexus palsy was studied to assess the lack of a fMRI signal in somatosensory areas in the case of total axonal disconnection. Stimulating the grafted hand revealed significant activation in the contralateral somatosensory cortical areas in all fMRI examinations. The activation was seen as early as 10 days after surgery; this effect cannot be explained by the known physiological mechanisms of nerve regeneration. Although an imagination effect cannot be excluded, the objective clinical recovery of sensory function led us to formulate the hypothesis that a connection to the somatosensory cortex was rapidly established. Additional cases and fundamental studies are needed to assess this hypothesis, but several observations were compatible with this explanation. Before surgery, imaginary motion of the amputated hand produced less intense responses than executed movements of the intact hand, whereas the normal activation pattern for right-handed subjects was found after surgery, in agreement with the good clinical motor recovery.