Standard MRI Research Articles

Longitudinal tracking of axonal loss using diffusion magnetic resonance imaging in multiple sclerosis.

Axonal loss in the CNS is a key driver of progressive neurological impairments in people with multiple sclerosis. Currently, there are no established methods for tracking axonal loss clinically. This study aimed to determine the sensitivity of longitudinal diffusion MRI-derived fibre-specific measures of axonal loss in people with multiple sclerosis. Fibre measures were derived from diffusion MRI acquired as part of a standard radiological MRI protocol and were compared (i) to establish measures of neuro-axonal degeneration: brain parenchymal fraction and retinal nerve fibre layer thickness and (ii) between different disease stages: clinically isolated syndrome and early/late relapsing–remitting multiple sclerosis. Retrospectively identified data from 59 people with multiple sclerosis (18 clinically isolated syndrome, 22 early and 19 late relapsing–remitting) who underwent diffusion MRI as part of their routine clinical monitoring were collated and analysed. Twenty-six patients had 1-year and 14 patients had a 2-year follow-up. Brain parenchymal fraction was calculated from 3D MRI scans, and fibre-specific measures were calculated from diffusion MRI using multi-tissue constrained spherical deconvolution. At each study visit, patients underwent optical coherence tomography to determine retinal nerve fibre layer thickness, and standard neurological assessment expanded the disability status scale. We found a significant annual fibre-specific neuro-axonal degeneration (mean ± SD = −3.49 ± 3.32%, P < 0.001) that was ∼7 times larger than the annual change of brain parenchymal fraction (−0.53 ± 0.95%, P < 0.001), and more than four times larger than annual retinal nerve fibre layer thinning (−0.75 ± 2.50% P = 0.036). Only fibre-specific measures showed a significant difference in annual degeneration between the disease stages (P = 0.029). Reduced brain parenchymal fraction, retinal nerve fibre layer thickness and fibre-specific measures were moderately related to higher expanded disability status scale (rho = −0.368, rho = −0.408 and rho = −0.365, respectively). Fibre-specific measures can be measured from data collected within a standard radiological multiple sclerosis study and are substantially more sensitive to longitudinal change compared with brain atrophy and retinal nerve fibre layer thinning.

Synthetic correlated diffusion imaging hyperintensity delineates clinically significant prostate cancer

Prostate cancer (PCa) is the second most common cancer in men worldwide and the most frequently diagnosed cancer among men in more developed countries. The prognosis of PCa is excellent if detected at an early stage, making early screening crucial for detection and treatment. In recent years, a new form of diffusion magnetic resonance imaging called correlated diffusion imaging (CDI) was introduced, and preliminary results show promise as a screening tool for PCa. In the largest study of its kind, we investigate the relationship between PCa presence and a new variant of CDI we term synthetic correlated diffusion imaging (CDI^s), as well as its performance for PCa delineation compared to current standard MRI techniques [T2-weighted (T2w) imaging, diffusion-weighted imaging (DWI), and dynamic contrast-enhanced (DCE) imaging] across a cohort of 200 patient cases. Statistical analyses reveal that hyperintensity in CDI^s is a strong indicator of PCa presence and achieves strong delineation of clinically significant cancerous tissue compared to T2w, DWI, and DCE. These results suggest that CDI^s hyperintensity may be a powerful biomarker for the presence of PCa, and may have a clinical impact as a diagnostic aid for improving PCa screening.

Macromolecular Proton Fraction as a Myelin Biomarker: Principles, Validation, and Applications.

Macromolecular proton fraction (MPF) is a quantitative MRI parameter describing the magnetization transfer (MT) effect and defined as a relative amount of protons bound to biological macromolecules with restricted molecular motion, which participate in magnetic cross-relaxation with water protons. MPF attracted significant interest during past decade as a biomarker of myelin. The purpose of this mini review is to provide a brief but comprehensive summary of MPF mapping methods, histological validation studies, and MPF applications in neuroscience. Technically, MPF maps can be obtained using a variety of quantitative MT methods. Some of them enable clinically reasonable scan time and resolution. Recent studies demonstrated the feasibility of MPF mapping using standard clinical MRI pulse sequences, thus substantially enhancing the method availability. A number of studies in animal models demonstrated strong correlations between MPF and histological markers of myelin with a minor influence of potential confounders. Histological studies validated the capability of MPF to monitor both demyelination and re-myelination. Clinical applications of MPF have been mainly focused on multiple sclerosis where this method provided new insights into both white and gray matter pathology. Besides, several studies used MPF to investigate myelin role in other neurological and psychiatric conditions. Another promising area of MPF applications is the brain development studies. MPF demonstrated the capabilities to quantitatively characterize the earliest stage of myelination during prenatal brain maturation and protracted myelin development in adolescence. In summary, MPF mapping provides a technically mature and comprehensively validated myelin imaging technology for various preclinical and clinical neuroscience applications.

3D pseudo-continuous arterial spin labeling-MRI (3D PCASL-MRI) in the differential diagnosis between glioblastomas and primary central nervous system lymphomas.

The aim of the study was to compare the parameters of blood flow in glioblastomas and primary central nervous system lymphomas (PCNSLs), measured by pseudo-continuous arterial spin labeling MRI (3D PCASL), and to determine the informativeness of this method in the differential diagnosis between these lesions. The study included MRI data of 139 patients with PCNSL (n = 21) and glioblastomas (n = 118), performed in the Burdenko Neurosurgical Center. No patients received chemotherapy, hormone therapy, or radiation therapy prior to MRI. On the 3D PCASL perfusion map, the absolute and normalized values of tumor blood flow were calculated in the glioblastoma and PCNSL groups (maxTBFmean and nTBF). MaxTBFmean and nTBF in the glioblastoma group were significantly higher than those in the PCNSL group: 168.9ml/100g/min versus 65.6 and 9.3 versus 3.7, respectively (p < 0.001). Arterial spin labeling perfusion had high sensitivity (86% for maxTBFmean, 95% for nTBF) and specificity (77% for maxTBFmean, 73% for nTBF) in the differential diagnosis between PCNSL and glioblastomas. Blood flow thresholds were 98.9ml/100g/min using absolute blood flow values and 6.1 using normalized values, AUC > 0.88. The inclusion of 3D PCASL in the standard MRI protocol can increase the specificity of the differential diagnosis between glioblastomas and PCNSL.

Diagnostic accuracy of vesical imaging-reporting and data system (VI-RADS) in suspected muscle invasive bladder cancer: A systematic review and diagnostic meta-analysis.

To investigate the accuracy of Vesical Imaging-Reporting and Data System (VI-RADS) in detection of muscle-invasive bladder cancer (MIBC) we performed a systematic review and meta-analysis of the available literature. Scopus, Web of Science, PubMed, and EMBASE were searched up to 8 March 2021 for the studies evaluating the diagnostic performance of VI-RADS for the detection of MIBC. Inclusion criteria were patients with bladder cancer; index test of VI-RADS based on multiparametric MRI; reference test of histopathological findings from TURBT, re-TURBT, or cystectomy and study design of cohort. Case reports, review articles, and editorials were eliminated, as well as studies with insufficient knowledge to acquire TP, FP, FN, and TN values of VI-RADS. The MIDAS module of STATA was for statistical analysis. The heterogeneity was explored using subgroup analysis and meta-regression analysis. Overall, 22 eligible studies, consisting of 2,576 participants and 5,414 MRI reports, were included in this meta-analysis. The area under curve (AUC) of VI-RADS at cut-point values of 3 and 4 were 0.93 (95%CI: 0.91, 0.95), 0.93 (95%CI: 0.90, 0.95), respectively. Based on Youden's J statistic, the optimal VI-RADS cutoff value for predicting MIBC was determined as 3 which granted a pooled sensitivity of 89% (95%CI: 87%, 91%; I2=48%) and a specificity of 84% (95%CI: 80%, 87%; I2=90%). Based on meta-regression, the sources of inter-study heterogeneity for VI-RADS ≥ 3 were the sample size > 70, study design, single-center vs multi-center, patient population characteristics (i.e., gender, age), reference standard, histology, magnetic strength, T2WI slice thickness, and the number of radiologists reporting the MRI results (P value ≤ 0.01). The VI-RADS demonstrates consistently high diagnostic accuracy to predict MIBC. This scoring system could be applied in standard staging MRI reports of bladder cancer and can be incorporated into future MIBC work up guidelines.

Impact of Brain MRI Markers on Major and Mild Vascular Cognitive Impairment in CADASIL

Background: Cognitive impairment is the second most common clinical manifestation in cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). However, understanding of cognitive impairment in CADASIL has been hampered by lack of consensus on diagnosis of vascular cognitive impairment (VCI). We used vascular impairment of cognition classification consensus study principles (VICCCS-1) and protocols (VICCCS-2) to assess the cognitive impairment in CADASIL. We also evaluated the impact of MRI markers on major and mild VCI in CADASIL.Methods: We prospectively recruited 64 patients who underwent standardized brain MRI and detailed neuropsychological test. MRI analysis included number of lacunes, number of cerebral microbleeds (CMB), normalized volume of white-matter hyperintensities (nWMH), and brain parenchymal fraction (BPF). BPF has been used to measure brain atrophy. The patients were divided into three groups: those with normal cognition (CADASIL-NC, n=14), those with mild VCI (CADASIL-mild VCI, n=38), and those with major VCI (CADASIL-major VCI, n=11).Results: The three groups differed according to age, with the major VCI group being older. The major VCI group had more lacunes, more CMB, more extensive white matter lesions and lower BPF than NC group. There were no significant differences between NC and mild VCI groups in BPF. BPF and age were the independent predictors of major VCI. There was a tendency that women were at higher risk for mild VCI, though it did not reach statistical significance. Women were older than men, but had lower number of lacunes in mild VCI.Conclusions: These findings suggest that brain atrophy and age are the main predictors of major VCI in CADASIL.

CT-like MRI: a qualitative assessment of ZTE sequences for knee osseous abnormalities.

To qualitatively evaluate the utility of zero echo-time (ZTE) MRI sequences in identifying osseous findings and to compare ZTE with optimized spoiled gradient echo (SPGR) sequences in detecting knee osseous abnormalities. ZTE and standard knee MRI sequences were acquired at 3T in 100 consecutive patients. Three radiologists rated confidence in evaluating osseous abnormalities and image quality on a 5-grade Likert scale in ZTE compared to standard sequences. In a subset of knees (n = 57) SPGR sequences were also obtained, and diagnostic confidence in identifying osseous structures was assessed, comparing ZTE and SPGR sequences. Statistical significance of using ZTE over SPGR was characterized with a paired t-test. Image quality of the ZTE sequences was rated high by all reviewers with 278 out of 299 (100 studies, 3 radiologists) scores ≥ 4 on the Likert scale. Diagnostic confidence in using ZTE sequences was rated "very high confidence" in 97%, 85%, 71%, and 73% of the cases for osteophytosis, subchondral cysts, fractures, and soft tissue calcifications/ossifications, respectively. In 74% of cases with osseous findings, reviewer scores indicated confidence levels (score ≥ 3) that ZTE sequences improved diagnostic certainty over standard sequences. The diagnostic confidence in using ZTE over SPGR sequences for osseous structures as well as abnormalities was favorable and statistically significant (p < 0.01). Incorporating ZTE sequences in the standard knee MRI protocol was technically feasible and improved diagnostic confidence for osseous findings in relation to standard MR sequences. In comparison to SPGR sequences, ZTE improved assessment of osseous abnormalities.

3D-T2W-TSE radiotherapy treatment planning MRI using compressed sensing acceleration for prostate cancer: Image quality and delineation value.

To assess the image quality and delineation value of compressed sensing (CS)-accelerated 3D T2W turbo-spin-echo (TSE) sequence for radiotherapy treatment planning (RTP) of prostate cancer. An optimized CS-accelerated 3D-T2W-TSE was determined by volunteer imaging and applied for clinical RTP-MRI. This optimized CS-accelerated planning MRI and the standardized adaptive MRI acquired at 1.5T were retrospectively analyzed in 26 prostate cancer patients who were to receive MR-guided radiotherapy. Signal-to-noise ratio (SNR) and relative contrast ratio (CR) were quantitatively assessed. Image quality and artifacts were qualitatively assessed using a five-point scale rating. Delineation value in the prostate and organs-at-risk (OARs) was also rated and compared. Wilcoxon signed-rank test was used for SNR, relative CR, and rating comparisons. The interobserver rating agreement was evaluated by percent agreement. Significantly better SNR and relative CR in the prostate, rectum, bowel, penis, and penile bulb, while significantly worse in the cauda equina, were observed on the planning MRI. Significantly better ratings of image quality and artifacts were given to the planning MRI, with much less Gibbs ringing and reconstruction artifacts. Significantly better delineation value rating was achieved on the planning MRI in the prostate, seminal vesicle, rectum, penis, penile bulb, and testes, while significantly worse in the cauda equina. A strong to almost perfect interobserver rating agreement was obtained. This study suggested that CS acceleration is applicable and valuable in prostate RTP-MRI. CS-accelerated 3D-T2W-TSE images should benefit the delineation of prostate and many OARs.

Diagnostic Accuracy of Abbreviated Bi-Parametric MRI (a-bpMRI) for Prostate Cancer Detection and Screening: A Multi-Reader Study.

(1) Background: There is currently limited evidence on the diagnostic accuracy of abbreviated biparametric MRI (a-bpMRI) protocols for prostate cancer (PCa) detection and screening. In the present study, we aim to investigate the performance of a-bpMRI among multiple readers and its potential application to an imaging-based screening setting. (2) Methods: A total of 151 men who underwent 3T multiparametric MRI (mpMRI) of the prostate and transperineal template prostate mapping biopsies were retrospectively selected. Corresponding bpMRI (multiplanar T2WI, DWI, ADC maps) and a-bpMRI (axial T2WI and b 2000 s/mm2 DWI only) dataset were derived from mpMRI. Three experienced radiologists scored a-bpMRI, standard biparametric MRI (bpMRI) and mpMRI in separate sessions. Diagnostic accuracy and interreader agreement of a-bpMRI was tested for different positivity thresholds and compared to bpMRI and mpMRI. Predictive values of a-bpMRI were computed for lower levels of PCa prevalence to simulate a screening setting. The primary definition of clinically significant PCa (csPCa) was Gleason ≥ 4 + 3, or cancer core length ≥ 6 mm. (3) Results: The median age was 62 years, the median PSA was 6.8 ng/mL, and the csPCa prevalence was 40%. Using a cut off of MRI score ≥ 3, the sensitivity and specificity of a-bpMRI were 92% and 48%, respectively. There was no significant difference in sensitivity compared to bpMRI and mpMRI. Interreader agreement of a-bpMRI was moderate (AC1 0.58). For a low prevalence of csPCa (e.g., <10%), higher cut offs (MRI score ≥ 4) yield a more favourable balance between the predictive values and positivity rate of MRI. (4) Conclusion: Abbreviated bpMRI protocols could match the diagnostic accuracy of bpMRI and mpMRI for the detection of csPCa. If a-bpMRI is used in low-prevalence settings, higher cut-offs for MRI positivity should be prioritised.

Dynamic contrast-enhanced magnetic resonance imaging for evaluating early response to radiosurgery in patients with vestibular schwannoma.

This study aimed to use dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to evaluate early treatment response in vestibular schwannoma (VS) patients after radiosurgery. Twenty-four VS patients who underwent gamma knife radiosurgery were prospectively followed up for at least four years. DCE-MRI sequences, in addition to standard MRI protocol, were obtained prior to radiosurgery, at 3 and 6months. Conventionally, treatment responses based on tumor volume changes were classified as regression or stable (RS), transient tumor enlargement (TTE), and continuous tumor enlargement (CTE). DCE-MRI parameters, such as Ktrans, Kep and Ve, were compared according to follow-up periods and between groups. The diagnostic performance was tested using receiver operating characteristic (ROC) curves. Changes in tumor volume were as follows at the last 48 months of follow-up: RS in 11 patients (45.8%), TTE in 10 patients (41.7%), and CTE in three patients (12.5%). The median time required to distinguish TTE from CTE using conventional MRI was 12months (range 9-18). The Ktrans and Ve were significantly decreased in patients with RS and TTE at 3 and 6months, but did not differ significantly in patients with CTE. There were no significant differences in Ktrans and Ve between patients with RS and TTE at 3 and 6months. Both Ktrans and Ve demonstrated high diagnostic performance in evaluating early treatment response to radiosurgery in patients with VS. DCE-MRI may aid in the monitoring and early prediction of treatment response in patients with VS following radiosurgery.

Perfusion-Diffusion Ratio: A New IVIM Approach in Differentiating Solid Benign and Malignant Primary Lesions of the Liver.

Introduction In order to improve the efficacy of intravoxel incoherent motion (IVIM) parameters in characterising specific tissues, a new concept is introduced: the perfusion–diffusion ratio (PDR), which expresses the relationship between the signal S(b) decline rate as a result of IVIM and the rate of signal S(b) decline due to diffusion. The aim of this study was to investigate this novel approach in the differentiation of solid primary liver lesions. Material and Methods. Eighty-three patients referred for liver MRI between August 2017 and January 2020 with a suspected liver tumour were prospectively examined with the standard liver MRI protocol extended by DWI-IVIM sequence. Patients with no liver lesions, haemangiomas, or metastases were excluded. The final study population consisted of 34 patients with primary solid liver masses, 9 with FNH, 4 with regenerative nodules, 10 with HCC, and 11 with CCC. The PDR coefficient was introduced, defined as the ratio of the rate of signal S(b) decrease due to the IVIM effect to the rate of signal S(b) decrease due to the diffusion process, for b = 0. Results No significant differences were found between benign and malignant lesions in the case of IVIM parameters (f, D, or D∗) and ADC. Significant differences were observed only for PDR, with lower values for malignant lesions (p = 0.03). The ROC analysis yielded an AUC value for PDR equal to 0.74, with a cut-off value of 5.06, sensitivity of 81%, specificity of 77%, and accuracy of 79%. Conclusion PDR proved to be more effective than IVIM parameters and ADC in the differentiation of solid benign and malignant primary liver lesions.

Staging of Endometrial Cancer Using Fusion T2-Weighted Images with Diffusion-Weighted Images: A Way to Avoid Gadolinium?

Simple SummaryThis work aims to evaluate the utility of fusing T2-weighted images with diffusion-weighted images to determinate the depth of myometrial invasion and the stage of endometrial cancer. By showing its superior diagnostic performance, we aim to encourage its use in endometrial cancer staging, and, in the future, obviate the need for intravenous contrast medium administration.Endometrial cancer is the eighth most common cancer worldwide, and its prognosis depends on various factors, with myometrial invasion having a major impact on prognosis. Optimizing MRI protocols is essential, and it would be useful to improve the diagnostic accuracy without the need for other sequences. We conducted a retrospective, single-center study, which included a total of 87 patients with surgically confirmed primary endometrial cancer, and who had undergone a pre-operative pelvic MRI. All exams were read by an experienced radiologist dedicated to urogenital radiology, and the depth of myometrial invasion was evaluated using T2-Weighted Images (T2WI) and fused T2WI with Diffusion-Weighted Images (DWI). Both results were compared to histopathological evaluations. When comparing both sets of imaging (T2WI and fused T2WI-DWI images) in diagnosing myometrial invasion, the fused images had better accuracy, and this difference was statistically significant (p < 0.001). T2WI analysis correctly diagnosed 82.1% (70.6–88.7) of cases, compared to 92.1% correctly diagnosed cases with fused images (79.5–97.2). The addition of fused images to a standard MRI protocol improves the diagnostic accuracy of myometrial invasion depth, encouraging its use, since it does not require more acquisition time.

Diagnostic accuracy of wrist MRI in comparison to wrist arthroscopy regarding TFCC lesions in clinical practice.

The purpose of this study was to arthroscopically verify MRI diagnostic accuracy for triangular fibrocartilage complex (TFCC) lesions in a regular clinical environment. A total of 859 patients' data with both preoperative MRI of the wrist and additional wrist arthroscopy were retrospectively reviewed. Two board-certified hand surgeons and one orthopaedic surgeon executed wrist arthroscopy, whereas more than 100 radiologists examined the MRI of the wrist. The accordance of TFCC lesion classification using MRI in comparison to wrist arthroscopy and diagnostic precision of the former depending on technical details were evaluated. Diagnostic accuracy of MRI for TFCC lesions is poor in comparison to wrist arthroscopy as the reference standard. Technical specifications for MRI of the wrist are heterogeneous among the radiologists. These parameters have not improved accuracy of TFCC evaluation at large. The accuracy of MRI in a regular clinical environment still remains inferior to wrist arthroscopy for detection of TFCC lesions. Development of a standard MRI protocol may be implemented on a regular basis and application of the Palmer classification for TFCC lesion should be sought.

Value rapid magnetic resonance imaging protocol for detecting femoral head avascular necrosis in high risk patient

Purpose: Evaluate the agreement between limited MRI, which using T1W sequence or STIR sequence in coronal direction, with standard MRI in diagnosis early femoral head necrosis(FHN) occurring in high riskpatients.Subjects and methods: descriptive cross-sectional study was performed on 58 patients, who warediagnosed of femoral head osteonecrosis at stage 2 or higher according to the Arlet Ficat classification. The patients were performed hip joints MRI at the Radiology Center, Bach Mai Hospital from June 2020 to August 2021.Results: The agreement in FHN staggingbetween limited MRI using T1Wsequence, or limited MRI using STIR sequence with the standard MRI was 0.98 and 0.86, respectively. The agreement in measurement extent of osteonecrosis areabetween limited MRI using T1Wsequence, or limited MRI using STIR sequence with the standard MRI was 0.98 and 0.85.Conclusion: There was excellent agreement between the full and limited MR examinations both forstagging and determining the extent of osteonecrosis area. The time and potential cost reduction achieved when taking limited MRImay lead to more widespread using in patient care.

Impact of white-matter mask selection on DTI histogram-based metrics as potential biomarkers in cerebral small vessel disease.

Histogram-based metrics extracted from diffusion-tensor imaging (DTI) have been suggested as potential biomarkers for cerebral small vessel disease (SVD), but methods and results have varied across studies. This work aims to assess the impact of mask selection for extracting histogram-based metrics of fractional anisotropy (FA) and mean diffusivity (MD) on their sensitivity as SVD biomarkers. DTI data were collected from 17 SVD patients and 12 healthy controls. FA and MD maps were estimated; from these, histograms were computed on two whole-brain white-matter masks: normal-appearing white-matter (NAWM) and mean FA tract skeleton (TBSS). Histogram-based metrics (median, peak height, peak width, peak value) were extracted from the FA and MD maps. These were compared between groups and correlated with the patients' cognitive scores (executive function and processing speed). White-matter mask selection significantly impacted FA and MD histogram metrics. In particular, significant interactions were found between Mask and Group for FA peak height (p = 0.027), MD Median (p = 0.035) and MD peak width (p = 0.047); indicating that the mask used affected their ability to discriminate between groups. In fact, MD peak width showed a significant 8.8% increase in patients when using TBSS (p = 0.037), but not when using NAWM (p = 0.69). Moreover, the mask may have an effect on the correlations with cognitive measures. Nevertheless, MD peak width (TBSS: r = - 0.75, NAWM: r = - 0.71) and MD peak height (TBSS: r = 0.65, NAWM: r = 0.62) remained significantly correlated with executive function, regardless of the mask. The impact of the processing methodology, in particular the choice of white-matter mask, highlights the need for standardized MRI data-processing pipelines.

A detailed manual segmentation procedure for the hypothalamus for 3T T1-weighted MRI

The hypothalamus is a small grey matter structure which plays a crucial role in many physiological functions. Some studies have found an association between hypothalamic volume and psychopathology, which stresses the need for a standardized method to maximize segmentation accuracy. Here, we provide a detailed step-by-step method outlining the procedures to manually segment the hypothalamus using anatomical T1w images from 3T scanners, which many neuroimaging studies collect as a standard anatomical reference image. We compared volumes generated by manual segmentation and those generated by an automatic algorithm, observing a significant difference between automatically and manually segmented hypothalamus volumes on both sides (left: U = 222842, p-value < 2.2e-16; right: U = 218520, p- value < 2.2e-16).•Significant difference exists between existing automatic segmentation methods and the manual segmentation procedure.•We discuss potential drift effects, segmentation quality issues, and suggestions on how to mitigate them.•We demonstrate that the present manual segmentation procedure using standard T1-weighted MRI may be significantly more accurate than automatic segmentation outputs.

"Haleem’s Hen"; A mnemonic for the anatomy of hindfoot structures at the level of sustentaculum tali on coronal T1-weighted magnetic resonance images

Magnetic resonance anatomy of the hindfoot as seen at the level of the sustentaculum tali is intricate due to surrounding muscles, tendons, aponeurosis and ligaments. The objective of this work is to provide a mnemonic with illustrative figures to simplify this complex anatomical region on coronal T1-weighted MR images (T1-MRIs).One hundred and twenty-four patients referred for foot and ankle complaints were scanned utilizing standard MRI imaging protocols for depiction of the hindfoot. Only coronal T1-MRIs of the calcaneus at the level of sustentaculum tali of unremarkably reported patients were selected for this work.Upon viewing the calcaneus with the adjacent anatomical structures on coronal T1-MRIs, the overall appearance resembles a “Hen in the Nest with Four Eggs’’. The calcaneus represents the body of the hen, while the sustentaculum tali forms the head and neck. The posterior tibial tendon represents the crest of the hen, and the flexor digitorum longus and flexor hallucis longus tendons represent its beak and wattle, respectively. The peroneus brevis and peroneus longus tendons represent the tail, and the long plantar ligament represents the flexed legs of Haleem’s hen. The plantar aponeurosis represents the hen’s nest. Whereas the abductor hallucis, flexor digitorum brevis, abductor digiti minimi and quadratus plantae muscles are the four eggs.The mnemonic, “Haleem’s Hen in the Nest with Four Eggs”, serves as a simplified phrase for radiologists and orthopedic surgeons to easily recall the anatomy of the hindfoot when viewing it at the level of the sustentaculum tali on coronal T1-MRIs.

A Robust 3-D Medical Watermarking Based on Wavelet Transform for Data Protection

In a telemedicine diagnosis system, the emergence of 3D imaging enables doctors to make clearer judgments, and its accuracy also directly affects doctors’ diagnosis of the disease. In order to ensure the safe transmission and storage of medical data, a 3D medical watermarking algorithm based on wavelet transform is proposed in this paper. The proposed algorithm employs the principal component analysis (PCA) transform to reduce the data dimension, which can minimize the error between the extracted components and the original data in the mean square sense. Especially, this algorithm helps to create a bacterial foraging model based on particle swarm optimization (BF-PSO), by which the optimal wavelet coefficient is found for embedding and is used as the absolute feature of watermark embedding, thereby achieving the optimal balance between embedding capacity and imperceptibility. A series of experimental results from MATLAB software based on the standard MRI brain volume dataset demonstrate that the proposed algorithm has strong robustness and make the 3D model have small deformation after embedding the watermark.

The Open-Access European Prevention of Alzheimer’s Dementia (EPAD) MRI dataset and processing workflow

The European Prevention of Alzheimer Dementia (EPAD) is a multi-center study that aims to characterize the preclinical and prodromal stages of Alzheimer’s Disease. The EPAD imaging dataset includes core (3D T1w, 3D FLAIR) and advanced (ASL, diffusion MRI, and resting-state fMRI) MRI sequences.Here, we give an overview of the semi-automatic multimodal and multisite pipeline that we developed to curate, preprocess, quality control (QC), and compute image-derived phenotypes (IDPs) from the EPAD MRI dataset. This pipeline harmonizes DICOM data structure across sites and performs standardized MRI preprocessing steps. A semi-automated MRI QC procedure was implemented to visualize and flag MRI images next to site-specific distributions of QC features — i.e. metrics that represent image quality. The value of each of these QC features was evaluated through comparison with visual assessment and step-wise parameter selection based on logistic regression. IDPs were computed from 5 different MRI modalities and their sanity and potential clinical relevance were ascertained by assessing their relationship with biological markers of aging and dementia.The EPAD v1500.0 data release encompassed core structural scans from 1356 participants 842 fMRI, 831 dMRI, and 858 ASL scans. From 1356 3D T1w images, we identified 17 images with poor quality and 61 with moderate quality. Five QC features — Signal to Noise Ratio (SNR), Contrast to Noise Ratio (CNR), Coefficient of Joint Variation (CJV), Foreground-Background energy Ratio (FBER), and Image Quality Rate (IQR) — were selected as the most informative on image quality by comparison with visual assessment. The multimodal IDPs showed greater impairment in associations with age and dementia biomarkers, demonstrating the potential of the dataset for future clinical analyses.

Diagnostic Performance of O-RADS MRI Scoring System for the Assessment of Adnexal Masses in Routine Clinical Radiology Practice- A Single Tertiary Centre Prospective Cohort Study

Introduction: In 2019-20, the American College of Radiology (ACR) introduced Ovarian-Adnexal Reporting and Data System Magnetic Resonance Imaging (O-RADS MRII). Application of the O-RADS MRI in routine clinical practice can increase lesion characterization accuracy, promote better interdisciplinary communication, and help in personalized patient management of adnexal masses. Aim: To assess the diagnostic performance of the ACR O-RADS MRI scoring system for the predicting malignancy in adnexal mass in routine clinical radiology practice by using histology/ imaging findings during a minimum 4 month follow-up as the reference standard. Materials and Methods: In this single- tertiary center prospective cohort study done in Jorhat Medical College, Assam, 42 patients with 46 adnexal masses who underwent MRI between April 2020 and June 2021 were assessed. The ACR O-RADS MR scores were assigned using the MRI protocol with a dynamic study. Sensitivity, specificity, positive and negative predictive values along with the area under the Receiver Operating Characteristic (ROC) curve were calculated (cut-off score ≥4 was considered malignancy,). Histopathologic diagnosis or &gt;4 months followup imaging findings was the reference standard used. Logistic regression analysis of MRI parameters used in identifying malignant masses was assessed. Statistical analysis was done using 95% confidence intervals (CIs). The p-values &lt;0.05 was considered statistically significant. Results: The mean age of subjects in the study was 35.9 (range 10-75 years), and 84.8% of adnexal masses (39) were premenopausal. Malignancy was more common in postmenopausal patients (57.1%). Of 46 lesions, 13 (33.3%) were malignant. The ACR O-RADS-MR scoring system, using a dynamic MRI protocol, showed 92.3% sensitivity and 87.8%specificity in malignancy prediction. The area under the ROC curve for predicting malignancy was 0.962. The positive and negative predictive values were 75% and 89.1%, respectively. Conclusion: In a teaching hospital in assam, the O-RADS MRI scoring system, based on a dynamic MRI protocol demonstrated good sensitivity, specificity and area under the Receiver Operator Characteristic (ROC) curve in identifying malignant adnexal masses. The ACR O-RADS MRI system enables standardized MRI reporting with uniform lexicon and interpretation guide on adnexal masses.This will help to improve communication between radiologists and referring physician and in patient management, particularly in indeterminate masses on ultrasound.