MR Examinations Research Articles

CPT® Codes for MRI Safety - A User's Guide.

The magnetic fields of the MR environment present unique safety challenges. Medical implants and retained foreign bodies can prevent patients from undergoing MR imaging due to interactions between the magnetic fields of the MR environment and the implant or foreign body. These hazards can be addressed through careful MR safety screening and MR examination customization, often allowing these patients with implants to undergo management-altering MR imaging. However, mitigating these risks takes additional time, expertise, and effort. Effective in 2025, this additional work is formally acknowledged with a new series of CPT® codes to report the work of assessing and addressing safety concerns associated with implants and foreign bodies in the MR environment. This user guide provides guidance on how to report these codes so physician led MR safety teams can be appropriately reimbursed for the additional work performed in preparing patients with implants or foreign bodies for MR imaging.ABBREVIATIONS: ACR = American College of Radiology™; ASNR = American Society of Neuroradiology; CPT® = Common Procedural Terminology; QHP = Qualified Healthcare Professional; ARRT® = American Registry of Radiologic Technologists; ABMRS = American Board of Magnetic Resonance Safety; MRSO = Magnetic Resonance Safety Officer; MRMD = Magnetic Resonance Medical Director; MRSE = Magnetic Resonance Safety Expert.

Motion-Compensated Multishot Pancreatic Diffusion-Weighted Imaging With Deep Learning-Based Denoising.

Pancreatic diffusion-weighted imaging (DWI) has numerous clinical applications, but conventional single-shot methods suffer from off resonance-induced artifacts like distortion and blurring while cardiovascular motion-induced phase inconsistency leads to quantitative errors and signal loss, limiting its utility. Multishot DWI (msDWI) offers reduced image distortion and blurring relative to single-shot methods but increases sensitivity to motion artifacts. Motion-compensated diffusion-encoding gradients (MCGs) reduce motion artifacts and could improve motion robustness of msDWI but come with the cost of extended echo time, further reducing signal. Thus, a method that combines msDWI with MCGs while minimizing the echo time penalty and maximizing signal would improve pancreatic DWI. In this work, we combine MCGs generated via convex-optimized diffusion encoding (CODE), which reduces the echo time penalty of motion compensation, with deep learning (DL)-based denoising to address residual signal loss. We hypothesize this method will qualitatively and quantitatively improve msDWI of the pancreas. This prospective institutional review board-approved study included 22 patients who underwent abdominal MR examinations from August 22, 2022 and May 17, 2023 on 3.0 T scanners. Following informed consent, 2-shot spin-echo echo-planar DWI (b = 0, 800 s/mm2) without (M0) and with (M1) CODE-generated first-order gradient moment nulling was added to their clinical examinations. DL-based denoising was applied to the M1 images (M1 + DL) off-line. ADC maps were reconstructed for all 3 methods. Blinded pair-wise comparisons of b = 800 s/mm2 images were done by 3 subspecialist radiologists. Five metrics were compared: pancreatic boundary delineation, motion artifacts, signal homogeneity, perceived noise, and diagnostic preference. Regions of interest of the pancreatic head, body, and tail were drawn, and mean ADC values were computed. Repeated analysis of variance and post hoc pairwise t test with Bonferroni correction were used for comparing mean ADC values. Bland-Altman analysis compared mean ADC values. Reader preferences were tabulated and compared using Wilcoxon signed rank test with Bonferroni correction and Fleiss κ. M1 was significantly preferred over M0 for perceived motion artifacts and signal homogeneity (P < 0.001). M0 was significantly preferred over M1 for perceived noise (P < 0.001), but DL-based denoising (M1 + DL) reversed this trend and was significantly favored over M0 (P < 0.001). ADC measurements from M0 varied between different regions of the pancreas (P = 0.001), whereas motion correction with M1 and M1 + DL resulted in homogeneous ADC values (P = 0.24), with values similar to those reported for ssDWI with motion correction. ADC values from M0 were significantly higher than M1 in the head (bias 16.6%; P < 0.0001), body (bias 11.0%; P < 0.0001), and tail (bias 8.6%; P = 0.001). A small but significant bias (2.6%) existed between ADC values from M1 and M1 + DL. CODE-generated motion compensating gradients improves multishot pancreatic DWI as interpreted by expert readers and eliminated ADC variation throughout the pancreas. DL-based denoising mitigated signal losses from motion compensation while maintaining ADC consistency. Integrating both techniques could improve the accuracy and reliability of multishot pancreatic DWI.

Differentiation of Early Sacroiliitis Using Machine-Learning- Supported Texture Analysis.

Objectives: We wished to compare the diagnostic performance of texture analysis (TA) against that of a visual qualitative assessment in identifying early sacroiliitis (nr-axSpA). Methods: A total of 92 participants were retrospectively included at our university hospital institution, comprising 30 controls and 62 patients with axSpA, including 32 with nr-axSpA and 30 with r-axSpA, who underwent MR examination of the sacroiliac joints. MRI at 3T of the lumbar spine and the sacroiliac joint was performed using oblique T1-weighted (W), fluid-sensitive, fat-saturated (Fs) T2WI images. The modified New York criteria for AS were used. Patients were classified into the nr-axSpA group if their digital radiography (DR) and/or CT results within 7 days from the MR examination showed a DR and/or CT grade < 2 for the bilateral sacroiliac joints or a DR and/or CT grade < 3 for the unilateral sacroiliac joint. Patients were classified into the r-axSpA group if their DR and/or CT grade was 2 to 3 for the bilateral sacroiliac joints or their DR and/or CT grade was 3 for the unilateral sacroiliac joint. Patients were considered to have a confirmed diagnosis if their DR or CT grade was 4 for the sacroiliac joints and were thereby excluded. A control group of healthy individuals matched in terms of age and sex to the patients was included in this study. First, two readers independently qualitatively scored the oblique coronal T1WI and FsT2WI non-enhanced sacroiliac joint images. The diagnostic efficacies of the two readers were judged and compared using an assigned Likert score, conducting a Kappa consistency test of the diagnostic results between two readers. Texture analysis models (the T1WI-TA model and the FsT2WI-TA model) were constructed through feature extraction and feature screening. The qualitative and quantitative results were evaluated for their diagnostic performance and compared against a clinical reference standard. Results: The qualitative scores of the two readers could significantly distinguish between the healthy controls and the nr-axSpA group and the nr-axSpA and r-axSpA groups (both p < 0.05). Both TA models could significantly distinguish between the healthy controls and the nr-axSpA group and the nr-axSpA group and the r-axSpA group (both p < 0.05). There was no significant difference in the differential diagnoses of the two TA models between the healthy controls and the nr-axSpA group (AUC: 0.934 vs. 0.976; p = 0.1838) and between the nr-axSpA and r-axSpA groups (AUC: 0.917 vs. 0.848; p = 0.2592). In terms of distinguishing between the healthy control and nr-axSpA groups, both the TA models were superior to the qualitative scores of the two readers (all p < 0.05). In terms of distinguishing between the nr-axSpA and r-axSpA groups, the T1WI-TA model was superior to the qualitative scores of the two readers (p = 0.023 and p = 0.007), whereas there was no significant difference between the fsT2WI-TA model and the qualitative scores of the two readers (p = 0.134 and p = 0.065). Conclusions: Based on MR imaging, the T1WI-TA and fsT2WI-TA models were highly effective for the early diagnosis of sacroiliac joint arthritis. The T1WI-TA model significantly improved the early diagnostic efficacy for sacroiliac arthritis compared to that of the qualitative scores of the readers, while the efficacy of the fsT2WI-TA model was comparable to that of the readers.

Comparison of ultrasound to MR and histological methods for liver fat quantification.

This prospective pilot study aims to evaluate the capabilities of novel quantitative ultrasound (QUS) methods based on attenuation (Att.PLUS) and sound speed (SSp.PLUS) for detecting liver fat. The study included 56 individuals with biopsy-proven steatosis (percutaneous liver biopsy) ranging from 0% to 90% of hepatocytes containing intracellular lipid vacuoles. Histopathology was considered reference standard. Abdominal QUS examinations were conducted using Att.PLUS and SSp.PLUS techniques on the Aixplorer MACH 30 system. Comparative assessments were made using the results of liver biopsy and magnetic resonance spectroscopy (MRS) together with magnetic resonance imaging proton density fat fraction (MRI-PDFF). MR examinations were performed on the Siemens VIDA 3T system. ROC analysis was conducted for two groups: (a) patients without steatosis (S0) versus those with steatosis (S1+S2+S3) yielded AUC values of 0.79 for Att.PLUS and 0.78 for SSp.PLUS, in contrast to an AUC>0.95 for MRS and MRI-PDFF; and (b) patients without or with mild steatosis (S0+S1) versus those with severe steatosis (S2+S3), yielded AUC values of 0.93 for Att.PLUS and 0.89 for SSp.PLUS, in contrast to an AUC>0.99 for MRS and MRI-PDFF. However, MR methods were superior in detecting liver fat content in obese patients and post-liver transplantation individuals. Both QUS parameters (Att.PLUS and SSp.PLUS) appear equivalent at differentiating S0 vs. (S1+S2+S3) patients, but the Att.PLUS parameter may be more effective at identifying advanced steatosis (S2+S3). MR techniques outperformed QUS methods, making them more suitable for clinical studies.

The feasibility of high-resolution organ-axial T2-weighted MRI when combined with federation of gynecology and obstetrics (FIGO) classification of uterine fibroid patients.

Correctly classifying uterine fibroids is essential for treatment planning. The objective of this study was to assess the accuracy and reliability of the FIGO classification system in categorizing uterine fibroids via organ-axial T2WI and to further investigate the factors associated with uterine compression. A total of 130 patients with ultrasound-confirmed fibroids were prospectively enrolled between March 2023 and May 2024. These patients underwent MR examinations, including body-axial T2W (sagittal and axial) and organ-axial T2W (high resolution with oblique coronal and double oblique axial). For postprocessing, the interobserver agreements between two radiologists and the interagreements between two MR examinations and operational descriptions were evaluated via kappa statistics. The accuracy of axial and organ-axial T2W assessments in the FIGO classification of uterine fibroids was compared when surgical outcomes were used as the gold standard. The Kruskal‒Wallis test was used to compare the differences in cavity deformation across various FIGO classifications. Spearman's rank correlation test was used to analyze the correlation between the FIGO classification and the parameters of uterine cavity deformation. In total, 170 fibroids from 130 patients were included. Compared with body-axial T2WI, organ-axial T2WI showed better interobserver agreement and greater interagreements with operational descriptions, with kappa values of 0.877 (P = 0.04) and 0.932 (P = 0.037), respectively. The accuracy of the organ-axial T2WI assessment in determining the FIGO classification of uterine fibroids was greater than that of the body-axial T2WI assessment, with an accuracy of 92.9% (P < 0.01). Thirty-two (38.1%) fibroids showed cavity deformation according to organ-axial T2WI, including fibroids with FIGO types 0-7 and 2-5. Among these factors, the size of the fibroids (S), base width (B), depth of compression (D), D/B, D/S, and compression angle (A) significantly differed among the different FIGO types of fibroids (P < 0.05). Compression angle exhibited a linear correlation with the FIGO type (P < 0.001). Compared with body-axial T2WI, organ-axial T2WI provides greater accuracy on the basis of the FIGO classification, which is more consistent with surgical outcomes. Given the excellent reliability and accuracy of the preoperative FIGO classification, organ-axial T2WI can contribute to treatment planning.

Pancreatic volume, fat content and T1 relaxation time using magnetic resonance imaging in patients with prior gestational diabetes mellitus.

To compare the volume, fat content, and T1 relaxation time of the pancreas in participants with and without prior gestational diabetes mellitus (GDM). In this prospective case-control study, we enrolled 29 women with prior GDM, and divided them into three groups (normoglycemic, prediabetic, and diabetic) based on their glycaemic status in the postpartum period; and a group of 13 participants as controls who had normoglycemia during pregnancy. Participants underwent MR examination including an axial multi-echo DIXON-based sequence and an axial-oblique T1 mapping sequence. The average proton density fat fraction (PDFF) and T1 value of the pancreas were measured by drawing multiple circular regions of interest (ROIs). Average hepatic PDFF was similarly calculated. Pancreatic volume was computed by summating cleaned freehand ROIs outlining pancreatic parenchyma. Women were evaluated at a mean age of 32.9 ± 4.0 years and with a mean BMI of 25.2 ± 2.9kg/m2. The median (IQR) duration of follow-up after childbirth was 24 (34-44) months. In controls, the pancreatic PDFF, T1 value, and volume were 5.4 ± 2.3%, 850.6 ± 101.6 ms, and 69.3 ± 16.2cm³, respectively, while in subjects with a history of GDM, these values were 4.7 ± 2.0%, 844.6 ± 91.8 ms, and 69.8 ± 16.6cm³, respectively. No statistical differences were observed (all p > 0.05). Mean hepatic PDFF was significantly higher in the diabetic and prediabetic groups (12.2 ± 6.4% and 11.0 ± 7.6% respectively) than in the control and normoglycemic groups (7.9 ± 7.3 and 4.7 ± 1.6% respectively; p -0.01). We did not find any significant changes in pancreatic volume, fat content, or fibrosis in women with prior GDM and with different glycaemic categories when evaluated in the early postpartum period, compared to the control group. These findings may be a consequence of the transient state of insulin resistance in GDM and the finite duration of the disease course in new-onset prediabetes and diabetes patients.

Accuracy of distinguishing benign, high-risk lesions and malignancies with inductive machine learning models in BIRADS 4 and BIRADS 5 lesions on breast MR examinations

Rationale and ObjectivesThe aim of this study is to explore the utility of Inductive Decision Tree models (IDTs) in distinguishing between benign, malignant, and high-risk (B3) breast lesions. Materials and MethodsWe analyzed 124 histologically confirmed lesions in 114 patients who underwent breast MR with BI-RADS 4 or 5 assessment. The dataset comprised 10 imaging parameters and one clinical observation. Using the IDTs method (algorithm C5.0 boosted with AdaBoost algorithm) combined with the data balancing method SMOTE (Synthetic Minority Oversampling Technique) and a corresponding new method called LCC (Leveling of Cases per Class), we developed corresponding 3-class classification models (Benign, B3, or Malignant). The training set used for classification model development consists of 112 cases with 12 variables, and the model’s performance was assessed using 10-fold Cross-Validation and Leave-One-Out methods (utilizing the training set) and the Use Test Set method (testing on an unknown (for the models) dataset of 12 cases with 12 variables). ResultsThis preliminary study demonstrates the potential for IDTs to accurately distinguish between benign, B3 and Malignant lesions based on extracted data from breast MRI exams with a high classification accuracy (88.70 %), mean sensitivity of 97.18 % and specificity of 98.59 % achieved by the optimal classification model, derived from the combination of the IDTs method and the LCC data balancing method.

Detecting endolymphatic hydrops in patients with cranial nerve VIII schwannoma using hydrops MR examination.

This study utilized Hydrops MRI in patients with cranial nerve (CN) VIII schwannoma to assess the concomitance with endolymphatic hydrops (EH), aiming to elucidate the mechanism of hydrops formation in these patients. Twenty-six patients diagnosed as CN VIII schwannoma including vestibular schwannoma (VS) in 24 and intracochlear schwannoma (ICS) in 2 were enrolled. Fifteen patients received radiosurgery and 11 patients opted for a wait-and-scan approach. All patients underwent an inner ear test battery, followed by Hydrops MRI. Based on Hydrops MRI, 6 patients (23%) with positive EH were assigned to Group A, while the other 20 patients showing negative EH were assigned to Group B. The abnormality rates of inner ear test battery in Group A ran from the audiometry (100%), cervical vestibular-evoked myogenic potential (cVEMP) test (83%), ocular VEMP (oVEMP) test (67%) to the caloric test (33%), exhibiting a significantly declining sequence. This declining sequence is consistent with the decreasing order in the prevalence of EH from the cochlea (83%), saccule (50%) to utricle (50%). However, Group B did not show such decreasing trend, indicating that Groups A and B did not share the common mechanism. The mean tumor size prior to radiosurgery was 1.91 ± 0.89cm, which significantly reduced to 1.53 ± 0.60cm at a mean interval of 6years following radiosurgery. In contrast, tumor size remained unchanged in those opted for a wait-and-scan approach. It is recommended to utilize Hydrops MRI for patients with CN VIII schwannoma during annual follow-up, particularly those experienced episodic vertigo and/or deteriorated hearing. The Hydrops MRI can not only monitor tumor size, but also detect the presence of EH, so as to guide treatment decision.

Rare Abdominal Desmoid Tumor: Case Report and Review of Literature

A desmoid tumor is a clonal fibroblast proliferation, occurring in deep soft tissues with a significant recurrence tendency. Aggressive fibromatosis is a rare disease. The prevalence in the population ranges from 2 to 4 cases per million. Mentioned neoplasms are highly unpredictable in terms of development. Typically, in the course of desmoid tumors, metastases do not occur, but they often infiltrate the surrounding tissues, which may be associated with numerous complications. There are currently no randomized standards of therapy designated, which is undoubtedly a challenge when referring to treatment. To a 37 year old patient, due to a pathological mass in the abdomen, the MR examination was performed. It showed the presence of an irregular, heterogeneous structure on the right side of the abdominal cavity. A laparotomy was performed. During the procedure adhesions were released and the giant abdominal tumor was removed in one block with part of the duodenum, caecum, ascending colon and part of ileum. End-to-end duodenal anastomosis and stapled, side-to-side ileo-transverse anastomosis were used. The surgical field was being drained. The postoperative course was uneventful. Tissue material was collected for a routine, histopathological examination in which the intra-abdominal form of fibromatosis was diagnosed. The macroscopic image describes a tumor with dimensions of 25.0 cm x 25.0 cm x 20.0 cm.

Acquisition and reconstruction with motion suppression DWI enhance image quality in nasopharyngeal carcinoma patients: Non-echo-planar DWI comparison with single-shot echo-planar DWI

PurposeTo evaluate the impact of application acquisition and reconstruction with motion suppression (ARMS) technology on improving the image quality of diffusion-weighted Imaging (DWI) for nasopharyngeal carcinoma (NPC), compared to single-shot echo-planar imaging (SS-EPI). MethodsA total of 90 patients with NPC underwent MR examination, including ARMS DWI and SS-EPI DWI sequences. Both DWI sequences were acquired with b-values 0 and 800 s/mm2. Two radiologists evaluated the visibility of the lesion, geometric distortion, and overall image quality of the two DWI sequences. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), geometric distortion degree, and apparent diffusion coefficient (ADC) values of the nasopharyngeal lesions were assessed and compared for two sequences. The Wilcoxon signed-rank test was used to compare the quantitative and qualitative parameters of the two sequences. ResultsThe lesion visibility, geometric distortion, and overall image quality scores were significantly higher in ARMS DWI (all P<0.001). Four small-sized lesions were not visible and four lesions were partially visible in the SS-EPI DWI sequence. Lesion detection rate of ARMS DWI is 100 %, while that of SS-EPI is 95.56 %, P<0.043. The mismatch distance between the fusion images of ARMS DWI and T2WI was smaller than that of SS-EPI DWI and T2WI (all P<0.001). The SNR and CNR of ARMS DWI were lower than that of SS-EPI DWI (114.48 ± 37.89 vs. 202.61 ± 78.84, P<0.001 and 1.81 ± 1.84 vs. 3.29 ± 3.71, P<0.003) while the ADC value was higher (839.19 ± 138.44 × 10−6 mm2/s vs. 788.82 ± 110.96 × 10−6 mm2/s, P<0.002). ConclusionARMS DWI improves the image quality by reducing geometric distortion and magnetic susceptibility artifacts. ARMS DWI is superior to SS-EPI DWI for diagnosing small-sized nasopharyngeal lesions, although it has lower SNR and CNR.

Incremental prognostic value of left atrial strain in apical hypertrophic cardiomyopathy: a cardiovascular magnetic resonance study.

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

Primary sclerosing cholangitis: Is qualitative and quantitative 3 T MR imaging useful for the evaluation of disease severity?

PurposeTo analyze the role of qualitative and quantitative 3 T MR imaging assessment as a non-invasive method for the evaluation of disease severity in patients with primary sclerosing cholangitis (PSC). MethodsA series of 26 patients, with histological diagnosis of PSC undergoing 3 T MRI and hepatological evaluation, was retrospectively enrolled. All MR examinations included diffusion-weighted imaging (DWI), T2-weighted (T2w) and T1-weighted (T1w) sequences, before and after administration of Gd-EOB-DTPA with the acquisition of both dynamic and hepato-biliary phase (HBP). Qualitative analysis was performed by assessment of liver parenchyma and biliary tract changes, also including biliary excretion of gadoxetic acid on HBP. Quantitative evaluation was conducted on liver parenchyma by measurement of apparent diffusion coefficient (ADC) and relative enhancement (RE) on 3-minute delayed phase and on HBP. Results of blood tests (ALT, ALP, GGT, total and direct bilirubin, albumin, and platelets) and transient elastography-derived liver stiffness measurements (TE-LSM) were collected and correlated with qualitative and quantitative MRI findings. ResultsAmong qualitative and quantitative findings, fibrosis visual assessment and RE had the best performance in estimating disease severity, showing a statistically significant correlation with both biomarkers of cholestasis and TE-LSM. Statistical analysis also revealed a significant correlation of gadoxetic acid biliary excretion with ALT and direct bilirubin, as well as of ADC with total bilirubin. ConclusionQualitative and quantitative 3 T MR evaluation is a promising non-invasive method for the assessment of disease severity in patients with PSC.

Fractional Anisotropy is a More Sensitive Diagnostic Biomarker Than Mean Kurtosis for Patients with Parkinson Disease with Cognitive Dysfunction: A Diffusional Kurtosis Map Tract-Based Spatial Statistics Study.

There is heterogeneity of white matter damage in Parkinson's disease patients with different cognitive states. Our aim was to find sensitive diffusional kurtosis imaging biomarkers to differentiate the white matter damage pattern of mild cognitive impairment and dementia. Nineteen patients with Parkinson disease with mild cognitive impairment and 18 patients with Parkinson disease with dementia were prospectively enrolled. All participants underwent MR examination with 3D-T1-weighted image and diffusional kurtosis imaging sequences. Demographic data were compared between the 2 groups. Voxelwise statistical analyses of diffusional kurtosis imaging parameters were performed using tract-based spatial statistics. The receiver operator characteristic curve of significantly different metrics was graphed. The correlation of significantly different metrics with global cognitive status was analyzed. Compared with the Parkinson disease with mild cognitive impairment group, the fractional anisotropy and mean kurtosis values decreased in 4 independent clusters in the forceps minor, forceps major, inferior fronto-occipital fasciculus, and the inferior and superior longitudinal fasciculus in patients with Parkinson disease with dementia; the mean diffusivity decreased in 1 cluster in the forceps minor. The fractional anisotropy value in the inferior fronto-occipital fasciculus and inferior longitudinal fasciculus would be the diffusional kurtosis imaging marker for the differential diagnosis of Parkinson disease with mild cognitive impairment and patients with Parkinson disease with dementia, with the best diagnostic efficiency of 0.853. The fractional anisotropy values in the forceps minor (β = 84.20, P < .001) and years of education (β = 0.38, P = .014) were positively correlated with the Montreal Cognitive Assessment. The diffusional kurtosis imaging-derived fractional anisotropy and mean kurtosis can detect the different white matter damage patterns of Parkinson disease with mild cognitive impairment and Parkinson disease with dementia. Fractional anisotropy is more sensitive than mean kurtosis in the differential diagnosis; fractional anisotropy derived from diffusional kurtosis imaging could become a promising imaging marker for the differential diagnosis of Parkinson disease with mild cognitive impairment and Parkinson disease with dementia.

Retrolabyrinthine Bone Thickness as a Radiologic Marker for the Hypoplastic Endotype in Menière Disease.

Menière disease (MD) manifests in 2 major endotypes: one with a hypoplastic, underdeveloped endolymphatic sac (MD-hp) and the other with a normally developed sac that degenerates over time (MD-dg). Determining the specific endotype in patients is important for predicting disease progression, tailoring patient counseling, and optimizing treatment strategies. Endotype diagnosis involves measuring an angular trajectory of the vestibular aqueduct (ATVA), with an ATVA ≥140° indicative of MD-hp and an ATVA ≤120° of MD-dg. However, assessing the ATVA can be challenging. This study aimed to explore the link between ATVA and the thickness of the retrolabyrinthine bone as an alternative diagnostic measure that could provide differentiation between MD endotypes using CT and MR imaging. Retrospective review of CT temporal bone imaging from 32 adult patients with definite MD (60 ears) and 33 age-matched controls without MD or other inner ear symptoms (61 ears) was performed. The ATVA and retrolabyrinthine bone thickness were measured using uniform methodology on standardized axial CT images. Comparative analyses were performed to determine the correlation between ATVA and retrolabyrinthine bone thickness. Additionally, from a separate cohort of 11 patients (22 ears), CT and MR examinations of the temporal bone were retrospectively reviewed for retrolabyrinthine bone thickness measurements, to verify the correlation across the 2 modalities. The average retrolabyrinthine bone thickness was statistically significantly different between MD endotypes, being a mean of 0.8 (SD, 0.3) mm in patients with MD-hp (ATVA ≥140°) and 2.0 (SD, 0.9) mm in patients with MD-dg (ATVA ≤120°), with a consistent pattern of thin retrolabyrinthine bone in MD-hp and variable thickness in MD-dg. Receiver operating characteristic curve analysis within the MD cohort revealed that a retrolabyrinthine bone thickness ≥1.2 mm effectively rules out MD-hp. Excellent interrater reliability was noted for the retrolabyrinthine measurement, and there was near-perfect correlation between CT and MR measurements. Retrolabyrinthine bone thickness proved to be a useful and straightforward alternative marker for distinguishing MD endotypes, being particularly useful for excluding MD-hp. Including information on retrolabyrinthine bone thickness should be considered a routine part of reporting in the context of MD imaging.

The application of B1 inhomogeneity-corrected variable flip angle T1 mapping for assessing liver fibrosis

PurposeThe aim of this study was to evaluate the diagnostic accuracy of the B1 inhomogeneity-corrected variable flip angle (VFA) method using native T1 values in the staging of liver fibrosis. MethodsEighty-three patients who presented for liver biopsy due to varying degrees of liver damage, underwent MR examinations and had T1-mapping images of the liver acquired using the B1 inhomogeneity-corrected VFA VIBE method. Among them, 65 patients underwent Fibroscan, and their results were used to evaluate the elasticity of liver tissue. Additionally, T1-mapping images were collected from 19 normal control patients. Independent sample t-tests were used to analyze the correlation between T1 mapping and Fibroscan. The diagnostic efficacy of T1 mapping in patients with different stages of liver fibrosis was evaluated using receiver operating characteristic (ROC) curves. ResultsThe consistency between different observer groups was intraclass correlation coefficient (ICC) =0.802. T1 mapping demonstrated significant differences between mid-stage liver fibrosis (S = 2) and late-stage liver fibrosis (S = 3), as well as moderate inflammation (G = 2) and severe inflammation (G = 3), P < 0.05. The Area Under Curve(AUC) values of T1 mapping for early liver fibrosis (S ≥ 1), significant liver fibrosis (S ≥ 2), advanced liver fibrosis (S ≥ 3), and end-stage liver fibrosis (S = 4) were 0.760, 0.709, 0.790, and 0.768, respectively. T1 mapping combined with Fibroscan had an AUC value of 0.860. ConclusionsThe B1 inhomogeneity-corrected VFA T1 mapping may be useful for the staging of liver fibrosis. It has a superior diagnostic efficiency for diagnosing advanced fibrosis (≥S3), while native T1 values combined with Fibroscan have potential value for the staging of liver fibrosis.

Anxiety in Healthy Subjects Participating in 7T Examinations—Longitudinal Study

Anxiety before an MRI examination is common, even though the technique is noninvasive and painless. In a 7T MRI study, healthy volunteers also reported anxiety before the examination. This study aimed to assess anxiety levels in healthy individuals undergoing 7T MRI and to determine if their anxiety decreased during subsequent examinations. Participants filled out a questionnaire on anxiety. Eleven questions were compared between the first and second examinations using a paired t-test. Results show that significantly more participants felt worried before the first examination compared with the second. However, more participants felt tense after the second examination. Participants felt better informed before the second examination, but more felt fine after the first one. Six participants (14%) felt nervous about the second examination despite having completed the first one. This study reveals that healthy participants still experience anxiety even after a prior MR examination. However, most participants felt retrospectively that their anxiety was unnecessary. This study suggests that providing more information may help reduce anxiety among healthy volunteers in research studies.

Role of MRI in Assessment of Central Nervous System Lesions and Post Treatment Complications in Pediatric Patents with Leukemia

Abstract Background In terms of pediatric oncology, leukemia is one of the most frequent deadly illnesses. Early CNS problem identification and appropriate therapy were enhanced by MRI. Aim Describe the MRI results brought on by leukemia's involvement in CNS structures and treatment-related CNS side effects, and evaluate their efficacy for early therapy and preventing long-term adverse effects. Patients and Methods A prospective observational study included 52 children with leukemia. All patients undergone MR examination including conventional MRI, MR diffusion imaging and MR venography (MRV). Results Regarding MRI finding of CNS, leukemic infiltration was found in 57.7%, sub volimic changes in mild manner in 50% and about 26% in a moderate manner while absent in 23.1%, PRES was present in 19.2%, venous thrombosis present in 30.8% and post treatment complications were found in 7.7%. Conclusion Diffusion-weighted MRI proved very helpful in the early diagnosis and distinction of various CNS lesions seen in young patients with leukemia and post-treatment CNS sequelae. These techniques included conventional, post- contrast, MR venography, and diffusion-weighted MRI.

Radiopalmar ganglion cysts: prevalence, morphology, and clinical significance in wrist MRI

ObjectivesTo assess radiopalmar ganglion cysts’ (RPG) prevalence, morphology, and clinical significance in consecutive patients.Materials and methodsIn this retrospective single-center study, two radiologists assessed the presence of RPG and morphologic features on wrist MRI. Radiopalmar complaints and scapholunate ligament (SLL) tears were evaluated.ResultsA total of 1053 wrists in 909 patients (mean age 43.4 ± 15.5 years, 602 females) were evaluated. All 308 RPG (Group 1; 308 patients, 29.2%) originated from the palmar capsule; 49 were unilocular, 95 oligolocular, and 164 multilocular; 745 wrists had no RPG (Group 2; 601 patients). One hundred and twenty-six RPG showed internal debris. The mean diameter was 8.5 ± 5.6 mm (cranio-caudal) (1.0–32.9 mm), 8.0 ± 4.1 mm (medio-lateral) (1.0–31.9 mm), and 3.7 ± 2.3 mm (dorso-palmar) (0.4–16.0 mm). 168 RPG showed direct contact with the radial vascular bundle, 24 with the flexor carpi radialis tendon, and 123 with the flexor pollicis longus tendon. In Group 1, significantly more patients showed partial (82/308) [group 2: 45/745, p < 0.001] or complete SLL tears (22/308) [group 2: 20/745, p < 0.001]. Of the patients with RPG, 15.3% presented with radiopalmar complaints. Only the dorso-palmar RPG diameter was positively correlated with radiopalmar complaints (for readers 1 and 2: rs = 0.66/0.61, p < 0.001, respectively), and the best dorso-palmar diameter cut-off value for the probability of having radiopalmar complaints was defined at 3 mm (area under the curve (AUC) 0.74). Other morphologic features were not eligible to discriminate symptomatic patients (AUC range 0.53–0.61).ConclusionThis study found RPG in 29% of patients, most of them asymptomatic. However, a dorso-palmar cyst diameter > 3 mm may be clinically significant.Clinical relevance statementRadiopalmar ganglion cysts, observed in 29% of wrist MR examinations, are mostly asymptomatic, but those with a larger dorso-palmar diameter may be associated with radiopalmar complaints.Key PointsRadiopalmar ganglion cysts are found in 29% of patients undergoing wrist MRI.Most patients with evidence of radiopalmar ganglion cysts do not show radiopalmar symptoms (85%).A dorso-palmar cyst diameter > 3 mm may be associated with radiopalmar complaints.

Could the Anatomic Variants of the Superior Thalamic Vein (STV) Be Considered a Possible Landmark for Target Identification in Magnetic-Resonance-Guided Focused Ultrasound Procedures? A Pilot Study Using Susceptibility Weighted Imaging Sequences.

During magnetic-resonance-guided focused ultrasound ablation of the ventral intermediate thalamic nucleus (VIM) for essential tremor (ET) and Parkinson's disease (PD), targeting is generally performed using a standard atlas-based stereotactic approach. The purpose of our work is to evaluate the anatomic variations in the venous vasculature of the thalamus in patients treated with MRgFUS, as a possible landmark for targeting. We retrospectively evaluated the relationship between the obtained thalamotomy lesion and the ipsilateral superior thalamic vein (STV). A total of 36 patients (25 ET and 11 PD) who underwent MRgFUS treatment were evaluated, and the STV was studied with susceptibility weighted imaging (SWI) sequences. Based on the axial SWI images, the distance between the STV and the center of the lesion at the presumed site of the VIM was measured in follow-up MRI images one month after treatment. Statistical analysis shows that there is a correlation between the STV and the presumed site of the VIM. The STV visible in SWI could be used as an additional, real-time, and patient-specific anatomical landmark for VIM identification during MR examination and just before and during FUS treatment.

Diffusion-weighted MR spectroscopy of the prostate.

Prostate tissue has a complex microstructure, mainly composed of epithelial and stromal cells, and of extracellular (acinar-luminal) spaces. Diffusion-weighted MR spectroscopy (DW-MRS) is ideally suited to explore complex microstructure in vivo with metabolites selectively distributed in different subspaces. To date, this technique has been applied to brain and muscle. This study presents the development and pioneering utilization of 1H-DW-MRS in the prostate, accompanied by in vitro studies to support interpretations of in vivo findings. Nine healthy volunteers underwent a prostate MR examination (mean age, 56 years; range, 31-66). Metabolic complexation was studied in vitro using solutions with major compounds found in prostatic fluid of the lumen. DW-MRS was performed at 3 T with a non-water-suppressed single-voxel sequence with metabolite-cycling to concurrently measure metabolite and water signals. The water signal was used in postprocessing as a reference in a motion-compensation scheme. The spectra were fitted simultaneously in the spectral and diffusion-weighting dimensions. Apparent diffusion coefficients (ADCs) were derived by fitting signal decays that were assumed to be mono-exponential for metabolites and biexponential for water. DW-MRS of the prostate revealed relatively low ADCs for Cho and Cr compounds, aligning with their intracellular location and higher ADCs for citrate and spermine supporting their luminal origin. In vitro assessments of the ADCs of citrate and spermine demonstrated their complex formation and protein binding. Tissue concentrations of MRS-detectable metabolites were as expected for the voxel location. This work successfully demonstrates the feasibility of 1H-DW-MRS of the prostate and its potential for providing valuable microstructural information.