Noncontrast Magnetic Resonance Imaging Research Articles

#2955 Incidental findings in a renal magnetic resonance imaging study for evaluation of chronic kidney disease in type 2 diabetes population

Abstract Background and Aims Novel Magnetic Resonance Imaging (MRI) techniques are potential methods to non-invasively assess and quantify functional, structural and pathophysiological changes in chronic kidney disease (CKD) that may improve diagnosis, prognosis and treatment of these patients. Advances in imaging techniques are also likely to result in the detection of unexpected and asymptomatic incidental findings. We retrospectively analyzed the overall prevalence of incidental findings in the participants of our previously reported study utilizing a non-contrast multiparametric MRI protocol in patients with type 2 DM (T2DM) as compared to healthy controls. Method The subjects of this sub-study were participants of our original prospective, single-center, observational study, in which several MRI biomarkers were evaluated to differentiate diabetic versus healthy kidneys, and various stages of CKD. A complete medical history and physical examination were performed. The inclusion criteria for the T2DM cohort were: Age 18-70 years, type II DM with CKD staged 3-4 (estimated glomerular filtration rate [eGFR] 15-60 ml/min/1.73 m2, body mass index (BMI) 18-35 and provision of written informed consent. The control group comprised of healthy volunteers who were age- and sex-matched and had the following inclusion criteria: Age 18-70 years, eGFR >80 ml/min/1.73 m2, UACR <30 mmol/g, BMI 18-35 and provision of written informed consent. Exclusion criteria for the diabetic group were any apparent cause/s of CKD other than diabetes, previous kidney transplantation, pregnancy, contraindication for MRI examination, heart failure (NYHA class III or IV), allergies to iodine-based contrast agents. Factors that excluded healthy participants were pregnancy, contraindication for MRI examination, allergy to iodine-based contrast agents and any active or chronic disease/diagnosis. Measured GFR (mGFR) was assessed in all participants using iohexol clearance. An MRI scan using a wide range of non-contrast techniques was performed at baseline. Total scan time for patients did not exceed 45 min per session and no gadolinium-based contrast agents were used in any of the MRI examinations. All patients with incidental findings on MRI were further evaluated and referred to appropriate specialists for management. Results A total of 38 T2DM patients with CKD and 20 age- and gender-matched healthy volunteers who completed the study were included in the analysis. Of the T2DM patients, 2 were found to have CKD stage 2 by mGFR and 36 CKD stages 3–4. Clinically significant incidental findings (excluding 4 cases of renal cysts requiring only follow-up without further intervention) were found in 13 of the 38 (34%) T2DM patients. The most frequent findings were intraductal papillary mucinous neoplasm (IPMN) in 7 patients, followed by 3 cancers (1 case of kidney cancer, 1 bladder cancer and 1 lymphoma) and 3 cases of adrenal gland mass later diagnosed to be benign adenoma on further investigation. In contrast, of the 20 healthy volunteers, 2 (10%) were found to have significant incidental findings, which were IPMN in both. The follow-up duration varied between 2-6 years. The patient with bladder cancer had metastatic disease and died shortly after the diagnosis, the one with kidney cancer is under observation and the one with lymphoma underwent adequate treatment and is under remission. The cases of IPMN are being followed up regularly at our surgical department. Conclusion Clinically important incidental findings on renal MRI appear to be more common in T2DM patients than in healthy volunteers, which would have been missed without MRI examination. Mechanisms for reporting and strategies for dealing with incidental findings need to be taken into account in such investigational imaging studies. The detection of incidental findings also poses various practical and ethical issues. Further larger studies with long-term follow-up are needed to delineate the clinical relevance, natural course and management of such incidental findings.

Utility of abbreviated MRI in the post-treatment evaluation of rectal cancer.

Post-treatment evaluation of patients with rectal cancer (RC) using magnetic resonance imaging (MRI) burdens medical resources, necessitating an exploration of abbreviated protocols. To evaluate the diagnostic performance of abbreviated MRI (A-MRI) for the post-treatment evaluation of RC patients. This retrospective study included RC patients who underwent non-contrast rectal MRI and standard liver MRI, as well as abdominal contrast-enhanced computed tomography (CECT) for post-treatment evaluation. A-MRI comprised diffusion-weighted imaging (DWI) and T2-weighted imaging of the upper abdomen and the pelvic cavity. Three radiologists independently reviewed A-MRI, CECT, and standard liver MRI in the detection of viable disease. The diagnostic performances were compared using a reference standard considering all available information, including pathology, FDG-PET, endoscopic results, and clinical follow-up. We included 78 patients (50 men, 28 women; mean age=60.9 ± 10.2 years) and observed viable disease in 34 (43.6%). On a per-patient-basis analysis, A-MRI showed significantly higher sensitivity (95% vs. 81%, P = 0.04) and higher accuracy (93% vs. 82%, P < 0.01), compared to those of CECT, while A-MRI showed comparable sensitivity (91% vs. 91%, P = 0.42) and accuracy (97% vs. 98%, P = 0.06) to that of standard liver MRI. On a per-lesion-based analysis, A-MRI exhibited significantly superior lesion detectability than that of CECT (figure of merit 0.91 vs. 0.77, P < 0.01) and comparable to that of standard liver MRI (figure of merit 0.91 vs. 0.92, P = 0.75). A-MRI exhibited higher sensitivity and diagnostic accuracy than those of CECT in the post-treatment evaluation of RC, while it showed comparable performances with standard liver MRI. A-MRI provides diagnostic added value in the follow-up of RC patients.

Diagnostic yield of computed tomography angiography in patients presenting with spontaneous intracerebral hemorrhage.

Hypertension and cerebral amyloid angiopathy are the most common causes of spontaneous intracerebral hemorrhage (ICH); however, these conditions do not imply macrovascular pathology. Still, computed tomography (CT) angiography (CTA) is often performed in the acute phase in patients with ICH. To assess the diagnostic yield of CTA in the detection of secondary etiology in consecutive patients with spontaneous ICH. We performed a retrospective analysis of data from a prospective single-center cohort study of 203 patients presenting with spontaneous ICH admitted to a comprehensive stroke center over a two-year period (15 October 2016 to 15 October 2018). The underlying vascular pathology was assessed using CTA. CTA was performed in addition to non-contrast CT and/or magnetic resonance imaging (MRI). Vascular pathology was found in 11 of 203 (5.4%) patients and included arteriovenous malformations (n=4), aneurysms (n=4), vasospasms (n=1), cerebral venous thrombosis (n=1), and other vascular malformations (n=1). In eight cases, the finding was deemed symptomatic. Patients with vascular pathology on CTA more often had lobar located hemorrhages (63.6% vs. 36.4%, P = 0.049). Numerically, patients with vascular pathology were younger, had smaller hematoma volumes, and lower mortality. Underlying macrovascular pathology was detected on CTA in only approximately 1 of 20 consecutive patients with ICH. The patients with vascular pathology more often had a hemorrhage with a lobar location and young age and the present study is supportive of a risk-based stratification approach in performing CTA.

Talocalcaneal coalition: an easily overlooked abnormality - A case report

Abstract Congenital tarsal coalition involves failure of segmentation between two or more tarsal bones. Although coalition can be asymptomatic, foot or ankle pain occasionally occurs, especially in young patients, and is often overlooked at the first presentation. Radiography can be used to diagnose or indirectly identify tarsal coalition, and computed tomography (CT) or magnetic resonance imaging (MRI) can be used to confirm the diagnosis. Here, we present a case of a patient with a delayed diagnosis of tarsal coalition. In our patient, plain radiography of the left ankle showed the typical C-sign. Moreover, a noncontrast MRI of the left ankle revealed focal bone hypertrophy over the medial aspect of the talus and the sustentaculum tali of the calcaneus separated by a low signal gap. Familiarity with the radiographic features and signs of the tarsal coalition might aid in its diagnosis, and CT or MRI might provide additional information for its clinical management.

Comparative Analysis of Costing Methods for Magnetic Resonance Imaging in a Tertiary Care Teaching Hospital: An Observational Study

Abstract Background: Health-care costs, often determined through outdated methods, fail to capture the true costs of care delivery. Traditional costing methods in the health-care sector have proven insufficient, leading to potential revenue losses and increased patient out-of-pocket expenses. Activity-based costing (ABC) and time-driven ABC (TDABC) offer alternative approaches to cost calculation, aiming for a more accurate reflection of resource consumption. Methodology: This descriptive observational study was conducted in the magnetic resonance imaging (MRI) center of a tertiary care teaching hospital, focusing on a single noncontrast MRI scan costing. Direct observations and record reviews, including standard operating procedures, policy letters, financial documents, and miscellaneous records, were employed. Results: Using traditional costing, the unit cost of an MRI scan was calculated at INR 1291.51. ABC yielded a unit cost of INR 3613.77, while TDABC resulted in a unit cost of INR 2764.39. A comparison between the three costing methods revealed potential revenue losses with traditional costing. In contrast, TDABC appeared to strike a balance between financial prudence and reduced patient out-of-pocket expenses. Conclusion: The study emphasizes the significance of understanding true costs in health-care delivery. The results advocate for the adoption of TDABC as a favorable compromise, enabling the hospital to retain revenue without burdening patients with additional costs. Notably, the study highlights the necessity for a granular understanding of true costs for successful transitions from volume to value in health care.

S1 vertebral bone quality score independently predicts pedicle screw loosening following surgery in patients with adult degenerative scoliosis

BACKGROUND CONTEXTMRI-based vertebral bone quality (VBQ) score is an effective predictor of pedicle screw loosening after lumbar fusion surgery and has been recognized as a valuable tool for assessing preoperative bone quality. Due to the lateral curvature of lumbar spine of degenerative scoliosis, accurate measurement of VBQ score by conventional measurement methods that capture MRI signal intensity at L1–4 may be limited under certain conditions. To this end, a new simplified S1 VBQ score method has been proposed, which is comparable to the previous L1–4 VBQ score or S1 Hounsfield unit (HU) value, and has high accuracy and reliability. PURPOSETo evaluate the predictive value of MRI-based S1 VBQ score for pedicle screw loosening following surgery for adult degenerative scoliosis (ADS). STUDY DESIGN/SETTINGRetrospective single-center cohort. PATIENT SAMPLEWe reviewed 92 patients who underwent posterior lumbar interbody fusion (PLIF) with pedicle screw fixation for ADS between January 2017 and January 2020. OUTCOME MEASURESAssociation between S1 VBQ score and pedicle screw loosening following surgery for ADS. METHODSWe retrospectively reviewed the records of all patients who performed PLIF between January 2017 and January 2020. The clear zone around pedicle screws≥1 mm can be identified as screw loosening. The S1 VBQ score is calculated from the S1 central-based non-contrast T1-weighted magnetic resonance imaging (MRI). The signal intensity (SI) of the cerebrospinal fluid (CSF) was then measured using ROI placed at the L3 level to normalize the results. Multivariate logistic regression analysis was performed to identify independent risk factors for screw loosening. Then, constructed a receiver operating characteristic (ROC) curve and determined the threshold (cut-off) of VBQ score with high sensitivity and specificity based on Youden Index. RESULTSA total of 92 patients were included, including 34 males and 58 females. The mean age of the patients was 61.23±1.23 years old. At 1-year follow-up, the screw loosening rate was 56.5% (52/92). The age and levels of fixation were higher in the loosening group than in the non-loosening group (p=.036, p=.025). Patients in the loosening group had a greater VBQ score compared to patients in the non-loosening group (3.31±0.41 vs 3.01±0.28, p=.001). Multivariate logistic regression analysis showed that advanced age (OR, 1.090; 95% CI 1.005–1.183; p=.039) and higher VBQ score (OR, 5.778; 95% CI 2.889–16.177; p=.001) were independent risk factors for screw loosening. In addition, the ROC curve were created to assess the role of VBQ score as predictors of screw loosening with a diagnostic accuracy of 74.6% (95% CI 64.2%–85.1%).The most suitable threshold for the VBQ score as determined by the Youden Index was 3.175 (sensitivity: 76.0%, specificity: 83.3%). CONCLUSIONSHigher S1 VBQ score was significantly associated with pedicle screw loosening following surgery for ADS. The S1 VBQ score can be used as an effective preoperative predictor, which has the potential clinical application.

Evaluation of fractional flow reserve and atherosclerotic plaque characteristics on coronary non-contrast T1-weighted magnetic resonance imaging

Background and aimsThe relationship between high-risk coronary plaque characteristics regardless of the severity of lesion stenosis and myocardial ischemia remains unsettled. High-intensity plaques (HIPs) on non-contrast T1-weighted magnetic resonance imaging (T1WI) have been characterized as high-risk coronary plaques. We sought to elucidate whether the presence of coronary HIPs on T1WI influences fractional flow reserve (FFR) in the distal segment of the vessel. MethodsWe retrospectively analyzed 281 vessels in 231 patients with chronic coronary syndrome who underwent invasive FFR measurement and coronary T1WI using a multicenter registry. The plaque-to-myocardial signal intensity ratio (PMR) of the most stenotic lesion was evaluated; a coronary plaque with PMR ≥1.4 was defined as a HIP. ResultsThe median PMR of coronary plaques on T1WI in vessels with FFR ≤0.80 was significantly higher than that of plaques with FFR >0.80 (1.17 [interquartile range (IQR): 0.99–1.44] vs. 0.97 [IQR: 0.85–1.09]; p < 0.001). Multivariable analysis showed that an increase in PMR of the most stenotic segment was associated with lower FFR (beta-coefficient, −0.050; p < 0.001). The presence of coronary HIPs was an independent predictor of FFR ≤0.80 (odds ratio (OR), 6.18; 95% confidence interval (CI), 1.93–19.77; p = 0.002). Even after adjusting for plaque composition characteristics based on computed tomography angiography, the presence of coronary HIPs was an independent predictor of FFR ≤0.80 (OR, 4.48; 95% CI, 1.19–16.80; p = 0.026). ConclusionsCoronary plaques with high PMR are associated with low FFR in the corresponding vessel, indicating that plaque morphology might influence myocardial ischemia severity.

Progression of fluid infiltration on non-contrast magnetic resonance imaging in breast cancer-related lymphedema: A comparative analysis with indocyanine green lymphography

BackgroundNon-contrast magnetic resonance imaging (NMRI) has been reported as valuable for the assessment of lymphedema. However, the correlation between NMRI findings and indocyanine green lymphography (ICG-L) findings remains elusive. MethodsThis single-center retrospective study included 26 patients diagnosed with breast cancer-related lymphedema. We examined the prevalence of fluid infiltration in eight regions of the upper extremity, the type of fluid distribution, and the dominant segment of edema on NMRI in comparison to the ICG-L stage. Statistical analysis was performed using the Cochran–Armitage trend test, Spearman’s rank correlation test, and Fisher’s exact test. ResultsThe regional fluid infiltration significantly increased with the progression of the ICG-L stage (hand, forearm, elbow, and upper arm: p = 0.003, <0.001, <0.001, and <0.001, respectively). The fluid distribution significantly advanced with the progression of the ICG-L stage as follows (rs = 0.80; p < 0.001): no edema in ICG-L stage 0, edema in either the hand or elbow in ICG-L stage I, edemas in both the elbow and hand in ICG-L stage II, three segmental edemas centered on the forearm or elbow in ICG-L stage III, and edema encompassing the entire upper limb in ICG-L stage IV-V. Additionally, the dominant segment of edema tended to shift from the hand to the elbow and further to the forearm as the ICG-L stage progressed (p < 0.001). ConclusionsFluid infiltration observed on NMRI exhibited distinct patterns with the progression of the ICG-L stage. We believe that anatomical information regarding fluid distribution would potentially contribute to optimizing surgical efficacy.

Magnetic Resonance Imaging in Breast Cancer Tissue In Vitro after PDT Therapy.

Photodynamic therapy (PDT) is increasingly used in modern medicine. It has found application in the treatment of breast cancer. The most common cancer among women is breast cancer. We collected cancer cells from the breast from the material received after surgery. We focused on tumors that were larger than 10 mm in size. Breast cancer tissues for this quantitative non-contrast magnetic resonance imaging (MRI) study could be seen macroscopically. The current study aimed to present findings on quantitative non-contrast MRI of breast cancer cells post-PDT through the evaluation of relaxation times. The aim of this work was to use and optimize a 1.5 T MRI system. MRI tests were performed using a clinical scanner, namely the OPTIMA MR360 manufactured by General Electric HealthCare. The work included analysis of T1 and T2 relaxation times. This analysis was performed using the MATLAB package (produced by MathWorks). The created application is based on medical MRI images saved in the DICOM3.0 standard. T1 and T2 measurements were subjected to the Shapiro-Wilk test, which showed that both samples belonged to a normal distribution, so a parametric t-test for dependent samples was used to test for between-sample variability. The study included 30 sections tested in 2 stages, with consistent technical parameters. For T1 measurements, 12 scans were performed with varying repetition times (TR) and a constant echo time (TE) of 3 ms. For T2 measurements, 12 scans were performed with a fixed repetition time of 10,000 ms and varying echo times. After treating samples with PpIX disodium salt and bubbling with pure oxygen, PDT irradiation was applied. The cell relaxation time after therapy was significantly shorter than the cell relaxation time before PDT. The cells were exposed to PpIX disodium salt as the administered pharmacological substance. The study showed that the therapy significantly affected tumor cells, which was confirmed by a significant reduction in tumor cell relaxation time on the MRI results.

Deep learning segmentation of the choroid plexus from structural magnetic resonance imaging (MRI): validation and normative ranges across the adult lifespan

BackgroundThe choroid plexus functions as the blood-cerebrospinal fluid (CSF) barrier, plays an important role in CSF production and circulation, and has gained increased attention in light of the recent elucidation of CSF circulation dysfunction in neurodegenerative conditions. However, methods for routinely quantifying choroid plexus volume are suboptimal and require technical improvements and validation. Here, we propose three deep learning models that can segment the choroid plexus from commonly-acquired anatomical MRI data and report performance metrics and changes across the adult lifespan.MethodsFully convolutional neural networks were trained from 3D T1-weighted, 3D T2-weighted, and 2D T2-weighted FLAIR MRI using gold-standard manual segmentations in control and neurodegenerative participants across the lifespan (n = 50; age = 21–85 years). Dice coefficients, 95% Hausdorff distances, and area-under-curve (AUCs) were calculated for each model and compared to segmentations from FreeSurfer using two-tailed Wilcoxon tests (significance criteria: p < 0.05 after false discovery rate multiple comparisons correction). Metrics were regressed against lateral ventricular volume using generalized linear models to assess model performance for varying levels of atrophy. Finally, models were applied to an expanded cohort of adult controls (n = 98; age = 21–89 years) to provide an exemplar of choroid plexus volumetry values across the lifespan.ResultsDeep learning results yielded Dice coefficient = 0.72, Hausdorff distance = 1.97 mm, AUC = 0.87 for T1-weighted MRI, Dice coefficient = 0.72, Hausdorff distance = 2.22 mm, AUC = 0.87 for T2-weighted MRI, and Dice coefficient = 0.74, Hausdorff distance = 1.69 mm, AUC = 0.87 for T2-weighted FLAIR MRI; values did not differ significantly between MRI sequences and were statistically improved compared to current commercially-available algorithms (p < 0.001). The intraclass coefficients were 0.95, 0.95, and 0.96 between T1-weighted and T2-weighted FLAIR, T1-weighted and T2-weighted, and T2-weighted and T2-weighted FLAIR models, respectively. Mean lateral ventricle choroid plexus volume across all participants was 3.20 ± 1.4 cm3; a significant, positive relationship (R2 = 0.54-0.60) was observed between participant age and choroid plexus volume for all MRI sequences (p < 0.001).ConclusionsFindings support comparable performance in choroid plexus delineation between standard, clinically available, non-contrasted anatomical MRI sequences. The software embedding the evaluated models is freely available online and should provide a useful tool for the growing number of studies that desire to quantitatively evaluate choroid plexus structure and function (https://github.com/hettk/chp_seg).

Non-Contrast Magnetic Resonance Imaging of Isolated Superior Mesenteric Artery Dissection.

Non-Contrast Magnetic Resonance Imaging of Isolated Superior Mesenteric Artery Dissection.

Can non-contrast magnetic resonance imaging replace contrast-enhanced computerized tomography in the local staging of pediatric renal tumors?

BackgroundRenal tumors account for approximately 6–7% of the total incidence of pediatric cancers. Wilms tumor (WT) is the most common renal malignancy observed in the pediatric population under 5 years old. Computed tomography (CT) is used for staging of the renal tumors. Magnetic resonance imaging (MRI) offers enhanced soft tissue resolution and provides more comprehensive insights into tumor extension through the capsule, including tumor infiltration into the renal vein or IVC. MRI is a noninvasive imaging modality that does not involve any radiation hazards, making it safe for children. In addition, MRI can be performed without the administration of contrast agents in patients with impaired renal function. Therefore, MRI plays a vital role in screening, staging, preoperative evaluation, and follow-up. Diffusion-weighted imaging (DWI) is a functional tool that aids in locating the most receptive tumoral region to guide confirmatory biopsies. In this study, we aim to evaluate the potential value of non-contrast MRI in staging pediatric renal tumors compared to contrast-enhanced CT.ResultsThis study included 50 patients presented with renal mass, with ages ranging from 1 to 8 years and a mean age of 4.27 ± 1.27 (mean ± SD). The final diagnosis was Wilm’s tumor at 86%, clear cell sarcoma at 4%, rhabdoid tumor at 4%, rhabdomyosarcoma at 2%, and nephroblastomatosis with no malignant transformation at 4%. CT accurately diagnosed stages 4 and 5 in agreement with pathological findings while upstaging the other cases, with a CT sensitivity of 90.91%, specificity of 82.35%, PPV of 92%, and NPV of 84%. MRI is superior to CT in stages 1 and 3, accurately diagnosing stages 2, 4, and 5, with a sensitivity of 93.30%, specificity of 95.65%, PPV of 95%, and NPV of 97%.ConclusionsNon-contrast MRI could be considered the optimal radiation-free imaging modality in staging pediatric renal tumors mainly Wilm’s tumor as it offers high sensitivity and specificity of capsular and vascular infiltration, compared to contrast-enhanced CT especially in cases with impaired renal functions.

Diagnostic accuracy of non-contrast MRI in frozen shoulder.

Despite being the most used exam today, few studies have evaluated the accuracy of findings on non-contrast magnetic resonance imaging (MRI). The primary objective of the study was to evaluate the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of non-contrast MRI findings in frozen shoulder, isolated and in combination. The secondary objectives were to define the interobserver and intraobserver agreement of the assessments and the odds ratio for frozen shoulder because of the various findings of MRI. A retrospective diagnostic accuracy study comparing non-contrast MRI findings between the frozen shoulder group and the control group. Sensitivity, specificity, positive and negative predictive value, accuracy, odds ratio, interobserver and intraobserver agreement were calculated for each finding and their possible associations. The hyperintensity on capsule in the axillary recess presented 84% sensitivity, 94% specificity, and 89% accuracy. The obliteration of the subcoracoid fat triangle in the rotator interval had sensitivity 34%, specificity 82% and accuracy 58%. For coracohumeral ligament thickness ≥ 2mm had specificity 66%, 48% specificity and 57% accuracy. Capsule thickness in the axillary recess ≥ 4mm resulted in 54% sensitivity, 82% specificity, and 68% accuracy. Regarding interobserver agreement, only the posteroinferior and posterosuperior quadrants showed moderate results, and all the others showed strong reliability. The odds ratio for hyperintensity in the axillary recess was 82.3 for frozen shoulder. The association of these findings increased specificity (95%). The accuracy of non-contrast magnetic resonance imaging is high for diagnosing frozen shoulder, especially when evaluating the hyperintensity of the axillary recess. The exam has high reliability and reproducibility. The presence of an association of signs increases the specificity of the test. Level III, study of diagnostic test.

A Non-Contrast Multi-Parametric MRI Biomarker for Assessment of MR-Guided Focused Ultrasound Thermal Therapies.

We present the development of a non-contrast multi-parametric magnetic resonance (MPMR) imaging biomarker to assess treatment outcomes for magnetic resonance-guided focused ultrasound (MRgFUS) ablations of localized tumors. Images obtained immediately following MRgFUS ablation were inputs for voxel-wise supervised learning classifiers, trained using registered histology as a label for thermal necrosis. VX2 tumors in New Zealand white rabbits quadriceps were thermally ablated using an MRgFUS system under 3 T MRI guidance. Animals were re-imaged three days post-ablation and euthanized. Histological necrosis labels were created by 3D registration between MR images and digitized H&E segmentations of thermal necrosis to enable voxel-wise classification of necrosis. Supervised MPMR classifier inputs included maximum temperature rise, cumulative thermal dose (CTD), post-FUS differences in T2-weighted images, and apparent diffusion coefficient, or ADC, maps. A logistic regression, support vector machine, and random forest classifier were trained in red a leave-one-out strategy in test data from four subjects. In the validation dataset, the MPMR classifiers achieved higher recall and Dice than a clinically adopted 240 cumulative equivalent minutes at 43 °C (CEM 43) threshold (0.43) in all subjects. The average Dice scores of overlap with the registered histological label for the logistic regression (0.63) and support vector machine (0.63) MPMR classifiers were within 6% of the acute contrast-enhanced non-perfused volume (0.67). Voxel-wise registration of MPMR data to histological outcomes facilitated supervised learning of an accurate non-contrast MR biomarker for MRgFUS ablations in a rabbit VX2 tumor model.

Growth kinetics of venous tumor thrombus in patients with renal cell carcinoma

Some patients with renal cell carcinoma (RCC) present with venous tumor thrombus (VTT). The extent of the VTT is related to survival, so prompt surgical care is recommended. However, studies evaluating the natural history of VTT in patients with RCC are rare. We sought to evaluate the growth kinetics of VTT in patients with RCC using preoperative cross-sectional images. We identified patients who underwent radical nephrectomy and venous tumor thrombectomy at our institution from 01/2009 to 02/2022. We included those with a minimum of 2 adequate preoperative imaging studies (contrast-enhanced Computerized Tomography (CT), noncontrast Magnetic resonance imaging (MRI), or contrast-enhanced MRI), at least 14 days apart. We measured VTT in each study to calculate growth rate, and evaluated predictors of faster growth (demographics, histology, laterality, tumor diameter, and staging). To assess the relation between clinical variables and VTT growth, we used the Wilcoxon Rank-Sum, Kruskal-Wallis, and Spearman correlation tests. A total of 30 patients were included in the analysis. The median time interval between studies was 33 days. Patients were mostly Caucasian and Males (90% and 70%, respectively). Most patients underwent a CT scan as their initial imaging study (66%), followed with an MRI as second study (73%). The mean venous tumor thrombus growth rate was 0.3 mm/d (standard deviation of 0.5mm), and only rhabdoid/sarcomatoid differentiation showed an association with tumor thrombus growth rate (0.3 vs. 0.63 mm/d, P = 0.038). To the best of our knowledge, this is the first study evaluating the natural growth rate of venous tumor thrombus in patients with renal cell carcinoma. We found that tumor thrombi grew an average of 0.3 mm/d (1.0 cm/month) and that those with sarcomatoid and/or rhabdoid differentiation grew faster (0.63 mm/d). Further studies are needed to validate these results and provide a better understanding of tumor thrombus kinetics.

Quantitative perfusion and water transport time model from multi b-value diffusion magnetic resonance imaging validated against neutron capture microspheres.

Quantification of perfusion in ml/100 g/min, rather than comparing relative values side-to-side, is critical at the clinical and research levels for large longitudinal and multi-center trials. Intravoxel incoherent motion (IVIM) is a non-contrast magnetic resonance imaging diffusion-based scan that uses a multitude of -values to measure various speeds of molecular perfusion and diffusion, sidestepping inaccuracy of arterial input functions or bolus kinetics. Questions remain as to the original of the signal and whether IVIM returns quantitative and accurate perfusion in a pathology setting. This study tests a novel method of IVIM perfusion quantification compared with neutron capture microspheres. We derive an expression for the quantification of capillary blood flow in ml/100 g/min by solving the three-dimensional Gaussian probability distribution and defining water transport time (WTT) as when 50% of the original water remains in the tissue of interest. Calculations were verified in a six-subject pre-clinical canine model of normocapnia, induced hypercapnia, and middle cerebral artery occlusion (ischemic stroke) and compared with quantitative microsphere perfusion. Linear regression analysis of IVIM and microsphere perfusion showed agreement (slope = 0.55, intercept = 52.5, ) with a Bland-Altman mean difference of . Linear regression between dynamic susceptibility contrast mean transit time and IVIM WTT asymmetry in infarcted tissue was excellent (, intercept = 0.3, ). Strong linear agreement was found between IVIM and reference standard infarct volume (slope = 1.01, ). The simulation of cerebrospinal fluid (CSF) suppression via inversion recovery returned a blood signal reduced by 82% from combined T1 and T2 effects. The accuracy and sensitivity of IVIM provides evidence that observed signal changes reflect cytotoxic edema and tissue perfusion and can be quantified with WTT. Partial volume contamination of CSF may be better removed during post-processing rather than with inversion recovery.

Reliability of ulnar collateral ligament findings in magnetic resonance imaging.

Ulnar collateral ligament (UCL) tears are common in baseball players. Although magnetic resonance imaging (MRI) is the most used imaging modality for UCL injuries, the inter-rater reliability of MRI analyzing specific characteristics of UCL pathology has not been defined. The purpose of this study was to define the inter-rater reliability of MRI for evaluating UCL characteristics. Three surgeons analyzed 45 noncontrast MRIs: 15 without UCL tears, 15 with intraoperatively confirmed partial-thickness tears, and 15 with intraoperatively confirmed full-thickness tears. Findings evaluated included ligament characteristics (periligamentous or osseous edema, ligament hypertrophy, calcifications, and partial- or full-thickness tearing) and location of the pathology (proximal, midsubstance, or distal). Fleiss' κ coefficients were used to assess interobserver reliability. There were high rates of agreement for midsubstance (κ: 0.50) and distal (κ: 0.69) ligament edema and proximal osseous edema (κ: 0.48). There were low rates of agreement for proximal ligament edema (κ: 0.08), ligament thickening (κ: -0.02 to 0.20), and proximal to midsubstance calcifications (κ: -0.04 to 0.10). Midsubstance (κ: 0.55) and distal full-thickness tears (κ: 0.63) demonstrated higher agreement than proximal (κ: 0.29). Proximal partial-thickness tears (κ: 0.45) had higher agreement than midsubstance (κ: -0.02) or distal (κ: -0.02). In our study, there was high inter-rater reliability regarding proximal osseous edema, midsubstance, and distal ligament edema and full-thickness tears. There was no agreement for midsubstance and distal partial-thickness UCL tears, but fair agreement for proximal tears. UCL tissue characteristics including ligament thickening and calcifications demonstrated low agreement. Challenges remain in effectively evaluating UCL tissue characteristics on noncontrast MRIs.

Efficient organisation of the contralateral hemisphere connectome is associated with improvement in intelligence quotient after paediatric epilepsy surgery

ObjectiveAims of epilepsy surgery in childhood include optimising seizure control and facilitating cognitive development. Predicting which children will improve cognitively is challenging. We investigated the association of the pre-operative structural connectome of the contralateral non-operated hemisphere with improvement in intelligence quotient (IQ) post-operatively. MethodsConsecutive children who had undergone unilateral resective procedures for epilepsy at a single centre were retrospectively identified. We included those with pre-operative volume T1-weighted non-contrast brain magnetic resonance imaging (MRI), no visible contralateral MRI abnormalities, and both pre-operative and two years post-operative IQ assessment. The MRI of the hemisphere contralateral to the side of resection was anatomically parcellated into 34 cortical regions and the covariance of cortical thickness between regions was used to create binary and weighted group connectomes. ResultsEleven patients with a post-operative IQ increase of at least 10 points at two years were compared with twenty-four patients with no change in IQ score. Children who gained at least 10 IQ points post-operatively had a more efficiently structured contralateral hemisphere connectome with higher global efficiency (0.74) compared to those whose IQ did not change at two years (0.58, p = 0.014). This was consistent across thresholds and both binary and weighted networks. There were no statistically significant group differences in age, sex, age at onset of epilepsy, pre-operative IQ, mean cortical thickness, side or site of procedure, two year post-operative Engel scores or use of anti-seizure medications between the two groups. ConclusionsSurgical procedures to reduce or stop seizures may allow children with an efficiently structured contralateral hemisphere to achieve their cognitive potential.

Characteristics of Recurrent Visions of the Nonphysical World Among Cognitively Unimpaired Elders of the Ojibwe Tribal Nation.

Visual hallucinations are a core feature of dementia with Lewy bodies and primary psychiatric disease, yet identification of a hallucination vs normal spiritual experience depends on cultural context. Almost no information exists in the medical literature regarding normal spiritual experiences in American Indian participants in the context of a neurocognitive evaluation. To assess the characteristics of a normal spiritual experience in an Ojibwe Tribal Nation. This prospective, cross-sectional study was conducted between August 1, 2021, and August 31, 2022, among an Ojibwe Tribal Nation in northern Minnesota. Participants were evaluated at their tribal nation clinic. Cognitively unimpaired tribal Elders who were enrolled members of the tribal nation and aged 55 years or older were invited to participate via fliers, radio advertisements, and health fair presentations. Thirty-seven tribal Elders volunteered. Each participant was asked whether they experienced hallucinations or visions of people, animals, or objects that are not part of the physical world. This was an a priori formulated question and part of a comprehensive neurocognitive evaluation consisting of history and physical examination (including cognitive screening with a subspecialty-trained behavioral neurologist); blood tests for metabolic, nutritional, and thyroid conditions; and noncontrast magnetic resonance imaging brain scan. Four patients were excluded from the present analysis due to having mild cognitive impairment or dementia. Thirty-three cognitively unimpaired tribal Elders (mean [SD] age, 66.0 [7.5] years; 22 women [67%]) were included. Sixteen (48%) answered affirmatively, reporting recurrent visions of the nonphysical world. Generally, these visions were well formed, benevolent in nature, and transient; started in preadolescence; involved spirits or ancestors; and were congruent with cultural and spiritual beliefs of the Ojibwe people. No patients had accompanying dream enactment behavior, dysautonomia, parkinsonism, sleep transition-related hallucinations, or moderate to severe depression to suggest a prodrome of an α-synucleinopathy, hypnopompic or hypnagogic hallucinations, or psychosis. Although based on only 1 Ojibwe Tribal Nation, this study suggests that formed visions of the nonphysical world are common among cognitively healthy Ojibwe individuals and can represent normal spiritual experiences. Clinicians would benefit from careful consideration of cultural or spiritual context to avoid misdiagnosis of neuropsychiatric disease.

Future of Breast Radiology.

The landscape of breast imaging has transformed significantly since mammography's introduction in the 1960s, accelerated by ultrasound and imageguided biopsies in the 1990s. The emergence of magnetic resonance imaging (MRI) in the 2000s added a valuable dimension to advanced imaging. Multimodality and multiparametric imaging have firmly established breast radiology's pivotal role in managing breast disorders. A shift from conventional to digital radiology emerged in the late 20th and early 21st centuries, enabling advanced techniques like digital breast tomosynthesis, contrast-enhanced mammography, and artificial intelligence (AI) integration. AI's impending integration into breast radiology may enhance diagnostics and workflows. It involves computer-aided diagnosis (CAD) algorithms, workflow support algorithms, and data processing algorithms. CAD systems, developed since the 1980s, optimize cancer detection rates by addressing false positives and negatives. Radiologists' roles will evolve into specialized clinicians collaborating with AI for efficient patient care and utilizing advanced techniques with multiparametric imaging and radiomics. Wearable technologies, non-contrast MRI, and innovative modalities like photoacoustic imaging show potential to enhance diagnostics. Imaging-guided therapy, notably cryotherapy, and theranostics, gains traction. Theranostics, integrating therapy and diagnostics, holds potential for precise treatment. Advanced imaging, AI, and novel therapies will revolutionize breast radiology, offering refined diagnostics and personalized treatments. Personalized screening, AI's role, and imaging-guided therapies will shape the future of breast radiology.