Standard MRI Research Articles

Advanced MR Imaging for Knee Osteoarthritis: A Review on Local and Brain Effects

Knee osteoarthritis is one of the leading causes of chronic disability worldwide and is a significant social and economic burden on healthcare systems; hence it has become essential to develop methods to identify patients at risk for developing knee osteoarthritis at an early stage. Standard morphological MRI sequences are focused mostly on alterations seen in advanced stages of osteoarthritis. However, they possess low sensitivity for early, subtle, and potentially reversible changes of the degenerative process. In this review, we have summarized the state of the art with regard to innovative quantitative MRI techniques that exploit objective and quantifiable biomarkers to identify subtle alterations that occur in early stages of osteoarthritis in knee cartilage before any morphological alteration occurs and to capture potential effects on the brain. These novel MRI imaging tools are believed to have great potential for improving the current standard of care, but further research is needed to address limitations before these compositional techniques can be robustly applied in research and clinical settings.

Correcting image distortions from a nonlinear -gradient field in frequency-modulated Rabi-encoded echoes.

To correct image distortions that result from nonlinear spatial variation in the transmit RF field amplitude ( ) when performing spatial encoding with the method called frequency-modulated Rabi encoded echoes (FREE). An algorithm developed to correct image distortion resulting from the use of nonlinear static field (B0 ) gradients in standard MRI is adapted herein to correct image distortion arising from a nonlinear -gradient field in FREE. From a -map, the algorithm performs linear interpolation and intensity scaling to correct the image. The quality of the distortion correction is evaluated in 1.5T images of a grid phantom and human occipital lobe. An expanded theoretical description of FREE revealed the symmetry between this -gradient field spatial-encoding and standard B0 -gradient field spatial-encoding. The adapted distortion-correction algorithm substantially reduced image distortions arising in the spatial dimension that was encoded by the nonlinear gradient of a circular surface coil. Image processing based on straightforward linear interpolation and intensity scaling, as previously applied in conventional MRI, can effectively reduce distortions in FREE images acquired with nonlinear -gradient fields.

18F-FET-PET imaging in high-grade gliomas and brain metastases: a systematic review and meta-analysis.

To provide a summary of the diagnostic performance of 18F-FET-PET in the management of patients with high-grade brain gliomas or metastases from extracranial primary malignancies. MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews databases were searched for studies that reported on diagnostic test parameters in radiotherapy planning, response assessment, and tumour recurrence/treatment-related changes differentiation. Radiomic studies were excluded. Quality assessment was performed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool and the GRADE approach. A bivariate, random-effects model was used to produce summary estimates of sensitivity and specificity. Twenty-six studies with a total of 1206 patients/lesions were included in the analysis. For radiotherapy planning of glioma, the pooled proportion of patients from 3 studies with 18F-FET uptake extending beyond the 20mm margin from the gadolinium enhancement on standard MRI was 39% (95% CI, 10-73%). In 3 studies, 18F-FET-PET was also shown to be predictive of early responders to treatment, whereas MRI failed to show any prognostic value. For the differentiation of glioma recurrence from treatment-related changes, the pooled sensitivity and specificity of TBRmax 1.9-2.3 from 6 studies were 91% (95% CI, 74-97%) and 84% (95% CI, 69-93%), respectively. The respective values for brain metastases from 4 studies were 82% (95% CI, 74-88%) and 82% (95% CI, 74-88%) using TBRmax 2.15-3.11. While 18F-FET shows promise as a complementary modality to standard-of-care MRI for the management of primary and metastatic brain malignancies, further validation with standardized image interpretation methods in well-designed prospective studies are warranted.

Standard deviations of MR signal intensities show a consistent trend during imaging follow-ups for glioblastoma patients when corrected for non-biological heterogeneity due to hardware and software variation

IntroductionGlioblastoma multiforme (GBM) has a poor prognosis in spite of advanced MRI guided treatments today. Routine MRI using conventional T1 or advanced permeability based MRI of GBM often does not adequately represent changing tumor phases or overall survival. In this work, region of interest (ROI) based tissue MR standard deviation (SD) is demonstrated as an important MRI variable that could be a potential biomarker of GBM heterogeneity and radioresistance. Materials and methodsMRI characterization is often qualitative and lacks reproducibility. Using standardized MRI phantoms we have normalized retrospective records of 12 radioresistant GBM patients that underwent radiation therapy (RT) with concomitant and adjuvant temozolomide (TMZ) chemotherapy followed by serial MR imaging with gadolinium contrast. Results and discussionWe have identified key variables like hardware, software and protocol variation and have standardized those using test phantoms at five MR systems. We suggest GBM growth during the treatment period can be linked to normalized MRI signal and its fluctuations from session to session and from magnet to magnet by using an ROI derived standard deviation that corresponds to heterogeneity of the tumor MRI signal and changes in magnetic susceptibility. The time period observed in our patient group for peak standard deviations is approximately halfway through the tumor course and may correspond to a growth of more aggressive MES subtype of cells. To model the GBM heterogeneity we performed in vitro T1 weighted inversion recovery MRI experiments at 3 T for porous media of silicate particles in 1% aq solution of Gadavist and linked SD with particle size and local gadolinium volume within porous media. Such in vitro models mimic the increased SD in radioresistant GBM and as a novel contribution suggest that finer texture with high surface area might arise approximately halfway through the overall survival duration in GBM. ConclusionStandard deviation as a measure of magnetic susceptibility may be collectively linked to the changes in texture, cell fractions (biological) and trapped contrast media (vascular as well as artifactual consequences) and should be evaluated as a potential biomarker of GBM aggressiveness than the overall MRI signal intensity from a GBM.

Diffusion Tensor Imaging in Syringomyelia Secondary to Chiari Malformation in Cavalier King Charles Spaniel—A Preliminary Study

Syringomyelia secondary to Chiari-like malformation (so-called CM-SM syndrome) is a common disorder in Cavalier King Charles Spaniels (CKCS) that is diagnosed using standard structural MRI, though imaging findings often do not correlate with the severity of clinical symptoms. Diffusion tensor imaging (DTI) is a technique that defines subtle microstructural changes in the course of many brain and spinal cord diseases, that are not visible on standard MRI. The aim of the study was to identify the correlation between the presence of clinical symptoms and DTI parameters, such as apparent diffusion coefficient (ADC) and fractional anisotropy (FA) within the spinal cord in the course of CM-SM. Study subjects included 18 dogs, CKCS with MRI-confirmed SM (SM group), and 12 CKCS dogs without SM (non-SM group). The SM group was divided into SM-symptomatic group (n = 8) and SM-asymptomatic group, n = 10). All dogs underwent same clinical and neurological assessment followed by MRI examination. All MRI studies were performed on a 1.5T MRI scanner. The MRI spine protocol included: transverse and sagittal T2-weighted images followed by DTI performed in the sagittal plane. The measurements of FA and ADC values were performed manually using the region of interest (ROI) method at the level of three intervertebral discs between C1 and C4. Notable differences in age and body weight were found. No significant differences in FA and ADC values between the SM and non-SM groups were found, but between non-SM, SM-asymptomatic and SM-symptomatic groups significant differences were found in ADC values in all three ROIs and in FA values in ROI-1 and ROI-3. SM-symptomatic dogs compared to non-SM, showed decreased FA value in ROI-1 and ROI-3 also increased ADC value in ROI-1, ROI-2 and ROI-3. SM-symptomatic dogs compared to SM-asymptomatic showed also decreased FA value in ROI-1 and ROI-3, and also increased ADC value in ROI-1, ROI-2 and ROI-3. The results suggest that the values of DTI parameters correlate with the severity of clinical symptoms in the course of CM-SM in animals. The use of DTI evaluation of CM-SM patients carries a potential value as a clinically relevant protocol for an objective assessment of the spinal cord.

Voxel to voxel validation of brainstem MRI novel sequences to postmortem tissue reconstruction

AbstractBackgroundNeuroimaging of brainstem structures has gained importance in ADRD as these regions degenerate early in AD. In recent years there has been an explosion of novel neuroimaging sequences to image the brainstem. However, most of these methods lack validation against the ground truth, i.e tissue visualization, making these methods less attractive for clinical use. Among the new proposed methods, high‐definition connectome promises to revolutionize BS imaging as it overcomes several limitations of standard structural MRI, including a high level of imaging deformation. In this project we have developed a pipeline to validate BS connectome sequences using a voxel to voxel comparison between 3D histological volumes and connectome signal. To this date we applied this pipeline to 6 human brains.MethodWe used 6 AD cases collected by the Neuroradiology Lab at the University of Sao Paulo. Patients underwent postmortem MRI prior to autopsy.We used a pipeline developed in‐house that allows for precise alignment of histology‐based cytoarchitectural 3D reconstructions of the brainstem to its T2 weighted 7T‐MRI counterpart. Upon procurement, the brains were fixed in formalin, embedded in celloidin, and cut in horizontal sections of 300um. Selected BS structures were delineated on these slides stained for Nissl(gallocyanin)(Fig.1). Delineated images underwent manual quality checks, a series of alignment and registration processes to recover original coordinates. The stained sections and corresponding ROI masks were registered to the blockface to correct for any deformation of tissue during the staining process. Freeview commands applied to reconstruct the brainstems and masks. We registered the resulting 3D reconstruction to the matching MRI coordinates(Fig. 2), enabling voxel‐to‐voxel comparisons.Result6 cases went through the pipeline with ROIs reconstructed on block reconstructions(Fig. 3). Currently, dice coefficient analysis between MRI signal and the manually outlined ROIs on histology are being finalized.ConclusionOur pipeline enables voxel‐to‐voxel correlation analysis between histology and MRI scans for validation of brainstem neuroimaging. Current finalization of a total 9 cases is ongoing. Validation of such correlation maps will inform interpretations of connectome results in living patients with the potential to act as an eventual diagnostic tool for ADRD.

Protocol for an observational cohort study investigating biomarkers predicting seizure recurrence following a first unprovoked seizure in adults

IntroductionA first unprovoked seizure is a common presentation, reliably identifying those that will have recurrent seizures is a challenge. This study will be the first to explore the combined utility...

A Semi-Blind Calibration and Compensation Method for Dynamic Range Recovery of Low-Power Pre-Amplifiers in MRI Receive Chains.

To enable wireless MRI receive arrays, per-channel power consumption must be reduced by a significant factor. To address this, a low-power SiGe alternative to industry standard MRI pre-amplifier blocks has been proposed and its impact on imaging performance evaluated in a benchtop environment. The SiGe amplifier reduces power consumption 28x, but exhibits increased non-linearity and reduced dynamic range relative to industry standard amplifiers. This distorts the images, causing reduced contrast and a blurring of fine features. In conjunction with the amplifier, a semi-blind calibration and compensation framework has been proposed to remove artifacts caused by this non-linearity. Requiring the knowledge of the calibration signal bandwidth, the associated peak transmit powers, and the distorted baseband signals, a second non-linearity is constructed that when cascaded with the receive chain produces a linear response. This method was evaluated for both knee and phantom image datasets of peak input power -20dBm with a -40dBm peak input power image as reference. In the benchtop environment, industry standard amplifiers produced input normalized RMSEs of 0.0199 and 0.0310 for phantom and knee datasets, respectively. The low-power SiGe amplifier resulted in RMSEs of 0.0869 and 0.1130 which were reduced to 0.0158 and 0.0168 following compensation, for phantom and knee images respectively. The ability to effectively compensate for this reduced dynamic range encourages further investigation of low-power SiGe amplifiers for power limited MRI receive arrays.

Prevalence and determinants of tricuspid regurgitation after repair of tetralogy of Fallot

BackgroundThe prevalence and determinants of tricuspid regurgitation (TR) in patients with repaired Tetralogy of Fallot (rTOF) remain incompletely understood. ObjectivesTo explore the prevalence of and factors associated with TR in patients with rTOF, specifically, the relationship of right ventricular (RV) dilatation with TR severity. MethodsPatients (≥17 yrs) with rTOF referred to our service (2000–2019) were identified. Those with severe pulmonary stenosis, significant shunt, or previous tricuspid valve surgery were excluded. Using standard cardiac MRI protocols, RV, right atrial (RA) and tricuspid valve (TV) parameters were measured and compared. Results68 consecutively eligible patients with rTOF were included in the study (27 ± 9 yrs., 35% female). Despite substantial RV volume overload (mean RVEDVi 153 mL/m2), the majority of the cohort (78%) had no or only mild TR. RA volumes, tenting height/area and annular diameter were normal (4.9 ± 2.0 mm, 1.1 ± 1.0 cm2 and 32.4 ± 6.2 mm, respectively). There was no significant correlation of TR fraction with RVEDVi (r = 0.13; p = 0.30), RVEF (r = 0.09; p = 0.44) or tricuspid annular diameter (r = 0.07; p = 0.62). Only RAVi showed a weak but significant correlation with TR fraction (0.29; p = 0.03). In a pooled cohort analysis, including both rTOF patients and adults with a dilated RV from pre-tricuspid shunt lesions, only rTOF was independently associated with higher TR fraction (p = 0.017). ConclusionDespite substantial RV dilatation in a cohort with rTOF, there was surprisingly little TR. We found poor correlation between RVEDVi, RA volumes, tricuspid annular dilatation and the presence of significant TR. These findings question commonly held notions regarding the pathophysiology of functional TR in these patients.

4D flow MRI in abdominal vessels: prospective comparison of k-t accelerated free breathing acquisition to standard respiratory navigator gated acquisition

Volumetric phase-contrast magnetic resonance imaging with three-dimensional velocity encoding (4D flow MRI) has shown utility as a non-invasive tool to examine altered blood flow in chronic liver disease. Novel 4D flow MRI pulse sequences with spatio-temporal acceleration can mitigate the long acquisition times of standard 4D flow MRI, which are an impediment to clinical adoption. The purpose of our study was to demonstrate feasibility of a free-breathing, spatio-temporal (k−t) accelerated 4D flow MRI acquisition for flow quantification in abdominal vessels and to compare its image quality, flow quantification and inter-observer reproducibility with a standard respiratory navigator-gated 4D flow MRI acquisition. Ten prospectively enrolled patients (M/F: 7/3, mean age = 58y) with suspected portal hypertension underwent both 4D flow MRI acquisitions. The k−t accelerated acquisition was approximately three times faster (3:11 min ± 0:12 min/9:17 min ± 1:41 min, p < 0.001) than the standard respiratory-triggered acquisition. Vessel identification agreement was substantial between acquisitions and observers. Average flow had substantial inter-sequence agreement in the portal vein and aorta (CV < 15%) and poorer agreement in hepatic and splenic arteries (CV = 11–38%). The k−t accelerated acquisition recorded reduced velocities in small arteries and reduced splenic vein flow. Respiratory gating combined with increased acceleration and spatial resolution are needed to improve flow measurements in these vessels.

The Posterior Transtriceps Approach for Intra-articular Elbow Arthrography: A Painless Method?

We determined the diagnostic and patient experience advantage of the transtriceps approach for elbow arthrograms. MRIs of two patients who underwent an MRI arthrogram of the elbow in May and June 2022 were retrospectively evaluated. All procedures were performed under fluoroscopic guidance with the patient in the prone position and the arm of interest extended above the head, and the elbow of interest flexed at 90 degrees. A 25 gauge needle was utilized. All MRI examinations were performed on 3-Tesla MRI scanners (Siemens,Hamburg, Germany) and in accordance with our institution's standard elbow arthrogram MRI protocol. The arthrogram was deemed successful if contrast was visualized in the elbow joint, and the MRI examinations were assessed for diagnostic ability and extra-articular leakage. Patient comfort and pain were also assessed. Both arthrograms demonstrated adequate contrast in the elbow joint, and the MRIs confirmed no leakage of contrast or bubbles. The patients felt 0 pain during the procedure on a scale of 0-10. Although the radiocapitellar approach is commonly used for elbow arthrograms, we found the transtriceps approach to be diagnostically sound, painless, and easier to perform.

Assessment of cognitive function, structural brain changes and fatigue 6 months after treatment of neuroborreliosis

BackgroundComplete recovery after adequately treated neuroborreliosis is common, but studies report that some patients experience persistent symptoms like self-reported cognitive problems and fatigue. Persisting symptoms are often termed post-Lyme disease syndrome, of which etiology is not clearly understood. The aim of this study was to investigate cognitive function, possible structural changes in brain regions and level of fatigue. We have not found previous studies on neuroborreliosis that use standardized neuropsychological tests and MRI with advanced image processing to investigate if there are subtle regional changes in cortical thickness and brain volumes after treatment.MethodsWe examined 68 patients treated for neuroborreliosis 6 months earlier and 66 healthy controls, with a comprehensive neuropsychological test protocol, quantitative structural MRI analysis of the brain and Fatigue Severity Scale.ResultsWe found no differences between the groups in either cognitive function, cortical thickness or brain volumes. The patients had higher score on Fatigue Severity Scale 3.8 vs. 2.9 (p = 0.001), and more patients (25.4%) than controls (5%) had severe fatigue (p = 0.002), but neither mean score nor proportion of patients with severe fatigue differed from findings in the general Norwegian population.ConclusionThe prognosis regarding cognitive function, brain MRI findings and fatigue after adequately treated neuroborreliosis is favorable.

NIMG-73. PREDICTING PERITUMORAL GLIOBLASTOMA INFILTRATION USING QUANTITATIVE MAGNETIC RESONANCE FINGERPRINTING RADIOMICS

Abstract PURPOSE Standard clinical magnetic resonance (MR) imaging of glioblastoma (GB) cannot identify malignant infiltration into the peritumoral non-enhancing region. This work implements quantitative MR fingerprinting (MRF) based radiomics to predict infiltrative regions of GB. METHODS Pre-operative MRF T1 and T2 maps along with multiparametric MR (mpMR) images (T1w, T2w, T1w-Gd, FLAIR, and ADC) from GB patients (n = 10) were analyzed. All subjects had histologically confirmed sites of non-enhancing peritumoral infiltration as identified by intra-operative 5-ALA fluorescence-guided tissue resection. These locations (n = 40) were manually annotated on pre-operative FLAIR by a board-certified neuroradiologist and labeled as “infiltration” (INF). For each patient, another FLAIR region ( &amp;gt; 3 cm from the enhancing tumor margin) was identified and labeled as “edema” (ED). Following image co-registration, 693 handcrafted radiomic voxel-based features were extracted from confirmed infiltration (INF) and edema (ED) voxels using a 3D 5x5x5 voxel sliding kernel. Feature selection was performed using the minimum redundancy maximal relevance (MRMR) algorithm, then INF and ED voxel features were used to train two cross-validated binary support vector machine (SVM) models for voxel-wise infiltration prediction: 1) MRF only model and 2) combined MRF and mpMRI model. Following MRMR selection, the combined model included features from T1, T1w, T2w, T1w-Gd, FLAIR, and ADC images. Model performance was evaluated using one withheld subject with multiple known infiltration sites. Balanced test accuracy and receiver operating characteristic (ROC) curve analysis was used to evaluate classification performance. RESULTS The MRF only and combined model achieved balanced test accuracies of 77.87% and 73.21% and AUCs of 0.91 and 0.97, respectively. CONCLUSIONS This study demonstrates that MRF-based radiomic features can predict GB tumor infiltration with high accuracy and provide complementary value to standard clinical MRI features. Our results indicate the high potential of employing MRF to guide personalized GB treatment strategies.

Utilization of functional MRI in the diagnosis and management of cervical cancer.

Imaging is integral part of cervical cancer management. Currently, MRI is used for staging, follow up and image guided adaptive brachytherapy. The ongoing IQ-EMBRACE sub-study is evaluating the use of MRI for functional imaging to aid in the assessment of hypoxia, metabolism, hemodynamics and tissue structure. This study reviews the current and potential future utilization of functional MRI imaging in diagnosis and management of cervical cancer. We searched PubMed for articles characterizing the uses of functional MRI (fMRI) for cervical cancer. The current literature regarding these techniques in diagnosis and outcomes for cervical cancer were then reviewed. The most used fMRI techniques identified for use in cervical cancer include diffusion weighted imaging (DWI) and dynamic contrast enhancement (DCE). DCE-MRI indirectly reflects tumor perfusion and hypoxia. This has been utilized to either characterize a functional risk volume of tumor with low perfusion or to characterize at-risk tumor voxels by analyzing signal intensity both pre-treatment and during treatment. DCE imaging in these situations has been associated with local control and disease-free survival and may have predictive/prognostic significance, however this has not yet been clinically validated. DWI allows for creation of ADC maps, that assists with diagnosis of local malignancy or nodal disease with high sensitivity and specificity. DWI findings have also been correlated with local control and overall survival in patients with an incomplete response after definitive chemoradiotherapy and thus may assist with post-treatment follow up. Other imaging techniques used in some instances are MR-spectroscopy and perfusion weighted imaging. T2-weighted imaging remains the standard technique used for diagnosis and radiation treatment planning. In many instances, it is unclear what additional information functional-MRI techniques provide compared to standard MRI imaging. Functional MRI provides potential for improved diagnosis, prediction of treatment response and prognostication in cervical cancer. Specific sequences such as DCE, DWI and ADC need to be validated in a large prospective setting prior to widespread use. The ongoing IQ-EMBRACE study will provide important clinical information regarding these imaging modalities.

Right Ventricular Remodeling Assessed by MRI in Duchenne Muscular Dystrophy.

In Duchenne muscular dystrophy (DMD), the right ventricle (RV) tends to be relatively well preserved, but characterization remains difficult due to its complex architecture. Tissue phase mapping (TPM) is a phase contrast cine MRI technique that allows for multidirectional assessment of myocardial velocities. To use TPM to elucidate relationships between myocardial structure, function, and clinical variables in DMD. Retrospective. A total of 20 patients with muscular dystrophy (median age: 16 years); 18 age-matched normal controls (median age: 15 years). Three-directional velocity encoded cine gradient echo sequence (TPM) at 1.5T, balanced steady-state free procession (bSSFP), T1 mapping with extracellular volume (ECV), and late gadolinium enhancement (LGE). TPM in basal, mid, and apical short-axis planes was performed as part of a standard MRI study with collection of clinical data. Radial, circumferential, and longitudinal velocities (Vr, Vφ, and Vz, respectively) and corresponding time to peak (TTP) velocities were quantified from TPM and used to calculate RV twist as well as intraventricular and interventricular dyssynchrony. The correlations between TPM velocities, myocardial structure/function, and clinical variables were assessed. Unpaired t-test, Wilcoxon rank-sum test, Bland-Altman analyses were used for comparisons between DMD patients and controls and between DMD subgroups. Pearson's test was used for correlations (r). Significance level: P< 0.05. Compared to controls, DMD patients had preserved RV ejection fraction (RVEF 53% ± 8%) but significantly increased interventricular dyssynchrony (Vφ: 0.49 ± 0.21 vs. 0.72 ± 0.17). Within the DMD cohort, RV dyssynchrony significantly increased with lower LV ejection fraction (intraventricular Vr and Vz: r=-0.49; interventricular Vz: r=0.48). In addition, RV intraventricular dyssynchrony significantly increased with older age (Vz: r=0.67). RV remodeling in DMD occurs in the context of preserved RVEF. Within DMD, this abnormal RV deformation is associated with older age and decreased LVEF. 4. Stage 2.

A Rapid Late Enhancement MRI Protocol Improves Differentiation between Brain Tumor Recurrence and Treatment-Related Contrast Enhancement of Brain Parenchyma.

Differentiation between tumor recurrence and treatment-related contrast enhancement in MRI can be difficult. Late enhancement MRI up to 75 min after contrast agent application has been shown to improve differentiation between tumor recurrence and treatment-related changes. We investigated the diagnostic performance of late enhancement using a rapid MRI protocol optimized for clinical workflow. Twenty-three patients with 28 lesions suspected for glioma recurrence underwent MRI including T1-MPRAGE-series acquired 2 and 20 min after contrast agent administration. Early contrast series were subtracted from late contrast series using motion correction. Contrast enhancing lesions were retrospectively and independently evaluated by two readers blinded to the patients' later clinical course and histology with or without the use of late enhancement series. Sensitivity, specificity, NPV, and PPV were calculated for both readers by comparing results of MRI with histological samples. Using standard MR sequences, sensitivity, specificity, PPV, and NPV were 0.84, 0, 0.875, and 0 (reader 1) and 0.92, 0, 0.885, and 0 (reader 2), respectively. Early late enhancement increased sensitivity, specificity, PPV, and NPV to 1 for each value and for both readers. Inter-reader reliability increased from 0.632 (standard MRI sequences) to 1.0 (with early late enhancement). The described rapid late enhancement MRI protocol improves MRI-based discrimination between tumor tissue and treatment-related changes of the brain parenchyma.

Is There a Relationship between Optic Nerve and Chiasm Measurements with HbA1c Levels in Diabetic Patients?

Objectives We investigated the optic nerve (ON) and chiasm (OC) in magnetic resonance (MR) in diabetic patients by comparing them with hemoglobin A1c (HbA1c) levels. Methods In this retrospective study, cranial MRIs of 42 adults (19 males and 23 females) with diabetes mellitus (DM) (group1) and 40 healthy controls (19 males and 21 females) (group 2) were included. In both groups, bilateral ON widths and OC area, width, and height were measured. In the DM group, HbA1c values were also obtained at the time of MRI or within the same month. Results In the DM group, the mean of the HbA1c values was 8.31 ± 2.51%. There were no significant differences between ON diameter; and OC area, width and height of the DM and control groups ( p > 0.05). In each of the DM and control groups, ON diameter was not different between the right and left sides ( p > 0.05). In DM groups, correlation tests showed that there were positive correlations between right and left ON diameters, OC area and OC width, and OC height ( p < 0.05). In males, ON diameters were higher than those in females bilaterally ( p < 0.05). In patients with higher HbA1c values, OC width was smaller ( p < 0.05). Conclusion A significant correlation of OC width and HbA1c levels suggests that uncontrolled DM causes ON atrophy. Our study represents a thorough assessment of OC measures using standard brain MRI to evaluate optic degeneration in DM patients and shows that the OC width measurement is suitable and reliable. This simple method can be obtained from clinically available scans.

P030 - Descriptive cost comparison between prostate standard biopsy and MRI guided biopsy protocols for the diagnosis of prostate cancer

P030 - Descriptive cost comparison between prostate standard biopsy and MRI guided biopsy protocols for the diagnosis of prostate cancer

Real-time, single breath-hold, multi-slice, 2D cine radial MR image reconstruction using sc-GROG k-t ESPIRiT

Background: Multi-slice, multiple breath-hold ECG-gated 2D cine MRI is a standard technique for evaluating heart function and restricted to one or two images per breath-hold. Therefore, the standard cine MRI requires long scan time and can result in slice-misalignments because of various breath-hold locations in the multiple acquisitions. Methods: This work proposes the sc-GROG based k-t ESPIRiT with Total Variation (TV) constraint (sc-GROG k-t ESPIRiT) to reconstruct unaliased cardiac real-time cine MR images from highly accelerated whole heart multi-slice, single breath-hold, real-time 2D cine radial data acquired using the balanced steady-state free precession (trueFISP) sequence in 8 patients. The proposed method quality is assessed via Artifact Power (AP), Root-Mean Square Error (RMSE), Structure Similarity Index (SSIM), Peak Signal-to-Noise Ratio (PSNR), blood-pool to myocardial Contrast-to-Noise-Ratio (CNR), Signal-to-Noise-Ratio (SNR) and spatial-temporal intensity plots through the blood-myocardium boundary. The proposed method quantitative results are compared with the NUFFT based k-t ESPIRiT with Total Variation (TV) constraint (NUFFT k-t ESPIRiT) approach. Furthermore, clinical analysis and function quantification are assessed by Bland–Altman (BA) analyses. Results: As supported by the visual assessment and evaluation parameters, the reconstruction results of the sc-GROG k-t ESPIRiT approach provide an average 21%, 12%, 1% and 47% improvement in AP, RMSE, SSIM and PSNR, respectively in comparison to the NUFFT k-t ESPIRiT approach. Furthermore, the proposed method gives on average 45% and 58% improved blood-pool to myocardial CNR and SNR than the NUFFT k-t ESPIRiT approach. Also, from the BA plot, the proposed method gives better left ventricular and right ventricular function measurements as compared to the NUFFT k-t ESPIRiT scheme. Conclusions: The sc-GROG k-t ESPIRiT (Proposed Method) improves the spatio-temporal quality of the whole heart multi-slice, single breath-hold, real-time 2D cine radial MR and semi-automated analysis using standard clinical software, as compared to the NUFFT k-t ESPIRiT approach.

Investigation of 3D Smart MRI in Surgical Efficiency and Planning

<h3>Study Objective</h3> The overall purpose of this study is to determine the surgical outcomes and patient reported experience associated with completing a 3D Smart MRI prior to surgery as opposed to completing a conventional 2D MRI prior to surgery. <h3>Design</h3> This study is a prospective randomized trial comparing outcomes of uterine myomectomies as determined by the length of the case, quantitative blood loss and conversion rate to laparotomy when standard MRI abdomen and pelvis screening is performed pre-surgery (control) as opposed to 3D Smart MRI rendering of their specific anatomy adapted from the coronal, sagittal and axial 2D MRI imaging (intervention). <h3>Setting</h3> University Hospital Setting. <h3>Patients or Participants</h3> Pilot study population will consist of 20 female patients who will undergo a robot-assisted myomectomy with 10 patients receiving conventional pre-surgical 2D MRI and 10 patients receiving 3D Smart MRI. <h3>Interventions</h3> The primary objectives of this study are to compare the effects of conventional presurgical MRI and 3D Smart MRI use on the execution of uterine leiomyoma resection surgeries by evaluating operative times, conversion rates, and blood loss. A secondary objective is to compare patient satisfaction and perceived understanding of surgery between both arms during pre- and post-surgical counseling. A tertiary objective to compare provider perceived experience between both arms using a post-surgical questionnaire. <h3>Measurements and Main Results</h3> The first 20 patients will be considered as a pilot phase to determine if the use of Smart 3D MRI can measurably improve operative speed and decrease complications such as blood loss or conversion to a more invasive surgical opening. If the Smart 3D MRI group is similar to or better than the conventional pre-surgical MRI group with respect to the primary outcomes, the study will proceed to evaluate 90 patients in total (45 patients per MRI modality group). <h3>Conclusion</h3> To be finalized and presented at AAGL in December 2022