Final Magnetic Resonance Imaging Research Articles

Transrectal ultrasound for intraoperative interstitial needle guidance in cervical cancer brachytherapy.

This study aimed to prospectively assess the visibility of interstitial needles on transrectal ultrasound (TRUS) in cervical cancer brachytherapy patients and evaluate its impact on implant and treatment plan quality. TRUS was utilized during and after applicator insertion, with each needle's visibility documented through axial images at the high-risk clinical target volume's largest diameter. Needle visibility on TRUS was scored from 0 (no visibility) to 3 (excellent discrimination, margins distinct). Quantitative assessment involved measuring the distance between tandem and each needle on TRUS and comparing it to respective magnetic resonance imaging (MRI) measurements. Expected treatment plan quality based on TRUS images was rated from 1 (meeting all planning objectives) to 4 (violation of High-risk clinical target volume (CTVHR) and/or organ at risk (OAR) hard constraints) and compared to the final MRI-based plan. Analysis included 23 patients with local FIGO stage IB2-IVA, comprising 41 applications with a total of 230 needles. A high visibility rate of 99.1% (228/230 needles) was observed, with a mean visibility score of 2.5 ± 0.7 for visible needles. The maximum and mean difference between MRI and TRUS measurements were 8 mm and -0.1 ± 1.6 mm, respectively, with > 3 mm discrepancies in 3.5% of needles. Expected treatment plan quality after TRUS assessment exactly aligned with the final MRI plan in 28 out of 41 applications with only minor deviations in all other cases. Real-time TRUS-guided interstitial needle placement yielded high-quality implants, thanks to excellent needle visibility during insertion. This supports the potential of TRUS-guided brachytherapy as a promising modality for gynecological indications.

Natural History of Hepatic Hemangiomas Larger Than 10 cm: Imaging Findings and Clinical Course of 22 Cases.

The natural history of a large hepatic hemangioma is important in determining the treatment strategy. Although several studies have assessed the natural history of hepatic hemangiomas, no study has focused on hepatic hemangiomas measuring >10 cm. The aim of this study was to assess the natural history of hepatic hemangiomas measuring >10 cm by evaluating imaging findings and clinical course. Computed tomography (CT) and magnetic resonance imaging (MRI) reports at Kyoto University Hospital, Kyoto, Japan, between January 2001 and March 2023 were retrospectively searched to find adult patients with hepatic hemangiomas >10 cm. Patients who were followed up without treatment for over six months were included. The maximum diameter of the hepatic hemangioma was compared between the baseline and the final CT or MRI. The clinical course of the patients was evaluated. Twenty-two patients (17 women, five men; median age, 51 years) were identified. The median diameter of hepatic hemangiomas in the baseline study was 114 mm. Two patients had abdominal distention at the time of the baseline imaging, whereas the others were asymptomatic. After follow-up without treatment (the median; 95.5 months), enlargement, no change, shrinkage of hepatic hemangioma was observed in six, 11, and five patients, respectively. The median growth rate of hepatic hemangiomas was 2.5 mm/year. Two patients underwent liver resection for hepatic hemangioma, while the others were followed up without treatment. In four patients, symptoms appeared or worsened. Two patients died: one patient died from prostate cancer progression; the cause of death for the other was not confirmed. Hepatic hemangiomas show a slow growth rate during follow-up, and shrinkage is occasionally observed. Some patients experience new symptoms or aggravation of symptoms; however, deaths associated with hepatic hemangiomas are uncommon.

Progressive Feature Reconstruction and Fusion to Accelerate MRI Imaging: Exploring Insights across Low, Mid, and High-Order Dimensions

Magnetic resonance imaging (MRI) faces ongoing challenges associated with prolonged acquisition times and susceptibility to motion artifacts. Compressed Sensing (CS) principles have emerged as a significant advancement, addressing these issues by subsampling k-space data points and enabling rapid imaging. Nevertheless, the recovery of intricate details from under-sampled data remains a complex endeavor. In this study, we introduce an innovative deep learning approach tailored to the restoration of high-fidelity MRI images from under-sampled k-space data. Our method employs a cascaded reconstruction strategy that progressively restores hierarchical features and fuses them to achieve the final reconstruction. This cascade encompasses low, intermediate, and high orders of reconstruction, which is followed by a return through intermediate and low orders. At distinct reconstruction stages, we introduce a novel reconstruction block to recapture diverse frequency information crucial for image reconstruction. The other core innovation of our proposal lies in a fusion algorithm that harmonizes results from various reconstruction tiers into the final MRI image. Our methodology is validated using two distinct datasets. Notably, our algorithm achieves impressive PSNR values of 32.60 and 31.02 at acceleration factors of 4× and 8× in the FastMRI dataset along with SSIM scores of 0.818 and 0.771, outperforming current state-of-the-art algorithms. Similarly, on the Calgary–Campinas dataset, our algorithm achieves even higher PSNR values, reaching 37.68 and 33.44, which is accompanied by substantial SSIM scores of 0.954 and 0.901. It is essential to highlight that our algorithm achieves these remarkable results with a relatively lower parameter count, underscoring its efficiency. Comparative analyses against analogous methods further emphasize the superior performance of our approach, providing robust evidence of its effectiveness.

N-Acetylcysteine-Loaded Magnetic Nanoparticles for Magnetic Resonance Imaging.

Acute respiratory distress syndrome (ARDS) is a life-threatening condition characterized by the rapid onset of lung inflammation Therefore, monitoring the spatial distribution of the drug directly administered to heterogeneously damaged lungs is desirable. In this work, we focus on optimizing the drug N-acetylcysteine (NAC) adsorption on poly-l-lysine-modified magnetic nanoparticles (PLLMNPs) to monitor the drug spatial distribution in the lungs using magnetic resonance imaging (MRI) techniques. The physicochemical characterizations of the samples were conducted in terms of morphology, particle size distributions, surface charge, and magnetic properties followed by the thermogravimetric quantification of NAC coating and cytotoxicity experiments. The sample with the theoretical NAC loading concentration of 0.25 mg/mL was selected as an optimum due to the hydrodynamic nanoparticle size of 154 nm, the surface charge of +32 mV, good stability, and no cytotoxicity. Finally, MRI relaxometry confirmed the suitability of the sample to study the spatial distribution of the drug in vivo using MRI protocols. We showed the prevailing transverse relaxation with high transverse relaxivity values and a high r2(*)/r1 ratio, causing visible hypointensity in the final MRI signal. Furthermore, NAC adsorption significantly affects the relaxation properties of PLLMNPs, which can help monitor drug release in vitro/in vivo.

Breast Cancer Growth on Serial MRI: Volume Doubling Time Based on 3-Dimensional Tumor Volume Assessment.

The volume doubling time (VDT) of breast cancer was most frequently calculated using the two-dimensional (2D) diameter, which is not reliable for irregular tumors. It was rarely investigated using three-dimensional (3D) imaging with tumor volume on serial magnetic resonance imaging (MRI). To investigate the VDT of breast cancer using 3D tumor volume assessment on serial breast MRIs. Retrospective. Sixty women (age at diagnosis: 57 ± 10 years) with breast cancer, assessed by two or more breast MRI examinations. The median interval time was 791 days (range: 70-3654 days). 3-T, fast spin-echo T2-weighted imaging (T2WI), single-shot echo-planar diffusion-weighted imaging (DWI), and gradient echo dynamic contrast-enhanced imaging. Three radiologists independently reviewed the morphological, DWI, and T2WI features of lesions. The whole tumor was segmented to measure the volume on contrast-enhanced images. The exponential growth model was fitted in the 11 patients with at least three MRI examinations. The VDT of breast cancer was calculated using the modified Schwartz equation. Mann-Whitney U test, Kruskal-Wallis test, Chi-squared test, intraclass correlation coefficients, and Fleiss kappa coefficients. A P-value <0.05 was considered statistically significant. The exponential growth model was evaluated using the adjusted R2 and root mean square error (RMSE). The median tumor diameter was 9.7 mm and 15.2 mm on the initial and final MRI, respectively. The median adjusted R2 and RMSE of the 11 exponential models were 0.97 and 15.8, respectively. The median VDT was 540 days (range: 68-2424 days). For invasive ductal carcinoma (N=33), the median VDT of the non-luminal type was shorter than that of the luminal type (178 days vs. 478 days). On initial MRI, breast cancer manifesting as a focus or mass lesion showed a shorter VDT than that of a non-mass enhancement (NME) lesion (median VDT: 426 days vs. 665 days). A shorter VDT was observed in breast cancer manifesting as focus or mass as compared to an NME lesion. 3 TECHNICAL EFFICACY: Stage 2.

Remodeling of Epidural Fluid Hematoma after Uniportal Lumbar Endoscopic Unilateral Laminotomy with Bilateral Decompression: Comparative Clinical and Radiological Outcomes with a Minimum Follow-up of 2 Years.

Retrospective cohort study. To evaluate the clinical and radiological effects of epidural fluid hematoma in the medium term after lumbar endoscopic decompression. There is limited literature comparing the effect of postoperative epidural fluid hematoma after uniportal endoscopic decompression. Magnetic resonance imaging (MRI) and clinical evaluation were performed for patients with single-level uniportal endoscopic lumbar decompression with a minimum follow-up of 2 years. A total of 126 patients were recruited with a minimum follow-up of 26 months. The incidence of epidural fluid hematoma was 27%. Postoperative MRI revealed a significant improvement in the postoperative dura sac area at postoperative day 1 and at the upper endplate at 6 months in the hematoma cohort (39.69±15.72 and 26.89±16.58 mm2) as compared with the nonhematoma cohort (48.92±21.36 and 35.1±20.44 mm2), respectively (p <0.05); and at the lower endplate on postoperative 1 day in the hematoma cohort (51.18±24.69 mm2) compared to the nonhematoma cohort (63.91±27.92 mm2) (p <0.05). No significant difference was observed in the dura sac area at postoperative 1 year in both cohorts. The hematoma cohort had statistically significant higher postoperative 1-week Visual Analog Scale (VAS; 3.32±0.68) pain and Oswestry Disability Index (ODI; 32.65±5.56) scores than the nonhematoma cohort (2.99±0.50 and 30.02±4.84, respectively; p <0.05). No significant difference was found at the final follow-up VAS, ODI, and MRI dura sac area. Epidural fluid hematoma is a common early postoperative MRI finding in lumbar endoscopic unilateral laminotomy with bilateral decompression. Conservative management is the preferred treatment option for patients who do not have a neurological deficit. Symptoms last only a few days and are self-limiting. A common endpoint is a remodeled fluid hematoma and the subsequent expansion of the dura sac area.

Association between contralateral background parenchymal enhancement on MRI and outcome in patients with unilateral invasive breast cancer receiving neoadjuvant chemotherapy

PurposeThe purpose of this study was to retrospectively investigate whether background parenchymal enhancement (BPE) of the contralateral breast on magnetic resonance imaging (MRI) is associated with clinical outcomes in patients with unilateral invasive breast cancer receiving neoadjuvant chemotherapy (NAC). Materials and methodsA total of 228 women (47.6 years ± 10 [SD]; range: 24–74 years) with invasive breast cancer who underwent NAC between 2005 and 2013 were included. All included patients underwent breast MRI before and after NAC. Quantitative semiautomated analysis of BPE of the contralateral healthy breast was performed. The enhancement level on baseline MRI (baseline BPE) and on MRI after chemotherapy (final BPE) and the change in enhancement rate between baseline MRI and final MRI were recorded. Cox regression was used to test associations between BPE variables, patient and tumor characteristics, overall survival (OS) and disease–free survival (DFS). Subgroup analyses based on menopausal status and immunohistochemical subtypes were performed. ResultsMedian follow-up was 92 months. Multivariable analysis revealed that Ki-67 level (P = 0.026) and receipt of mastectomy (P = 0.015) were independent variables associated with OS while Ki-67 level (P = 0.010) and post-NAC pathological node categorization (P = 0.027) were independent variables associated with DFS. BPE was not associated with OS (P = 0.500, 0.546 and 0.712 for baseline BPE, final BPE and BPE change, respectively) or with DFS (P = 0.568, 0.412 and 0.327, respectively). ConclusionBPE of the contralateral breast on MRI may have limited prognostic value in patients with breast cancer treated with NAC.

Association of Intensive vs Standard Blood Pressure Control With Cerebral Blood Flow

Antihypertensive treatments benefit cerebrovascular health and cognitive function in patients with hypertension, but it is uncertain whether an intensive blood pressure target leads to potentially harmful cerebral hypoperfusion. To investigate the association of intensive systolic blood pressure (SBP) control vs standard control with whole-brain cerebral blood flow (CBF). This substudy of the Systolic Blood Pressure Intervention Trial (SPRINT) randomized clinical trial compared the efficacy of 2 different blood pressure-lowering strategies with longitudinal brain magnetic resonance imaging (MRI) including arterial spin labeled perfusion imaging to quantify CBF. A total of 1267 adults 50 years or older with hypertension and increased cardiovascular risk but free of diabetes or dementia were screened for the SPRINT substudy from 6 sites in the US. Randomization began in November 2010 with final follow-up MRI in July 2016. Analyses were performed from September 2020 through December 2021. Study participants with baseline CBF measures were randomized to an intensive SBP target less than 120 mm Hg or standard SBP target less than 140 mm Hg. The primary outcome was change in whole-brain CBF from baseline. Secondary outcomes were change in gray matter, white matter, and periventricular white matter CBF. Among 547 participants with CBF measured at baseline, the mean (SD) age was 67.5 (8.1) years and 219 (40.0%) were women; 315 completed follow-up MRI at a median (IQR) of 4.0 (3.7-4.1) years after randomization. Mean whole-brain CBF increased from 38.90 to 40.36 (difference, 1.46 [95% CI, 0.08-2.83]) mL/100 g/min in the intensive treatment group, with no mean increase in the standard treatment group (37.96 to 37.12; difference, -0.84 [95% CI, -2.30 to 0.61] mL/100 g/min; between-group difference, 2.30 [95% CI, 0.30-4.30; P = .02]). Gray, white, and periventricular white matter CBF showed similar changes. The association of intensive vs standard treatment with CBF was generally similar across subgroups defined by age, sex, race, chronic kidney disease, SBP, orthostatic hypotension, and frailty, with the exception of an indication of larger mean increases in CBF associated with intensive treatment among participants with a history of cardiovascular disease (interaction P = .05). Intensive vs standard antihypertensive treatment was associated with increased, rather than decreased, cerebral perfusion, most notably in participants with a history of cardiovascular disease. ClinicalTrials.gov Identifier: NCT01206062.

Moving silicone oil particles in the ventricle: a case report and updated review

BackgroundThe movement of intraventricular silicone oil observed in the supine position is extremely rare. Herein, we describe a patient who presented with dynamically moving silicone oil particles in the ventricle when changing position and provide an updated review of this phenomenon.Case presentationWe report a case of a 70-year-old woman who presented with intraventricular hyperdensities that were occasionally found on brain computed tomography (CT). Initial nonenhanced brain CT demonstrated nondependent hyperdensities in the bilateral anterior horns of the lateral ventricles, the third ventricle, and the right suprasellar cistern, mimicking an intraventricular hemorrhage. Further brain magnetic resonance imaging (MRI) in the supine position revealed abnormal signals in the bilateral anterior horns of the lateral ventricles, the posterior horn of the right lateral ventricle, the third ventricle, the right suprasellar cistern, and the bilateral eyeballs, with isosignal intensities surrounded by low-signal chemical shift artifacts on T1-weighted imaging and variable signals (hypo- or hyperintensity) on T2-weighted imaging. The lesion in the anterior horn of the right ventricle largely moved to the posterior horn of the ipsilateral ventricle. The final craniocervical CT angiography showed that the lesion in the posterior horn had moved back to the anterior horn of the right lateral ventricle. These features were consistent with intraventricular silicone oil migration. The final spinal MRI did not demonstrate a migration of silicone oil into the spinal subarachnoid space.Discussion and conclusionsThis case report describes a dynamic process of silicone oil displacement in the supine position and provides a comprehensive imaging presentation. The moving pattern and a characteristic chemical shift artifact on MRI are key to the diagnosis and may help prevent unnecessary examinations or intervention.

PARCEL: Physics-Based Unsupervised Contrastive Representation Learning for Multi-Coil MR Imaging.

With the successful application of deep learning to magnetic resonance (MR) imaging, parallel imaging techniques based on neural networks have attracted wide attention. However, in the absence of high-quality, fully sampled datasets for training, the performance of these methods is limited. And the interpretability of models is not strong enough. To tackle this issue, this paper proposes a Physics-bAsed unsupeRvised Contrastive rEpresentation Learning (PARCEL) method to speed up parallel MR imaging. Specifically, PARCEL has a parallel framework to contrastively learn two branches of model-based unrolling networks from augmented undersampled multi-coil k-space data. A sophisticated co-training loss with three essential components has been designed to guide the two networks in capturing the inherent features and representations for MR images. And the final MR image is reconstructed with the trained contrastive networks. PARCEL was evaluated on two vivo datasets and compared to five state-of-the-art methods. The results show that PARCEL is able to learn essential representations for accurate MR reconstruction without relying on fully sampled datasets. The code will be made available at https://github.com/ternencewu123/PARCEL.

Occipital Interhemispheric Transtentorial Approach for Tumors of Posterior Third Ventricular Region: Review of Surgical Results.

Controversies exist regarding the ideal surgical approach for tumors in posterior third ventricular region (PTV). To evaluate the results of occipital interhemispheric transtentorial (OITT) approach for tumors in PTV. Thirty-three patients underwent surgery via OITT approach for PTV tumors at Sri Sathya Sai Institute of Higher Medical Sciences during the study period of 5 years (June 2011-May 2016). Ideal trajectory for OITT approach was determined by neuronavigation. Endoscope was used for removing any residual lesion at the blind spots. Postoperative magnetic resonance imaging (MRI) performed in all the patients revealed gross total or near-total (>95%) excision of tumor in 31 patients (93.9%). Preoperative neurological deficits improved either completely or significantly following excision of the tumor in 73.3% (11/15) of the patients. Outcome was good (modified Rankin scale ≤2) at discharge in 93.9% (31/33) and at a final follow-up of 3 months or more in 96.8% (30/31) of the patients. None of the patients died during the postoperative period. Complications included upgaze palsy (transient- 6.1% [2/33], persisting- 3% [1/33]), visual field defects (transient- 3% [1/33], persisting- 3% [1/33]), transient third nerve paresis (1/33-3%), transient hemiparesis (1/33-3%), operative site hematoma (1/33-3%), small posterior cerebral artery (PCA) territory infarct (1/33-3%), and small venous infarct (1/33-3%). At least one follow-up MRI could be performed in 23 patients. Final follow-up MRI revealed no recurrence or increase in the size of the residual lesion compared to postoperative images in 20 patients (20/23-87%) and large recurrence in 3 patients (3/23-13%) with high-grade lesions. Gross total/near-total excision can be performed in majority of the PTV tumors through OITT approach with minimal morbidity and mortality.

INNV-18. EFFECT OF DURATION OF TUMOR TREATING FIELDS THERAPY ON CELLULARITY DISTRIBUTIONS BEYOND T1W MRI CONTRAST ENHANCING MARGIN AT AUTOPSY IN GLIOMA PATIENTS: PRELIMINARY RESULTS

Abstract Tumor treating fields (TTFields) are thought to disrupt the cell division process in glioma. This study uses autopsy tissue samples from patients recruited for brain donation to determine whether TTFields treatment duration and usage affects cellularity distributions beyond the gadolinium contrast enhancing region on T1-weighted (T1w) magnetic resonance imaging (MRI). At autopsy, 43 tissue samples from 18 patients who had undergone TTFields treatment (inclusion criteria: &amp;gt;50% compliance and 25-day duration) were collected from brain slices sectioned in-line with slices from the patients’ final MRI prior to death. Nuclei were segmented on the digitized hematoxylin and eosin (HE) stained tissue samples, which were then used to compute cell count across the slides. Tissue was then aligned to the patient’s final MRI scan prior to death using a custom in-house software, where manually defined control points were used to compute a nonlinear transform to warp the tissue to match the MRI. Histogram features including mean, median, 90th percentile, variance, and skewness, were computed from the cellularity distributions within regions outside the traditional tumor margin defined by T1w contrast enhancement for each subject. General linear models were fit to assess the effects of TTFields usage (percent of day) and duration (in days) on each histogram feature, controlling for age, overall survival, and time between TTFields treatment and death, as well as time between MRI acquisition and death. Longer TTFields treatment duration and overall survival was associated with significantly decreased skewness in the non-enhancing cellularity distributions (p&amp;lt; 0.05) while associations with other metrics remained statistically insignificant. These preliminary results in a small patient cohort suggest that TTFields duration may reduce the presence of high cellularity tails in the non-contrast enhancing distributions. Additional research in larger patient populations is warranted to better understand these findings given the number of confounding factors.

Nonoperatively managed small- to medium-sized subscapularis tendon tears: magnetic resonance imaging evaluation with a minimum of 5 years of follow-up.

BackgroundIsolated or combined subscapularis (SSC) tendon tears are frequently found in patients with shoulder pain. The purpose of this study was to evaluate the structural changes associated with SSC tear in a consecutive series of patients with nonoperatively treated small size to midsize SSC tendon tears using magnetic resonance imaging (MRI).MethodsIn this retrospective case series, all patients with an isolated or combined SSC tendon tear treated nonoperatively between 1999 and 2019 were identified from our MRI and clinical databases. Twenty-one patients with a mean age of 52.6 years (range 26.6-64.8, standard deviation 9.3) with a second MRI scan at a minimum of 5 years of follow-up were enrolled. The mean follow-up was 8.6 years (range 5.6-12.6, standard deviation 1.8). Initial and last follow-up MRI scans were used to determine concomitant cuff lesions, size of the SSC tear, fatty infiltration of the SSC muscle, and biceps pathology.ResultsFive patients had an isolated SSC lesion; 7 patients had a concomitant tear of the supraspinatus, and 9 patients had a supraspinatus and anterior infraspinatus tendon tear. At diagnosis, 14 patients had a type 1 SSC lesion as classified by Lafosse et al, 4 patients had type 2, and 3 patients had type 3 lesions. Nineteen patients (90%) were found to have an SSC tear progression of at least one Lafosse grade (P < .001); however, no tear had progressed to an irreparable type lesion (defined as Lafosse type 5). In addition, the size of SSC tendon tears increased significantly from 75 mm2 to 228 mm2 (P < .001). At the final MRI scan, the grading of fatty infiltration increased by 1 grade in 4 cases and by 2 grades in 4 cases (P = .042). At the final follow-up, in eight patients, the condition of the long head of biceps tendon was unchanged from the initial MRI; in nine patients, there was a newly subluxated biceps tendon, and in 6 patients, there was a newly ruptured long head of biceps tendon (P < .001).ConclusionAfter a mean of 8.6 years, almost all nonoperatively treated SSC tendon tears had increased in size, but only one-third showed additional progression of muscle fatty degeneration on MRI scan. None of the SSC lesions became irreparable during the observation period.

Evaluation of the Effect of Multiple Linear Gadolinium-Based Contrast Agent Exposures on the Signal Intensity of the Dentate Nucleus in Multiple Sclerosis Patients

Background: Magnetic resonance imaging (MRI) with gadolinium (GAD)-based contrast agents has been the imaging modality of choice for early detection and monitoring of multiple sclerosis (MS) patients. Objectives: This study aimed to assess the effect of multiple injections of linear GAD-based contrast agents on the signal intensity of the dentate nucleus (DN) in MS patients. Patients and Methods: A cohort of 122 MS patients with GAD-enhanced MRI scans and 61 healthy controls were enrolled in this study. The final standard GAD-enhanced MRI scans were acquired using 1.5T MRI systems. Non-enhanced T1-weighted MRI was performed to assess the DN hyperintensity. The signal intensity ratio (SIR) was also calculated by setting the regions of interest (ROIs) on the DN and pons and dividing the signal intensity of DN to that of pons. The patients were also divided into two subgroups, based on the total number of MRI exposures (&gt; 4 times vs. others), and the subgroups were compared in terms of the mean SIR and hyperintensity. Results: Overall, 68% (n = 83) of the patients were exposed to a contrast agent more than four times. Of these patients, 31.3% (n = 26) showed DN hyperintensity, while no hyperintensity was found in other patients or healthy controls (P &lt; 0.02 for both). The mean SIRs were 1.10 ± 0.07 and 1.04 ± 0.02 in the patients and healthy controls, respectively (P &lt; 0.001). Besides, the mean SIR was 1.14 ± 0.04 in patients with DN hyperintensity and 1.09 ± 0.07 in other patients (P &lt; 0.001). Based on the results, the mean SIR was 1.12 ± 0.7 in patients with &gt; 4 contrast injections, while it was 1.06 ± 0.04 in patients with ≤ 4 contrast injections (P &lt; 0.001). Conclusion: The SIR and visible DN hyperintensity increased by increasing the number of GAD injections, which could be due to the tissue deposition of GAD.

Radiologic criteria of retropharyngeal lymph node metastasis in maxillary sinus cancer

ObjectiveTo determine the most appropriate radiologic criteria of metastatic retropharyngeal lymph nodes (RLNs) in patients with maxillary sinus cancer (MSC).Materials and methodsWe retrospectively evaluated 16 consecutive patients who underwent magnetic resonance imaging (MRI) before and after the treatment of locally advanced squamous cell carcinoma of the maxillary sinus. The minimal and maximal diameters of all RLNS were recorded. RLNs were classified as metastatic on the basis of the MRI follow-up (f/u). RLNs were considered non-metastatic if stable disease continued until the final MRI f/u and metastatic in cases with different evaluations (complete response, partial response, progressive disease) determined using Response Evaluation Criteria in Solid Tumours (RECIST) ver. 1.1. The receiver operating characteristic curve (ROC) and area under the curve (AUC) were used to assess the accuracy of various criteria in the diagnosis of metastatic RLNs.ResultsOf the 34 RLNs in 16 cases observed on pretreatment MRI, 7 were classified as metastatic RLNs and 27 as non-metastatic RLNs. Using the radiologic criteria, metastatic RLNs tended to be diagnosed more accurately with the minimal axial diameter than with the maximal axial diameter (AUC; 0.97 vs. 0.73, p = 0.06). The most accurate size criterion of metastatic RLNs was a minimal axial diameter of 5 mm or larger, with an accuracy of 94.1% (32 of 34).ConclusionsThe most appropriate radiologic criterion of metastatic RLNs in MSC is a minimal axial diameter of 5 mm or longer.

The design and rationale of a multi-center randomized clinical trial comparing one avocado per day to usual diet: The Habitual Diet and Avocado Trial (HAT)

Excess visceral adiposity is associated with increased risk of diabetes and cardiovascular disease. In the U.S. approximately 60% of adults have visceral obesity. Despite high calorie and fat, small, well-controlled clinical studies suggest that avocado consumption has favorable effects on body weight and visceral adiposity. Additionally, short-term studies also suggest that consuming avocados increases satiety, hence, may decrease overall energy intake. The Habitual Diet and Avocado Trial HAT is a multi-center, randomized, controlled trial designed to test whether in a large, diverse cohort providing one avocado per day for consumption for six months compared to a habitual diet essentially devoid of avocados, will result in a decrease in visceral adiposity as measured by magnetic resonance imaging (MRI) in individuals with an increased waist circumference (WC). Additional outcome measures include hepatic lipid content, plasma lipid profiles, blood pressure and high sensitivity C-reactive protein. Inclusion criteria were increased WC and not currently eating more than two avocados per month. Major exclusion criteria were not eating or being allergic to avocados, and not willing or able to undergo MRI scans.From June 27, 2018 to March 4, 2020, 1008 participants were randomized at 4 clinics. The cohort was 72% women, 53% Non-Hispanic White, and had a mean age of 50 years. Follow-up was completed in October 2020 when 936 participants had final MRI scans. HAT will provide information on the effects of avocado consumption on visceral fat adiposity and cardiometabolic disease risk in a diverse sample of participants.

Morphological Changes in the Residual Meniscus After Reshaping Surgery for a Discoid Lateral Meniscus

Background: Arthroscopic reshaping surgery is the first treatment option for a symptomatic discoid lateral meniscus (DLM) to preserve the peripheral rim. However, the degree of postoperative morphological change in the residual meniscus is unclear. Purpose/Hypothesis: The purpose of this study was to measure the meniscus after reshaping surgery for a DLM, to verify when the morphological change occurred, and to examine the related risk factors. The hypothesis was that the residual meniscal width would decrease throughout the postoperative course. Study Design: Case-control study; Level of evidence, 3. Methods: We retrospectively reviewed the medical records of patients who underwent reshaping surgery for a symptomatic DLM and had undergone follow-up for ≥2 years. Magnetic resonance imaging (MRI) was routinely performed preoperatively and at 3, 6, 12, and 24 months postoperatively, and the width, height, and extrusion of the residual meniscus were measured. According to the width of the midbody on final MRI scans, we compared the preoperative and postoperative data for the preserved group (≥5 mm) and decreased group (<5 mm). The associated risk factors for a decreased meniscal width (<5 mm) of the midbody were analyzed on final MRI scans. Results: We included 61 knees of 54 patients in this study. The mean age at the time of surgery was 11.7 years. The intraobserver and interobserver reliabilities of the midbody width were 0.937 and 0.921, respectively. The width of the anterior horn, midbody, and posterior horn decreased significantly from 3 to 24 months after surgery (from 9.1 to 8.6 mm [P < .001], from 7.5 to 6.1 mm [P < .001], and from 9.5 to 8.9 mm [P = .001], respectively). Meniscal extrusion of the midbody did not change significantly (from 1.2 to 1.5 mm; P = .062). Overall, 46 knees (n = 20/32 in the preserved group and n = 26/29 in the decreased group) had longitudinal tears that required meniscal repair. Clinical outcomes did not differ significantly between the 2 groups. Multivariate logistic analysis showed that intrameniscal degeneration (odds ratio, 4.36; P = .023) significantly increased the risk of a decreased meniscal width. Conclusion: The width of the anterior horn, midbody, and posterior horn decreased significantly from 3 to 24 months after surgery. In particular, the average decrease rate of the midbody was 19%. No clinical difference was seen in patients with a decreased width and height or with peripheral extrusion. Increased intrameniscal signals on preoperative MRI scans were associated with an increased risk of a decreased meniscal width. Surgeons should consider this result to determine the amount of resection.

Modified amino-dextrans as carriers of Gd-chelates for retrograde transport and visualization of peripheral nerves by magnetic resonance imaging (MRI)

Amino-dextrans (AD) conjugated with gadolinium (Gd3+) were developed as neuro-specific contrast agents (CA) for the visualization of the sciatic nerve in rats by magnetic resonance imaging (MRI). AD with 3, 10, and 70 kDa molecular weights were assessed as carrier molecules known to be transported with various speed by axonal microtubules. Detailed spectroscopic characterizations, analyses by Fast Protein Liquid Chromatography (FPLC), Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE), and inductively coupled plasma-mass spectrometry (ICP-MS), were carried out. For MRI, the paramagnetic Gd3+ ion was coupled as a T1 signal enhancer. The well-established linear chelator, diethylenetriaminepentaacetic acid (DTPA), was used and subsequently replaced by the more stable cyclic chelator 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). In addition, a fluorescently labeled AD-DTPA-Gd was prepared to demonstrate an active transport to the spinal cord by histochemistry. After successful synthesis and characterization, molecular migration of the AD-DTPA-Gd in the sciatic nerve of healthy Sprague Dawley rats was monitored by MRI for up to seven days. Enhancement of nerve structures was evaluated by MRI and correlated with ICP-MS analyses. To investigate the distribution of CA along the neuraxis, all animals were sacrificed after the final MRI monitoring. Nerves, spinal ganglions, and corresponding spinal cord sections were harvested, to determine the localization and concentration of the paramagnetic element. This is the first report that demonstrates the active uptake and transport of AD-Gd conjugates within the sciatic nerve. This new concept may serve as a potential diagnostic tool for the direct visualization and monitoring of the continuity of injured nerves.

Response Predictivity to Neoadjuvant Therapies in Breast Cancer: A Qualitative Analysis of Background Parenchymal Enhancement in DCE-MRI

Background: For assessing the predictability of oncology neoadjuvant therapy results, the background parenchymal enhancement (BPE) parameter in breast magnetic resonance imaging (MRI) has acquired increased interest. This work aims to qualitatively evaluate the BPE parameter as a potential predictive marker for neoadjuvant therapy. Method: Three radiologists examined, in triple-blind modality, the MRIs of 80 patients performed before the start of chemotherapy, after three months from the start of treatment, and after surgery. They identified the portion of fibroglandular tissue (FGT) and BPE of the contralateral breast to the tumor in the basal control pre-treatment (baseline). Results: We observed a reduction of BPE classes in serial MRI checks performed during neoadjuvant therapy, as compared to baseline pre-treatment conditions, in 61.3% of patients in the intermediate step, and in 86.7% of patients in the final step. BPE reduction was significantly associated with sequential anthracyclines/taxane administration in the first cycle of neoadjuvant therapy compared to anti-HER2 containing therapies. The therapy response was also significantly related to tumor size. There were no associations with menopausal status, fibroglandular tissue (FGT) amount, age, BPE baseline, BPE in intermediate, and in the final MRI step. Conclusions: The measured variability of this parameter during therapy could predict therapy effectiveness in early stages, improving decision-making in the perspective of personalized medicine. Our preliminary results suggest that BPE may represent a predictive factor in response to neoadjuvant therapy in breast cancer, warranting future investigations in conjunction with radiomics.

Radial shortening osteotomy vs partial capitate shortening osteotomy in Kienböck’s disease: Medium-term radiological and clinical results

This study aimed to compare medium-term results for partial capitate shortening (PCS) and radial shortening (RS) osteotomies on lunate bone revascularization and disease progression in patients with stage II or IIIA Kienböck’s disease. Patients who underwent surgery for Kienböck’s disease between March 2010 and July 2020 were retrospectively evaluated. Clinical evaluation included assessment of pain, joint range of motion, strength, DASH, visual analog scale (VAS) for pain, Modified Mayo Wrist Score (MMWS), satisfaction and time to return to work, with comparison as appropriate to the contralateral side. Preoperative and postoperative plain radiographs and magnetic resonance imaging (MRI) were used for radiological evaluation. Lichtman staging and signal changes in the lunate were evaluated using MRI. Group 1 (PCS) included 14 patients and Group 2 (RS) 14. Mean follow-up was 57.8 months (range 24–102) in Group 1 and 49.4 months (range 36–73) in Group 2. Clinical evaluation included pain on VAS, DASH score, MMWS, range of motion, and grip, palmar and key pinch strength. Regarding lunate bone vascularization, increased signal on final follow-up MRI was observed in 10 of the 14 patients in Group 1 and 7 of the 14 patients in Group 2. There was a positive correlation between revascularization and final follow-up MMWS (p = 0.006). The present study thus showed that functional scores were improved by revascularization in Kienböck’s disease. Both osteotomies had clinically and radiologically satisfactory results. However, we believe that PCS osteotomy is preferable, as it leads to higher revascularization rates without increasing ulnolunate load.