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Introduction: Magnetic resonance imaging (MRI) is being increasingly used to improve radiation therapy planning by allowing visualisation of organs at risk that cannot be well-defined on computed tomography (CT). Diagnostic sequences are increasingly being adapted for radiation therapy planning, such as the use of heavily T2-weighted 3D SPACE (Sampling Perfection with Application optimised Contrasts using different flip angle Evolution) sequence for cranial nerve identification in head and neck tumour treatment planning., Methods: A 3D isotropic T2 SPACE sequence used for cranial nerve identification was adapted for radiation therapy purposes. Distortion was minimised using a spin-echo-based sequence, 3D distortion correction, isocentre scanning and an increased readout bandwidth. Radiation therapy positioning was accounted for by utilising two small flex, 4-channel coils. The protocol was validated for cranial nerve identification in clinical applications and distortion minimisation using an MRI QA phantom., Results: Normal anatomy of the cranial nerves CI-CIX, were presented, along with a selection of clinical applications and abnormal anatomy. The usefulness of cranial nerve identification is discussed for several case studies, particularly in proximity to tumours extending into the base of skull region. In-house testing validated that higher bandwidths of 600 Hz resulted in minimal displacement well below 1 mm., Conclusion: The use of MRI for radiation therapy planning allows for greater individualisation and prediction of patient outcomes. Dose reduction to cranial nerves can decrease late side effects such as cranial neuropathy. In addition to current applications, future directions include further applications of this technology for radiation therapy treatments., (© 2023 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.)

Purpose: Previous work on Magnetic Resonance Imaging (MRI) only planning has been applied to limited treatment regions with a focus on male anatomy. This research aimed to validate the use of a hybrid multi-atlas synthetic computed tomography (sCT) generation technique from a MRI, using a female and male atlas, for MRI only radiation therapy treatment planning of rectum, anal canal, cervix and endometrial malignancies., Patients and Methods: Forty patients receiving radiation treatment for a range of pelvic malignancies, were separated into male (n = 20) and female (n = 20) cohorts for the creation of gender specific atlases. A multi-atlas local weighted voting method was used to generate a sCT from a T1-weighted VIBE DIXON MRI sequence. The original treatment plans were copied from the CT scan to the corresponding sCT for dosimetric validation., Results: The median percentage dose difference between the treatment plan on the CT and sCT at the ICRU reference point for the male cohort was - 0.4% (IQR of 0 to - 0.6), and - 0.3% (IQR of 0 to - 0.6) for the female cohort. The mean gamma agreement for both cohorts was > 99% for criteria of 3%/2 mm and 2%/2 mm. With dose criteria of 1%/1 mm, the pass rate was higher for the male cohort at 96.3% than the female cohort at 93.4%. MRI to sCT anatomical agreement for bone and body delineated contours was assessed, with a resulting Dice score of 0.91 ± 0.2 (mean ± 1 SD) and 0.97 ± 0.0 for the male cohort respectively; and 0.96 ± 0.0 and 0.98 ± 0.0 for the female cohort respectively. The mean absolute error in Hounsfield units (HUs) within the entire body for the male and female cohorts was 59.1 HU ± 7.2 HU and 53.3 HU ± 8.9 HU respectively., Conclusions: A multi-atlas based method for sCT generation can be applied to a standard T1-weighted MRI sequence for male and female pelvic patients. The implications of this study support MRI only planning being applied more broadly for both male and female pelvic sites. Trial registration This trial was registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) ( www.anzctr.org.au ) on 04/10/2017. Trial identifier ACTRN12617001406392., (© 2022. The Author(s).)

Background and Purpose: Dose planning requires a CT scan which provides the electron density distribution for dose calculation. MR provides superior soft tissue contrast compared to CT and the use of MR-alone for prostate planning would provide further benefits such as lower cost to the patient. This study compares the accuracy of MR-alone based dose calculations with bulk electron density assignment to CT-based dose calculations for prostate radiotherapy., Materials and Methods: CT and whole pelvis MR images were contoured for 39 prostate patients. Plans with uniform density and plans with bulk density values assigned to bone and tissue were compared to the patient's gold standard full density CT plan. The optimal bulk density for bone was calculated using effective depth measurements. The plans were evaluated using ICRU point doses, dose volume histograms, and Chi comparisons. Differences in spatial uniformity were investigated for the CT and MR scans., Results: The calculated dose for CT bulk bone and tissue density plans was 0.1±0.6% (mean±1 SD) higher than the corresponding full density CT plan. MR bulk bone and tissue density plans were 1.3±0.8% lower than the full density CT plan. CT uniform density plans and MR uniform density plans were 1.4±0.9% and 2.6±0.9% lower, respectively. Paired t-tests performed on specific points on the DVH graphs showed that points on DVHs for all bulk electron density plans were equivalent with two exceptions. There was no significant difference between doses calculated on Pinnacle and Eclipse. The dose distributions of six patients produced Chi values outside the acceptable range of values when MR-based plans were compared to the full density plan., Conclusions: MR-alone bulk density planning is feasible provided bone is assigned a density, however, manual segmentation of bone on MR images will have to be replaced with automatic methods. The major dose differences for MR bulk density plans are due to differences in patient external contours introduced by the MR couch-top and pelvic coil., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Retrospective descriptive study reporting the rate of occurrence of cerebral venous sinus thrombosis (CVST), highlighting the role of magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) in patients with presumed idiopathic intracranial hypertension (IIH). Study was conducted in the department of neuro-ophthalmology at a tertiary eye care center in South India. Data from 331 patients diagnosed with IIH from June 2005 to September 2007 was included. Inclusion criteria were: Elevated opening cerebrospinal fluid (CSF) pressure of more than 200 mm of water on lumbar puncture, normal CSF biochemistry and microbiology,and normal neuroimaging as depicted by computed tomography(CT) scan. Exclusion criteria were: Space-occupying lesions, hydrocephalus, meningitis, intracranial pressure within normal range, abnormal CSF biochemistry and microbiology. The remaining patients were evaluated with MRI and MRV. CVST was present in 11.4% of patients who were presumed to have IIH (35/308). MRI alone identified 24 cases (68%) of CVST, while MRI used in combination with MRV revealed an additional 11 cases (32%). Risk factors associated with CVST were identified in nine out of 35 patients (26%). CVST may be misdiagnosed as IIH if prompt neuroimaging by MRI and MRV is not undertaken. Risk factors of CVST may not be apparent in all the cases and these patients are liable to be missed if CT scan alone is used for neuroimaging, hence MRI, combined with MRV should be undertaken to rule out CVST.

Purpose: To characterize benign and malignant prostate peripheral zone (PZ) tissue retrospectively by using a commercial magnetic resonance (MR) spectroscopic imaging package and incorporating the choline plus creatine-to-citrate ratio ([Cho + Cr]/Cit) and polyamine (PA) information into a statistically based voxel classification procedure., Materials and Methods: The institutional review board approved this HIPAA-compliant study and waived the requirement for informed consent. Fifty men (median age, 60 years; range, 44-69 years) with untreated biopsy-proved prostate cancer underwent combined endorectal MR imaging and MR spectroscopic imaging. Commercial software was used to acquire and process MR spectroscopic imaging data. The (Cho + Cr)/Cit and the PA level were tabulated for each voxel. The PA level was scored on a scale of 0 (PA undetectable) to 2 (PA peak as high as or higher than Cho peak). Whole-mount step-section histopathologic analysis constituted the reference standard. Classification and regression tree analysis in a training set generated a decision-making tree (rule) for classifying voxels as malignant or benign, which was validated in a test set. Receiver operating characteristic and generalized estimating equation regression analyses were used to assess accuracy and sensitivity, respectively., Results: The median (Cho + Cr)/Cit was 0.55 (mean +/- standard deviation, 0.59 +/- 0.03) in benign and 0.77 (mean, 1.08 +/- 0.20) in malignant PZ voxels (P = .027). A significantly higher percentage of benign (compared with malignant) voxels had higher PA than choline peaks (P < .001). In the 24-patient training set (584 voxels), the rule yielded 54% sensitivity and 91% specificity for cancer detection; in the 26-patient test set (667 voxels), it yielded 42% sensitivity and 85% specificity. The percentage of cancer in the voxel at histopathologic analysis correlated positively (P < .001) with the sensitivity of the classification and regression tree rule, which was 75% in voxels with more than 90% malignancy., Conclusion: The statistically based classification rule developed indicated that PAs have an important role in the detection of PZ prostate cancer. With commercial software, this method can be applied in clinical settings.

This study investigates the comparative changes in the sodium MRI signal and proton diffusion following treatment using a 9L rat glioma model to develop markers of earliest response to cancer therapy. Sodium MRI and proton diffusion mapping were performed on untreated (n = 5) and chemotherapy 1,3-bis(2-chloroethyl)-1-nitrosourea-treated rats (n = 5). Animals were scanned serially at 2- to 3-day intervals for up to 30 days following therapy. The time course of Na concentration in a tumor showed a dramatic increase in the treated brain tumor compared to the untreated tumor, which correlates in time with an increase in tumor water diffusion. The largest posttreatment increase in sodium signal occurred 7-9 days following treatment and correlated to the period of the greatest chemotherapy-induced cellular necrosis based on diffusion and histopathology. Both Na MRI and proton ADC mapping revealed early changes in tumor sodium content and cellularity. This study demonstrates the possibility of Na MRI to function as a biomarker for monitoring early tumor treatment and validates the use of monitoring changes in diffusion MRI values for assessing tumor cellularity., (Copyright 2004 Wiley-Liss, Inc.)

Objective: To determine the frequency of Baker's cyst in patients presenting with knee pain, considering MRI as imaging modality. Study Design: Descriptive, Cross-sectional study. Setting: Department of Radiology, JPMC, Karachi. Period: 03 January 2021 till 02 July 2021. Material & Methods: Total 113 patients presenting with knee pain for >4 weeks duration who were referred for knee MRI were selected in the study. Both male and female patients between 15-65 years included in the study. Post-surgical patients and those with contraindication to MRI were excluded from the study. MRI of effected knee was performed in every selected patient by using 1.5 Tesla MRI by placing the knee in extended position with slight external rotation to facilitate imaging. MR images were interpreted by one consultant radiologist for presence or absence of Baker's cyst. Results: Patients of 15 to 65 years age were included in the study with mean age of 44.94 ± 6.69 years. Out of 113 patients, 65 (57.52%) were male and 48 (42.48%) were female with male to female ratio of 1.4:1. Mean BMI of patients was 27.45 ± 3.02 kg/m2. Mean duration of pain was 5.78 ± 2.30 months. In our study, 22 patients with knee pain were found to have Baker's cyst on MRI with frequency of 19.47%. Conclusion: This study concluded that frequency of Baker's cyst on MRI in patients with knee pain is quite high. [ABSTRACT FROM AUTHOR]

Introduction: Left bundle branch pacing (LBBP) involves the deployment of the lead deep inside the septum. Penetration of the septum by the lead depends on the texture of the septum, rapidity of rotations, operator experience, and implantation tools. Objectives: The aim of our study was to assess the behavior of the lumenless lead during rapid rotations and the physiological property of the interventricular septum(IVS) during LBBP. Methods: Patients undergoing LBBP between January 2021 and December 2022 were retrospectively included in the study. Results: Among 255 attempted patients, 20 (7.9%) had procedural failure(no LBB capture—four, inability to penetrate septum—seven, and dislodgements after sheath removal—nine). Septal penetration achieved in 248/255 patients (97.2%). Lead movement inside the IVS was assessed by lead traverse time. Based on the behavior of the IVS (n = 255), three different responses were noted. Type‐I response(normal/firm septum) in 93.7% (n = 239) characterized by constant and progressive movement of lead. Neither perforation nor further change in premature‐ventricular‐complex morphology beyond M‐beat were observed despite additional few unintentional rotations indicating the protective mechanism of LV‐endocardium. Type‐II response(soft/cheesy septum) in 3.5% (n = 9) characterized by hyper‐movement of lead without resistance due to altered texture of septum and poor LV subendocardial barrier resulting in perforation. No patients in this group had LV dysfunction or associated coronary artery disease. In type‐III response, seen in 2.8% (n = 7), lead could not be penetrated due to scar in IVS. Conclusion: Three different patterns of responses were observed during LBBP. The most distinct type‐ll response was associated with soft/cheesy septum with hyper‐movement of the lead predisposing for future dislodgments in patients without structural heart disease. [ABSTRACT FROM AUTHOR]

Primary bone sarcomas account for less than 1% of diagnosed cancers each year. In this era of multiplanar and functional imaging, the approach to the radiographic diagnosis of bone cancers goes much beyond traditional radiography. Radiographs are still the most pertinent part of the initial diagnosis of bone tumors. Multimodal imaging, such as computed tomography (CT) and magnetic resonance imaging (MRI), can help with issues such as complex anatomy, marrow assessment, soft assessment, and better local staging. The emerging imaging modality such as positron emission tomography (PET)-CT/PET-MRI has further transformed the imaging of bone malignancies. Radiologist plays an important role in the workup, staging, and management of bone tumors. The purpose of this article is to review imaging recommendations for better diagnosis, staging, and management of bone tumors. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 42-year-old male patient with neck pain radiating to the outer aspect of the left arm for the last two years. It discusses the results of contrast magnetic resonance imaging (MRI) and the postoperative MRI of his cervical spine. The patient was diagnosed of spinal idiopathic hypertrophic pachymeningitis (IHP).

We report a rare case of low-grade systemic B-cell non-Hodgkin's lymphoma (NHL) causing central retinal artery and vein occlusion, which was the only manifestation of disease recurrence. A young man with resolved systemic NHL underwent fluorescein angiography, magnetic resonance imaging and computed tomography to investigate a severe unilateral visual loss. A combined vascular occlusion was observed in the right eye. Neuroimaging detected optic nerve infiltration; but no systemic/ central nervous system involvement was observed. The patient was treated with high-doses of corticosteroids and optic nerve irradiation. The optic neuropathy and vascular occlusion were resistant to treatment. The subsequent neovascular glaucoma was treated by panretinal photocoagulation, which relieved the pain, but vision was not recovered. No further recurrence was observed over the following year. [ABSTRACT FROM AUTHOR]

• Multi-parametric MRI performed during chemo-radiotherapy for anal cancer is predictive of recurrence. • DW-MRI parameters appear more prognostic than DCE parameters. • Multi-parametric MRI requires further validation as a biomarker in anal cancer. To investigate the role of multi-parametric magnetic resonance imaging (MP-MRI) as a biomarker for squamous cell carcinoma of the anal canal (SCCAC). From January 2013 to January 2017, 25 patients with non-metastatic SCCAC were enrolled in a multi-centre prospective clinical trial, of whom 20 completed protocol treatment. MP-MRIs, incorporating diffusion weighted magnetic resonance imaging (DW-MRI) and dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) sequences, were performed before (baseline), during the second and fourth weeks of chemo-radiotherapy (CRT), and 8 weeks following treatment completion. Histogram analysis of multi-parametric maps generated maximum, mean, median, minimum, skewness, kurtosis, and standard deviation metrics. Exact logistic regression and ROC AUC analyses were performed for each metric at every timepoint. An elastic net LASSO logistic regression was also performed using all measures at each timepoint. With a median follow up of 17.1 months, 3/20 patients had a local recurrence, and 5/20 had any recurrence. Several apparent diffusion coefficient (ADC) metrics extracted from DW-MRIs correlated with local recurrence and demonstrated excellent discrimination: baseline skewness (p = 0.04, ROC AUC 0.90) and standard deviation (SD) (p = 0.02, ROC AUC 0.90), week 2 skewness (p = 0.02, ROC AUC 0.91) and SD (p = 0.01, ROC AUC 0.94), week 4 kurtosis (p = 0.01, AUC 0.92) and SD (p = 0.01, ROC AUC 0.96). Changes in minimum ADC between baseline and week 2 (p = 0.02, ROC AUC 0.94) and baseline and week 4 (p = 0.02, ROC AUC 0.94) were prognostic for local recurrence. For prediction of any recurrence, ADC minimum (p = 0.02, ROC AUC 0.87) and SD (p = 0.01, ROC AUC 0.85) at baseline, and ADC maximum (p = 0.03, ROC AUC 0.77) and SD (p = 0.02, ROC AUC 0.81) at week 4 were significant. On LASSO logistic regression, ADC minimum and SD at baseline were retained for any recurrence. The only significant finding for DCE-MRI was a correlation of k-trans min at the second follow-up with local recurrence (p = 0.05, AUC 0.84). Several ADC parameters at various time points correlate with recurrence suggesting DW-MRI is a potential biomarker for SCCAC. [ABSTRACT FROM AUTHOR]