Diffusion MRI Methods for Improved Treatment Monitoring in Breast Cancer

As of the time of this writing, the gold standard for monitoring primary breast tumor response to chemotherapy treatment is clinical examination based on palpable changes in tumor size. This method is non-quantitative, highly subjective and generally imposes that treatment is completed before efficacy can be assessed, defeating the purpose of monitoring and eliminating the prospect of adaptive treatment. MRI methods including tissue enhancement kinetics are increasingly used to provide improved monitoring of treatment response in breast and other cancers. In this work, I investigate the added value of diffusion weighted imaging, an MRI technique, for treatment monitoring in breast cancer. This investigation was first conducted in a thoroughly characterized animal model of breast cancer and subsequently in breast cancer patients. I furthered this work by exploring the potential benefit of diffusion tensor imaging, an MRI technique relatively novel to breast imaging, for breast cancer treatment monitoring. To achieve this, I developed a facile MRI protocol which was also used to study the effect of modulating diffusion time on diffusion measurements. I found that diffusion weighted imaging parameters were sensitive to treatment induced changes both in an animal model of breast cancer and in breast cancer patients. Diffusion tensor imaging parameters were able to distinguish normal breast tissue from breast cancer but modulating the diffusion time did not result in any significant changes in diffusion measurements

Uric acid profile in apparently healthy people and diabetics

In recent times, hyperuricaemia has been widely diagnosed in individuals due to changes in lifestyle and as a result of disease conditions that lead to elevated levels of uric acid in the blood. Our present work is on determination of the levels of uric acid in healthy individuals and patients with type 2 diabetes mellitus. Prevalence of hyperuricaemia in relation to age, gender and disease condition was monitored. The results indicated that, levels of uric acid are much higher in subjects that have a combined case of hyperuricaemia and type 2 diabetes mellitus

Real-Time Measurement of Functional Tumor Volume by MRI to Assess Treatment Response in Breast Cancer Neoadjuvant Clinical Trials: Validation of the Aegis SER Software Platform.

PurposeTo evaluate the Aegis software implementation for real-time calculation of functional tumor volume (FTV) in the neoadjuvant breast cancer treatment trial setting.MethodsThe validation data set consisted of 689 contrast-enhanced magnetic resonance imaging (MRI) examinations from the multicenter American College of Radiology Imaging Network 6657 study. Subjects had stage III tumors ≥3 cm in diameter and underwent MRI before, during, and after receiving anthracycline-cyclophosphamide chemotherapy. Studies were previously analyzed by the University of California San Francisco core laboratory using the three-timepoint signal enhancement ratio (SER) FTV algorithm; FTV measurement was subsequently implemented on the Hologic (formerly Sentinelle Medical Inc) Aegis platform. All cases were processed using predefined volumes of interest with no user interaction. Spearman rank correlation was evaluated for all study sites and visits. Cox proportional hazards analysis was used to compare predictive performance of the platforms for recurrence-free survival (RFS) time.ResultsOverall agreement between platforms was good; ρ varied from 0.96 to 0.98 for different study visits. Site-by-site analysis showed considerable variation, from ρ = 0.54 to near perfect agreement (ρ = 1.000) for several sites. Mean absolute difference between platforms ranged from 1.67 cm(3) pretreatment to 0.2 cm(3) posttreatment. The two platforms showed essentially identical performance for predicting RFS using pretreatment or posttreatment FTV.ConclusionImplementation of the SER FTV algorithm on a commercial platform for real-time MRI volume assessments showed very good agreement with the reference core laboratory system, but variations by site and outlier analysis point out sensitivities to implementation-specific differences

Design of a breast phantom for quantitative MRI

PurposeWe present a breast phantom designed to enable quantitative assessment of measurements of T1 relaxation time, apparent diffusion coefficient (ADC), and other attributes of breast tissue, with long-term support from a national metrology institute.Materials and methodsA breast phantom was created with two independent, interchangeable units for diffusion and T1 /T2 relaxation, each with flexible outer shells. The T1 unit was filled with corn syrup solution and grapeseed oil to mimic the relaxation behavior of fibroglandular and fatty tissues, respectively. The diffusion unit contains plastic tubes filled with aqueous solutions of polyvinylpyrrolidone (PVP) to modulate the ADC. The phantom was imaged at 1.5T and 3.0T using magnetic resonance imaging (MRI) scanners and common breast coils from multiple manufacturers to assess T1 and T2 relaxation time and ADC values.ResultsThe fibroglandular mimic exhibited target T1 values on 1.5T and 3.0T clinical systems (25-75 percentile range: 1289 to 1400 msec and 1533 to 1845 msec, respectively) across all bore temperatures. PVP solutions mimicked the range of ADC values from malignant tumors to normal breast tissue (40% PVP median: 633 × 10(-6) mm(2) /s to 0% PVP median: 2231 × 10(-6) mm(2) /s) at temperatures of 17-24°C. The interchangeable phantom units allowed both the diffusion and T1 /T2 units to be tested on the left and right sides of the coil to assess any variation.ConclusionThis phantom enables T1 and ADC measurements, fits in a variety of clinical breast coils, and can serve as a quality control tool to facilitate the standardization of quantitative measurements for breast MRI. J. Magn. Reson. Imaging 2016;44:610-619

Repeatability of Quantitative MRI Measurements in Normal Breast Tissue

AbstractPURPOSE: To evaluate the variability and repeatability of repeated magnetic resonance imaging (MRI) measurements in normal breast tissues between and within subjects. METHODS: Eighteen normal premenopausal subjects underwent two contrast-enhanced MRI scans within 72 hours or during the same menstrual phase in two consecutive months. A subset of nine women also completed diffusion-weighted imaging (DWI). Fibroglandular tissue (FGT) density and FGT enhancement were measured on the contrast-enhanced MRI. Apparent diffusion coefficient (ADC) values were computed from DWI. Between- and within-subject coefficients of variation (bCV and wCV, respectively) were assessed. Repeatability of all measurements was assessed by the coefficient of repeatability (CR) and Bland-Altman plots. RESULTS: The bCV of FGT density and FGT enhancement at visit 1 and visit 2 ranged from 47% to 63%. The wCV was 13% for FGT density, 22% for FGT enhancement, and 11% for ADC. The CRs of FGT density and FGT enhancement were 0.15 and 0.19, respectively, and for ADC, it was 6.1 x 10-4 mm2/s. CONCLUSIONS: We present an estimate of the variability and repeatability of MR measurements in normal breasts. These estimates provide the basis for understanding the normal variation of healthy breast tissue in MRI and establishing thresholds for agreement between measurements