Analysis of heterogeneity in T2-weighted MR images can differentiate pseudoprogression from progression in glioblastoma.

Purpose: To develop an image analysis technique that distinguishes pseudoprogression from true progression by analyzing tumour heterogeneity in T2-weighted images using topological descriptors of image heterogeneity called Minkowski functionals (MFs).

Methods: Using a retrospective patient cohort (n = 50), and blinded to treatment response outcome, unsupervised feature estimation was performed to investigate MFs for the presence of outliers, potential confounders, and sensitivity to treatment response. The progression and pseudoprogression groups were then unblinded and supervised feature selection was performed using MFs, size and signal intensity features.

Analysis of image heterogeneity using 2D Minkowski functionals detects tumor responses to treatment.

Purpose: The acquisition of ever increasing volumes of high resolution magnetic resonance imaging (MRI) data has created an urgent need to develop automated and objective image analysis algorithms that can assist in determining tumor margins, diagnosing tumor stage, and detecting treatment response.

Methods: We have shown previously that Minkowski functionals, which are precise morphological and structural descriptors of image heterogeneity, can be used to enhance the detection, in T1 -weighted images, of a targeted Gd(3+) -chelate-based contrast agent for detecting tumor cell death. We have used Minkowski functionals here to characterize heterogeneity in T2 -weighted images acquired before and after drug treatment, and obtained without contrast agent administration.

Cardiac phenotype induced by a dysfunctional α 1C transgene: a general problem for the transgenic approach.

Based on stable integration of recombinant DNA into a host genome, transgenic technology has become an important genetic engineering methodology. An organism whose genetic characteristics have been altered by the insertion of foreign DNA is supposed to exhibit a new phenotype associated with the function of the transgene. However, successful insertion may not be sufficient to achieve specific modification of function.

Characterization of image heterogeneity using 2D Minkowski functionals increases the sensitivity of detection of a targeted MRI contrast agent.

A targeted Gd(3+)-based contrast agent has been developed that detects tumor cell death by binding to the phosphatidylserine (PS) exposed on the plasma membrane of dying cells. Although this agent has been used to detect tumor cell death in vivo, the differences in signal intensity between treated and untreated tumors was relatively small. As cell death is often spatially heterogeneous within tumors, we investigated whether an image analysis technique that parameterizes heterogeneity could be used to increase the sensitivity of detection of this targeted contrast agent.

Optimal methods for the preservation of cartilage samples in MRI and correlative biochemical studies.

MRI studies of cartilage require the prevention of sample degradation before and during scanning and during shipment for correlative studies. Methods to achieve this include immersion in protease inhibitors (PIs), refrigeration, and freezing. In this study, bovine nasal cartilage (BNC) samples were stored in Dulbecco's phosphate-buffered saline (DPBS), DPBS with standard PIs, or PI solution with GM6001, a potent metalloproteinase inhibitor.

Tendon and neurovascular bundle displacement in the palm with hand flexion and extension: an MRI and gross anatomy correlative study.

This study evaluated the correlative use of MRI methods and gross anatomy to monitor tendon displacement in the central region of the palm at rest and during flexion and extension of the metacarpophalangeal and interphalangeal joints with respect to the corresponding neurovascular bundles (NVBs). In all of the samples the neutral and extended positions showed the NVB to be palmar with respect to the flexor tendons, while during flexion tendon displacement caused the NVB to be dorsal to both the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons. T1-weighted MR images correlated with gross anatomical slides demonstrated that significant changes occur in the relative positions of the flexor tendons and associated NVBs of the palm upon flexion and extension.