Devkumar Mustafi PhD, Presenter: Patent application, Magnetic Resonance Imaging method using Vanadyl based contrast agents

Jonathan River, Abstract Co-Author: Nothing to Disclose

Sean Foxley BS, Abstract Co-Author: Nothing to Disclose

Sanaz A. Jansen, Abstract Co-Author: Nothing to Disclose

Gillian Maclaine Newstead MD, Abstract Co-Author: Advisory Board, Konica Minolta Group Research support, Koninklijke Philips Electronics NV Spouse, stockholder, Hologic, Inc

Gregory Stanislaus Karczmar PhD, Abstract Co-Author: Nothing to Disclose

Micro-calcifications associated with breast lesions are considered to be a useful radiological indicator of breast carcinoma. The presence of calcium oxalate micro-calcifications appears to be a reliable criterion in favor of the benign nature of breast lesions. In contrast, the micro-calcifications associated with malignant breast lesions are generally found to be calcium hydroxyapatite. The aim of this study was to develop an MRI method for identifying and characterizing these micro-crystals.

For in vitro MRI studies at 9.4 T, we developed a method for making small Ca-crystals embedded in agar phantoms. Special precautions were taken to remove air bubbles from agar by flushing helium gas followed by vacuum suction in sealed glass tubes. A typical crystal dimension embedded in agar was 135 μm3. High resolution MR images were acquired with spin echo (SE), gradient echo (GE) and echo planner spectroscopic imaging (EPSI) sequences with multiple slices with thickness of ≤500 μm and in-plane resolution of 156 μm.

SE images measured small Ca-crystals that corroborated with the precise caliper measurements. GE images with long TE amplified the sizes of crystals (>300%). Variations in magnetic susceptibility between agar and Ca-crystals produced microscopic magnetic field gradients. EPSI is particularly sensitive to such variations. B0 maps, spectral asymmetry and water peak height image analyses produced from EPSI datasets were used to isolate features specific to these susceptibility discontinuities, and thereby localize Ca-crystals.

Elimination of air bubbles from the agar phantoms made it possible to accurately evaluate the appearance of small calcifications on MRI. SE images accurately depicted the true size of the calcifications. Although GE images significantly amplified crystal sizes due to ‘blooming’ artifacts, images were distorted. Calcifications were amplified and easily seen in water peak height images derived from high resolution EPSI data.

Detection of calcifications directly on MR images would have significant diagnostic utility.

Mustafi, D, River, J, Foxley, S, Jansen, S, Newstead, G, Karczmar, G, In Vitro MRI Identification and Characterization of Small Calcium Crystals for Probing Micro-calcifications in Breast Cancer.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6018186.html