Phosphorus MRI of the Lower Extremeties in Diabetics

Summary

Principal Investigator: ROBERT GREENMAN
Abstract: DESCRIPTION (Provided by applicant): The overall objective of this proposal is to develop a three-dimensional MR imaging protocol to investigate the phosphorus-31 metabolism in the muscle tissue in the lower extremities of diabetic patients. Fifteen million people suffer from diabetes mellitus in the United States and there are 650,000 new cases diagnosed each year. Changes in the structure of the basement membrane of capillaries and neuropathy of the autonomic nerves create an effective ischemia in localized capillary beds in the lower leg and foot. Anatomical methods exist for assessing the blood flow and nerve viability in the lower legs and feet of diabetics. However, these techniques do not provide a direct assessment of the metabolic state of the affected muscle tissue. Phosphorus magnetic resonance spectroscopy (MRS) has been used to study the metabolism of muscle tissue and assess the metabolic state of ischemic tissue in a noninvasive way in humans. The current MRS localization technique that can be used to provide a regional assessment of the lower leg and foot with the ability to identify focal areas of ischemia is chemical shift imaging (CSI). However, a scan of the lower extremities having a resolution that is high enough to identify local areas with poor blood flow using the currently available CSI technique would take more than 21 minutes making the MR examination prohibitively long. We have exploited the recent advances in high-speed magnetic resonance imaging techniques to develop a method for directly creating images of a single phosphorus metabolite (e.g. phosphocreatine) in human skeletal muscle. We have successfully acquired pure phosphocreatine images of human skeletal muscle in normal volunteers having a spatial resolution of 0.23 cm3 in 2 minutes on a whole body MR scanner. We propose to establish a protocol using a 3-dimensional technique for the study of muscle viability in the lower extremities of diabetic patients who suffer from complications resulting from polyneuropathy and localized ischemia.
Funding Period: 2002-08-01 - 2005-07-31
more information: NIH RePORT

Top Publications

  1. pmc Foot small muscle atrophy is present before the detection of clinical neuropathy
    Robert L Greenman
    Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Rd, Boston, MA 02115, USA
    Diabetes Care 28:1425-30. 2005
  2. ncbi Evaluation of the RF field uniformity of a double-tuned 31P/1H birdcage RF coil for spin-echo MRI/MRS of the diabetic foot
    Robert L Greenman
    Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115, USA
    J Magn Reson Imaging 22:427-32. 2005
  3. ncbi Early changes in the skin microcirculation and muscle metabolism of the diabetic foot
    Robert L Greenman
    Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
    Lancet 366:1711-7. 2005
  4. pmc The feasibility of measuring phosphocreatine recovery kinetics in muscle using a single-shot (31)P RARE MRI sequence
    Robert L Greenman
    Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA
    Acad Radiol 18:917-23. 2011
  5. pmc Simultaneous acquisition of phosphocreatine and inorganic phosphate images for Pi:PCr ratio mapping using a RARE sequence with chemically selective interleaving
    Robert L Greenman
    Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
    Magn Reson Imaging 29:1138-44. 2011
  6. ncbi An assessment of the sharpness of carotid artery tissue boundaries with acquisition voxel size and field strength
    Robert L Greenman
    Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
    Magn Reson Imaging 26:246-53. 2008

Scientific Experts

Detail Information

Publications6

  1. pmc Foot small muscle atrophy is present before the detection of clinical neuropathy
    Robert L Greenman
    Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Rd, Boston, MA 02115, USA
    Diabetes Care 28:1425-30. 2005
    ....
  2. ncbi Evaluation of the RF field uniformity of a double-tuned 31P/1H birdcage RF coil for spin-echo MRI/MRS of the diabetic foot
    Robert L Greenman
    Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115, USA
    J Magn Reson Imaging 22:427-32. 2005
    ..To evaluate the B1 field uniformity of a double-tuned birdcage coil designed for (31)P/(1)H MRI/MRS spin-echo (SE) imaging of the metatarsal head region of the foot in neuropathic diabetic patients...
  3. ncbi Early changes in the skin microcirculation and muscle metabolism of the diabetic foot
    Robert L Greenman
    Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
    Lancet 366:1711-7. 2005
    ..We investigated whether oxygen delivery and muscle metabolism of the lower extremity were factors in diabetic foot disease...
  4. pmc The feasibility of measuring phosphocreatine recovery kinetics in muscle using a single-shot (31)P RARE MRI sequence
    Robert L Greenman
    Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA
    Acad Radiol 18:917-23. 2011
    ....
  5. pmc Simultaneous acquisition of phosphocreatine and inorganic phosphate images for Pi:PCr ratio mapping using a RARE sequence with chemically selective interleaving
    Robert L Greenman
    Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
    Magn Reson Imaging 29:1138-44. 2011
    ..41±1.66). This work demonstrates the feasibility of creating Pi:PCr ratio maps in human muscle with Pi and PCr images acquired simultaneously by interleaving between the Pi and PCr resonances in a single scan...
  6. ncbi An assessment of the sharpness of carotid artery tissue boundaries with acquisition voxel size and field strength
    Robert L Greenman
    Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
    Magn Reson Imaging 26:246-53. 2008
    ..The use of acquisition voxels smaller than those previously used at 1.5 T can improve the visualization of carotid artery structures at 1.5 and 3.0 T with surface coil reception...