NIHDA201800264_Purchase_Description.pdf

PURCHASE DESCRIPTION

1. Statement of Need and Purpose: The Neurophysiology Imaging Facility (NIF) core at the National Institute of Mental Health (NIMH) needs to acquire two (2) high performance millipede micro-imaging radio frequency probes customized for a 14T vertical MRI scanner at the National Institutes of Health (NIH) to conduct high quality ultra-high resolution anatomical and diffusion MRI of extracted brains.

2. Background Information and Objective: Magnetic Resonance (MR) imaging is one of the most impressive tools of modern medicine, allowing for the visualization of normal and pathological tissues in the body. In no field has imaging impacted biomedical research more than in the study of the brain, in which MR allows one to visualize not only neural structures but also neural function. The Neurophysiology Imaging Facility (NIF) is a centralized core facility that brings together a broad range of techniques to provide the most integrated and efficient study of brain physiology in nonhuman primates. The NIF core facility is an intramural resource shared by three institutes at the NIH – NIMH, NINDS, and NEI.

The NIF core staff, in collaboration with other researchers at NIH and other academic institutions, develops methodologies to obtain high resolution anatomical and diffusion MRI in extracted animal brains. Several such collaboratory projects have yielded excellent results and published several peer-reviewed papers in the past 5 years. Most of that research has been done at small-bore, high field scanners, including a 7T scanner in Dr. Silva’s lab in NINDS, and a 14T scanner in the Mouse Imaging Facility at the NMR center. The 14T scanner is a vertical scanner equipped with high performance 40-millimeter-bore gradient coil. We have recently been able to get diffusion imaging at 64-micron resolution on that scanner, which is a resolution difficult to achieve at lower fields. The ultra-high resolution diffusion imaging of brains allows us to visualize fine details of white matter organization, which represents highly insightful neuroanatomical data. However, the lack of good quality coils has impeded the advance of this research because the current capacity of the 14T scanner is limited in terms of producing the high quality imaging required. The existing 30mm coil has poor signal-to-noise ratio (SNR) and is currently nonfunctional. The 20mm coil, which was in frequent use over the last year, has also become nonfunctional. Consequently, the NIF core needs to procure high performance coils for the 14T scanner to acquire the high-quality images necessary for ex-vivo imaging studies.

The existing RF coils in the 14T scanner are linear birdcage coils. In an effort to advance the research programs supported by NIMH, NINDS, and NEI, the 14T scanner needs to be upgraded to the latest innovation in RF coils, namely millipede quadrature RF coils. Millipede coil technology was invented by Wai Ha Wong in 1999 and still protected under patent (https://patents.google.com/patent/US6285189). While existing birdcage coil technology only allows for about a dozen elements in a coil, millipede coils have hundreds of elements, representing a marked technological advancement.

Specifically, the millipede coils provide higher RF homogeneity, better filling factor and SNR, and smaller requirement for scanner bore size. Collaborators at NINDS acquired a 30 mm millipede coil for the 7T scanner in 2017 from ExtendMR, and our tests confirmed that its sensitivity out performed a 25 mm birdcage coil, a result that demonstrates a marked capability increase beyond that obtainable using all known traditional birdcage coils.

This acquisition is for two (2) millipede coils of appropriate size. A 30mm coil is required to scan an entire marmoset brain, and a 20mm coil is needed to scan half a marmoset brain. The 20mm coil provides very high sensitivity but is not appropriate for scanning a whole marmoset brain or other similar sized sample. The 30mm coil is appropriate for scanning a whole marmoset brain but presents certain production difficulties for the 14T scanner due to the 40mm gradient bore size limitation. Thus, the acquisition of both the 20mm and 30mm millipede coils will allow for a wide range of scanning applications while circumventing the limitations of purchasing only a single (either 20mm or 30mm) coil.

3. Generic Name of Product: MRI Radio Frequency coils, for 14T, 600 MHz.

4. Purchase Description: Millipede micro-imaging probe for 14T, 600 MHz. 1H quadrature Radio Frequency coil. Coil 1: Inner/outer diameter 20/40 mm. Coil 2:

Inner/Outer diameter 30/40mm.

5. Salient Characteristics The Contractor shall provide the high-performance millipede micro-imaging radio frequency probes customized for a 14T vertical MRI scanner that includes the following characteristics:

• 100 element birdcage coil micro-imaging probe 14 T, 600 MHz.

• 1H quadrature coil.

• Coil 1: Inner/outer diameter 20/40 mm.

• Coil 2: Inner/Outer diameter 30/40mm.

• The probe must fit into the Bruker 14T scanner owned by NIH (a design showing the geometric requirement is attached, produced by ExtendMR)

• Vendor must give a one-year product warranty that includes repair and / or replacement for defects in manufacturing.

• The above criteria represent the Government’s minimum acceptable standards.

6. Quantity: Two (2) millipede micro-imaging probes.

7. Delivery Date: Delivery shall be within 90 days after receipt of order (ARO).