Monte Carlo Demonstration of Small Animal in-vivo Functional And Anatomical Imaging With Neutrons

David C. Medich, Ph.D., CHPDavid C. Medich, Ph.D., CHP

Monte Carlo Demonstration of Small Monte Carlo Demonstration of Small Animal in-vivo Functional And Animal in-vivo Functional And

Anatomical Imaging With NeutronsAnatomical Imaging With Neutrons

1.1. To provide a justification as to why we could use a new To provide a justification as to why we could use a new clinical and biomedical imaging tool.clinical and biomedical imaging tool.

2.2. To discuss how neutrons can be used to obtain an To discuss how neutrons can be used to obtain an in-vivoin-vivo biological image that contains functional and anatomical biological image that contains functional and anatomical information. information. NOTE: focus here is on a small animal model..

3.3. To present Monte Carlo simulated results for:To present Monte Carlo simulated results for:1.1. Basic neutron images comparing quality both with and without Basic neutron images comparing quality both with and without

scatter contributions,scatter contributions,

2.2. S/N ratio of different tissues and materials relative to water, S/N ratio of different tissues and materials relative to water,

3.3. S/N ratio of tumors relative to their normal tissue counterpart, S/N ratio of tumors relative to their normal tissue counterpart,

4.4. S/N ratio of B-10 and Gd-157, to determine the concentrations S/N ratio of B-10 and Gd-157, to determine the concentrations needed to obtain a useful functional image in a mouse model.needed to obtain a useful functional image in a mouse model.

Goals of this Presentation

• Poor spatial resolution : fMRI (2-3mm), PET (3-5mm), SPECT (5-Poor spatial resolution : fMRI (2-3mm), PET (3-5mm), SPECT (5-10mm),10mm),

• fMRI – poor temporal resolution,fMRI – poor temporal resolution,

• Little to no anatomical imaging info is obtained from the technology Little to no anatomical imaging info is obtained from the technology

• PET – requires on-site (or close proximity) cyclotron to produce PET – requires on-site (or close proximity) cyclotron to produce positron emitters with positron emitters with veryvery short half-lives, short half-lives,

• SPECT – isotopes produced at very limited number of foreign SPECT – isotopes produced at very limited number of foreign reactors. A temporary shutdown of one of these reactors leads to reactors. A temporary shutdown of one of these reactors leads to clinical isotope shortages...clinical isotope shortages...

Limitations:

Current Technology

Technologies such as f-MRI, PET, and SPECT have been very successful in identifying changes in tissue metabolism and function, but these technologies have limitations...

Possible Role of Neutrons in Possible Role of Neutrons in Functional Imaging...Functional Imaging...

Neutron Radiography

• Neutrons interact directly with the atomic nucleus (unlike photons which Neutrons interact directly with the atomic nucleus (unlike photons which interact with atomic electrons).interact with atomic electrons).

• Neutrons therefore have different reaction rates for isotopes of the Neutrons therefore have different reaction rates for isotopes of the same element.same element.

• Neutrons also have a high dynamic range of interaction cross-sections.Neutrons also have a high dynamic range of interaction cross-sections.

General Advantages: – why neutrons?

• neutron radiography, which our neutron radiography, which our technique is based, has very technique is based, has very high spatial resolution and high spatial resolution and efficiency.efficiency.

• Kardjilov, for example, used a Kardjilov, for example, used a 10 10 m Gdm Gd22OO22S(Tb) screen and S(Tb) screen and

reported a 90% detection reported a 90% detection efficiency with a spatial efficiency with a spatial resolution of 25 resolution of 25 m.m.(1)(1)

1. N. Kardjilov et al. Nucl. Instr. and Meth. A 651 95-99 (2011)

1.1. Neutrons interact readily with hydrogen, and nitrogen (and Neutrons interact readily with hydrogen, and nitrogen (and to a lesser extent carbon and oxygen) compared to many to a lesser extent carbon and oxygen) compared to many other materials. other materials.

• Therefore, Neutrons are Therefore, Neutrons are very sensitive very sensitive to local changes in a to local changes in a tissue’s H, C, O, N content. tissue’s H, C, O, N content.

• This is important because, as we know from MRI, changes in This is important because, as we know from MRI, changes in hydrogen content enables us to anatomically differentiate and hydrogen content enables us to anatomically differentiate and image soft tissues.image soft tissues.

2.2. And, certain stable and non-toxic isotopes are much more And, certain stable and non-toxic isotopes are much more opaque to neutrons than lead is to diagnostic x-rays!opaque to neutrons than lead is to diagnostic x-rays!

• Therefore, these isotopes could be used with neutrons as Therefore, these isotopes could be used with neutrons as a very effective contrast agent..

Neutron Radiography

Potential Clinical Advantages

Advantages of Neutron Imaging

Here is a quick summary of the thermal neutron Here is a quick summary of the thermal neutron absorption in B-10 and Gd-157 as compared typical x-absorption in B-10 and Gd-157 as compared typical x-ray photon absorption in lead...ray photon absorption in lead...


Radiation Shielding Cross Section Transmission (10 m) TVLSource Material (1/cm) (percent) ( m)

0.025 eV Neutron Gd-157 7716.8 4.5E-02 30.025 eV Neutron B-10 501.5 60.56 46

50 keV Photon lead 90.9 91.31 253100 keV Photon lead 62.7 93.92 367

Transmission through 10 um of shielding material and shield TVL

Comparison of raw tumor imaging capabilities in neutron radiography and x-ray radiography: The top images demonstrate that native neutron radiography has basic tumor detection capabilities.

Neuron Radiography

X-ray Radiography

IdentifiableTumors

Image From: Brown and Parks, “Neutron Radiography in Biologic Media”, Am. J. Roentg 106, 472 (1969)



Comparison between (a) histology and (b) Neutron Capture Radiography of a 70µm thick liver tissue sample with liver metastases after infusion of BPA.

From: Wittig, A., J. Michel, et al. (2008). "Boron analysis and boron imaging in biological materials for Boron Neutron Capture Therapy (BNCT)." Critical reviews in oncology/hematology 68(1): 66-90.

X-ray ImageNeutron Image



From: Metzke et. Al. “Neutron computed tomography of rat lungs” 2011 Phys. Med. Biol. 56 (2011) N1–N10

1. Both native and functional tumor detection have been demonstrated.

2.2. Possible identification of early-stage osteosarcoma in both Possible identification of early-stage osteosarcoma in both trabecular and compact cortical bone.trabecular and compact cortical bone.

3. Ability to image near or through metallic implants or pacemakers.

• Also could assess blood flow around an aneurism embolization coil or vascular stent.

• And assess the status and function of mechanical and cosmetic implants.


More importantly importantly, when combined with a neutron-opaque imaging , when combined with a neutron-opaque imaging agent, neutron imaging could be an excellent alternative to current agent, neutron imaging could be an excellent alternative to current functional imaging functional imaging modalities (i.e. modalities (i.e. Neutron Functional Imaging)...Neutron Functional Imaging)...

Potential Clinical Applications for Anatomical Imaging::

We are investigating B-10 and Gd-157 labeled contrast agents to provide high contrast between diseased and normal tissue and with spatial resolutions orders of magnitude better than PET, SPECT, or f-MRI.

• We call our technique Contrast Enhanced Neutron Imaging (CENI)

• In addition to high spatial resolution in functional imaging, CENI also could offer anatomical information

• CENI would not use any radioactive materials. • No need to inject radioactive materials into patient.• No reliance on foreign nuclear reactors for SPECT isotopes.• No need for on-site cyclotrons for PET isotopes.• Lower patient radiation exposures.

Functional Neutron Imaging

A Picture is worth a Thousand Words...

Depiction of how spatial resolution affects the ability to identify disease. Here, an ischemia is located on the distal end of a mouse heart which is represented at spatial resolutions of 30m, 250m, and 2mm.

Functional Neutron Imaging

NOTE: UML is in the process of upgrading its CCD radiography camera. The resolution of the new camera system (so far) appears to be around 80 m.

So, why haven’t we been using this !

A Neutron also pose a greater biological risk to tissue relative to an x-ray A Neutron also pose a greater biological risk to tissue relative to an x-ray photon photon •concern exists that biological neutron radiography could lead to concern exists that biological neutron radiography could lead to potentially high radiation exposures to the patient…potentially high radiation exposures to the patient…

Previous biological imaging research with neutrons found that the Previous biological imaging research with neutrons found that the image quality obtained when imaging biological organisms thicker than image quality obtained when imaging biological organisms thicker than ~1 mm is ~1 mm is extremelyextremely poor . poor .

Problems with Biological Imaging

Ultimately, many of the interesting interaction mechanisms between Ultimately, many of the interesting interaction mechanisms between neutrons and tissue also cause difficulties when trying to obtain a good neutrons and tissue also cause difficulties when trying to obtain a good biological image... biological image... •We will show that neutron energy selection is very important...We will show that neutron energy selection is very important...

•And, that the interaction mechanism with hydrogen causes problems for And, that the interaction mechanism with hydrogen causes problems for biological imaging of large objects.biological imaging of large objects.

Most neutron imaging systems use thermal neutrons but, to image large biological

objects, we will require energetic neutrons.

Neutron Energy Selection

Tissue Thickness (cm)

0 5 10 15 20 25 30 35 40

Neu

tron

Tra

nsm

issi

on (

%)

0.001

0.01

0.1

1

10

100

0.025 eV Neutron Transmission2 MeV Neutron Transmission

I am focusing my research on small animal functional imaging using thermal neutrons.

1. Present tech. can’t functionally image small animals!

2. The mouse is the most studied, characterized, and cheapest bio-model to use (also the quickest to obtain results due to life-span).

3. This also is the easiest way to being implementing CENI.

Why?

A) Neutron Radiograph of a Mouse cranium using a 16:1 cadmium coated bucky-grid. B) X-ray radiography image of the same mouse cranium. The grid ratio used to form this image

was not specified but is assumed to be 16:1.

Image From: Brown and Parks, “Neutron Radiography in Biologic Media”, Am. J. Roentg 106, 472 (1969)

Let us examine closely the neutron interaction with hydrogen…

Problems with Biological Imaging

Comparison of X ray and Thermal Neutron Comparison of X ray and Thermal Neutron Interaction Probabilities...Interaction Probabilities...

Neutron Scatter with Hydrogen…

While photoelectrons will not degrade image quality, scattered While photoelectrons will not degrade image quality, scattered neutrons will neutrons will strongly degrade image quality… degrade image quality…

Neutron Energy (MeV)

1e-8 1e-7 1e-6 1e-5 1e-4 1e-3 1e-2 1e-1 1e+0 1e+1

Cro

ss S

ect

ion

(b

arn

s)

1e-5

1e-4

1e-3

1e-2

1e-1

1e+0

1e+1

1e+2

1e+3

1e+4

1e+5

Neutron Absorption Cross Section with HydrogenNeutron Scatter Cross Section with Hydrogen

Photon Energy (MeV)

0.001 0.01 0.1 1

Cro

ss S

ect

ion

(b

arn

s)

1e-5

1e-4

1e-3

1e-2

1e-1

1e+0

1e+1

1e+2

1e+3

1e+4

1e+5

Photon Absorption Cross Section with WaterPhoton Scatter Cross Section with Water

Photon Cross Section Neutron Cross Section

Hypothesis #1Hypothesis #1: : The limitations observed with The limitations observed with biological neutron radiography predominately are biological neutron radiography predominately are due to the inability to adequately remove hydrogen due to the inability to adequately remove hydrogen scattered neutrons from image formation scattered neutrons from image formation (anatomical imaging).(anatomical imaging).

Hypothesis #2Hypothesis #2: : That That 1010Boron and Boron and 157157Gadolinium have Gadolinium have sufficiently high absorption cross-sections for use sufficiently high absorption cross-sections for use as a non-radioactive contrast agent for functional as a non-radioactive contrast agent for functional neutron imaging studies (functional imaging).neutron imaging studies (functional imaging).

Research Hypotheses

Scatter vs. Image Quality

We tested our first hypothesis through a series of basic computer simulations using the MCNP5 radiation transport program.

•MCNP5 is a software package developed by Los Alamos National Laboratories.

•It is used to model coupled neutron / photon / electron transport through material and their resulting interactions.

•Images were formed using the FIR Radiography fluence tally.

•We included S(,) transport corrections for the thermal motion (vibration/rotation) of hydrogenous molecules.


First: We performed a simple Monte Carlo contrast analysis of four major tissues and materials common in medical imaging to see if we could natively differentiate anatomical tissues with neutron biological imaging (non-optimized).

muscle

bone

adiposewater


• We analyzed muscle, cortical bone, adipose tissue, water, and air contrast from thermal neutrons (0.025 eV) .

• Two images were obtained: one with neutron-scatter contributions to image formation and one without neutron scatter contributions.

• We used an image resolution of 1mm2

• Each material was modeled as being a rectangle with a thickness of 1 cm.

• No special image processing was done on the resulting image.

1


RESULTS:

Resulting contrast differences between muscle, bone, adipose tissue, water, and air under conditions of complete neutron scatter removal.

position

-5 -4 -3 -2 -1 0 1 2 3 4 5

Neu

tron

Tra

nsm

issi

on

1

10

100

1000

MuscleTissue(5.4%)

Bone(104%)

AdiposeTissue(2.1%) Water

Air(~800%)



Representation of the Monte Carlo simulated phantom.

NextNext: We simulated (again using MCNP5) a basic arm phantom consisting of: muscle, bone, and an added bone-fracture.


• We modeled muscle, bone, and a bone fracture:

• Muscle OD=5cm,

• bone OD=2cm,

• Fracture 1mm thick through bone center.

• Again, (non-optimized) images were simulated in MCNP environment both with-and without image contributions from scattered neutrons

• Again, used a receptor grid resolution of 1mm2 (not all that important)

• Again, no special image processing was done on the resulting image.

A: Scatter Included B: Scatter Removed

Comparison of images formed with scattered neutron contributions and without…



Neutrons of various energiesScatter removed…


Neutrons of various energiesScatter included…

Tissue Contrast: S/N

Most recently, we used MCNP to quantify the neutron fluence needed to obtain a suitable signal to noise ratio in a small animal model for functional and anatomical imaging.

Our goal is to quantify object tissue and tracer contrast (and, to an extent the dose equivalence delivered per image).

We analyzed:

•Different anatomical tissues contrasts relative to water.

•Tumor cell contrast vs. their normal cell counterpart.

•The required boron-10 concentration in tissue needed to act as a suitable contrast agent in functional imaging.

•The required gadolinium-157 concentration in tissue needed to act as a suitable contrast agent in functional imaging.


Note: the dose equivalence from neutrons of fluence 0 also is presented as a benchmark. This value was obtained using the 10CFR20 flux to dose conversion factors.


For this experiment, we simulated a basic 3 cm thick phantom in the MCNP code (similar to the thickness of a large mouse); the Monte Carlo methodology used was similar to that used for the other studies...

1. Various target tissues (and materials) were modeled in a water phantom with tissue thicknesses varied between: 0.1mm & 10mm. These target tissues studied included:a)Adiposeb)Musclec)Soft Tissued)Bone (cortical)e)Waterf)air


2. Also, tumor cell types were compared to their normal cell counter-parts at various target thicknesses (0.1-10mm):

a) Carcinoma to soft tissueb) Melanoma to skin / soft tissuec) Sarcoma to muscle tissued) Squamous lung to normal lung tissue

3. Lastly, B-10 and Gd-157 concentrations were simulated as contrast agents in a water phantom. Again, target tissues were modeled between 0.1mm and 10 mm.

a) [B-10]: Concentrations of B-10 simulated were:

10, 50, 100, 300, 500, 700, 1000, 2000 g / g.

b) [Gd-157]: Concentrations of Gd-157 simulated were:

1, 5, 10, 30, 50, 80, 100, 200 g / g.

Side Note: What Can I “See”?

S/N = 2

S/N = 5

S/N = 1

Note: S/N = 5 required for single pixel contrast(Rose Criteria)

Background (1 sigma)

K=1 : 15.9% chance of background exceeding limitK=2: 2.3% chance of background exceeding limitK=3 : 0.13% chance of background exceeding limitK=4 : 3E-3% chance of background exceeding limitK=5 : 3E-5% chance of background exceeding limit

Probabilities of exceeding K:

1 * (background & signal)

2 * (background and signal)

3 * (background and signal)

S/N = 2,

Tissue Contrast

Signal To Noise Ratio between Tissue and Water: Flux = 5E6 n/cm2. HE = 0.05 mSv (5 mrem)

Target tissue thickness (mm)tissue type 0.1 0.3 0.5 0.7 1 3 5 7 10

Adipose 1.3 2.7 4.0 5.3 6.7 20 32 43 55Air 6.7 21.3 34 55 84 377 984 2248 7072

Bone 4.0 13.3 24 33 51 194 426 798 1808Muscle 0.1 0.4 0.7 1.0 1.5 4.5 7.5 10.6 15.3

Soft tissue 0.1 0.4 0.6 0.8 1.2 3.5 5.9 8.2 11.6

RESULTS: Differentiation of Tissue vs. Water

Tissue Contrast

Signal To Noise Ratio between Tissue and Water: Flux = 2E7 n/cm2. HE = 0.2 mSv (20 mrem)


Adipose 2.7 5.3 8.0 11 13 40 64 85 117Air 13.3 42.6 74.6 109 168 754 1970 4496 14144

Bone 8.0 26.7 48.0 67 101 389 853 1596 3617Muscle 0.3 0.9 1.5 2 3 9 15 21 31

Soft tissue 0.2 0.7 1.2 2 2 7 12 16 23

Tissue Contrast

Signal To Noise Ratio between Tissue and Water: Flux = 1E8 n/cm2. HE = 1mSv (100 mrem)


Adipose 6.0 11.9 17.9 24 30 89 143 191 261Air 29.8 95.4 166.9 244 375 1687 4404 10054 31627

Bone 17.9 59.6 107.3 149 226 870 1907 3570 8087Muscle 0.7 2.0 3.3 5 7 20 34 47 68

Soft tissue 0.5 1.6 2.7 4 5 16 26 37 52

Tumor Contrast

S/N - Tumor to Normal Cell Type: Flux = 5E6 n/cm2. HE = 0.05 mSvTarget tumor thickness (mm)

tumor type 0.1 0.3 0.5 0.7 1 3 5 7 10Carcinoma/soft 0.8 2.3 3.9 5.5 8 25 43 63 95Melanoma/soft 0.8 2.3 3.9 5.5 8 25 43 63 95Sarcoma/muscle 0.1 0.3 0.6 0.8 1 3 6 8 11Squamous/lung 0.3 0.9 1.5 2.2 3 9 16 23 33

RESULTS: Differentiation of Tumor vs. Normal Tissue

Tumor Contrast

S/N - Tumor to Normal Cell Type: Flux = 1E8 n/cm2. HE = 1.0 mSvTarget tumor thickness (mm)

tumor type 0.1 0.3 0.5 0.7 1 3 5 7 10Carcinoma/soft 3.5 10.4 17.5 24.6 35 110 192 280 427Melanoma/soft 3.5 10.4 17.5 24.6 35 110 192 280 427Sarcoma/muscle 0.5 1.6 2.6 3.6 5 15 26 36 50Squamous /lung 1.4 4.1 6.9 9.7 14 42 72 102 149

Boron Contrast

S/N for Boron-10 Concentration: Flux = 5E8 n/cm2, HE = 5.1mSv

[B-10] Borated water thicknesses (mm)(ug/g) 0.3 0.5 0.7 1 3 5 7 10 20

10 0.1 0.2 0 0 1 2 2 3 750 0.6 1.0 1 2 6 10 15 21 41

100 1.3 2.2 3 4 13 22 30 43 85300 4.0 6.6 9 13 39 65 90 127 246500 6.6 11.0 15 22 65 107 148 208 394700 7.9 13.2 18 26 78 128 177 248 463

1000 9.3 15.4 22 31 91 149 204 286 5282000 13.2 22.0 31 44 128 209 286 394 709

Yellow: B-10 concentration presently used in 10BPA BNCTRed: B-10 boron-carbide nanoparticle concentration used by Mortensen for BNCT

RESULTS: Contrast from Various Boron-10 Concentrations

Boron Contrast

S/N for Boron-10 Concentration: Flux = 1.5E9 n/cm2, HE = 15.3 mSv[B-10] Borated water thicknesses (mm)(ug/g) 0.3 0.5 0.7 1 3 5 7 10 20

10 0.2 0.3 0 1 2 3 4 6 1150 1.1 1.8 3 4 11 18 25 36 71

100 2.2 3.7 5 7 22 37 52 74 147300 6.8 11.4 16 23 68 112 156 221 426500 11.4 19.0 27 38 113 186 257 360 683700 13.7 22.9 32 46 135 222 306 429 802

1000 16.0 26.7 37 53 157 257 353 495 9142000 22.9 38.1 53 76 222 362 495 683 1228

Yellow: B-10 concentration presently used in 10BPA BNCTRed: B-10 boron-carbide nanoparticle concentration used by Mortensen for BNCT

Gadolinium Contrast

S/N for Gd-157 Concentration: Flux = 5E8 n/cm2, HE = 5 mSv[Gd-157] Gd-water thicknesses (mm)

(ug/g) 0.3 0.5 0.7 1 3 5 7 10 201 0.0 0.0 0.1 0 0 0 1 1 75 0.3 0.4 0.6 1 3 4 6 8 41

10 0.5 0.9 1.3 2 5 9 13 18 8530 1.7 2.8 3.9 6 17 28 39 55 24650 2.8 4.7 6.6 9 28 46 65 92 39480 4.5 7.5 10.6 15 45 74 103 145 463

100 5.7 9.5 13.2 19 56 92 128 180 528200 11.4 18.9 26.5 38 111 181 248 345 709

Yellow: Gadolinium concentration presently for Gd-DTPA MRI

RESULTS: Contrast from various Gd-157 concentrations

Gadolinium Contrast

S/N for Gd-157 Concentration: Flux = 1.5E9 n/cm2, HE = 15.3 mSv[Gd-157] Gd-water thicknesses (mm)

(ug/g) 0.3 0.5 0.7 1 3 5 7 10 201 0.0 0.1 0.1 0 0 1 1 1 115 0.4 0.7 1.0 1 4 7 10 15 71

10 0.9 1.5 2.2 3 9 16 22 31 14730 2.9 4.9 6.8 10 29 48 67 96 42650 4.9 8.2 11.4 16 49 81 112 159 68380 7.9 13.1 18.3 26 78 128 179 252 802

100 9.8 16.4 22.9 33 97 160 222 312 914200 19.7 32.8 45.9 65 192 314 429 597 1228

Yellow: Gadolinium concentration presently for Gd-DTPA MRI

Dose Eqvt. for 0.3 mm contrast

B-10: Dose Equivalence (mSv) to obtain S/N Ratio for 0.3mm sliceconcentration S/N =

(ug/g) 1 2 3 4 510 585 2339 5262 9355 1461750 13 52 117 208 324

100 3 12 27 49 76300 0.33 1.3 2.9 5.2 8.2500 0.12 0.47 1.05 1.87 2.92700 0.08 0.32 0.73 1.30 2.03

1000 0.06 0.24 0.54 0.95 1.492000 0.03 0.12 0.26 0.47 0.73

Summary: Dose Required for 0.3mm slice identification for various S/N Ratios (B-10)

Dose Eqvt. for 0.3 mm contrast

Gd-157: Dose Equivalence (mSv) to obtain S/N Ratio for 0.3mm sliceconcentration S/N =

(ug/g) 1 2 3 4 51 7168 28673 64515 114693 1792085 79 318 715 1271 1986

10 18 72 161 287 44830 2 7 16 29 4550 1 3 6 10 1680 0.25 0.99 2.23 3.97 6.20

100 0.16 0.63 1.42 2.53 3.96200 0.04 0.16 0.35 0.63 0.99

Summary: Dose Required for 0.3mm slice identification for various S/N Ratios (Gd-157)

1. With proper scatter-removal, neutrons can obtain usable anatomical information in a mouse modela) This information would be complementary to that

obtained using x-ray, CT, and MRI.

b) All tissue types can be imaged with this technique and with minimal radiation exposure to the mouse

c) CENI also has been shown to be able to natively differentiate tumors from their normal cell counterpart!

Conclusions

2. More importantly, neutrons can be used with B-10 or Gd-157 to obtain metabolic and functional imaging information in a mouse model:a) Our technique would have spatial resolutions better than 10x

that presently obtained with PET/SPECT and fMRI.

b) It would require quantities of B-10 and Gd-157 that are biologically safe and in quantities used in present medical procedures.

c) CENI can be used with any type of functional imaging study presently performed.

d) From a safety perspective, CENI also is expected to provide lower (or at least equivalent) radiation exposures since no radioactive materials are used.

Conclusions

I wish to thank my collaborators:

Acknowledgements

Dr. Andrew KarellasDirector of Radiological PhysicsProfessor of RadiologyUniversity of Massachusetts Medical School

Dr. Peter GainesAssistant Professor of BiologyUniversity of Massachusetts Lowell

And my research assistants, who have or are working on this project:•Blake Currier•Daniel Cutright, Ph.D.

Questions?

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Monte Carlo Demonstration of Small Animal in-vivo Functional And Anatomical Imaging With Neutrons