Name: quantitative [18f]-naf-pet-mri analysis for the evaluation of dynamic bone turnover in a patient with facetogenic low back pain
Uploaded: 2019-08-08T11:45:00
Description: Watch this Scientific Journal Video about Quantitative [18F]-Naf-PET-MRI Analysis for the Evaluation of Dynamic Bone Turnover in a Patient with Facetogenic Low Back Pain at JoVE.com

Research support was provided by NIH P50AR060752 and GE Healthcare. We would like to acknowledge the support by Vahid Ravanfar.

This prospective feasibility study recruited patients after obtaining Human Study IRB approval and complying with HIPAA regulations.
1. Phantom
<ol>
	<li>Fill a hollow cylindrical phantom with an insert that has hollow cylinders with a range of diameters (5 -&#160;38 mm) with 185 MBq of [18F]-NaF.</li>
	<li>Generate an attenuation map of the phantom using CT or a template that was generated previously for this phantom.</li>
	<li>Place the phantom into the center of PET/MR and acqu...

<ol>
	<li>Brinjikji, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systematic+literature+review+of+imaging+features+of+spinal+degeneration+in+asymptomatic+populations.">Systematic literature review of imaging features of spinal degeneration in asymptomatic populations.</a> AJNR American Journal of Neuroradiology. 36 (4), 811-816 (2015).</li><li>Binder, D. S., Nampiaparampil, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+provocative+lumbar+facet+joint.">The provocative lumbar facet joint.</a> Current Reviews in Musculoskeletal Medicine. 2 (1), 15-24 (2009).</li><li>Spick, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+Bone+Metastases+Using+11C-Acetate+PET+in+Patients+with+Prostate+Cancer+with+Biochemical+Recurrence.">Detection of Bone Metastases Using 11C-Acetate PET in Patients with Prostate Cancer with Biochemical Recurrence.</a> Anticancer Research. 35 (12), 6787-6791 (2015).</li><li>Brans, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+bone+graft+incorporation+by+18+F-fluoride+positron-emission+tomography/computed+tomography+in+patients+with+persisting+symptoms+after+posterior+lumbar+interbody+fusion.">Assessment of bone graft incorporation by 18 F-fluoride positron-emission tomography/computed tomography in patients with persisting symptoms after posterior lumbar interbody fusion.</a> EJNMMI Research. 2 (1), 42 (2012).</li><li>Jadvar, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prospective+evaluation+of+18F-NaF+and+18F-FDG+PET/CT+in+detection+of+occult+metastatic+disease+in+biochemical+recurrence+of+prostate+cancer.">Prospective evaluation of 18F-NaF and 18F-FDG PET/CT in detection of occult metastatic disease in biochemical recurrence of prostate cancer.</a> Clinical Nuclear Medicine. 37 (7), 637-643 (2012).</li><li>Kinahan, P. E., Fletcher, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Positron+emission+tomography-computed+tomography+standardized+uptake+values+in+clinical+practice+and+assessing+response+to+therapy.">Positron emission tomography-computed tomography standardized uptake values in clinical practice and assessing response to therapy.</a> Seminars in Ultrasound, CT, and MR. 31 (6), 496-505 (2010).</li><li>Hawkins, R. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+the+skeletal+kinetics+of+fluorine-18-fluoride+ion+with+PET.">Evaluation of the skeletal kinetics of fluorine-18-fluoride ion with PET.</a> Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine. 33 (5), 633-642 (1992).</li><li>Hancock, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systematic+review+of+tests+to+identify+the+disc,+SIJ+or+facet+joint+as+the+source+of+low+back+pain.">Systematic review of tests to identify the disc, SIJ or facet joint as the source of low back pain.</a> European Spine Journal: Official Publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 16 (10), 1539-1550 (2007).</li><li>Jenkins, N. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=[18)F]-Sodium+Fluoride+PET+MR-Based+Localization+and+Quantification+of+Bone+Turnover+as+a+Biomarker+for+Facet+Joint-Induced+Disability.">[18)F]-Sodium Fluoride PET MR-Based Localization and Quantification of Bone Turnover as a Biomarker for Facet Joint-Induced Disability.</a> AJNR American Journal of Neuroradiology. 38 (10), 2028-2031 (2017).</li><li>Czervionke, L. F., Fenton, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fat-saturated+MR+imaging+in+the+detection+of+inflammatory+facet+arthropathy+(facet+synovitis)+in+the+lumbar+spine.">Fat-saturated MR imaging in the detection of inflammatory facet arthropathy (facet synovitis) in the lumbar spine.</a> Pain Medicine. 9 (4), 400-406 (2008).</li><li>Phelps, M. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tomographic+measurement+of+local+cerebral+glucose+metabolic+rate+in+humans+with+(F-18)2-fluoro-2-deoxy-D-glucose:+validation+of+method.">Tomographic measurement of local cerebral glucose metabolic rate in humans with (F-18)2-fluoro-2-deoxy-D-glucose: validation of method.</a> Annals of Neurology. 6 (5), 371-388 (1979).</li><li>Brenner, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+different+quantitative+approaches+to+18F-fluoride+PET+scans.">Comparison of different quantitative approaches to 18F-fluoride PET scans.</a> Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine. 45 (9), 1493-1500 (2004).</li><li>Schellinger, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Facet+joint+disorders+and+their+role+in+the+production+of+back+pain+and+sciatica.">Facet joint disorders and their role in the production of back pain and sciatica.</a> Radiographics: A Review Publication of the Radiological Society of North America, Inc. 7 (5), 923-944 (1987).</li><li>Schett, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Joint+remodelling+in+inflammatory+disease.">Joint remodelling in inflammatory disease.</a> Annals of the Rheumatic Diseases. 66, 42-44 (2007).</li><li>Baum, R., Gravallese, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+inflammation+on+the+osteoblast+in+rheumatic+diseases.">Impact of inflammation on the osteoblast in rheumatic diseases.</a> Current Osteoporosis Reports. 12 (1), 9-16 (2014).</li></ol>

In this methodological manuscript, we have provided background on the potential utility of dynamic [18F]-NaF-PET-MRI for evaluating a wide range of bone pathologies and have outlined the techniques for dynamic [18F]-NaF-PET-MRI image acquisition and analysis using the human lumbar facet joints as prototypical regions of interest. Dual modality PET-MRI allows for acquisition of dynamic PET data over a time period similar to that required for MR data acquisition alone, thus maximizing the overlap of s...

Standard clinical imaging techniques of bone pathology are primarily limited to characterizing structural changes, which can be nonspecific. For example, asymptomatic morphologic abnormalities related to the normal aging may be indistinguishable from degenerative alterations which are responsible for severe pain and disability1. Bone is a dynamic tissue undergoing continuous remodeling with the competing activity of osteoblasts, which produce the new bone matrix, and osteoclasts, whose function is to eliminate mineralized bone2. [18F]-NaF is a positron emission tomography (PET) radiotracer that enables visualization of bone tissue metabolism. [18F]-NaF is chemically absorbed into hydroxyapatite in the bone matrix by osteoblasts and can thus noninvasively detect osteoblastic activity, thereby detecting a metabolic process which is occult to conventional imaging techniques. As a result, [18F]-NaF has been used for characterizing bone pathology in an increasing number of bone disorders including neoplasms, inflammatory, and degenerative disease of the bone and joints3,4,5.
PET data is most commonly analyzed in a semi-quantitative fashion, which can be readily performed in routine clinical practice with standardized uptake values (SUVs). As a metric, SUVs are useful to clinicians as they represent tissue uptake relative to the rest of the body6. Values from subsequent scans may be used to observe changes in uptake as a result of treatment or disease progression. The numerical nature of SUVs also aids in comparison between patients and between successive scans in the same patient. The algorithm used to calculate SUVs, Equation 1, makes the assumption that the tracer is equally distributed throughout the body and that the lean body mass accurately represents whole body volume. As such, SUVs are a semi-quantitative measurement. For a given region of interest (ROI), SUVmax (the maximum SUV value within a ROI), and SUVmean (the mean of all sampled SUVs within an ROI) are commonly used SUV metrics in clinical practice6.
Kinetic modeling of dynamic PET data can also be performed for more detailed quantitative analysis. While SUV data acquisition is static, kinetic modeling utilizes dynamic image data where tracer levels are continuously acquired providing a temporal dimension.&#160; From the more complex kinetic modeling of dynamic data, quantitative values and informative metrics of tracer dynamics can be extracted with respect to the measured activity in the image data. A sample two-tissue compartment model employed for dynamic kinetic modeling is shown in Figure 17. &#160;Cp is the concentration of tracer in the blood plasma while Ce and Ct represent the concentration in the unbound interstitial space and bound tracer in the target bone matrix respectively. K1, k2, k3, k4, are 4 rate parameters that describe the kinetic model for tracer wash in/out and binding. K1 describes the tracer taken up from arterial plasma into interstitial space (Ct), k2 describes the fraction of tracer that diffuses back from the interstitial space to plasma, k3 describes the tracer that moves from interstitial (Ce) space to bone (Ct), and k4 describes the tracer that moves from bone (Ct) back to the interstitial space (Ce).
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/58491/58491fig1.jpg" /> 
Figure 1. A sample two-tissue compartment model for dynamic kinetic modeling. Cp is the tracer concentration in the blood plasma compartment, Ce free and non-specifically bound tracer concentration in tissue, and Ct specifically bound tracer concentration in the tissue. <a href="https://www.jove.com/files/ftp_upload/58491/58491fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
The Patlak kinetic model produces Ki_Patlak as a measure of radiotracer influx rate (mL/ccm/min, cubic cm = ccm) from the blood pool into the bone matrix. The tracer influx rate from the blood pool to the bone matrix can then be calculated using Equation 2 and Equation 3 for Ki_Patlak and Ki_NonLinear respectively. Ki_Patlak and Ki_NonLinear are the rates at which [18F]-NaF leaves the arterial blood pool and irreversibly binds to a subsite bone matrix, using the two models respectively. A difference between the Patlak and non-linear kinetic model is in their utilization of the dynamic data. The Patlak model requires equilibrium to be met and then calculates the influx rate from the established linear slope. The Patlak kinetic model produces Ki_Patlak influx rates, by using a 24-minute time to equilibration of the plasma pool, Cp, to the unbound pool, Cu.&#160; The 24-minute time can change depending on the time found for all subsites to reach equilibration with the plasma pool in the sample. The more computationally rigorous non-linear model uses the entirety of the temporal data to fit a curve.
The goal of this methodological manuscript is to outline detailed techniques for performing dynamic [18F]-NaF-PET-MRI.&#160; The lumbar facet joint is a common site of degenerative arthritis disease and a common cause for axial low back pain8.&#160; Recent studies suggest [18F]-NaF-PET-MRI may serve as a useful biomarker of painful facetogenic disease9.&#160; The human lumbar facet joints from a single patient with facetogenic low back pain will thus be analyzed as a prototypical ROI for dynamic [18F]-NaF-PET-MRI analysis.

<table border="0" cellpadding="0" cellspacing="0" style="width:1045px;" width="1046">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:307px;">Gadolinium Contrast agent (Gadovist)</td>
			<td style="width:211px;">Bayer</td>
			<td style="width:271px;">na</td>
			<td style="width:257px;">1.0mmol/ml solution for IV injection.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:307px;">[18F]-NaF Radiotracer</td>
			<td style="width:211px;">na</td>
			<td style="width:271px;">na</td>
			<td>2.96 MBq/kg</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:307px;">GE Signa PET-MRI Scanner</td>
			<td style="width:211px;">General Electric</td>
			<td style="width:271px;">na</td>
			<td>3.0Tesla 60cm Bore PET-MRI scanner</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:307px;">PMOD Kinetic Modeling Software</td>
			<td style="width:211px;">PMOD Technologies, LLC</td>
			<td style="width:271px;">na</td>
			<td>Version 3.8</td>
		</tr>
	</tbody>
</table>

quantitative [18f]-naf-pet-mri analysis for the evaluation of dynamic bone turnover in a patient with facetogenic low back pain

Imaging techniques that reflect dynamic bone turnover may aid in characterizing a wide range of bone pathologies. Bone is a dynamic tissue undergoing continuous remodeling with the competing activity of osteoblasts, which produce the new bone matrix, and osteoclasts, whose function is to eliminate mineralized bone. [18F]-NaF is a positron emission tomography (PET) radiotracer that enables visualization of bone metabolism. [18F]-NaF is chemically absorbed into hydroxyapatite in the bone matrix by osteoblasts and can thus noninvasively detect osteoblastic activity, which is occult to conventional imaging techniques. Kinetic modeling of dynamic [18F]-NaF-PET data provides detailed quantitative measures of bone metabolism. Conventional semi-quantitative PET data, which utilizes standardized uptake values (SUVs) as a measure of radiotracer activity, is referred to as a static technique due to its snapshot of tracer uptake in time.&#160; Kinetic modeling, however, utilizes dynamic image data where tracer levels are continuously acquired providing tracer uptake temporal resolution. From the kinetic modeling of dynamic data, quantitative values like blood flow and metabolic rate (i.e., potentially informative metrics of tracer dynamics) can be extracted, all with respect to the measured activity in the image data. When combined with dual modality PET-MRI, region-specific kinetic data can be correlated with anatomically registered high-resolution structural and pathologic information afforded by MRI. The goal of this methodological manuscript is to outline detailed techniques for performing and analyzing dynamic [18F]-NaF-PET-MRI data. The lumbar facet joint is a common site of degenerative arthritis disease and a common cause for axial low back pain.&#160; Recent studies suggest [18F]-NaF-PET may serve as a useful biomarker of painful facetogenic disease.&#160; The human lumbar facet joint will, therefore, be used as a prototypical region of interest for dynamic [18F]-NaF-PET-MRI analysis in this manuscript.

18NaF-PET uptake values are measured in the bilateral facet joints at the L1-L2 through L5-S1 vertebral levels for a total of 10 ROIs in a single representative patient with axial low back pain. Representative [18F]-NaF-PET, axial T2 fat suppressed, and axial T1 post-contrast fat-suppressed MR images through the level of the L3-L4 facet joints are shown in Figure 2.&#160; The Ki_Patlak, SUVmean, SUVmax, and MRI facet arthropathy grade fo...

Watch this Scientific Journal Video about Quantitative [18F]-Naf-PET-MRI Analysis for the Evaluation of Dynamic Bone Turnover in a Patient with Facetogenic Low Back Pain at JoVE.com

Quantitative [18F]-Naf-PET-MRI Analysis for the Evaluation of Dynamic Bone Turnover in a Patient with Facetogenic Low Back Pain

Imaging techniques that reflect dynamic bone turnover may aid in characterizing a wide range of bone pathologies. We present detailed methodologies for performing and analyzing dynamic [18F]-NaF-PET-MRI data in a patient with facetogenic low back pain using the lumbar facet joints as a prototypical region of interest.

Quantitative [18F]-Naf-PET-MRI Analysis for the Evaluation of Dynamic Bone Turnover in a Patient with Facetogenic Low Back Pain

Imaging techniques that reflect dynamic bone turnover may aid in characterizing a wide range of bone pathologies. Bone is a dynamic tissue undergoing ...

With this technique, we use PET-MRI to identify physiologic biomarkers of bone turnover. We believe these physiologic biomarkers may more accurately reflect facet joint pathology than CT and MRI static images. We believe this technique may help us identify painful and symptomatic joints in the lumbar spine.We also hope that this technique can be applied to other regions of the spine, such as the cervical and thoracic spine for identification of symptomatic facet joints, and even degenerative disc disease. For simultaneous PET and magnetic resonance image or MRI acquisition, using a posterior array central molecular imaging array coil and a 3.0 PET and MR imager, center the field of view in both imaging modalities to cover the lower spine region from T-12 to S-3. Set the appropriate parameters for a PET acquisition and for a clinical MRI sequence for a lumbar spine protocol.Immediately before acquiring the MRI sequences, intravenously inject a 0.1 millimeters per kilogram of gadobutrol contrast into the patient's antecubital fossa and a 2.96 megabecquerel per kilogram radioactive dose of sodium fluoride F-18. Next, using three separate temporal phases centered over the lower spine, perform a 60-minute dynamic PET scan acquiring the first phase of the scan with 12 frames of 10 seconds each, the second phase of four frames of 30 seconds each, and the last phase of 14 frames of four minutes each. Then set a 60 centimeter field of view with a three millimeter filter cutoff, a standard Z-axis filter, no cardiac 3D filter, 28 subsets, and a Time-of-Flight ordered subsets expectation maximization with four iterations to reconstruct the PET data on the console.For analysis of the acquired PET and MR images, transfer the images to a dedicated work station equipped to analyze dynamic PET data. Locate the bilateral facet joints of the lumbar spine from L-1 to L-2 and L-5 to S-1. Visually triangulate with the sagittal and axial plane T-2 MR images and record the the slice number of the approximate center to identify the center point of each lumbar facet joint.With the patient data open in the view tab, click the volume of interest button and select sphere object. Within the predefined popup window, enter 7.5 millimeters as the radius and click create new volume of interest. Left click to place a 7.5 millimeter spherical volume of interest in the center of each facet joint, adjusting the sphere by left clicking and dragging until the volume is visually centered on the facet.When a volume of interest has been placed onto each facet, place a five millimeter spherical volume of interest in the right iliac crest in the central marrow cavity to exclude the cortex involvement as a reference region. Then position the volume of interest so the edges are within the marrow entirely. Right click on the axial image and select data inspection to measure the diameter of the abdominal aorta proximal to its bifurcation.To calculate the partial volume correction coefficient, left click on the right side of the aortic wall and move the cursor to the left side of the aortic wall to record the distance of the aortic wall diameter in the data inspector window. Next, left click the volume of interest button and select circle region of interest to create a circular region of interest with a radius of half of the aortic diameter. Click create new volume of interest and left click in the center of the aorta, repositioning the volume as necessary to ensure the circle approximates the aortic wall position.Then descend one slice in the axial plane and create a second circular region of interest to make a cylindrical region of interest from the two overlapping circular regions of interest. To create a partial volume corrected arterial input, use the recovery coefficients derived from the PET computed tomography phantom to apply the recovery coefficients to the image-based measurement over the descending aorta. Then substitute this partial volume-corrected arterial input into the image analysis software for use in kinetic modeling and the accurate quantification of tracer kinetics.Here, represented of sodium fluoride F-18 PET, axial T-2 fat suppressed, and axial T-1 post-contrast fat suppressed MR images through the level of the L-3 to L-4 facet joints can be seen. In this table, the Patlak kinetic model, standardized uptake value mean and maximum, and MRI facet arthropathy grade for each of the 10 sampled facet joints in a representative patient have been summarized. When the patient Patlak kinetic model influx rates were plotted against the standardized uptake value mean and the MRI-based facet arthropathy grades, the facet joint with the highest MRI grade of degenerative facet arthropathy had the highest Patlak kinetic model and standardized uptake value mean values.We are in the midst of a clinical trial to validate our technique in patients with lumbar facet joint pain. We look forward to publishing this data soon. There's a steep learning curve for understanding how to do the analysis with the PET MR software.Additionally, it can be difficult to locate the facet joints for those people unfamiliar with spinal anatomy. As a result, we believe that a visual depiction of the image processing steps will greatly enhance understanding of our process.

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Quantitative Visualization and Detection of Skin Cancer Using Dynamic Thermal Imaging

In 2010 approximately 68,720 melanomas will be diagnosed in the US alone, with around 8,650 resulting in death 1. To date, the only effective treatment for melanoma remains surgical excision, therefore, the key to extended survival is early detection 2,3. Considering the large numbers of patients diagnosed every year and the limitations in accessing specialized care quickly, the development of objective in vivo diagnostic instruments to aid the diagnosis is essential. New techniques to detect skin cancer, especially non-invasive diagnostic tools, are being explored in numerous laboratories. Along with the surgical methods, techniques such as digital photography, dermoscopy, multispectral imaging systems (MelaFind), laser-based systems (confocal scanning laser microscopy, laser doppler perfusion imaging, optical coherence tomography), ultrasound, magnetic resonance imaging, are being tested. Each technique offers unique advantages and disadvantages, many of which pose a compromise between effectiveness and accuracy versus ease of use and cost considerations. Details about these techniques and comparisons are available in the literature 4.
Infrared (IR) imaging was shown to be a useful method to diagnose the signs of certain diseases by measuring the local skin temperature. There is a large body of evidence showing that disease or deviation from normal functioning are accompanied by changes of the temperature of the body, which again affect the temperature of the skin 5,6. Accurate data about the temperature of the human body and skin can provide a wealth of information on the processes responsible for heat generation and thermoregulation, in particular the deviation from normal conditions, often caused by disease. However, IR imaging has not been widely recognized in medicine due to the premature use of the technology 7,8 several decades ago, when temperature measurement accuracy and the spatial resolution were inadequate and sophisticated image processing tools were unavailable. This situation changed dramatically in the late 1990s-2000s. Advances in IR instrumentation, implementation of digital image processing algorithms and dynamic IR imaging, which enables scientists to analyze not only the spatial, but also the temporal thermal behavior of the skin 9, allowed breakthroughs in the field.
In our research, we explore the feasibility of IR imaging, combined with theoretical and experimental studies, as a cost effective, non-invasive, in vivo optical measurement technique for tumor detection, with emphasis on the screening and early detection of melanoma 10-13. In this study, we show data obtained in a patient study in which patients that possess a pigmented lesion with a clinical indication for biopsy are selected for imaging. We compared the difference in thermal responses between healthy and malignant tissue and compared our data with biopsy results. We concluded that the increased metabolic activity of the melanoma lesion can be detected by dynamic infrared imaging.

We demonstrated that malignant pigmented lesions with increased metabolic activity generate quantifiable amounts of heat and the measurement of the transient thermal response of the skin to a cooling excitation allows quantitative identification of melanoma and other skin cancers (vs. non-proliferative nevi) at an early stage of the disease.

In 2010 approximately 68,720 melanomas will be diagnosed in the US alone, with around 8,650 resulting in death 1. To date, the only effective treatment ...

Pre-clinical Evaluation of Tyrosine Kinase Inhibitors for Treatment of Acute Leukemia

Receptor tyrosine kinases have been implicated in the development and progression of many cancers, including both leukemia and solid tumors, and are attractive druggable therapeutic targets. Here we describe an efficient four-step strategy for pre-clinical evaluation of tyrosine kinase inhibitors (TKIs) in the treatment of acute leukemia. Initially, western blot analysis is used to confirm target inhibition in cultured leukemia cells. Functional activity is then evaluated using clonogenic assays in methylcellulose or soft agar cultures. Experimental compounds that demonstrate activity in cell culture assays are evaluated in vivo using NOD-SCID-gamma (NSG) mice transplanted orthotopically with human leukemia cell lines. Initial in vivo pharmacodynamic studies evaluate target inhibition in leukemic blasts isolated from the bone marrow. This approach is used to determine the dose and schedule of administration required for effective target inhibition. Subsequent studies evaluate the efficacy of the TKIs in vivo using luciferase expressing leukemia cells, thereby allowing for non-invasive bioluminescent monitoring of leukemia burden and assessment of therapeutic response using an in vivo bioluminescence imaging system. This strategy has been effective for evaluation of TKIs in vitro and in vivo and can be applied for identification of molecularly-targeted agents with therapeutic potential or for direct comparison and prioritization of multiple compounds.

Receptor tyrosine kinases are ectopically expressed in many cancers and have been identified as therapeutic targets in acute leukemia. This manuscript describes an efficient strategy for pre-clinical evaluation of tyrosine kinase inhibitors for the treatment of acute leukemia.

Receptor tyrosine kinases have been implicated in the development and progression of many cancers, including both leukemia and solid tumors, and are ...

Computerized Dynamic Posturography for Postural Control Assessment in Patients with Intermittent Claudication

Computerized dynamic posturography with the EquiTest is an objective technique for measuring postural strategies under challenging static and dynamic conditions. As part of a diagnostic assessment, the early detection of postural deficits is important so that appropriate and targeted interventions can be prescribed. The Sensory Organization Test (SOT) on the EquiTest determines an individual&#39;s use of the sensory systems (somatosensory, visual, and vestibular) that are responsible for postural control. Somatosensory and visual input are altered by the calibrated sway-referenced support surface and visual surround, which move in the anterior-posterior direction in response to the individual&#39;s postural sway. This creates a conflicting sensory experience. The Motor Control Test (MCT) challenges postural control by creating unexpected postural disturbances in the form of backwards and forwards translations. The translations are graded in magnitude and the time to recover from the perturbation is computed.
Intermittent claudication, the most common symptom of peripheral arterial disease, is characterized by a cramping pain in the lower limbs and caused by muscle ischemia secondary to reduced blood flow to working muscles during physical exertion. Claudicants often display poor balance, making them susceptible to falls and activity avoidance. The Ankle Brachial Pressure Index (ABPI) is a noninvasive method for indicating the presence of peripheral arterial disease and intermittent claudication, a common symptom in the lower extremities. ABPI is measured as the highest systolic pressure from either the dorsalis pedis or posterior tibial artery divided by the highest brachial artery systolic pressure from either arm. This paper will focus on the use of computerized dynamic posturography in the assessment of balance in claudicants.

Individuals with intermittent claudication exhibit poor balance compared to healthy controls. Computerized dynamic posturography is an objective method for measuring an individual's postural responses to balance disturbances. This provides an objective reflection of the person&#x2019;s ability to respond to situations under which sensory stimuli are altered and unexpected perturbations occur.

Computerized dynamic posturography with the EquiTest is an objective technique for measuring postural strategies under challenging static and dynamic ...

Quantitative Fundus Autofluorescence for the Evaluation of Retinal Diseases

The retinal pigment epithelium (RPE) is juxtaposed to the overlying sensory retina, and supports the function of the visual system. Among the tasks performed by the RPE are phagocytosis and processing of outer photoreceptor segments through lysosome-derived organelles. These degradation products, stored and referred to as lipofuscin granules, are composed partially of bisretinoids, which have broad fluorescence absorption and emission spectra that can be detected clinically as fundus autofluorescence with confocal scanning laser ophthalmoscopy (cSLO). Lipofuscin accumulation is associated with increasing age, but is also found in various patterns in both acquired and inherited degenerative diseases of the retina. Thus, studying its pattern of accumulation and correlating such patterns with changes in the overlying sensory retina are essential to understanding the pathophysiology and progression of retinal disease. Here, we describe a technique employed by our lab and others that uses cSLO in order to quantify the level of RPE lipofuscin in both healthy and diseased eyes.

The retinal pigment epithelium (RPE) supports the sensory retina through recycling visual cycle byproducts, which accumulate as lipofuscin. These products are autofluorescent and can be qualitatively imaged in vivo. Here, we describe a method to quantitatively image RPE lipofuscin using confocal scanning laser ophthalmoscopy.

The retinal pigment epithelium (RPE) is juxtaposed to the overlying sensory retina, and supports the function of the visual system. Among the tasks ...

Quantitative Immunohistochemistry of the Cellular Microenvironment in Patient Glioblastoma Resections

With the growing interest in the tumor microenvironment, we set out to develop a method to specifically determine the microenvironment components within patient samples of glioblastoma, the deadliest and most invasive brain cancer. Not only are quantitative methods beneficial for accurately describing diseased tissues, they can also potentially contribute to more accurate prognosis, diagnosis, and the development of tissue-engineered systems and replacements. In glioblastoma, glial cells, such as microglia and astrocytes, have been independently correlated with poor prognosis based on pathologist grading. However, the state of these cells and other glial cell components has not been well-described quantitatively. This can be difficult due to the large processes that mark these glial cells. Furthermore, most histological analyses focus on the overall tissue sample or only within the bulk of the tumor, as opposed to delineating quantifications based on regions within the highly heterogeneous tissue. Here, we describe a method for identifying and quantitatively analyzing the populations of glial cells within the tumor bulk and adjacent regions of tumor resections from glioblastoma patients. We used chromogenic immunohistochemistry to identify the glial cell populations in patient tumor resections and ImageJ to analyze percent coverage of staining for each glial population. With these techniques we are able to better describe the glial cells throughout regions of the glioma tumor microenvironment.

This protocol was developed to quantitatively identify tumor microenvironment components in glioblastoma patient resections using chromogenic immunohistochemistry and ImageJ.

With the growing interest in the tumor microenvironment, we set out to develop a method to specifically determine the microenvironment components within ...

Evaluation of Capnography Sampling Line Compatibility and Accuracy when Used with a Portable Capnography Monitor

Capnography is commonly used to monitor patient&#8217;s ventilatory status. While sidestream capnography has been shown to provide a reliable assessment of end-tidal CO2 (ETCO2), its accuracy is commonly validated using commercial kits composed of a capnography monitor and its matching disposable nasal cannula sampling lines. The purpose of this study was to assess the compatibility and accuracy of cross-paired capnography sampling lines with a single portable bedside capnography monitor. A series of 4 bench tests were performed to evaluate the tensile strength, rise time, ETCO2 accuracy as a function of respiratory rate, and ETCO2 accuracy in the presence of supplemental O2. Each bench test was performed using specialized, validated equipment to allow for a full evaluation of sampling line performance. The 4 bench tests successfully differentiated between sampling lines from different commercial sources and suggested that due to increased rise time and decreased ETCO2 accuracy, not all nasal cannula sampling lines provide reliable clinical data when cross-paired with a commercial capnography monitor. Care should be taken to ensure that any cross-pairing of capnography monitors and disposable sampling lines is fully validated for use across respiratory rates and supplemental O2 flow rates commonly encountered in clinical settings.

The goal of this study was to evaluate the accuracy of capnography sampling lines used in conjunction with a portable bedside capnography monitor. Sampling lines from 7 manufacturers were evaluated for tensile strength, rise time, and ETCO2 accuracy as a function of respiratory rate or supplemental oxygen flow rate.

Capnography is commonly used to monitor patient&#8217;s ventilatory status. While sidestream capnography has been shown to provide a reliable assessment ...

Real-Time Dynamic Navigation System for the Precise Quad-Zygomatic Implant Placement in a Patient with a Severely Atrophic Maxilla

Zygomatic implants (ZIs) are an ideal way to address cases of a severely atrophic edentulous maxilla and maxilla defects because they replace extensive bone augmentation and shorten the treatment cycle. However, there are risks associated with the placement of ZIs, such as penetration of the orbital cavity or infra-temporal fossa. Furthermore, the placement of multiple ZIs makes this surgery risky and more difficult to perform. Potential intraoperative complications are extremely dangerous and may cause irreparable losses. Here, we describe a practical, feasible, and reproducible protocol for a real-time surgical navigation system for precisely placing quad-zygomatic implants in the severely atrophic maxilla of patients with residual bone that does not meet the requirements of conventional implants. Hundreds of patients have received ZIs at our department based on this protocol. The clinical outcomes have been satisfactory, the intraoperative and postoperative complications have been low, and the accuracy indicated by infusion of the designed image and postoperative three-dimensional image has been high. This method should be utilized during the entire surgical procedure to ensure ZI placement safety.

Here, we present a protocol to achieve precise quad-zygomatic implant placement in patients with severely atrophic maxilla using a real-time dynamic navigation system.

Zygomatic implants (ZIs) are an ideal way to address cases of a severely atrophic edentulous maxilla and maxilla defects because they replace extensive ...

Software-Assisted Quantitative Measurement of Osteoarthritic Subchondral Bone Thickness

Subchondral bone thickening and sclerosis are the major hallmarks of osteoarthritis (OA), both in animal models and in humans. Currently, the severity of the histologic subchondral bone thickening is mostly determined by visual estimation based semi-quantitative grading systems. This article presents a reproducible and easily executed protocol to quantitatively measure subchondral bone thickness in a mouse model of knee OA induced by destabilization of the medial meniscus (DMM). This protocol utilized ImageJ software to quantify subchondral bone thickness on histologic images after defining a region of interest in the medial femoral condyle and the medical tibial plateau where subchondral bone thickening usually occurs in DMM-induced knee OA. Histologic images from knee joints with a sham procedure were used as controls. Statistical analysis indicated that the newly developed quantitative subchondral bone measurement system was highly reproducible with low intra- and inter-observer variabilities. The results suggest that the new protocol is more sensitive to subtle or mild subchondral bone thickening than the widely used visual grading systems. This protocol is suitable for detecting both early and progressing osteoarthritic subchondral bone changes and for assessing in vivo efficacy of OA treatments in concert with OA cartilage grading.

This methodology article presents a software-assisted quantitative measurement protocol to quantify histologic subchondral bone thickness in murine osteoarthritic knee joints and normal knee joints as controls. This protocol is highly sensitive to subtle thickening and is suitable for detecting early osteoarthritic subchondral bone changes.

Subchondral bone thickening and sclerosis are the major hallmarks of osteoarthritis (OA), both in animal models and in humans. Currently, the severity of ...

Evaluation of Amino Acid Consumption in Cultured Bone Cells and Isolated Bone Shafts

Bone development and homeostasis is dependent upon the differentiation and activity of bone forming osteoblasts. Osteoblast differentiation is sequentially characterized by proliferation followed by protein synthesis and ultimately bone matrix secretion. Proliferation and protein synthesis require a constant supply of amino acids. Despite this, very little is known about amino acid consumption in osteoblasts. Here we describe a very sensitive protocol that is designed to measure amino acid consumption using radiolabeled amino acids. This method is optimized to quantify changes in amino acid uptake that are associated with osteoblast proliferation or differentiation, drug or growth factor treatments, or various genetic manipulations. Importantly, this method can be used interchangeably to quantify amino acid consumption in cultured cell lines or primary cells in vitro or in isolated bone shafts ex vivo. Finally, our method can be easily adapted to measure the transport of any of the amino acids as well as glucose and other radiolabeled nutrients.

This protocol presents a radiolabeled amino acid uptake assay, which is useful for evaluating amino acid consumption either in primary cells or in isolated bones.

Bone development and homeostasis is dependent upon the differentiation and activity of bone forming osteoblasts. Osteoblast differentiation is ...

Developing an Exercise Program for Rheumatoid Arthritis Patients

Evaluation of Changes in Hydration and Body Cell Mass with Bioelectrical Impedance Analysis after Exercise Program for Rheumatoid Arthritis Patients

Rheumatoid arthritis (RA) is a debilitating disease that can result in complications such as rheumatoid cachexia. While physical exercise has shown benefits for RA patients, its impact on hydration and body cell mass remains uncertain. The presence of pain, inflammation, and joint changes often restrict activity and make traditional body composition assessments unreliable due to altered hydration levels. Bioelectrical impedance is a commonly used method for estimating body composition, but it has limitations since it was primarily developed for the general population and does not consider changes in body composition. On the other hand, bioelectrical impedance vectorial analysis (BIVA) offers a more comprehensive approach. BIVA involves graphically interpreting resistance (R) and reactance (Xc), adjusted for height, to provide valuable information about hydration status and the integrity of the cell mass.
Twelve women with RA were included in this study. At the beginning of the study, hydration and body cell mass measurements were obtained using the BIVA method. Subsequently, the patients participated in a six-month dynamic exercise program encompassing cardiovascular capacity, strength, and coordination training. To evaluate changes in hydration and body cell mass, the differences in the R and Xc parameters, adjusted for height, were compared using BIVA confidence software. The results showed notable changes: resistance decreased after the exercise program, while reactance increased. BIVA, as a classification method, can effectively categorize patients into dehydration, overhydration, normal, athlete, thin, cachectic, and obese categories. This makes it a valuable tool for assessing RA patients, as it provides information independent of body weight or prediction equations. Overall, the implementation of BIVA in this study shed light on the effects of the exercise program on hydration and body cell mass in RA patients. Its advantages lie in its ability to provide comprehensive information and overcome the limitations of traditional body composition assessment methods.

Author Spotlight: Implementation of BIVA for Analyzing Disease Risk Factors in Patients with Low Body Cell Mass 

This protocol assesses alterations in hydration and body cell mass status using bioelectrical impedance vectorial analysis following a dynamic exercise program designed for patients with rheumatoid arthritis. The dynamic exercise program itself is detailed, highlighting its components focused on cardiovascular capacity, strength, and coordination. The protocol details steps, instruments, and limitations.

Rheumatoid arthritis (RA) is a debilitating disease that can result in complications such as rheumatoid cachexia. While physical exercise has shown ...