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Tomography: a Journal for Imaging Research

Ashley M Stokes, Charles P Hart, C Chad Quarles
High-grade gliomas are often characterized by hypoxia, which is associated with both poor long-term prognosis and therapy resistance. The adverse role hypoxia plays in treatment resistance and disease progression has led to the development of hypoxia imaging methods and hypoxia-targeted treatments. Here, we determined the tumor hypoxia and vascular perfusion characteristics of 2 rat orthotopic glioma models using 18-fluoromisonidozole positron emission tomography. In addition, we determined tumor response to the hypoxia-activated prodrug evofosfamide (TH-302) in these rat glioma models...
September 2016: Tomography: a Journal for Imaging Research
Younghyoun Yoon, Aaron M Mohs, Michael C Mancini, Shuming Nie, Hyunsuk Shim
Despite major advances in targeted drug therapy and radiation therapy, surgery remains the most effective treatment for most solid tumors. The single most important predictor of patient survival is a complete surgical resection of the primary tumor, draining lymph nodes, and metastatic lesions. Presently, however, 20%-30% of patients with head and neck cancer who undergo surgery still leave the operating room without complete resection because of missed lesions. Thus, major opportunities exist to develop advanced imaging tracers and intraoperative instrumentation that would allow surgeons to visualize microscopic tumors during surgery...
September 2016: Tomography: a Journal for Imaging Research
Galen D Reed, Cornelius von Morze, Alan S Verkman, Bertram L Koelsch, Myriam M Chaumeil, Michael Lustig, Sabrina M Ronen, Robert A Bok, Jeff M Sands, Peder E Z Larson, Zhen J Wang, Jan Henrik Ardenkjær Larsen, John Kurhanewicz, Daniel B Vigneron
In vivo spin spin relaxation time (T 2) heterogeneity of hyperpolarized [(13)C,(15)N2]urea in the rat kidney was investigated. Selective quenching of the vascular hyperpolarized (13)C signal with a macromolecular relaxation agent revealed that a long-T 2 component of the [(13)C,(15)N2]urea signal originated from the renal extravascular space, thus allowing the vascular and renal filtrate contrast agent pools of the [(13)C,(15)N2]urea to be distinguished via multi-exponential analysis. The T 2 response to induced diuresis and antidiuresis was performed with two imaging agents: hyperpolarized [(13)C,(15)N2]urea and a control agent hyperpolarized bis-1,1-(hydroxymethyl)-1-(13)C-cyclopropane-(2)H8...
June 2016: Tomography: a Journal for Imaging Research
Adam Berrington, Natalie L Voets, Puneet Plaha, Sarah J Larkin, James Mccullagh, Richard Stacey, Muhammed Yildirim, Christopher J Schofield, Peter Jezzard, Tom Cadoux-Hudson, Olaf Ansorge, Uzay E Emir
2-hydroxyglutarate (2-HG) has emerged as a biomarker of tumour cell IDH mutations that may enable the differential diagnosis of glioma patients. At 3 Tesla, detection of 2-HG with magnetic resonance spectroscopy is challenging because of metabolite signal overlap and a spectral pattern modulated by slice selection and chemical shift displacement. Using density matrix simulations and phantom experiments, an optimised semi-LASER scheme (TE = 110 ms) improves localisation of the 2-HG spin system considerably compared to an existing PRESS sequence...
June 2016: Tomography: a Journal for Imaging Research
J Scott Cordova, Saumya S Gurbani, Jeffrey J Olson, Zhongxing Liang, Lee A D Cooper, Hui-Kuo G Shu, Eduard Schreibmann, Stewart G Neill, Constantinos G Hadjipanayis, Chad A Holder, Hyunsuk Shim
The diagnosis, prognosis, and management of patients with gliomas are largely dictated by the pathological analysis of tissue biopsied from a selected region within the lesion. However, due to the heterogeneous and infiltrative nature of gliomas, identifying the optimal region for biopsy with conventional magnetic resonance imaging (MRI) can be quite difficult. This is especially true for low grade gliomas, which often are non-enhancing tumors. To improve the management of patients with these tumors, the field of neuro-oncology requires an imaging modality that can specifically identify a tumor's most anaplastic/aggressive region(s) for biopsy targeting...
June 2016: Tomography: a Journal for Imaging Research
Moussa Chehade, Amit K Srivastava, Jeff W M Bulte
We present a practical approach for co-registration of bioluminescence tomography (BLT), computed tomography (CT), and magnetic resonance (MR) images. To this end, we developed a customized animal shuttle composed of non-fluorescent, MR-compatible Delrin plastic that fits a commercially available MR surface coil. Mouse embryonic stem cells (mESCs) were transfected with the luciferase gene and labeled with superparamagnetic iron oxide (SPIO) nanoparticles. Cells were stereotaxically implanted in mouse brain and imaged weekly for 4 weeks with BLI (IVIS Spectrum CT scanner) and MRI (11...
June 2016: Tomography: a Journal for Imaging Research
Stephen P Cavnar, Annie Xiao, Anne E Gibbons, Andrew D Rickelmann, Taylor Neely, Kathryn E Luker, Shuichi Takayama, Gary D Luker
Malignant cells from breast cancer and other common cancers such as prostate and melanoma may persist in bone marrow as quiescent, non-dividing cells that remain viable for years or even decades before resuming proliferation to cause recurrent disease. This phenomenon, referred to clinically as tumor dormancy, poses tremendous challenges to curing patients with breast cancer. Quiescent tumor cells resist chemotherapy drugs that predominantly target proliferating cells, limiting success of neo-adjuvant and adjuvant therapies...
June 2016: Tomography: a Journal for Imaging Research
Brian D Ross
Publications which present images containing multi-dimensional image content have traditionally been confined to present information in a static 2-dimensional format. Inclusion of videos within a publication provides enhanced opportunities to present multi-dimensional image views rather than relying on static images to communicate findings. However, asignificant advance is presented in which an image viewer in integrated into Tomography's digital publication format allowing foruser manipulated and interactive multi-dimensional viewing of published image data directly inline with the manuscript...
March 2016: Tomography: a Journal for Imaging Research
Kirill V Kovtunov, Alexey S Romanov, Oleg G Salnikov, Danila A Barskiy, Eduard Y Chekmenev, Igor V Koptyug
(1)H MRI of gases can potentially enable functional lung imaging to probe gas ventilation and other functions. In this work, (1)H MR images of hyperpolarized and thermally polarized propane gas were obtained using UTE (ultrashort echo time) pulse sequence. A 2D image of thermally polarized propane gas with ~0.9×0.9 mm(2) spatial resolution was obtained in less than 2 seconds, demonstrating that even non-hyperpolarized hydrocarbon gases can be successfully utilized for conventional proton MRI. The experiments were also performed with hyperpolarized propane gas and demonstrated acquisition of high-resolution multi-slice FLASH 2D images in ca...
March 2016: Tomography: a Journal for Imaging Research
Renuka Sriram, Mark Van Criekinge, Justin DeLos Santos, Kayvan R Keshari, David M Wilson, Donna Peehl, John Kurhanewicz, Zhen J Wang
Localized renal tumors are increasingly detected incidentally at imaging. Conventional imaging cannot reliably differentiate the 20% of these tumors that are benign from malignant renal cell carcinomas (RCCs), leading to unnecessary surgical resection and resulting morbidity associated with surgery. Here, we investigated hyperpolarized (13)C pyruvate metabolism in live patient-derived renal tumor tissue slices using a novel magnetic resonance (MR) -compatible bioreactor platform. We demonstrated for the first time that clear cell RCCs (ccRCCs), which account for 70-80% of all RCCs, have increased lactate production as well as rapid lactate efflux compared to benign renal tumors...
March 2016: Tomography: a Journal for Imaging Research
Daiqin Chen, Casey A Dougherty, Dongzhi Yang, Hongwei Wu, Hao Hong
Nuclear imaging techniques, including primarily positron emission tomography (PET) and single-photon emission computed tomography (SPECT), can provide quantitative information for a biological event in vivo with ultra-high sensitivity, however, the comparatively low spatial resolution is their major limitation in clinical application. By convergence of nuclear imaging with other imaging modalities like computed tomography (CT), magnetic resonance imaging (MRI) and optical imaging, the hybrid imaging platforms can overcome the limitations from each individual imaging technique...
March 2016: Tomography: a Journal for Imaging Research
Gary D Luker, Huong Marie Nguyen, Benjamin A Hoff, Craig J Galbán, Diego Hernando, Thomas L Chenevert, Moshe Talpaz, Brian D Ross
Myelofibrosis (MF) is a hematologic neoplasm arising as a primary disease or secondary to other myeloproliferative neoplasms (MPNs). Both primary and secondary MF are uniquely associated with progressive bone marrow fibrosis, displacing normal hematopoietic cells from the marrow space and disrupting normal production of mature blood cells. Activation of the JAK2 signaling pathway in hematopoietic stem cells commonly causes MF, and ruxolitinib, a drug targeting this pathway, is the treatment of choice for many patients...
March 2016: Tomography: a Journal for Imaging Research
Wei Huang, Yiyi Chen, Andriy Fedorov, Xia Li, Guido H Jajamovich, Dariya I Malyarenko, Madhava P Aryal, Peter S LaViolette, Matthew J Oborski, Finbarr O'Sullivan, Richard G Abramson, Kourosh Jafari-Khouzani, Aneela Afzal, Alina Tudorica, Brendan Moloney, Sandeep N Gupta, Cecilia Besa, Jayashree Kalpathy-Cramer, James M Mountz, Charles M Laymon, Mark Muzi, Kathleen Schmainda, Yue Cao, Thomas L Chenevert, Bachir Taouli, Thomas E Yankeelov, Fiona Fennessy, Xin Li
Dynamic contrast-enhanced MRI (DCE-MRI) has been widely used in tumor detection and therapy response evaluation. Pharmacokinetic analysis of DCE-MRI time-course data allows estimation of quantitative imaging biomarkers such as K(trans)(rate constant for plasma/interstitium contrast reagent (CR) transfer) and ve (extravascular and extracellular volume fraction). However, the use of quantitative DCE-MRI in clinical prostate imaging islimited, with uncertainty in arterial input function (AIF, i.e., the time rate of change of the concentration of CR in the blood plasma) determination being one of the primary reasons...
March 2016: Tomography: a Journal for Imaging Research
Jessica P Miller, Christopher Egbulefu, Julie L Prior, Mingzhou Zhou, Samuel Achilefu
Planar fluorescence imaging is widely used in biological research because of its simplicity, use of non-ionizing radiation, and high-throughput data acquisition. In cancer research, where small animal models are used to study the in vivo effects of cancer therapeutics, the output of interest is often the tumor volume. Unfortunately, inaccuracies in determining tumor volume from surface-weighted projection fluorescence images undermine the data, and alternative physical or conventional tomographic approaches are prone to error or are tedious for most laboratories...
March 2016: Tomography: a Journal for Imaging Research
Eric Gibbs, Chunlei Liu
Tissue conductivity is a biophysical marker of tissue structure and physiology. Present methods of measuring tissue conductivity are limited. Electrical impedance tomography, and magnetic resonance electrical impedance tomography rely on passing external current through the object being imaged, which prevents its use in most human imaging. Recently, the RF field used for MR excitation has been used to non-invasively measure tissue conductivity. This technique is promising, but conductivity at higher frequencies is less sensitive to tissue structure...
December 2015: Tomography: a Journal for Imaging Research
Chaitra Badve, Alice Yu, Matthew Rogers, Dan Ma, Yiying Liu, Mark Schluchter, Jeffrey Sunshine, Mark Griswold, Vikas Gulani
Magnetic resonance fingerprinting (MRF) is a method of image acquisition that produces multiple MR parametric maps from a single scan. Here, we describe the normal range and progression of MRF-derived relaxometry values with age in healthy individuals. 56 normal volunteers (ages 11-71 years, M:F 24:32) were scanned. Regions of interest were drawn on T1 and T2 maps in 38 areas, including lobar and deep white matter, deep gray nuclei, thalami and posterior fossa structures. Relaxometry differences were assessed using a forward stepwise selection of a baseline model including either gender, age, or both, where variables were included if they contributed significantly (p<0...
December 2015: Tomography: a Journal for Imaging Research
Dariya I Malyarenko, Yuxi Pang, Julien Senegas, Marko K Ivancevic, Brian D Ross, Thomas L Chenevert
Spatially non-uniform diffusion weighting bias due to gradient nonlinearity (GNL) causes substantial errors in apparent diffusion coefficient (ADC) maps for anatomical regions imaged distant from magnet isocenter. Our previously-described approach allowed effective removal of spatial ADC bias from three orthogonal DWI measurements for mono-exponential media of arbitrary anisotropy. The present work evaluates correction feasibility and performance for quantitative diffusion parameters of the two-component IVIM model for well-perfused and nearly isotropic renal tissue...
December 2015: Tomography: a Journal for Imaging Research
Steven P Rowe, Curtiland Deville, Channing Paller, Steve Y Cho, Elliot K Fishman, Martin G Pomper, Ashley E Ross, Michael A Gorin
Prostate-specific membrane antigen (PSMA)-targeted PET imaging is an emerging technique for evaluating patients with prostate cancer (PCa) in a variety of clinical contexts. As with any new imaging modality, there are interpretive pitfalls that are beginning to be recognized. In this image report, we describe the findings in a 63-year-old male with biochemically recurrent PCa after radical prostatectomy who was imaged with (18)F-DCFPyL, a small molecule inhibitor of PSMA. Diffuse radiotracer uptake was noted throughout the sacrum, corresponding to imaging findings on contrast-enhanced CT, bone scan, and pelvic MRI consistent with Paget's disease of bone...
December 2015: Tomography: a Journal for Imaging Research
Xiang Xu, Nirbhay N Yadav, Linda Knutsson, Jun Hua, Rita Kalyani, Erica Hall, John Laterra, Jaishri Blakeley, Roy Strowd, Martin Pomper, Peter Barker, Kannie Chan, Guanshu Liu, Michael T McMahon, Robert D Stevens, Peter C M van Zijl
Recent animal studies have shown that D-glucose is a potential biodegradable MRI contrast agent for imaging glucose uptake in tumors. Here, we show the first translation of that use of D-glucose to human studies. Chemical exchange saturation transfer (CEST) MRI at a single frequency offset optimized for detection of hydroxyl protons in D-glucose (glucoCEST) was used to image dynamic signal changes in the human brain at 7T during and after infusion of D-glucose. Dynamic glucose-enhanced (DGE) image data from four normal volunteers and three glioma patients showed strong signal enhancement in blood vessels, while the enhancement varied spatially over the tumor...
December 2015: Tomography: a Journal for Imaging Research
Brian D Ross
No abstract text is available yet for this article.
December 2015: Tomography: a Journal for Imaging Research
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