DAVID IZQUIERDO-GARCIA¹, VALENTIN FUSTER^2,3, JEFFREY KASTE⁴, TROY HAVENS⁴, GARY MUSWICK⁵, NAVDEEP OJHA⁴, ZHIQIANG HU⁴, JOSEF MACHAC⁶, and ZAHI A. FAYAD^1,2
1Translational and Molecular Imaging Institute, Mount Sinai School of Medicine, NEW YORK, NY, United States, ²Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute, Mount Sinai School of Medicine, NEW YORK, NY, United States, ³Department of Cardiology, Marie-Josée and Henry R. Kravis Cardiovascular Health Center, Mount Sinai School of Medicine, NEW YORK, NY, United States, ⁴Philips Healthcare, CLEVELAND, OH, United States, ⁵Philips Healthcare, CLEVELAND, United States,⁶Division of Nuclear Medicine, Department of Radiology, Mount Sinai School of Medicine, NEW YORK, NY, United States

The objective of this study is to evaluate the performance of the new combined Whole-Body MR-PET scanner in terms of a qualitative and quantitative analysis compared to a conventional clinical PET/CT scanner. 15 patients were scanned on the combined Whole-Body MR-PET scanner (Philips) immediately following a clinical PET/CT scanner (GE DLS) to allow comparison of the images. The results on this study show a high correlation between SUV mean and max values (r = 0.91 and r= 0.97, p<0.0001 respectively). These results reflect the possibilities of FDG-PET imaging with the combined MR-PET scanner compared with a conventional PET/CT system.

Daniel Burje Chonde^1,2, Nasreddin Abolmaali³, Alma Gregory Sorensen¹, and Ciprian Catana^1
1Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, ²Department of Biophysics, Harvard University, Cambridge, MA, ³OncoRay - Center for Radiation Research in Oncology, Dresden, Germany

Simultaneous MRI and PET imaging for clinical application has recently become feasible. While significant work has been done to limit hardware interference, less has been done to explore potential physiologic interference. This study explores the impact of MR acoustic noise on FDP-PET uptake in the human auditory cortex. Healthy volunteers were injected with 5 mCi of FDG and dynamic PET imaging was performed for 40 minutes using the BrainPET in the presence and absence of simultaneously acquired MR. Static 40 to 60 minute frames were also examined. No significant change was noted in either the PET data or the PET detector performance.

Valerie Simone Honndorf¹, Sally-Ann Ricketts², Jane Halliday², Hans F. Wehrl¹, Stefan Wiehr¹, Damaris Kukuk¹, Maren K. Koenig¹, Mareike Lehnhoff¹, Julia Mannheim¹, Gerald Reischl³, and Bernd J. Pichler^1
1Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, University of Tuebingen, Tuebingen, Germany, ²Imaging, Translational Sciences, AstraZeneca, Alderley Park, Macclesfield, Cheshire, United Kingdom, ³Radiopharmacy and PET-Center, University of Tuebingen, Tuebingen, Germany

Diffusion-weighted MRI in combination with PET is a powerful tool to monitor cancer therapy. We show the correlation between the [¹⁸F]FLT-PET imaging and the apparent diffusion coefficient (ADC) in a colon cancer mouse model in a control group and a group treated with docetaxel. We found that the ADC maps reveal an inverse spatial correlation to the [¹⁸F]FLT uptake in the tumor demonstrating the relationship between water diffusion in necrotic regions and the thymidine kinase activity in proliferating cells. Such complementarities between MR diffusivity and [¹⁸F]FLT-PET open new insights for the usability of diffusion-weighted imaging as diagnostic tool in oncology.

Jana Cebulla^1,2, Eugene Kim³, Jiangyang Zhang⁴, and Arvind P. Pathak^5
1University Halle-Wittenberg, Halle, Germany, ²Johns Hopkins University School of Medicine, Baltimore, MD, United States, ³Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ⁴Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University Shool of Medicine, Baltimore, MD, United States, ⁵JHU ICMIC Program, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States

Multi-scale characterization of angiogenesis in pre-clinical breast cancer models helps elucidate its role in tumor progression and facilitates investigations into the systems biology of angiogenesis. By imaging the tumor vasculature with three independent methods (in vivo MRI, ex vivo micro-CT and MR-microscopy), we acquired complementary data that yields information about tumor angiogenesis at different spatial scales. The extracted vasculature and fractional blood volume maps computed from these complementary datasets showed excellent agreement over all spatial scales. In addition to characterizing breast cancer angiogenesis, we use these multi-scale data in biophysical models of MR image contrast, and computational models of angiogenesis.

Shelby Katherine Wyatt¹, Kai H Barck¹, Jason R Oeh², Hani Bou-Reslan¹, Tim C Cao¹, Hartmut Koeppen³, Lori S Friedman², Deepak Sampath², and Richard A. D. Carano^1
1Biomedical Imaging, Genentech, Inc, South San Francisco, CA, United States, ²Translational Oncology, Genentech, Inc, South San Francisco, CA, United States,³Pathology, Genentech, Inc, South San Francisco, CA, United States

Multispectral (MS)-DCE-MRI and DCE-ultrasound studies were performed to assess the PI3K/mTORi effects on vascular function. MS-DCE-MRI demonstrated tumor growth suppression, Ktrans reduction, and suggests potential vp changes, while DCE-US demonstrated a decrease in blood flow and enhancement factor following PI3K/mTORi. These responses are consistent with vasoconstriction as well as vessel density reduction. These results help elucidate PI3K/mTORi effects on tumor vasculature function and advocate the use of MS-DCE-MRI and DCE-US as biomarkers for similar therapies.

Katja Pinker¹, Stephan Gruber¹, Wolfgang Bogner¹, Siegfried Trattnig¹, and Thomas H Helbich^1
1Department of Radiology, Medical University Vienna, Vienna, Vienna, Austria

To demonstrate the feasibility of combined 3T contrast-enhanced MRI and 18FDG-PET-CT for molecular imaging of breast lesions and to assess possible increase in diagnostic sensitivity and specificity. 31 breast lesions were examined with 18FDG-PET-CT and 3T MRI of the breast, classified according to BIRADS and histopathologically verified. Sensitivity and specificity of PET-MRI was 100% and 100% respectively. Molecular imaging of breast lesions with PET-MRI is feasible. PET-MRI seems to improve diagnostic confidence in the diagnosis of breast lesions and enables accurate assessment of nodal status.

Osman Ratib¹, Magalie Viallon², Habib Zaidi¹, Minerva Becker³, Jean-Paul Vallée⁴, Michael Wissmeyer¹, Jean-pierre Willi¹, Pierre Loubeyre⁵, Navdeep Ojha⁶, Piotr Maniawski⁶, and Christoph Becker^3
1Nuclear Medicine, Hopital Universitaire de Genève, GENEVE, Switzerland, ²Radiology, Hopital Universitaire de Genève, GENEVA, Switzerland, ³Radiology, Hopital Universitaire de Genève, GENEVE, Switzerland, ⁴Radiology, Hopital Universitaire de Genève, ⁵Breast Oncology, Hopital Universitaire de Genève, GENEVE, Switzerland,⁶Philips Healthcare, Cleveland, United States

A prototype hybrid PET-MR scanner for sequential whole body scanning was implemented and tested to evaluate the performance and clinical applicability for oncology. The device consists of a 3T MR and a time-of-flight PET scanner sharing a single bed allowing sequential acquisition of co-registered images. 64 patients were scanned following a routine clinical PET/CT study. Optimized imaging protocols allowing full diagnostic quality of both modalities while reducing the total time of the study were developed. Clinical interpretation of PET-MR studies were compared to those of PET-CT. Results showed similar diagnostic accuracy in detection and localization of focal lesions and tumors. Whole-body MR attenuation scans were insufficient for accurate anatomical lesion localization comparable and additional high resolution MR sequences were needed.

Keiko Matsumoto¹, Yoshiharu Ohno², Hisanobu Koyama², Takeshi Yoshikawa², Mizuho Nishio², Yumiko Onishi², Nobukazu Aoyama³, Daisuke Takenaka², and Kazuro Sugimura^2
1Radiology, Yamanashi Hospital of Social Insurance, Kofu, Yamanashi, Japan, ²Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ³Radiology, Kobe University Hospital, Kobe, Hyogo, Japan

To the best of our knowledge, the capability of diffusion-weighted MR imaging (DWI) for prediction of therapeutic effect in advanced non-small cell carcinoma (NSCLC) patients with chemoradiotherapy as not yet been demonstrated. In the present study, we hypothesized that quantitatively assessed DWI can be utilized for prediction of therapeutic effect after chemoradiotherapy in NSCLC patients as well as FDG-PET/CT. Thus, the purpose of the present study was to directly and prospectively compare the predictive capability for therapeutic effect of chemoradiotherapy between DWI and FDG-PET/CT in NSCLC patients.

Jing Gu¹, Tao Chan¹, Wailun LAW², JingBo Zhang³, and Pek-Lan Khong^1
1Diagnostic Radiology, The University of Hong Kong, Hong Kong, China, People's Republic of, ²Colorectal Surgery, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China, People's Republic of, ³Radiology, Memorial Sloan-Kettering Cancer Center, United States

As functional imaging modalities, DWI, DCE-MRI, and PET/CT have been applied in monitoring treatment response. However, the underlying biophysical basis for changes of imaging parameters during a course of chemoradiation therapy (CRT) is far from fully understood. An increase of apparent diffusion coefficient (ADC), a quantitative parameter from DWI, suggests treatment-induced cell lysis and necrosis. However, increase in ADC can also result from change in vessel permeability due to radiation therapy. For this, DCE-MRI may provide useful information. On the other hand, late decrease in ADC can be considered result of tissue compaction and fibrosis or presence of residual active disease, which may be distinguished by PET/CT. So the aim of this study was to investigate DWI, DCE-MRI and PET/CT for response assessment over a course of pre-operative combined CRT for primary rectal adenocarcinoma, to see if the combination of different techniques can best predict biological behavior and clinical outcome.