Whole-Body Magnetic Resonance Imaging, Including Diffusion-Weighted Imaging, for Diagnosing Bone Marrow Involvement in Malignant Lymphoma
Thomas Kwee¹, Rob Fijnheer², Inge Ludwig³, Henriëtte Quarles van Ufford¹, Cuno Uiterwaal⁴, Marc Bierings⁵, Taro Takahara¹, Rutger-Jan Nievelstein^1
1Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands; ²Department of Hematology, Meander Medical Center, Amersfoort, Netherlands; ³Department of Hematology, University Medical Center Utrecht, Utrecht, Netherlands; ⁴Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, Netherlands; ⁵Department of Pediatric Hematology, University Medical Center Utrecht, Utrecht, Netherlands

This study aimed to determine the value of whole-body MRI, including diffusion-weighted imaging (DWI), for diagnosing bone marrow involvement in malignant lymphoma using blind bone marrow biopsy (BMB) as reference standard. To that end, 48 consecutive patients with newly diagnosed malignant lymphoma prospectively underwent whole-body MRI (T1-weighted and short inversion time inversion recovery [n=48] and DWI [n=44]) and BMB of the posterior iliac crest. Whole-body MRI (without and with DWI) was negative for bone marrow involvement in a considerable proportion of patients with a positive BMB. Therefore, whole-body MRI cannot replace BMB for bone marrow assessment in malignant lymphoma yet.

Comparison of DWIBS and 18F-FDG PET/CT in Newly Diagnosed Lymphoma
Jing Gu¹, Yok-Lam Kwong², Tao Chan¹, Wing-Yan Au², Queenie Chan³, JingBo Zhang^1,4, Raymond Liang², Pek-Lan Khong^1
1Diagnostic Radiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China; ²Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China; ³Philips Healthcare, Philips Electronics Hong Kong Limited, Hong Kong; ⁴Memorial Sloan-Kettering Cancer Center, United States

The aim of this study was to evaluate the diagnostic performance of DWIBS in detection of lymphoma compared with PET/CT, and to assess the correlation between ADC and SUV in lymphoma lesions. We found that (1) DWIBS provides satisfactory diagnostic accuracy in lymphoma compared with PET/CT, and with the advantage of no ionizing radiation. (2) There were significant differences in ADCmin and SUVmax between aggressive and indolent B-cell lymphoma. ADCmin may therefore be another useful quantitative marker for tumor characterization and classification. (3) Negative correlation was found between ADCmin and SUVmax suggesting an association between tumor cellularity and metabolic activity.

Apparent Diffusion Coefficient Predicts Biochemical Response in Neuroendocrine Liver Metastases Treated Using Targeted Radiolabelled Therapy
Dow-Mu Koh¹, Keiko Miyazaki², Matthew Orton², Toni Wallace¹, David J. Collins², Martin O. Leach², Val Lewington^3
1Department of Radiology, Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom; ²CRUK-EPSRC Cancer Imaging Centre, Institute of Cancer Research, Sutton, Surrey, United Kingdom; ³Department of Nuclear Medicine, Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom

We investigated diffusion-weighted MR imaging (DW-MRI) for assessing treatment response of liver metastases of neuroendocrine origin to targeted radiolabelled therapy 90Y-DOTATOC. The quantitative apparent diffusion coefficient (ADC) appears to be a promising response and prognostic biomarker. Responders were found to have a lower pre-treatment value compared with non-responders; and also demonstrated a significant increase in ADC at 2 months after the first cycle of treatment. Response defined by ADC changes also showed good agreement with biochemical response.

Diffusion-Weighted MR Imaging of Pulmonary Lesions: Effectiveness of Apparent Diffusion Coefficient Quantification and Lesion-To-Spinal Cord Signal Intensity Ratio in the Lesion Characterization
Nevzat Karabulut¹, Vefa Çakmak^1
1Radiology, Pamukkale University, School of Medicine, Denizli, Turkey

Diffusion-weighted imaging (DWI) of lung is a useful adjunct to conventional chest MR imaging sequences improving lesion characterization. Differentiation of malignant tumors from benign lesions can be achieved using apparent diffusion coefficient (ADC) quantification and lesion-to-spinal cord signal intensity ratio (LSR). Due to increased cellularity and less extracellular space impeding the water diffusion, malignant tumors tend to have reduced ADC and increased LSR. Our results show that ADC quantification is more accurate than LSR for the differentiation of lung lesions. Because DWI is a non-invasive technique improving lesion characterization, it should be incorporated into routine chest MR imaging protocols.

Improving IVIM Derived F-Maps of Pancreatic Tumors with Automatic Duct and Vessel Segmentation
Thomas Joseph Re^1,2, Mirium Klauss³, Andreas Lemke⁴, Frederik B. Laun², Dirk Simon⁵, Riccardo Manfredi¹, Roberto Pozzi Mucelli¹, Stefan Delorme², Bram Stieltjes^2
1Radiology, University of Verona, Verona, Italy; ²Radiology, DKFZ, Heidelberg, BW, Germany; ³Radiology, University of Heidelberg, Heidelberg, BW, Germany; ⁴MS Computer Assisted Clinical Medicine, University of Heidelberg; ⁵Software Development for Integrated Diagnostics and Therapy, DKFZ, Heidelberg, BW, Germany

Maps of IVIM model derived perfusion fraction f (f-maps) of the pancreas show potential for the identification of pancreatic adenocarcinoma lesions which appear hypointense in these images. Unfortunately, since bile and pancreatic ducts also appear as hypointense in f-maps, their presence adjacent to tumors can lead to tumor delineation  errors.  A novel approach which automatically segmented vessels and ducts in the f-maps based on integrated diffusion coefficient D data was tested in 43 patients and proved to be superior to both the ADC or f-map for tumor delineation.

Higher Pre-Treatment Apparent Diffusion Coefficient Predicts Poorer Disease Survival in Patients with Colorectal Hepatic Metastasis
Henry Ho Ching Tam¹, David J. Collins², Gina Brown¹, Ian Chau³, David Cunningham³, Martin O. Leach², Dow-Mu Koh^1
1Department of Radiology, Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom; ²CRUK-EPSRC Cancer Imaging Centre, Institute of Cancer Research, Sutton, Surrey, United Kingdom; ³Department of Medical Oncology (Gastrointestinal), Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom

We report the use of DW-MRI for assessing response to chemotherapy and long-term outcome in patients with colorectal hepatic metastasis. Non-responders were found to have a higher pre-treatment apparent diffusion coefficient (ADC). High pre-treatment ADC was also associated with a shorter progression free survival time, independent of response to chemotherapy and other prognostic factors. This study demonstrates the potential of DW-MRI as a biologically relevant response and prognostic biomarker.

Value of Diffusion Weighted Imaging (DWI) as an Early Imaging Biomarker for Prediction of Therapy Effect in Patients with Colorectal Metastases Following Selective Internal Radiotherapy (SIRT)
Martin Zeile¹, Christian Wybranski¹, David Loewenthal¹, Maciej Pech¹, Frank Fischbach¹, Ricarda Ruehl¹, Holger Amthauer¹, Jens Ricke¹, Oliver Dudeck^1
1Clinic for Radiology and Nuclear Medicine, University Clinic Magdeburg, Magdeburg, Germany

Clinical studies revealed the potential of diffusion weighted imaging (DWI) as a biomarker for predicting tumor response. 41 colorectal liver metastases in 18 patients who underwent SIRT were examined before, 1 to 3 days after and 6 weeks following radioembolization by MRI including DWI. Lesions were categorized in responding (RL) and non-responding (NRL) according to change in tumor volume after 6 weeks. On early MRI, NRL showed no change in apparent diffusion coefficient (ADC), while a significant decrease in ADC was noted for RL (p<0.0001). DWI was capable of predicting therapy response in patients with colorectal liver metastases following radioembolization.

Medullar Architecture Mapping of the Human Kidney in Vivo Using an Optimized DTI Protocol at 3 T
Petros Martirosian¹, Christina Schraml², Nina Franziska Schwenzer², Günter Steidle¹, Cristina Rossi¹, Andreas Boss², Vinod Kumar³, Michael Erb³, Uwe Klose³, Thorsten Feiweier⁴, Fritz Schick^1
1Section on Experimental Radiology, University of Tübingen, Tübingen, Germany; ²Department of Diagnostic and Interventional Radiology, University of Tübingen, Tübingen, Germany; ³Section on Experimental Magnetic Resonance of CNS, University of Tübingen, Tübingen, Germany; ⁴Department of Magnetic Resonance, Siemens Healthcare, Erlangen, Germany

The aim of the present study was to develop an optimized DTI protocol for the assessment of the renal medullar architecture in healthy volunteers. Examinations were performed on a 3T MR scanner, using a respiratory triggered diffusion-weighted EPI sequence with a monopolar diffusion preparation scheme. Diffusion-sensitizing gradients with b-values of 400s/mm² were applied along 30 different directions. Ten slices were acquired with a voxel size of 2×2×3mm³. Tractography was performed in order to visualize the architecture of renal medulla. The presented protocol provides high SNR and high spatial resolution with good discrimination between cortex and medulla and allows for detailed tractography of renal medulla.

Diffusion Tensor Imaging as a Biomarker of Diabetic Nephropathy
Lan Lu¹, Gregory Lee¹, Vikas Gulani^1,2, John Sedor^3,4, Katherine Dell, ^4,5, Chris Flask^1,2
1Department of Radiology, Case Western Reserve University, Cleveland, OH, United States; ²Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; ³Department of Medicine, Case Western Reserve University, Cleveland, OH, United States; ⁴Rammelkamp Renal Research Center, MetroHealth Medical Center, Cleveland, OH, United States; ⁵Department of Pediatrics, Case Western Reserve University, Cleveland, OH, United States

Our understanding of and treatment options for Diabetic Nephropathy (DN) is limited by a lack of a non-invasive means to detect early-stage DN. In this study, we used Diffusion Tensor Imaging to quantitatively assess renal diffusion changes relative to estimated GFR (eGFR) in diabetic subjects. Our initial results suggest that medullary fractional anisotropy (FA) decreases with eGFR while Apparent Diffusion Coefficient is less sensitive. Further, FA differentiates subjects with mild DN (eGFR = 60-89) from healthy subjects (eGFR > 90), suggesting an opportunity for early detection of DN and progression as well as therapeutic intervention.

Diffusion-Weighted MR Imaging of Kidneys Using Targeted-SPLICE
Ning Jin¹, Jie Deng², Andrew C. Larson^1,3
1Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, United States; ²Children's Memorial Hospital, Chicago, IL, United States; ³Robert H. Lurie Comprehensive Cancer Center, Chicago, IL, United States

Diffusion-weighted (DW) imaging is particularly useful for functional interrogation of the kidney. Single-shot DW spin-echo echo-planner imaging (DW-SE-EPI) is commonly used for DW acquisition; however, this technique can experience image distortion and chemical shift artifacts. We recently developed targeted-SPLICE technique by combining the inner volume imaging technique with SPLICE for DWI without image distortion and blurring. The purpose of our study is to apply targeted-SPLICE technique for DWI in the kidneys and compare these targeted-SPLICE diffusion measurements to conventional DW-SE-EPI measurements. Targeted-SPLICE effectively reduced geometric distortion and image blurring and produced accurate diffusion parameter measurements in the kidney.