Hybrid FDG-PET/MR compared to FDG-PET/CT in adult lymphoma patients.
The goal of this study is to evaluate the diagnostic performance of simultaneous FDG-PET/MR including diffusion compared to FDG-PET/CT in patients with lymphoma.



Eighteen patients with a confirmed diagnosis of non-Hodgkin's (NHL) or Hodgkin's lymphoma (HL) underwent an IRB-approved, single-injection/dual-imaging protocol consisting of a clinical FDG-PET/CT and subsequent FDG-PET/MR scan. PET images from both modalities were reconstructed iteratively. Attenuation correction was performed using low-dose CT data for PET/CT and Dixon-MR sequences for PET/MR. Diffusion-weighted imaging was performed. SUVmax was measured and compared between modalities and the apparent diffusion coefficient (ADC) using ROI analysis by an experienced radiologist using OsiriX. Strength of correlation between variables was measured using the Pearson correlation coefficient (r p).



Of the 18 patients included in this study, 5 had HL and 13 had NHL. The median age was 51 ± 14.8 years. Sixty-five FDG-avid lesions were identified. All FDG-avid lesions were visible with comparable contrast, and therefore initial and follow-up staging was identical between both examinations. SUVmax from FDG-PET/MR [(mean ± sem) (21.3 ± 2.07)] vs. FDG-PET/CT (mean 23.2 ± 2.8) demonstrated a strongly positive correlation [r s = 0.95 (0.94, 0.99); p < 0.0001]. There was no correlation found between ADCmin and SUVmax from FDG-PET/MR [r = 0.17(-0.07, 0.66); p = 0.09].



FDG-PET/MR offers an equivalent whole-body staging examination as compared with PET/CT with an improved radiation safety profile in lymphoma patients. Correlation of ADC to SUVmax was weak, understating their lack of equivalence, but not undermining their potential synergy and differing importance.
Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, 02129, USA.
Wendy
W
Atkinson
Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, 02129, USA.
Ciprian
C
Catana
Division of Hematology and Oncology, Department of Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA.
Jeremy S
JS
Abramson
Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, 02129, USA.
Grae
G
Arabasz
Division of Abdominal Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, 02114, USA.
Shanaugh
S
McDermott
Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, 02129, USA.
Onofrio
O
Catalano
Division of Thoracic Radiology, Department of Radiology, Massachusetts General Hospital, Boston, MA, 02114, USA.
Victorine
V
Muse
Division of Abdominal Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, 02114, USA.
Michael A
MA
Blake
Division of Hematology and Oncology, Department of Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA.
Jeffrey
J
Barnes
Division of Abdominal Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, 02114, USA.
Martin
M
Shelly
Division of Hematology and Oncology, Department of Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA.
Ephraim
E
Hochberg
Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, 02129, USA.
Bruce R
BR
Rosen
Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, 02129, USA. guimaraa@ohsu.edu.|Division of Abdominal Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, 02114, USA. guimaraa@ohsu.edu.|Division of Body Imaging, Department of Diagnostic Radiology, Oregon Health Sciences University, 3181 SW Sam Jackson Park Rd., Mail Code L340, Portland, OR, 97239, USA. guimaraa@ohsu.edu.
Alexander R
AR
Guimaraes
D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D019788:Fluorodeoxyglucose F18; D006689:Hodgkin Disease / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D000072078:Positron Emission Tomography Computed Tomography; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
Diffusion-weighted imaging; FDG; Lymphoma; PET/MRI; SUV