Keywords:
Tissue characterisation, Lymphoma, Image verification, Staging, Diagnostic procedure, Comparative studies, PET-CT, MR-Diffusion/Perfusion, Oncology, Radiation physics, MR physics
Authors:
K. Matera, D. Baranska, M. T. Podgórski, M. Górska-Chrząstek, K. Krajewska, J. Trelińska, P. Grzelak; Łódź/PL
DOI:
10.26044/ecr2019/C-1156
Methods and materials
Patients
In 11 patients with Hodgkin lymphoma,
who followed a standard diagnostic EuroNET protocol with 18F-FDG PET/CT examination,
we performed DWIBS study in short time intervals (3 days).
All visible groups of lymphatic nodes were included in the analysis (with the exclusion of extra-nodal lesions).
Newly diagnosed,
histologically proven lymphoma and age below 18 years were inclusion criteria.
18F-FDG PET/CT procedure
18F-FDG PET/CT procedure was performed using a PET/CT (Discovery iQ 4-Ring,
General Electric Healthcare Milwaukee,
WI,
USA) scanner.
Images were acquired in cauda-cranial direction from the proximal one-third of the thigh to the skull-base.
The lesion’s SUVmax with each visible 18F-FDG uptake,
among all foci was identified [20].
For the purpose of correlation between the WB MRI and 18F-FDG PET/CT,
a lesion-by-lesion analysis was performed.
SUVmax was recorded from the largest uptake area visible in PET.
Whole-body Magnetic Resonance Imaging procedure
All examinations were performed using a 1.5 T MRI system (Ingenia Omega HP,
Philips Healthcare Nederland) equipped with a torso coil,
head and neck coil to cover head,
neck and trunk [21].
The protocols were split over the field of view covering patient’s body from skull base to mid thighs.
WB MRI exam consisted of coronal T1-weighted turbo spin echo sequence with breath-holding in chest and abdomen,
coronal fat-suppressed T2-weighted short tau inversion recovery (STIR) with respiratory triggering in chest and abdomen.
Diffusion-type WB MRI was performed with DWIBS using echo planar imaging during free breathing [4].
Each listed sequence was equipped with parallel acquisition technique.
Double b-values were selected for ADC calculation,
0 and 800 [22].
The lowest mean apparent diffusion coefficient (ADCmean) of ROI was generated from the ADC map.
Data evaluation
SUVmax was recorded from the largest uptake area visible in PET.
Mean ADC from MRI and ellipse surface area of each lesion were assessed [3,4].
About 26 locations of lymphatic tissues were evaluated visually and quantitatively using ADCmean (DWIBS) and SUVmax (18F-FDG PET/CT)(Fig.
1).
Fig. 1: 8-year-old girl with stage IIA Hodgkin disease. Magnetic resonance coronal whole-body greyscale inverted MIP (a) whole-body STIR image as a detailed anatomical reference scan for DWIBS (b) DWIBS(b0),(c) DWIBS(b800) reconstructions and (d) coronal whole-body 18F-FDG PET/CT MIP show left group of cervical lymph node involvement. Note normal inguinal lymph nodes visualization on DWIBS (b,c).
References: Department of Diagnostic Imaging, Polish Mother's Memorial Hospital- Research Institute in Lodz/ Poland 2018