Diffusion-weighted MR imaging in head and neck cancer: comparison between half-fourier acquired single-shot turbo spin-echo and EPI techniques.
OBJECTIVE
Several studies have reported on the clinical utility of DWI in head and neck cancer, but none of these studies compared HASTE with EPI-DWI in patients with head and neck cancer. The aim of our study was to compare detection and delineation of primary tumors and lymph nodes by using HASTE and EPI-DWI techniques in patients with HNSCC.


METHODS
Twelve patients with HNSCC and a total of 12 primary tumors and 77 visualized lymph nodes on MR imaging underwent DWI by using both EPI-based and HASTE techniques. Interobserver agreement for detection, delineation, and ADC values of primary tumors and lymph nodes was assessed by 2 radiologists, and artifacts for both DWI techniques were described.


RESULTS
The number of lesions (primary tumors and lymph nodes) identified on pretreatment EPI-DWI was higher compared with pretreatment HASTE-DWI, with means of total lesions of 88.5 and 69.0, respectively. Delineation of lesions was also better on pretreatment EPI-DWI compared with pretreatment HASTE-DWI, with means of well-delineated lesions of 80.5 and 27.5, respectively. Both EPI- and HASTE-DWI showed good interobserver agreement between radiologists of ADC values in lesions with ICC values of 0.79 and 0.92, respectively. Intraobserver agreement for ADC values in lesions assessed with EPI- versus HASTE-DWI techniques was low, with ICC values of 0.31 and 0.42, respectively. Significant interobserver disagreement concerning detection was only seen with HASTE-DWI, and none of the DWI techniques showed significant interobserver disagreements regarding delineation. EPI-DWI was more prone to susceptibility artifacts than HASTE-DWI: Ninety-one percent of primary tumors and 16% of lymph nodes were affected by susceptibility artifacts on pretreatment EPI-DWI, whereas these artifacts were not seen on HASTE-DWI.


CONCLUSIONS
Primary tumors and lymph nodes are more easily visualized on EPI-DWI compared with HASTE-DWI. EPI-DWI has geometric distortion, however, which has a negative effect on interobserver agreement of ADC values.
Department of Radiology, VU University Medical Center, Amsterdam, the Netherlands.
M H
MH
Verhappen
P J W
PJ
Pouwels
R
R
Ljumanovic
L
L
van der Putten
D L
DL
Knol
R
R
De Bree
J A
JA
Castelijns
D000368:Aged; D002277:Carcinoma / Q000473:pathology* / Q000556:secondary*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D005583:Fourier Analysis; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity