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Functional imaging of parotid glands: diffusion-weighted echo-planar MRI before and after stimulation.
Rofo. 2004 Oct; 176(10):1385-9.ROFO

Abstract

PURPOSE

To investigate the feasibility of diffusion-weighted (DW) echo-planar imaging (EPI) for measuring different functional conditions of the parotid gland and to compare different measurement approaches.

MATERIALS AND METHODS

Parotid glands of 27 healthy volunteers were examined with a DW EPI sequence (TR 1,500 msec, TE 77 msec, field-of-view 250 x 250 mm, pixel size 2.10 x 1.95 mm, section thickness 5 mm) before and after oral stimulation with commercially available lemon juice. The b factors used were 0, 500, and 1,000 sec/mm (2). Apparent diffusion coefficient (ADC) maps were digitally transferred to MRIcro (Chris Rorden, University of Nottingham, Great Britain) and evaluated with a manually placed circular region of interest (ROI) containing 100 - 200 pixel. Additional ROIs including the entire parotid gland were placed on either side. The results of both measurements were compared, using the Student's t test based on the median ADC values for each person. A two-tailed p-value of less than.05 was determined to indicate statistical significance. To compare both measurement approaches, the Pearson's correlation coefficient (r) was calculated.

RESULTS

Diffusion-weighted echo-planar MR imaging successfully visualized the parotid glands of all volunteers. In a first step, the median ADC value per person was computed. Using ROIs of 100 - 200 pixels, the mean was calculated to be 1.08 x 10 (- 3) mm (2)/sec +/- 0.12 x 10 (- 3) mm (2)/sec for both parotid glands prior to stimulation. After stimulation, the mean ADC was measured at 1.15 x 10 (- 3) mm (2)/sec +/- 0.11 x 10 (- 3) mm (2)/sec for both parotid glands. Evaluating the entire parotid gland, the ADC was 1.12 x 10 (- 3) mm (2)/sec +/- 0.08 x 10 (- 3) mm (2)/sec prior to stimulation, whereas the ADC increased to 1.18 x 10 (- 3) mm (2)/sec +/- 0.09 x 10 (- 3) mm (2)/sec after stimulation with lemon juice. For both types of measurements, the increase in ADC after stimulation proved to be significant (p < 0.001). High correlations between both measurement types were found (r >.83).

CONCLUSION

Diffusion-weighted echo-planar MR imaging allows non-invasive quantification of functional changes in the parotid glands.

Authors+Show Affiliations

Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany. c.habermann@uke.uni-hamburg.deNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Evaluation Study
Journal Article

Language

eng

PubMed ID

15383968

Citation

Habermann, C R., et al. "Functional Imaging of Parotid Glands: Diffusion-weighted Echo-planar MRI Before and After Stimulation." RoFo : Fortschritte Auf Dem Gebiete Der Rontgenstrahlen Und Der Nuklearmedizin, vol. 176, no. 10, 2004, pp. 1385-9.
Habermann CR, Cramer MC, Graessner J, et al. Functional imaging of parotid glands: diffusion-weighted echo-planar MRI before and after stimulation. Rofo. 2004;176(10):1385-9.
Habermann, C. R., Cramer, M. C., Graessner, J., Gossrau, P., Reitmeier, F., Fiehler, J., Schoder, V., Jaehne, M., & Adam, G. (2004). Functional imaging of parotid glands: diffusion-weighted echo-planar MRI before and after stimulation. RoFo : Fortschritte Auf Dem Gebiete Der Rontgenstrahlen Und Der Nuklearmedizin, 176(10), 1385-9.
Habermann CR, et al. Functional Imaging of Parotid Glands: Diffusion-weighted Echo-planar MRI Before and After Stimulation. Rofo. 2004;176(10):1385-9. PubMed PMID: 15383968.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Functional imaging of parotid glands: diffusion-weighted echo-planar MRI before and after stimulation. AU - Habermann,C R, AU - Cramer,M C, AU - Graessner,J, AU - Gossrau,P, AU - Reitmeier,F, AU - Fiehler,J, AU - Schoder,V, AU - Jaehne,M, AU - Adam,G, PY - 2004/9/24/pubmed PY - 2004/11/9/medline PY - 2004/9/24/entrez SP - 1385 EP - 9 JF - RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin JO - Rofo VL - 176 IS - 10 N2 - PURPOSE: To investigate the feasibility of diffusion-weighted (DW) echo-planar imaging (EPI) for measuring different functional conditions of the parotid gland and to compare different measurement approaches. MATERIALS AND METHODS: Parotid glands of 27 healthy volunteers were examined with a DW EPI sequence (TR 1,500 msec, TE 77 msec, field-of-view 250 x 250 mm, pixel size 2.10 x 1.95 mm, section thickness 5 mm) before and after oral stimulation with commercially available lemon juice. The b factors used were 0, 500, and 1,000 sec/mm (2). Apparent diffusion coefficient (ADC) maps were digitally transferred to MRIcro (Chris Rorden, University of Nottingham, Great Britain) and evaluated with a manually placed circular region of interest (ROI) containing 100 - 200 pixel. Additional ROIs including the entire parotid gland were placed on either side. The results of both measurements were compared, using the Student's t test based on the median ADC values for each person. A two-tailed p-value of less than.05 was determined to indicate statistical significance. To compare both measurement approaches, the Pearson's correlation coefficient (r) was calculated. RESULTS: Diffusion-weighted echo-planar MR imaging successfully visualized the parotid glands of all volunteers. In a first step, the median ADC value per person was computed. Using ROIs of 100 - 200 pixels, the mean was calculated to be 1.08 x 10 (- 3) mm (2)/sec +/- 0.12 x 10 (- 3) mm (2)/sec for both parotid glands prior to stimulation. After stimulation, the mean ADC was measured at 1.15 x 10 (- 3) mm (2)/sec +/- 0.11 x 10 (- 3) mm (2)/sec for both parotid glands. Evaluating the entire parotid gland, the ADC was 1.12 x 10 (- 3) mm (2)/sec +/- 0.08 x 10 (- 3) mm (2)/sec prior to stimulation, whereas the ADC increased to 1.18 x 10 (- 3) mm (2)/sec +/- 0.09 x 10 (- 3) mm (2)/sec after stimulation with lemon juice. For both types of measurements, the increase in ADC after stimulation proved to be significant (p < 0.001). High correlations between both measurement types were found (r >.83). CONCLUSION: Diffusion-weighted echo-planar MR imaging allows non-invasive quantification of functional changes in the parotid glands. SN - 1438-9029 UR - https://www.unboundmedicine.com/medline/citation/15383968/Functional_imaging_of_parotid_glands:_diffusion_weighted_echo_planar_MRI_before_and_after_stimulation_ L2 - https://www.thieme-connect.com/DOI/DOI?10.1055/s-2004-813564 DB - PRIME DP - Unbound Medicine ER -