The choline/creatine ratio in five benign neoplasms: comparison with squamous cell carcinoma by use of in vitro MR spectroscopy.
OBJECTIVE
The choline (Cho)/creatine (Cr) ratio has been shown to be a reliable proton MR spectroscopy metabolic marker for differentiating squamous cell carcinoma (SCCA) from normal muscle in the upper aerodigestive tract. However, it is unclear whether the Cho/Cr ratio can be used to differentiate a malignant tumor from a benign neoplasm in the extracranial head and neck. Our purpose was to determine whether the Cho/Cr ratio can be used to differentiate benign from malignant tumors in this region.


METHODS
In vitro one-dimensional proton MR spectroscopy (2,000/136,272 [TR/TE]) was performed at 11 T on tissue specimens obtained from glomus tumors (n = 3), inverting papilloma (n = 1), and schwannoma (n = 1). Cho/Cr area ratios were calculated and compared with similar, previously reported in vitro (11 T) findings and with samples of SCCA and normal muscle.


RESULTS
The Cho/Cr ratio was elevated in relation to muscle in all benign tumors at TE = 136 (glomus tumors = 4.52, inverting papilloma = 3.85, schwannoma = 2.2) and at TE = 272 (glomus tumors = 8.01, inverting papilloma = 2.1, schwannoma = 4.28). The average Cho/Cr ratio for benign lesions was 3.92 (TE = 136) and 6.11 (TE = 272). The Cho/Cr ratio was significantly higher in benign tumors than in both SCCA and muscle. The average Cho/Cr ratio for muscle at TEs of 136 and 272 was 1.16 and 1.31, respectively, whereas for SCCA the average Cho/Cr ratio at TEs of 136 and 272 was 1.67 and 2.45, respectively.


CONCLUSIONS
In our small group, the Cho/Cr ratio was significantly higher in benign tumors than in muscle and SCCA of the extracranial head and neck.
Maheshwari
S R
SR
Department of Radiology, University of North Carolina, Chapel Hill 27599, USA.
Mukherji
S K
SK
Neelon
B
B
Schiro
S
S
Fatterpekar
G M
GM
Stone
J A
JA
Castillo
M
M
D019540:Area Under Curve; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology*; D002794:Choline / Q000378:metabolism*; D003401:Creatine / Q000378:metabolism*; D003937:Diagnosis, Differential; D005770:Gastrointestinal Neoplasms / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D009132:Muscles / Q000378:metabolism*; D011446:Prospective Studies; D018709:Statistics, Nonparametric
D003401:Creatine; D002794:Choline