T(1) and T(2) measurements of the fine structures of the in vivo and enucleated human eye.
OBJECTIVE
To measure T(1) and T(2) of the fine structures of the in vivo eye.


METHODS
Involuntary saccades make it difficult to obtain artifact-free images. Using a method recently reported (Bert et al, Acad Radiol 2006;12:368-378), near artifact-free spin-echo images were obtained. Both an isolated enucleated eye and eight human subjects were studied at 1.5 T. Spin-echo variable TR/TE data was acquired for T(1)/T(2) determination. Average relaxation times were calculated two ways. First, an arithmetic average over different subjects was computed. Second, all data was normalized using the fitted amplitudes of each data set and pooled to obtain a single least squares fit.


RESULTS
In vivo T(1)/T(2) (msec) are: arithmetic average T(1), T(2), normalized data T(1), T(2). Anterior chamber: 6233 +/- 979, 468 +/- 149, 5053 +/- 1052, 450 +/- 49. Ciliary body: 1916 +/- 184, 80 +/- 7, 2038 +/- 114, 76 +/- 3. Chorioretina: 1717 +/- 500, 72 +/- 25, 1511 +/- 230, 78 +/- 3. Extraocular muscle: 1581 +/- 646, 41 +/- 7, 1470 +/- 231, 41 +/- 1. Iris: 3334 +/- 989, 163 +/- 63, 3376 +/- 338, 153 +/- 10. Lens cortex: 1712 +/- 466, 93 +/- 36, 1413 +/- 177, 100 +/- 5. Lens nucleus: 1133 +/- 40, 26 +/- 3, 1138 +/- 47, 25 +/- 0.4. Optic nerve: 1906 +/- 301, 68 +/- 16, 1805 +/- 244, 71 +/- 2. Posterior chamber: 7915 +/- 4897, 241 +/- 14, 3323 +/- 2154, 251 +/- 38. Vitreous humor: 5768 +/- 1190, 756 +/- 804, 4855 +/- 1846, 390 +/- 8.


CONCLUSIONS
In vivo T(1) and T(2) for many of the fine structures of the human eye have been measured.
Patz
Samuel
S
Department Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA. patz@bwh.harvard.edu
Bert
Robert J
RJ
Frederick
Eric
E
Freddo
Thomas F
TF
D016477:Artifacts; D003287:Contrast Media / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005123:Eye / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015233:Models, Statistical; D011859:Radiography; D013499:Surface Properties; D013997:Time Factors
D003287:Contrast Media