J. Vandergrond, DIAGNOSING TESTICULAR FUNCTION USING P-31 MAGNETIC-RESONANCE SPECTROSCOPY - A CURRENT REVIEW, Human reproduction update, 1(3), 1995, pp. 276-283
Patients with low sperm counts combined with normal concentrations of
gonadotrophins, and in whom physical examination and post-ejaculatory
urine analysis are normal, present a diagnostic dilemma. This situatio
n can be caused by testicular failure or by ductal obstruction, which
have very different clinical prognoses, Ductal obstruction might be co
rrectable by microsurgical vasovaso/vasoepididymostomy, whereas this a
pproach is of no use in primary testicular failure. A possible diagnos
tic step for these patients is a testicular biopsy to differentiate be
tween hypospermatogenesis and a normal gonad. However, to date testicu
lar biopsy is seldom performed because of its invasive character. An a
lternative accurate, non-invasive method to assess testicular function
could be very helpful in the evaluation of idiopathic azoospermia or
idiopathic oligozoospermia. During the past decade, magnetic resonance
(MR) spectroscopy has been developed from a scientific tool into a no
n-invasive clinical diagnostic tool and has also been used to study te
sticular function. Recent studies have shown that P-31-MR spectroscopy
, based upon differences in the ratio of peaks of phosphomonoester to
beta-adenosinetriphosphate, is a non-invasive technique able to differ
entiate between groups of patients with testicular failure and ductal
obstruction, and it correlates reasonably well with the averaged mean
Johnsen score of testicular biopsy. The role for a non-invasive techni
que in the diagnosis of male infertility, such as P-31- MR spectroscop
y, carl he manifold. It serves not only as an alternative for biopsy b
ut can also be used to assess obstruction as the cause of infertility
in patients with subnormal sperm counts, and to predict the chances of
pregnancy in patients planned for vasovasostomy to correct a prior va
sectomy. However, the main limitation to MR spectroscopy becoming a un
iversal clinical diagnostic technique is the limited availability of 1
.5 Tesla MR scanners.