The reliability of gray-scale ultrasonography in diagnosing torsion of
the testicular appendages was studied in a series of 54 boys with acu
te non-traumatic scrotal pain. All boys were operated upon, and the ap
pendages extirpated irrespective of their appearance at exploration; t
he final diagnosis was based on histological examination. Forty-two bo
ys had appendicular torsion, 2 had testicular torsion and 10 had other
diagnoses. Using the sign of appendicular torsion - an echogenic extr
atesticular structure situated between the head of the epididymis and
the upper pole of the testis - as the criterion, 37 displayed a true p
ositive, 9 a true negative, 3 a false positive and 5 a false negative
diagnosis. Thus, the sensitivity was 88 %, the specificity 75 % and th
e positive predictive value 93 % respectively. The echogenic mass vari
ed in size from 3 to 17 mm in diameter. In 34 of the 42 cases of appen
dicular torsion extratesticular fluid was present, and 19 patients sho
wed enlargement of the head of the epididymis. It is concluded that gr
ay-scale sonography is an accurate and valuable tool in diagnosing tor
sion of the testicular appendages.