TABLE 3:

Distribution of Abnormalities by Subject Age at MR Imaging Examination

Classification and Abnormality	No. of Subjects by Age (y)
Classification and Abnormality	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17
No referral required
Chronic sinusitis	0	1	0	0	0	0	1	3	3	2	4	1	4	2	0	0	0	0
Arachnoid cyst	0	0	0	0	0	0	0	0	0	1	0	0	0	0	1	0	0	0
Frontal venous angioma	0	0	0	0	0	0	0	0	0	0	0	2	0	0	0	0	0	0
Mega cisterna magna	0	0	0	0	0	0	0	0	0	1	0	0	0	0	1	0	0	0
Ventricular asymmetry	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Chronic sinusitis with pineal cyst	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0
Routine referral required
Acute sinusitis	0	0	0	0	0	0	1	2	0	0	1	0	0	1	1	0	0	0
Focal white matter lesion of uncertain etiology	0	0	0	0	0	0	0	0	0	1	0	0	0	0	2	1	1	0
Tonsillar ectopia	0	0	0	0	0	0	0	1	1	0	0	0	0	0	1	0	0	0
Hypoplasia pons	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Petrous apex lesion	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0
Acute sinusitis with arachnoid cyst	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0
Urgent referral required, cerebellar tonsil lesion uncertain etiology	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0