TABLE 1:

Conventional MR imaging findings in primitive neuroectodermal tumors

Patient No.	Volume (cm3)	T1 Signal	T2 Signal	Enhancement* (%)	Edema	Mass Effect	Necrotic/Cystic	Lesion Delineation	Heterogeneity	Calcification
1	5 × 3 × 2.5	Iso	Iso	50	+	+	Yes	Well	Yes	Yes
2	2.5 × 2 × 2	Iso	Hypo	90	−	+	Yes	Well	Yes	No
3	6 × 6 × 6	Hypo	Iso	30	++	+++	Yes	Well	Yes	No
4	6 × 6 × 6	Hypo	Iso	80	+	++	Yes	Well	Yes	No
5	3.5 × 2.5 × 1.5	Iso	Hyper	70	++	+	Yes	Well	Yes	No
6	3.5 × 4 × 3	Hypo	Hyper	50	+	++	Yes	Ill	Yes	Yes
7	5 × 3 × 2	Iso	Iso	50	+	+	Yes	Ill	Yes	No
8	2.5 × 1.5 × 2	Iso	Hyper	80	−	−	No	Well	No	No
9	3 × 3 × 3	Iso	Hyper	90	+	+	No	Well	Yes	No
10	7 × 6 × 5	Iso	Iso	30	++	+++	Yes	Well	Yes	Yes
11	1.5 × 2 × 2	Iso	Hypo	50	+++	+	Yes	Well	Yes	No
12	1 × 1 × 1	Iso	Hypo	50	−	−	No	Well	No	No

Note.—Iso indicates isointense to gray matter; Hypo, hypointense; Hyper, hyperintense; +, mild; ++, moderate; +++, severe.

^*Enhancement is shown as the percentage of the lesion volume that enhanced.