Characteristics of reported cases of idiopathic hypertrophic spinal pachymeningitis (IHSP) that included MR imaging findings

Study	Patient Age (years) and Sex	Spinal Levels Involved	Lesion Length in Segments	Location in Spinal Canal	Relationship to Dura	MRI Signal Intensity	MRI Enhancement Pattern
Ashkenazi et al⁸	65/F	T1–T5	5	Dorsal	Dural	NA	Homogenous*
Botella et al¹⁰	55/F	Cranial–C2	2	Dorsal & ventral	Dural	↓T2 ≈T1	Peripheral
Claus et al¹⁸	31/F	T3–L1	11	Circumferential	Intradural	↓T2 ≈T1	Homogenous
Digman et al¹⁵	70/F	All	25	Circumferential	Dural	NA	Peripheral*
Dumont et al¹⁴	30/F	C4–T3	7	Dorsal	Dural	↓T2 ≈T1	Peripheral
Friedman and Flanders¹³	24/F	Cranial–C7	7	Circumferential	Dural	↓T2 ↓T1	Peripheral
Friedman and Flanders¹³	51/M	All	25	Dorsal	Dural	↓T2 ↓T1	Peripheral
Friedman and Flanders¹³	65/F	Cranial–C2	2	Circumferential	Dural	↓T2 ↓T1	Peripheral
Kanamori et al¹¹	28/M	T5–L2	9	Circumferential	Dural	NA	Peripheral
Mikawa et al⁹	58/F	C7–T11	12	Dorsal & ventral	Dural	↓T1	Peripheral
Park et al¹⁶	56/F	C6–T8	10	Dorsal & ventral	Dural	↓T2 ≈T1	Peripheral
Pai et al**	47/F	T1–T6	6	Dorsal & ventral	Intra- and extradural	↓T2 ↓T1	Peripheral
Pai et al**	68/F	C3–T3	8	Dorsal & ventral	Intradural	↓T2 ≈T1	Peripheral
Sridhar et al¹²	48/F	C7–T11	12	Circumferential	Dural	↓T2 ↓T1	NA
Voller et al¹⁷	54/M	Cranial-C7	7	Dorsal	Dural	NA	Peripheral

Note:—The imaging features were assessed based on inspection of the provided images or on the description of findings, in cases when the respective images were not included in the reports. ↓ indicates hypointense; ≈ , isointense; *, poor image quality; **, this study; NA, not applicable (not performed or not mentioned).