Table 1.

UCSF 2017 Proposal of MRI Criteria for JCD Diagnosis

Diagnosis	UCSF 2017 Modified JCD MRI criteriaa
MRI definitely JCD	DWIb > FLAIR cortical ribboningc hyperintensity in:
	1. Classic pathognomonic: cingulate,d striatum, and > 1 neocortical gyrus (often precuneus, angular, superior parietal, superior frontal, middle frontal, or lateral temporal gyrus)
	a. Supportive for subcorticale involvement:
	i. Striatum with decreasing anterior–posterior gradient
	ii. Corresponding ADC hypointensity
	b. Supportive for cortical involvement:
	i. Asymmetric involvement of midline neocortex or cingulated
	ii. Sparing of precentral gyrusf
	iii. Corresponding ADC cortical ribboning hypointensity
	2. Cortex only (> 3 gyri); see supportive for cortex (above)
MRI probably JCD	1. Unilateral striatum or cortex (≤ 3 gyri); see supportive for subcortical and cortex (above)
	2. Bilateral striatum (see supportive for subcortical) or posteromedial thalamus; see supportive for subcortical (above)
	3. DWI > FLAIR hyperintensities only in limbic areas, with corresponding ADC hypointensityg
MRI probably not JCD	1. Only FLAIR/DWI abnormalities only in limbic areas, where hyperintensity can be normal (e.g., insula, anterior cingulate, and hippocampi), and ADC map does not show corresponding restricted diffusion (hypointensity)
	2. DWI hyperintensities due to artifact (signal distortion); see other MRI issues (below)
	3. FLAIR > DWI hyperintensitiesh; see other MRI issues (below)
MRI definitely not JCD	1. Normal
	2. Abnormalities not consistent with JCD
Other MRI issues	In prolonged courses of sJCD (~ >1 year), brain MRI might show significant atrophy with loss of DWI hyperintensity, particularly in areas previously with restricted diffusion.
	To help distinguish abnormality from artifact, obtain b2000 diffusion sequences in multiple directions (e.g., axial and coronal).

Abbreviations: ADC, apparent diffusion coefficient; DWI, diffusion-weighted imaging; FLAIR, fluid-attenuated inversion recovery; JCD, Jakob–Creutzfeldt disease; MRI, magnetic resonance imaging.

^aModified from Vitali et al 2011.²¹⁵

^bRecommended minimum standard diffusion sequence parameters to best identify cortical ribboning: axial and coronal DWI/ADC b = 1000 second cm2 or b = 2000 second cm2, depending on scanner field strength and capabilities to achieve satisfactory image quality. At 3T, b = 2000 may be preferred due to higher contrast to background for abnormal gray matter diffusion.

^cInvolvement of cortical gray matter with sparing of underlying or adjacent white matter.

^dMid and posterior cingulate preferred over anterior due to anterior air-brain artifact especially on axial acquisition (anterior acceptable if coronal acquisition). Can be symmetric, but if so prefer ADC hypointensity correlate.

^eSubcortical = deep nuclei, in decreasing order of frequency caudate, putamen, thalamus (posteriomedial or diffuse), globus pallidus (rare). ADC often shows corresponding and earlier involvement than DWI.

^fIf precentral gyrus is preferentially involved consider nonprion diagnoses (e.g., seizures and Wernicke’s).

^gDWI > FLAIR with reduced ADC in limbic or other cortical regions also can occur in HSV encephalitis^360,361 and seizures^362,363 depending on clinical picture, these should be ruled out.

^hConsider T2-shine through.³⁶⁴