Table 4:

Comparison of the NIST Study to previous MRI studies on OAB

Previous MRI studies on OAB	NIST neuroimaging studies
Almost exclusively on women	Men and women (target 1:1 ratio)
Almost exclusively focused on patients with UUI and/or detrusor overactivity (DO)	Recruit urgency with UUI, and urgency without UUI (target 1:1 ratio)
Most studies have small sample size (n≤20)	Large sample size (n>250) permits evaluation of patient subgroups. NIST is the largest study of its kind
Primarily single center studies	Multi-center study across the US, with geographically diverse group of patients
Many studies have no control groups for Comparison	Age and sex matched control group (target cases: control ratio = 2:1)
Participants may be community subjects with OAB symptoms	Participants are clinic patients seeking evaluation and treatment of OAB
Participants were catheterized and filled inside the scanner (invasive, may sensitize the bladder, urethra or pelvic floor, and confound brain signals)	No bladder catheterization
Rapid, repeated, alternating cycles of bladder filling and emptying to elicit BOLD fMRI signals (non-physiologic, does not reproduce clinical urgency)	Bladder is filled by natural diuresis after water consumption.
Most previous studies have used BOLD functional MRI to study activation and deactivation of specific brain regions	Advanced multi-modal techniques (RS-fcMRI, DTI, T1) are used to understand functional connectivity, structural connectivity, and gray matter volume.
Isolated functional MRI studies	Integration with detailed phenotyping data available through the LURN Observational Cohort Study (clinical, questionnaires, and biosample).[18] Comprehensive integrationof MRI data with quantitative sensory testing (QST) data to assess CNS roles in urgency.