Investigation of effects of dose- or acquisition time reduction on image quality for FDG brain PET

Not Applicable

Recruiting

Conditions: Investigation of effects of dose- or acquisition time reduction on image quality for FDG brain PET
G30.9
Alzheimer disease, unspecified

Registration Number: DRKS00022225

Lead Sponsor: Klinik für Nuklearmedizin des Universitätsklinikums Freiburg

Brief Summary: Not available

Detailed Description: Not available

Recruitment & Eligibility

Status: Recruiting

Sex: All

Target Recruitment: 26

Inclusion Criteria

• Capacity to consent (prerequisite, except the responsible physician has severe doubts in the subject ability to consent)
• Consent given
• Above 50 years of age
• AD-group: clinically diagnosed with Alzheimer’s dementia – from ZGGF
• AD-group: amyloid PET available (less than 3 months old) positively diagnosed for amyloid pathology, or liquor diagnostic with AD-typical finding (reduced A-beta1-42 and increased phosphor-tau)
• Healthy control group: clinically excluded neuro-degeneration (MRI scans) and cognitive deficits (neuro-psychological testing)
• No neurological or psychiatric pre-existing condition
• No severe acute condition (e.g. tumor)
• No diabetes mellitus

Exclusion Criteria

• Circumstances which prohibit MRI or PET examination (severe back pain, claustrophobia, metal implants)
• Previously enrolled in a nuclear medicine study

Study & Design

Study Type: interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Investigation of the effect of dose reduction on group separation between subjects with Alzheimers disease and healthy controls using regional cerebral glucose metabolism. Starting from the reference dose (full dose from guidelines), the values from the regions-of-interest (ROI) will be evaluated at lower doses (simulated by evaluation of a shortened measuring time). The target dose is the one at which a group difference passes the significance threshold of p=0.05, employing an unpaired t-test.<br>Effect size (Cohen’s d) and significance (p-value) of unpaired t-tests comparing the AD-group against healthy controls cohort, based on an analysis of cerebral regions (ROIs), using measuring times between 2 seconds and 10 minutes for FDG brain PET.

Secondary Outcome Measures

Name	Time	Method
Investigation of the effect of dose reduction on group separation between subjects with Alzheimers disease and healthy controls using regional cerebral glucose metabolism. Three experienced nuclear medicine physicians will evaluate imaging data in a blinded and randomized fashion, for scans with reference FDG dose (full dose from guidelines) to scans with reduced dose (simulated by evaluation of a shortened measuring time).<br>Sensitivity, specificity and inter-rater-reliability of single-case diagnosis of three experienced nuclear medicine physicians for a blinded and randomized evaluation of FDG brain PET scans with reduced dose (simulated by evaluation of a shortened measuring time). Consensus diagnosis at full dose (according to guidelines) will serve as reference. Moreover, diagnostic confidence will be recorded (e.g. on a scale from -3 to +3, where -3 relates to high confidence in the diagnosis of AD, and +3 relates to high confidence in the diagnosis as healthy).