How accurate are Da Tscans?

[BigTexan]

Anyone had a Da Tscan be wrong?

[park_bear]

False positive rare but possible:

n.neurology.org/content/78/...

"Design/Methods: 9 raters experienced in movement disorders or nuclear medicine, blinded to the clinical diagnosis, interpreted 21 DaTscans individually and in consensus. Raters interpreted scans according to Benamer's criteria and commented on asymmetry of striatal uptake. The consensus interpretation was compared to clinical diagnosis: Parkinson's disease (PD) (N=14), essential tremor (ET) (N=1), healthy controls (N=6). The mean symptom duration among PD patients was 4.0 years (SD ±2.22, range 1- 9 years), mean UPDRS III score was 15.15; (SD ±13.46, range 1-42). The sensitivity, specificity, positive and negative predictive values of the consensus, and the inter-rater reliability of individual visual interpretations were calculated.

Results: Sensitivity of identifying abnormal scans was 1.0 for consensus review. Specificity was 0.714, negative predictive value 1.0, positive predictive value 0.875. Two subjects had false-positive images (1 healthy control, 1 ET). Inter-rater reliability was 0.948 for identifying abnormal scans, 0.896 for grading abnormal scans, 0.790 for detecting asymmetry of decreased uptake."

[MarionP in reply to park_bear]

Well, without being able to read specifically how many clinicians gave each person his/her clinical diagnosis, and then assessing the inter-rater reliability of agreement among them, against some sort of stratification of persons' individual degrees of time from onset of diagnosis, UDPRS test scores (which would of course themselves have had to been done more than once each time, by different personnel, and for each person having endured through multiple stages of disease (or some other measure of disease stage) groups, and then measured further against autopsy in cases where death had occurred some time after the DAT evaluation, and finally wanting to see DaT done more than once over some decently long time in each case, even this result might underestimate the actual reliability of DaT scan agreement with clinical diagnosis and UDPRS scores. In the meantime, describing false positives, at least as a global impression, as "rare" would have to be the confident word. Rare, correct.

[Boscoejean]

maybe in the future alpha synuclein skin tests or skin swab tests will become available to detect Parkinson and hopefully they will be less invasive than Datscan.

cedars-sinai.org/programs/i...

bbc.com/news/health-56358257

[Gcf51]

I often wonder, if mine would have been positive if I had taken my C/L before. Not taking the day before, is not a recommendation for the scan

[Jmellano]

for me, my datscan results were definitive that I had PD. My left side is weaker than right (I tend to drag left foot). Right side of brain controls left side of body and my datscan image showed less lit up area on right side of brain. Also both lit up areas in brain were shaped like 2 circles as opposed to normal scan shape of comma. I don’t understand why many in the medical field don’t believe in datscan. I wish it could be sued for a baseline to gauge disease progression over time

My datscan image

[MarionP in reply to Jmellano]

I just had my second DaT scan, the last being 7 years ago. However, my neurologist is an "a..hole," unfortunately in my estimation significantly overestimates his diagnostic abilities and doesn't like followup questions, have caught him in several errors of judging something too quickly and then on subsequent meetings prevaricating without admitting it until sounding irritated and raising his voice when I would ask a question that might innocently but subtly imply a reversal or departure from a prior confident interpretation...so I don't know if I am going to be about asking for a comparison, because I have no intention of seeing him again (somebody else performed the first scan). We'll see whether I seek a comparison, but if I do I will certainly share it, fwiw.