Table 6.
Comparison of QSPECT with CT-based AC: deviation of the measured activity from the calibrated activity in physical phantoms and patients
| Beauregard et al. | Zeintl et al. [16] | Willowson et al. [8] | Shcherbinin et al. [9] | Vandervoort et al. [17] | He et al. [18] | Du et al. [19] | Koral et al. [20] | |
|---|---|---|---|---|---|---|---|---|
| Radionuclide(s)/ radiopharmaceutical(s) | [177Lu]Octreotate | [99mTc]Diphosphonate | [99mTc]MAA, [99mTc]Technegas | 99mTc, 123I, 131I, 111In | 99mTc | 111In | 123I | 131I |
| SC method | DEW | DEW | TDSC | APD | APD, APDI | ESSE | ESSE, MBDC | TEW |
| Other corrections | DT, RR | RR, PVa | DT | RR | RR | RR | RR, PVa | RR, PVa |
| Sensitivity factor determination method | Corrected SPECT | Corrected SPECT | Non-corrected planar | Non-corrected planar | Not specified | Not specified | Planar geometric collimation | Corrected SPECT |
| Physical phantom studies | ||||||||
| Type(s) of phantom | Cylindrical | Cylindrical | Cylindrical, torso | Torso | Torso | Torso | Brain | Cylindrical |
| n (VOI/studies) | 23/7 | 6/1 | 3/2 | 8/4 | 6/2 | 6/1 | 5/1 | 8/2 |
| Mean absolute deviation (%)b | 5.6 | 4.6 | 2.6 | 3.9 | 3.1 | 2.7 | – | 9.9 |
| Deviation range (%) | −14.9 to + 4.3 | −6.8 to +2.8 | −4.1 to −1.7 | −4.5 to +5.1 | −8.0 to +4.0 | −5.1 to +4.3 | <2.4 | −23.8 to +18.5 |
| Clinical studies | ||||||||
| Type of acquisition | 2-bed | 1-bed | 1-bed | – | – | – | – | – |
| n (studies) | 6 | 16 | 12 | – | – | – | – | – |
| Mean absolute deviation (%)b | 2.6 | 8.1c | 2.6 | – | – | – | – | – |
| Deviation range (%) | −4.9 to 0.0 | −7.8 to +16.9 | −7.4 to +3.7 | – | – | – | – | – |
APD, analytic photon distribution; APDI, analytic photon distribution-interpolative; DT, dead-time; ESSE, effective source scatter estimation; DEW, dual-energy window; MBDC, model-based downscatter correction; MAA, macro-aggregated albumin; PV, partial volume; RR, resolution recovery; TDSC, transmission-dependent scatter correction; TEW, triple-energy window; VOI, volume of interest.
aPV correction was applied as a post-processing correction to recover activity from relatively small VOI in phantoms studies.
bIn cases where reported mean deviation was calculated from signed deviation results, we recalculated the mean absolute deviation from published data.
cUrine activity concentration.