Myocardial Perfusion SPECT and ATTR imaging 2021 in Germany: Results of the 9th Survey.

AIM: This paper presents the results of the 9th survey of myocardial perfusion SPECT (MPS) from the reporting year 2021. METHODS: 218 questionnaires (131 practices (PR), 58 hospitals (HO), 29 university hospitals (UH)) were evaluated. Results of the last survey 2018 are set in squared brackets. RESULTS: MPS data from a total of 133,057 [145,930] patients (-8.8%) with 131,868 [143,707] stress and 106,546 [121,899] rest MPS were analysed. A comparison with official data revealed that 54% all MPS were recorded. From 2018 to 2021, official data showed a every year an increase in MPS numbers. On average, 610 [502] MPS patients (+22%) were examined in each department. 74% [69%] of the responders reported an increase or no changes in their MPS patient numbers. Ambulatory care cardiologists represented as always, the mayor referral group (68% [69%]). For the first time, pharmacological stress was more frequently applied than ergometry (42% [51]). Regadenoson was mostly used. The use of the different protocols remained nearly unchanged. Two-day protocols were predominantly applied (49% [48%]). A shift from multi-headed cameras (58% [72%]) to SPECT-CT systems (24% [17%]) was found. Attenuation correction was performed in 33% [26%] of all MPS. 88% [86%] of all stress, 88% [87%] of all rest and 87% [83%] of all stress and rest MPS were acquired as gated SPECT. 72% [67%] of all departments performed scoring by default. The number of departments without scoring decreased to 13% [16%]. CONCLUSIONS: The MPS Study 2021 shows that the long-term positive development of MPS imaging in Germany is continuing. The COVID-19 pandemia did not change this trend. The procedural and technical details of MPS imaging reveal a high level of guideline conformity.

Volume/perfusion ratio from lung SPECT/CT.

AIM: In pulmonary emphysema lung volume reduction procedures (LVRP) can optimize respiratory pump function. Identification of the most affected lobe can be reached using relative lobar volume (relVol) from CT, but this approach disregards the corresponding lobar perfusion. The aim of the study was therefore to establish a new parameter combining relVol from CT and relative perfusion (relPerf) from perfusion SPECT as a single parameter (volume/perfusion ratio (VPR)) to optimize the identification procedure. METHODS: As a proof of principle VPR was calculated from hybrid V-/P-SPECT/CT scans from 20 patients with severe pulmonary emphysema (SPE) before LVRP. Lung V-/P-SPECT/CT (Siemens SymbiaT) was done with Technegas and 99mTc-MAA. Quantification of lobar perfusion from scintigraphy and volume from CT was performed using "HERMES Hybrid 3D - Lung Lobe Quantification". Using normal ranges - from 12 patients with suspected pulmonary embolism and normal lung structure and perfusion - all lobes were classified as normal or abnormal to identify targets for LVRP. RESULTS: Normal values for VPR: right upper lobe 1.09 ± 0.10, middle lobe 1.31 ± 0.31, right lower lobe 0.87 ± 0.08; left upper lobe 1.09 ± 0.11, left lower lobe 0.87 ± 0.12. In the 20 SPE patients there were only 7 lobes with pathological values for rel- Vol, 14 lobes with pathological values for rel- Perf but 31 lobes with pathological VPR. CONCLUSION: Estimation of VPR from lung SPECT/CT enables a combined view of lobar volume and perfusion with one parameter. In SPE patients VPR allows identifying possible target structures with much higher sensitivity than when using relPerf or relVol alone. The specificity and the prognostic value of this new parameter have to be tested in a clinical trial.