SPECT and PET myocardial perfusion imaging in Austria, Germany, and Switzerland results of the first joint survey of 2021

PURPOSE

This paper presents the results of the first joint survey on the use of SPECT and PET myocardial perfusion imaging (MPI) and cardiac amyloidosis imaging in Austria, Germany, and Switzerland of the year 2021.

METHODS

A questionnaire was sent in 2022 to centres practicing nuclear medicine.

RESULTS

Data from 14 Austrian (10,710 SPECT), 218 German (133,047 SPECT), and 16 Swiss centres (11,601 MPI (6,879 SPECT, 4722 PET)) were analysed. In Austria and Germany, the PET MPI numbers were close to zero and not considered. Official MPS numbers from 2015 to 2021 from Austria and Germany revealed a decline in Austria by about 40% in the pandemic years 2020 to 2021, but an increase in Germany by 9%. Ambulatory care cardiologists represented the major referral group (56-71%). Mostly, stress tests were performed pharmacologically (58-92%). Contrary to Germany, a 1-day protocol was predominant (58-97%) in Austria and Switzerland. The leading camera systems were SPECT-CT in Austria and Switzerland (57-79%) and multi-head systems in Germany (58%). Switzerland had the highest proportion of SPECT MPI with attenuation correction (84%), followed by Austria (43%), and Germany (33%). Electrocardiogram-gated SPECT MPI showed an overall high penetration of 87-99%. Scoring was most frequently applied in Germany (72%), followed by Austria (64%), and Switzerland (60%). Related to the population, the number of cardiac amyloidosis imaging was highest in Austria, followed by Switzerland and Germany.

CONCLUSIONS

This first joint survey of 2021 shows considerable differences among the countries. The Swiss situation is outstanding due to the wide use of PET MPI. In terms of camera equipment, Switzerland is also leading, followed by Austria and Germany. Despite the differences in procedural issues, the results reveal an overall high standard of MPI imaging.

Myocardial perfusion SPECT in Germany from 2012 to 2021: insights into development and quality indicators

PURPOSE

This paper summarises the results of 4 national surveys on the numbers, utilisation and technique of myocardial perfusion SPECT (MPS) from 2012 to 2021.

METHODS

A one-page questionnaire for information on MPS in 2012, 2015, 2018 and 2021 was sent to German centres practising nuclear medicine. To check for representativeness, the numbers obtained were related to official annual data and furthermore to the numbers of invasive coronary angiography procedures (ICA).

RESULTS

MPS examinations increased by > 40% from 2012 to 2021 and showed a centralisation with increasing MPS per centre. In 2020, a mild impact of the COVID-19 pandemic could be observed in the form of only a slight MPS increase, which was compensated in the following year. Outpatient care cardiologists represent the most important referrer (70%). Mostly, 2-day protocols were used. One-day protocols and stress-only protocols showed insignificant changes. The use of exercise stress decreased steadily. In 2021, exercise stress was replaced by pharmacological stress as the most frequent stress modality. Camera systems showed a shift to more SPECT-CT systems. The use of gated SPECT increased to almost 90%. Quantitative scoring showed an increasing acceptance. The ratio of invasive coronary angiographies (ICA) to MPS was between 3.9 and 4.5. A significant proportion of ICA in the context of CCS (chronic coronary syndrome) was performed without prior testing for ischaemia.

CONCLUSION

The 2012 to 2021 MPS surveys reveal a continuously growing number of examinations with only a mild temporary effect of the COVID-19 pandemic and a centralisation with increasing numbers per centre. Performance and technical data reveal a high-grade adherence of MPS practice to the current ESC guideline. A large potential of non-invasive diagnostics remains for the future.

Glycoprotein IIb/IIIa receptor targeted PET/CT imaging: a novel diagnostic tool for detecting bioprosthetic valve thrombosis

Background/Introduction

Bioprosthetic valve thrombosis (BPVT) is an important clinical entity eventually following both bioprosthetic surgical and transcatheter aortic valve replacement. Although dynamic contrast-enhanced 4D-MDCT has improved the diagnosis of BPVT, more sensitive and pathology-specific non-invasive imaging tools are lacking. Recently, the glycoprotein IIb/IIIa receptor targeted, elarofiban-derived PET/CT imaging radiotracer [18F]GP1 has been successfully used for visualization of acute venous and arterial thrombi.

Purpose

We hypothesized that [18F]GP1 PET/CT imaging is suitable to detect BPVT.

Methods

In this proof-of-concept study, patients after bioprosthetic aortic valve replacement with symptomatic, severe hemodynamic valve dysfunction and confirmed hypoattenuated leaflet thickening (HALT) in dynamic 4D-MDCT were offered to participate in compassionate use examinations to undergo PET/CT imaging with the investigational [18F]GP1 PET tracer at baseline and after a 12-week course of therapeutic oral anticoagulation.

Results

This case series reports on three patients after aortic valve replacement. Two patients with symptomatic, obstructive BPVT as confirmed by echocardiography and 4D-MDCT fulfilled specified criteria and underwent [18F]GP1 PET/CT imaging. [18F]GP1 PET/CT clearly distinguished between blood pool activity and thrombotic foci. Clot-to-blood ratios at baseline were 8.2 and 4.5, respectively. A 12-week trial of therapeutic oral anticoagulation was associated with a regression of mean transprosthetic pressure gradient and reversal of HALT. Follow-up 4D-MDCT corroborated thrombus resolution in both patients. Correspondingly, [18F]GP1 PET/CT imaging demonstrated decreased tracer uptake in both patients. Clot-to-blood ratio at follow-up visit decreased to 1.2 and 2.9, respectively. While absent tracer uptake was seen in patient #1, residual tracer uptake was observed in patient #2 suggestive of ongoing platelet aggregation. One asymptomatic SAVR patient was examined with [18F]GP1 PET/CT for a different compassionate use and no thrombotic foci were detected on the leaflets.

Conclusions

[18F]GP1 PET/CT is a novel imaging technique in patients with obstructive BPVT. In a head-to-head comparison we show that [18F]GP1 PET/CT may have incremental diagnostic value over dynamic contrast-enhanced 4D-MDCT alone by detection of sites of ongoing platelet aggregation at the molecular level. [18F]GP1 PET/CT may serve as a novel, highly sensitive tool to overcome some limitations of current diagnostic imaging modalities for detecting BPVT and may prove useful for the monitoring and guidance of therapeutic interventions.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Life Molecular Imaging provided material for [18F]GP1 radiolabeling free of charge as part of an ongoing research collaboration.

Correction to: The effect of beta blocker withdrawal on adenosine myocardial perfusion imaging

Regrettably the original version of the above article contained errors in Table 2 and wrong values in the text. The corrected table is presented here and the values which have been corrected now appear in bold text. Page 1223 abstract Global MBF showed an increase from 180.2 ± 59.9 to 193.6 ± 60.8 mL minute/100 g (P = .002) after beta blocker withdrawal. Page 1225 Mean systolic and mean diastolic blood pressure during adenosine were nearly identical (P = .77 and P = .79) with and without beta blocker. Mean heart rate and mean RPP during adenosine significantly increased after beta blocker withdrawal by 15.2% ± 17% (P = .001) and 16.2% ± 23% (P = .004), respectively. Page 1226 The data are listed in Table 2, lower third. Global MBF showed a significant increase by 7.4% ± 10% (P = .002) after beta blocker withdrawal. The individual data are depicted in Figure 1. All but three patients had a lower global MBF without beta blocker than with. The segmental MBF values (Figure 2) demonstrated a strong correlation over the entire range of perfusion values. The average effect was a slight perfusion shift of about 1015 mL minute-1/100 g in the range of 100-300 mL minute-1/100 g. The mCR under adenosine declined by 8.1%  ± 11% (P = .038) and the normalized RPP by 16.2% ± 21% (P = .004) after betablocker discontinuation. Table 2 Hemodynamic response under adenosine, perfusion, and left-ventricular function.

[Lutetium-177-PSMA radioligand therapy : Consensus within the framework of GKV-funded care between the university hospitals in Aachen, Bonn, Düsseldorf, Essen, and Cologne and the MDK Nordrhein]

In the last 3 years, Lutetium-177 prostate-specific membrane antigen radioligand therapy (Lu-177-PSMA-RLT) has received increasing attention in nuclear medicine as a new form of treatment for castration-resistant metastatic prostate cancer. This therapy combines the radionuclide Lutetium-177, which has been therapeutically used in nuclear medicine for many years, with a molecular target of the transmembrane prostate-specific membrane antigen expressed by prostate cancer cells. Since there are no prospective randomized studies on Lu-177-PSMA-RLT and the question of reimbursement has repeatedly been the subject of review by the MDK Nordrhein (Medischenische Dienst der Krankenversicherung), there was a desire because of the increasing number of patients being treated to clarify under which circumstances Lu-177-PSMA-RLT can be reimbursed by German statutory health insurance. The goals of this article are to help treating physicians understand how this new therapy option works, to integrate it in the overall therapy concept for castration-resistant metastatic prostate cancer, and, above all, to use Lu-177-PSMA-RLT-based on the current data-at the right place in the therapy sequence of castration-resistant metastatic prostate cancer.

[18F]Fluoride PET Indicates Reduced Bone Formation in Severe Glucocorticoid-induced Osteoporosis

A 61-year-old female patient presenting with mixed connective tissue disease (Sharp syndrome), underwent a long-term high dose glucocorticoid treatment because of multiple organ manifestations. Under steroid therapy she developed severe osteoporosis resulting in multiple fractures. A dynamic [18F]fluoride PET study in this patient revealed reduced fluoride influx in non-fractured vertebrae. This finding corresponds to pathogenetic concepts which propose an inhibition of bone formation as major cause of glucocorticoid-induced osteoporosis. In the light of the presented case it seems to be promising to evaluate the diagnostic benefit of [18F]fluoride PET in osteoporosis.

Improvement of Brain SPECT by Stabilization of Tc-99m-HMPAO with Methylene Blue or Cobalt Chloride

Aim: This present study was carried out to investigate whether stabilization of Tc-99m-HMPAO with methylene blue (MB) or cobalt chloride (CC) causes a sensible improvement in image quality and how cerebral to noncerebral activity ratios compare with those of Tc-99m-ECD. Methods: 30 minutes after preparation 400-600 MBq unstabilized Tc-99m-HMPAO (N = 35 patients), Tc-99m-HMPAO added with MB (N = 24 patients), added with CC (N = 30 patients) or Tc-99m-ECD (N = 28 patients) were injected. Radiochemical stability was measured in vitro with three chromatographical methods. Image quality was assessed quantitatively using two ratios, one of them determined by count densities of brain/scalp (QS), the other one by count densities of brain/ nose (QN). In addition, image quality (0 = bad, 3 = excellent) and background activity (0 = high, 3 = no) were visually assessed by three independent observers. Results: In contrast to unstabilized Tc-99m-HMPAO the integrity of the complexes of MB-Tc-99m-HMPAO, CC-Tc-99m-HMPAO and Tc-99m-ECD decreased only by a few percent during a period of 2 hours after reconstitution (66.8 ± 9.9 vs. 93.0 ± 2.5, 91.8 ± 1.9 and 96.9 ± 1.4%, p <0.001). Qs and Qn (m.v. ± SD) differed significantly between studies using unstabilized Tc-99m-HMPAO (3.0 ± 0.4 and 2.1 ± 0.3), MB-Tc-99m-HMPAO (3.4 ± 0.4 and 2.3 ± 0.3), CC-Tc-99m-H M PAO (3.6 ± 0.6 and 2.6 ± 0.4) and those using Tc-99m-ECD (4.3 ± 0.7 and 4.8 ± 1.4; p <0.05 and <0.001). Stabilization with CC or MB resulted in significant higher scoring of image quality and lower scoring of background activity in comparison to that of unstabilized Tc-99m-HMPAO, without reaching the scores obtained with Tc-99m-ECD. Conclusions: It is concluded that stabilization of Tc-99m-HMPAO with MB or CC definitely improves image quality in rCBF-SPECT, without reaching that of Tc-99m-ECD. Improvement of image quality results from the reduction of the amount of decomposition products that contribute to considerable extracerebral activity.

Position paper nuclear cardiology: Update 2008

Nuclear cardiology is well established in clinical diagnostic algorithms for many years. This is an update 2008 of the first common position paper of the German Association of Nuclear Medicine and the German Association of Cardiology, Heart and Circulation Research published in 2001 aiming at an overview of state-of-the-art scintigraphic methods.

Myocardial perfusion after one year of spinal cord stimulation in patients with refractory angina

Aim: Spinal cord stimulation (SCS) is recommended for patients with coronary artery disease (CAD) and refractory angina. We used positron emission tomography (PET) to investigate the long-term effect of SCS on regional myocardial perfusion in patients suffering from angina pectoris refractory to medical treatment and without option for coronary intervention. Patients, methods: We analyzed data of 44 patients with stable CAD (91% three vessel disease). At baseline, we determined coronary flow reserve (CFR) using 13N-ammonia-PET and myocardial viability with 18F-FDG. SCS was performed for one year (Medtronic Itrell III or Synergy, Düsseldorf, Germany). During follow-up, no cardiac interventions were necessary and no myocardial infarctions occurred. At one year follow-up, CFR was measured again. Results: In the majority of patients (77%), SCS led to an improvement of clinical symptoms. CFR did not change significantly during follow-up. Subjective improvement did not correlate with an increase of CFR. Conclusions: Despite its clinical effect, SCS does not have a direct impact on CFR in patients with stable CAD. According to our results, the pain relief is not due to an improvement of the myocardial blood supply.

Cardiac resynchronisation therapy

Aim: Cardiac resynchronisation therapy (CRT) has been shown to improve haemodynamics and clinical symptoms in heart failure patients. The present study evaluated the effects of a 4-month CRT on myocardial blood flow (MBF) at rest, after vasodilation and on myocardial oxygen consumption (MVO2). Patients, Methods: We studied 16 patients with idiopathic dilated cardiomyopathy prior to and during CRT performed as biventricular pacing. Resting MBF and MVO2 were determined from an 11C-acetate PET study and vasodilator MBF from a 13N-ammonia study. Results: MBF at rest (0.55 ± 0.10 ml/min/g), after vasodilation (1.20 ± 0.45 ml/min/g), and MVO2 (0.082 ± 0.014/min) did not change by mid-term CRT at a global level (0.57 ± 0.11 ml/min/g; 1.32 ± 0.49 ml/min/g; 0.085 ± 0.018/min), whereas the rate pressure product (RPP) normalised MVO2 decreased from 0.104 ± 0.024 to 0.086 ± 0.018/min (p = 0.02). At baseline, the regional analysis revealed significantly higher values for all parameters in the lateral wall than for those in the other walls. Under CRT the regional differences between the resting parameters equalised and all parameters showed significant lower coefficients of variation. Conclusion: Effects of mid-term CRT on resting MBF, vasodilator MBF and MVO2 occur at a regional level. The resynchronisation is associated with a more homogenous distribution pattern of these parameters among the myocardial walls. Substantial alterations to global MBF at rest, after vasodilation or to MVO2 are not detectable. Regarding the RPP normalised MVO2, there is evidence of improved ventricular efficiency through CRT.

Myocardial perfusion scintigraphy in Germany

The working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine (DGN), in cooperation with the working group Nuclear Cardiology of the German Cardiac Society (DGK), decided to conduct a national survey on myocardial perfusion scintigraphy (MPS). Method: A questionnaire to evaluate MPS for the year 2005 was sent. Results: 346 completed questionnaires had been returned (213 private practices, 99 hospitals and 33 university hospitals). MPS of 112 707 patients were reported with 110 747 stress and 95 878 rest studies. The majority (>75%) was performed with 99mTc-MIBI or tetrofosmin. 201Tl stress-redistribution was used in 22 637 patients (20%). The types of stress were exercise in 78%, vasodilation with adenosine or dipyridamol in 21% and dobutamine in 1%. 99.97% of all MPS were SPECT studies. Gated SPECT was performed in 36% of the stress and in 32% of the rest studies. An attenuation correction was used in 21%. 29 institutions (8%) performed gated SPECT (stress and rest) and attenuation correction. 47% of all MPS were requested by ambulatory care cardiologists, 17% by internists, 12% by primary care physicians, 21% by hospital departments and 2% by others. Conclusion: In Germany, MPS is predominantly performed with 99mTc-perfusion agents. The common type of stress is ergometry. Gated SPECT and attenuation correction do not yet represent standards of MPS practice in Germany, which indicates some potential of optimization.

Myocardial perfusion scintigraphy 2006 in Germany

Aim: This second survey was to deliver further information on myocardial perfusion scintigraphy (MPS) in Germany in 2006. Method: 351 questionnaires were evaluated: 207 private practices (PP), 117 hospitals (HO), 27 from university hospitals (UH). Results: MPS of 106 331 patients were reported, 85% were investigated with 99mTc-perfusion tracers. 74% [2005=72%] were performed in PP, 17% [2005=15%] in HO and 9% [2005=13%] in UH. PP, which participated in 2005 and 2006, demonstrated an increase by 3,9% (HO 0%, UH –13,0%). The type of stress was pharmacological in 27% [2005=22%]; 54% adenosine (of these 29% with exercise), 37% dipyridamole (of these 56% with exercise), and 9% dobutamine. Gated SPECT was performed in 42% [2005=36%] of all restand in 39% [2005=32%] of all stress MPS. An attenuation correction was used by 69 [2005=78] institutions. 40% of all MPS were performed in patients suspected to have CAD. 24% of all institutions reported changes in the use of MPS by competing methods. Conclusion: There is a small increase of MPS between 2005 and 2006 despite competing methods. Gated SPECT has experienced more acceptance. Suspicion of CAD is an important indication of MPS. In order to tap the full potential of MPS a gated SPECT should be performed routinely.

Myocardial sympathetic innervation in diabetic patients with symptomatic coronary artery disease

Aim: In non-diabetic patients, sympathetic innervation can be preserved even if there is major impairment of myocardial blood supply. Matters may be more complex in diabetic patients because denervation can be caused by cardiac autonomic neuropathy (CAN) or by ischemic injury. Our aim was to determine whether restrictions in myocardial blood supply have a pronounced influence on sympathetic innervation in diabetics and if this effect can be differentiated from CAN. Patients, methods: We analyzed 20 diabetics with advanced coronary artery disease (CAD) and without known CAN. We determined quantitative myocardial blood flow using 13N-ammonia-PET, myocardial viability with 18F-FDG, and cardiac innervation with 11C-HED. We investigated the relationship between regional HED retention, blood flow, and coronary flow reserve (CFR). Attenuated heart rate response to adenosine was taken as indicator for CAN (HR ratio). Results: There was minor correlation of segmental stress flow and HED retention (r2 = 0.063, p <0.0001). Correlation improved when stress flow as well as HED retention were normalized to the individual maximum (r2 = 0.162, p <0.0001). In nine patients, a HR ratio < 1.2 implicated subclinical CAN. Duration of diabetic disease or glycaemic control (HbA1c) did not correlate with mean HED retention in the viable segments, but with its variation coefficient. Conclusions: As in non-diabetic patients, a slight correlation exists between CFR and sympathetic innervation. The sensitivity of sympathetic nerves to reductions in CFR does not seem to be increased as compared to the results reported for non-diabetics. Besides impaired blood supply, long duration of diabetic disease and bad glycaemic control also seem to impair sympathetic innervation provoking higher heterogeneity.

The effect of beta blocker withdrawal on myocardial SPECT modeled from adenosine 13N-ammonia PET

AIM

The effect of beta blockers (BB) on myocardial imaging has been studied in several SPECT and PET studies with divergent results concerning perfusion and impact on diagnostic accuracy. The present study evaluated the effect of BB withdrawal on virtual SPECT studies modeled from quantitative PET perfusion scans.

PATIENTS, METHODS

Data from 20 CAD patients scheduled for adenosine 13N-ammonia imaging with and without BB were considered. Modeling the uptake characteristics of 99mTc-MIBI, all parametric stress PET polarmaps were transferred to virtual 20-segment SPECT polarmaps. The SPECT studies were categorized with a 5-point score and read to assess the effect of the BB withdrawal on scan result and interpretation.

RESULTS

The SPECT analysis revealed a mean score of 6.0 ± 4.7 with, and of 5.9 ± 4.5 without BB (p = 0.84). In 260 (74.9%) segments the scores were equal in both conditions. Without BB a downstaging was recorded in 44 segments (12.7%), an upstaging in 43 segments (12.4%). An essentially different interpretation (shift from medical therapy recommendation to angiography) was recorded in one patient. In six cases the interpretation differed mildly.

CONCLUSION

In the majority of patients studied, scan results and interpretation remain unchanged after discontinuation of the BB. Nevertheless, the segmental scan results are not uniformly affected. The recommendation to stop BBs prior to stress testing in order to ensure the highest MBF remains advisable. If temporary BB withdrawal is unfeasible due to contraindications, a tight clinical schedule, or because a patient forgot to withhold the BB, it is appropriate to perform adenosine stress testing according to the results of this study.

Cardiac shock wave therapy and myocardial perfusion in severe coronary artery disease

BACKGROUND

Ultrasound guided cardiac shock wave therapy (CSWT) is a noninvasive therapeutic option in the treatment of chronic-refractory angina. Clinical trials have shown that CSWT reduces angina symptoms, improves regional systolic function, LV ejection fraction, myocardial perfusion and quality of life parameters. Absolute measurements of myocardial perfusion before and after CSWT have not been performed so far.

METHODS AND RESULTS

We studied a total of 21 CCS III patients with history of CAD and multiple interventions who suffered from disabling angina despite individually optimized medical therapy. An N-13 NH3 PET perfusion scan under adenosine was performed before and after CSWT treatment. CSWT was well tolerated in all patients. Absolute perfusion under adenosine of the global left-ventricular myocardium did not change under therapy or minimal coronary resistance. The treated segments, however, showed in terms of both perfusion and resistance a mild but significant improvement, by 11 and 15 %, respectively, whereas no change could be observed in the remote segments. Considering a threshold of increased perfusion of 5 %, 10 (77 %) out of 13 patients with a better target perfusion improved in their CCS class, whereas 3 (43 %) out of 7 patients without improved target perfusion improved in their CCS class too.

CONCLUSION

Standard CSWT has the potential to improve myocardial perfusion of the therapy zone and clinical CAD symptomatology without affecting global myocardial perfusion. As a noninvasive and well tolerated therapeutic option, these data suggest the use of CSWT in patients with end-stage CAD.

The effect of beta blocker withdrawal on adenosine myocardial perfusion imaging

BACKGROUND

The effect of beta blockers on myocardial blood flow (MBF) under vasodilators has been studied in several SPECT and PET myocardial perfusion imaging (MPI) studies with divergent results. The present study evaluated the effect of a beta blocker withdrawal on quantitative adenosine MBF and on MPI results.

METHODS

Twenty patients with beta blockers and CAD history were studied with quantitative adenosine N-13 ammonia PET. The first study was performed under complete medication and the second after beta blocker withdrawal. The PET studies were independently read with respect to MPI result and clinical decision making.

RESULTS

Global MBF showed an increase from 180.2 ± 59.9 to 193.6 ± 60.8 mL·minute(-1)/100 g (P = .02) after beta blocker withdrawal. The segmental perfusion values were closely correlated (R(2) = 0.82) over the entire range of perfusion values. An essentially different interpretation after beta blocker discontinuation was found in two cases (10%).

CONCLUSION

A beta blocker withdrawal induces an increase in adenosine MBF. In the majority of cases, MPI interpretation and decision making are independent of beta blocker intake. If a temporary beta blocker withdrawal before MPI is not possible or was not realized by the patient, it is appropriate to perform adenosine stress testing without loss of the essential MPI result.

Use of myocardial perfusion imaging and estimation of associated radiation doses in Germany from 2005 to 2012

PURPOSE

For several years the Working Group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine has been performing a regular survey to obtain information on technique, utilization and development of myocardial perfusion scintigraphy (MPS). Currently, data of six surveys from 2005 to 2012 are available. The aim of this paper is to deliver a general and comprehensive overview of all surveys documenting the course of patient doses over time and the development of the method.

METHODS

A one-page questionnaire with number of MPS patients, number of stress and rest MPS, referral structure and several technical issues was sent to all centres performing MPS in Germany and evaluated. With the data on protocol utilization, effective MPS patient doses were estimated.

RESULTS

MPS per million population (pmp) varied between 2,380 and 2,770. In 2012, MPS pmp showed a slight increase for the first time. From 2005 to 2009 the angiography to MPS ratio increased from 3.4 to 4.4, and the revascularization to MPS ratio decreased from 0.66 to 0.53. In 2012, both indices demonstrated an opposite trend for the first time (4.1 and 0.55). A total of 108 centres participated in all surveys. They showed an increase in MPS patients of 4.0 % over the reporting period. In 2012, more than 50 % of the centres experienced no change or an increase in MPS numbers. The leading single competitor was MRI, followed by angiography and stress echocardiography. (201)Tl studies have decreased since 2005 from 20 to 5 %. (99m)Tc MPS studies showed a mild increase in 2-day protocols. In 2012, the average effective dose per patient was estimated at 7.4 mSv. Due to the decreasing use of (201)Tl, a mild decline over the observation period can be documented. Dynamic exercise stress was the most common stress test and adenosine the leading pharmacological stress agent, with a growing percentage. In 2012, the regadenoson percentage was 9 %. Gated single photon emission computed tomography (SPECT) noted an increasing acceptance with >70 % in 2012. The segmental scoring of perfusion studies had a low acceptance. Ambulatory care cardiologists represented the major referral group.

CONCLUSION

Germany has a moderate to moderate-high MPS utilization rate. Nevertheless, coronary artery disease (CAD) diagnosis and disease management are dominated by angiography. The survey data reveal a positive trend in MPS and a decrease in average patient dose reflecting good practice with guideline adherence, the implementation of technical improvements and success in training.

[Myocardial perfusion scintigraphy 2012 in Germany. Results of the 6th Query]

AIM

The working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine presents the results of the 6th survey on myocardial perfusion scintigraphy (MPS) of the reporting year 2012.

METHOD

278 questionnaires (177 private practices (PP), 78 hospitals (HO), 23 university hospitals (UH)) were evaluated.

RESULTS

MPS of 105,941 patients were reported. 95% [2005 = 80%] of MPS studies were conducted with (99m)Tc perfusion radiopharmaceuticals and only 5% with 201Tl. 79% [2009 = 76%] of the MPS were performed in PP, 15% [2009 = 17%] in HO, and 6% [2009 = 7%] in UH. Data from 108 centres which participated in all surveys from 2005 to 2012 showed an increase in MPS numbers of 4.0% (PP +6.1%, HO +18.2%, UH -18.3%). 29% of all participants (27% of PP, 31% of HO, and 26% of UH) noticed no change and 26% of all participants (28% of PP, 17% of HO and 35% of UH) an increase in their MPS requests since the 2009 query. The type of stress was pharmacological in 39% [2009 = 31%]. Of these 61% with adenosine (39% with exercise), 22% with regadenoson (51% with exercise), 14% with dipyridamole (60% with exercise), and 3% with dobutamine. Gated SPECT was performed in 73% [2009 = 56%] of all rest, in 70% [2009 = 56%] of all stress and in 67% [47%] of all stress and rest MPS. Only 36% [2009 = 33%] of the centres performed a quantification of all their studies with scores, whereas 41% [2009 = 52%] did not apply any quantification. 60% [2009 = 49%] of the MPS were requested by ambulatory care cardiologists.

CONCLUSION

The survey on MPS in Germany reveals a good conformity of imaging procedures with the current guideline. A positive development in MPS practice and referral can be stated. However, there is still some potential of MPS processing considering the quantitative perfusion analysis.

[Myocardial perfusion scintigraphy - short form of the German guideline]

This guideline is a short summary of the guideline for myocardial perfusion scintigraphy published by the Association of the Scientific Medical Societies in Ger-many (AWMF). The purpose of this guideline is to provide practical assistance for indication and examination procedures as well as image analysis and to present the state-of-the-art of myocardial-perfusion-scintigraphy. After a short introduction on the fundamentals of imaging, precise and detailed information is given on the indications, patient preparation, stress testing, radiopharmaceuticals, examination protocols and techniques, radiation exposure, data reconstruction as well as information on visual and quantitative image analysis and interpretation. In addition possible pitfalls, artefacts and key elements of reporting are described.

[Inventory resources of nuclear medicine]

AIM

The first survey of the German Society of Nuclear Medicine (DGN) to assess the resources of our speciality named "Inventory Resources of Nuclear Medicine" aims to provide a reliable data basis for existing and future activities of the DGN. The involvement and participation of as many colleagues as possible will play an important role for the success of the development of our profession.

METHODS

214 leading nuclear medicine professionals were identified as the target group. The questionnaire contained 13 different categories. Apart from individual-related questions, memberships in other societies as well as activities in federal or governmental boards, professional self-government or support groups were inquired. Participation in guideline programmes as well as other special experiences, knowledge or contacts, which could be relevant for the work of our boards and working groups, were also subject of the survey.

RESULTS

The data of 112 (52.3%) returned questionnaires were analysed. 57 persons state that they have already been involved in the activities of the DGN. Almost three quarters of these persons (n = 42) explicitly affirm their further commitment to the DGN in the future. Another 35 respondents can envisage such a future commitment for themselves. More than half of all colleagues (n = 69) are members of a regional society of nuclear medicine, and 80 are members of at least one professional society or association. This amounts to 3.3 memberships per person. 43 respondents are or have been involved in the clinical guideline development by the DGN or by other medical disciplines. In the future more than half of these persons are willing to participate in the guideline development furthermore. 13 colleagues have participated in the 30 reviews or official hearings concerning the clinical evidence evaluation of PET/CT by the German Institute for Quality and Efficiency in Health Care (IQWiG) (effective date: January 15, 2012). 21 (18.8%) persons are members of 23 federal, governmental or other political boards with relevance for research. 38 persons (33.9%) are committed to professional self-governmental bodies. 14 colleagues stated that they support the work of patient interest groups or other non-profit organisations as consultants or advisors. In most cases, this work is related to the patient interest group "Living without Thyroid". 14 colleagues report special experiences or knowledge that could be helpful for our DGN working groups. In the same manner, good contacts to government departments and agencies or representatives of politics and economy (stated by 24 respondents) can be of advantage to further shape the DGN's professional profile in the German health care sector.

CONCLUSION

As the result of a continuously advanced professionalization (2), the DGN has a good infrastructure concerning the political and professional work of its boards (executive committee and working groups). The operational and administrative work of the society and its boards is carried out or coordinated entirely by the society's office. Especially the development of the professional potential within the DGN by increasingly involving leaders working in clinical routine or research is the basis for the future of nuclear medicine.

Erdheim-Chester disease in a female cardiac surgery patient

We report a case of Erdheim-Chester disease (ECD) with isolated cardiac involvement in a 74-year-old female patient. The patient initially presented with superior vena cava syndrome and PET-CT imaging demonstrating an obstructing hypermetabolic lesion in the right atrium, and a distinct nonobstructing hypermetabolic lesion in the left atrium, expected to be malignant. There was no evidence of extracardiac disease. At surgical exploration, consistent with malignancy, the right atrial tumor was found to have grown into the pericardium and was resected to address symptoms and for histological diagnosis which revealed ECD on immunohistochemistry. We conclude that isolated cardiac ECD should be included in the surgical strategy for cardiac tumors showing infiltrative growth.

Diffusion-weighted magnetic resonance imaging for the detection of ischemic brain lesions in coronary artery bypass graft surgery: relation to extracorporeal circulation and heparinization

AIM

Cognitive decline is a well recognized complication after on-pump coronary artery bypass graft (CABG) surgery. We investigated whether the design of extracorporeal circulation (ECC) and the extent of perioperative heparinization have an impact on neurological dysfunction.

METHODS

Sixty-three CABG surgery patients were randomly perfused with an uncoated ECC-set (group A) or with two different heparin-coated ECC-sets (groups B and C). In groups A and B, systemic heparin was given in doses of 400 IU/kg body weight, whereas group C received 150 IU/kg body weight. ECC sets in group C included a diagonal pump and low priming as opposed to roller pumps in groups A and B. Furthermore, in group C blood contact to surfaces other than endothelium and heparin coated material was eliminated. Brain lesions were detected by diffusion-weighted magnetic resonance imaging (DWI). Neurological complications were assessed clinically until discharge (manifest motoric, sensitive or cognitive disturbance). Biochemical coagulation and inflammation parameters were measured pre-, peri-, and postoperatively.

RESULTS

No major neurological events were observed in either group until discharge. DWIs showed 61 new lesions in 19 of 45 patients who terminated all MRI study procedures. Number and volume of the lesions did not differ between groups (P>0.05). Biochemical and inflammatory parameters showed the expected time courses and variations between groups.

CONCLUSION

Ischemic brain lesions are frequently observed in CABG surgery patients but are neither associated with clinically relevant neurological complications nor with ECC set-up and intraoperative heparin dosage. DWI may help in the development of new surgical strategies to reduce postoperative brain damage.

[Myocardial perfusion scintigraphy 2008 in Germany - results of the fourth query]

AIM

The working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine in cooperation with the working group Nuclear Cardiology of the German Cardiac Society herewith present the results of the 4th survey on myocardial perfusion scintigraphy (MPS) of the year 2008.

METHOD

310 questionnaires (191 private practices (PP), 93 hospitals (HO), 31 university hospitals (UH)) were evaluated.

RESULTS

MPS of 98947 patients were reported. 15% of them were younger than 50 y, 57% between 50 and 70 y and 28% older than 70 y. 88% [2007: 83%] of all were studied with Tc-99m perfusion tracers. The patient radiation exposure of a stress and rest protocol considering German standard recommended doses was 8.5 mSv, of a stress-only protocol 1.9 mSv. 77% [2007: 76%] of the MPS were performed in PP, 15% [2007: 15%] in HO and 8% [2007: 9%] in UH. From 2005 to 2008 there was a mild increase in the MPS numbers by 1.2% (PP +7.1%, HO -5.5%, UH -31.4%). The type of stress was pharmacological in 30% [2007: 27%]; 68% adenosine (of these 22% with exercise), 29% dipyridamole (of these 64% with exercise), and <1% dobutamine. Gated SPECT was performed in 46% [2007: 47%] of all rest and in 42% [2007: 44%] of all stress MPS. 62% [2007: 61%] of all institutions did not use perfusion scores.

CONCLUSION

The MPS numbers from 2005 to 2008 in Germany can be regarded as stable. However, there are considerable shifts from HO and UH to PP. The well known potential of MPS considering risk stratification and functional analysis has not been tapped so far. Both gated SPECT and a quantitative perfusion analysis should be performed routinely in every patient.

[Myocardial perfusion scintigraphy 2007 in Germany--results of the query and current status]

AIM

This third survey of the working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine in cooperation with the working group Nuclear Cardiology of the German Cardiac Society was to deliver information on the procedures and in particular on the development of myocardial perfusion scintigraphy (MPS) from 2005 to 2007.

METHOD

370 questionnaires (222 private practices (PP), 117 hospitals (HO), 31 university hospitals (UH)) were evaluated.

RESULTS

MPS of 114,374 patients were reported, 83% were investigated with 99mTc-perfusion tracers. 76% [2006=74%] were performed in PP, 15% [2006=17%] in HO and 9% [2006=9%] in UH. Diabetics represented 21% of all MPS patients in 2007. Data of 215 institutions which participated all from 2005 to 2007 showed an increase in MPS of 2.3% (PP +6.8%, HO -4.5%, UH -18.2%). The type of stress was pharmacological in 27% [2006 = 27%]; 67% adenosine (of these 25% with exercise), 31% dipyridamole (of these 55% with exercise), and 2% dobutamine. Gated SPECT was performed in 47% [2006 = 42%] of all rest and in 44% [2006 = 39%] of all stress MPS. 61% [2006 = 83%] of all institutions did not apply perfusion scores. 20% [2006 = 24%] of the institutions reported changes in the use of MPS by competing methods.

CONCLUSION

There is a small increase of MPS between 2005 and 2007 despite competing methods. Gated SPECT has experienced more acceptance, but is still underrepresented. As compared to the European average and general standards of MPS a considerable backlog accounts to pharmacological stress tests, gated SPECT and perfusion scores.

[Myocardial perfusion scintigraphy 2006 in Germany. Results of the query and current status]

AIM

This second survey was to deliver further information on myocardial perfusion scintigraphy (MPS) in Germany in 2006.

METHOD

351 questionnaires were evaluated: 207 private practices (PP), 117 hospitals (HO), 27 from university hospitals (UH).

RESULTS

MPS of 106 331 patients were reported, 85% were investigated with (99m)Tc-perfusion tracers. 74% [2005 = 72%] were performed in PP, 17% [2005 = 15%] in HO and 9% [2005 = 13%] in UH. PP, which participated in 2005 and 2006, demonstrated an increase by 3,9% (HO 0%, UH - 13,0%). The type of stress was pharmacological in 27% [2005 = 22%]; 54% adenosine (of these 29% with exercise), 37% dipyridamole (of these 56% with exercise), and 9% dobutamine. Gated SPECT was performed in 42% [2005 = 36%] of all rest- and in 39% [2005 = 32%] of all stress MPS. An attenuation correction was used by 69 [2005 = 78] institutions. 40% of all MPS were performed in patients suspected to have CAD. 24% of all institutions reported changes in the use of MPS by competing methods.

CONCLUSION

There is a small increase of MPS between 2005 and 2006 despite competing methods. Gated SPECT has experienced more acceptance. Suspicion of CAD is an important indication of MPS. In order to tap the full potential of MPS a gated SPECT should be performed routinely.

[Myocardial perfusion scintigraphy in Germany. Results of the 2005 query and current status]

The working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine (DGN), in cooperation with the working group Nuclear Cardiology of the German Cardiac Society (DGK), decided to conduct a national survey on myocardial perfusion scintigraphy (MPS).

METHOD

A questionnaire to evaluate MPS for the year 2005 was sent.

RESULTS

346 completed questionnaires had been returned (213 private practices, 99 hospitals and 33 university hospitals). MPS of 112 707 patients were reported with 110 747 stress and 95 878 rest studies. The majority (>75%) was performed with (99m)Tc-MIBI or tetrofosmin. (201)Tl stress-redistribution was used in 22 637 patients (20%). The types of stress were exercise in 78%, vasodilation with adenosine or dipyridamol in 21% and dobutamine in 1%. 99.97% of all MPS were SPECT studies. Gated SPECT was performed in 36% of the stress and in 32% of the rest studies. An attenuation correction was used in 21%. 29 institutions (8%) performed gated SPECT (stress and rest) and attenuation correction. 47% of all MPS were requested by ambulatory care cardiologists, 17% by internists, 12% by primary care physicians, 21% by hospital departments and 2% by others.

CONCLUSION

In Germany, MPS is predominantly performed with (99m)Tc-perfusion agents. The common type of stress is ergometry. Gated SPECT and attenuation correction do not yet represent standards of MPS practice in Germany, which indicates some potential of optimization.

Synthesis and evaluation of fluorine-18 labelled compounds for imaging of bacterial infections with pet

Syntheses of no carrier added (n.c.a.) 6-fluoro-1,4-dihydro-1-cyclopropyl-4-oxo-7-[4-[18F]fluoro-phenacyl-1-piperacinyl]-chinolincarboxylic acid ([18F]COPCA) and n.c.a. 4-[18F]fluoro-benzoyl-ubiquicidin 29-41 ([18F]UBI 29-41) are described. [18F]COPCA was synthesised within 120 min with a radiochemical yield of 9-12%. [18F]UBI 29-41 was synthesised within 150 min with a radiochemical yield of 15-20%. Both compounds had a specific activity of more than 35 GBq/micromol. The biological activity was verified by measuring its binding to Staphylococcus aureus bacteria. Specific binding was found for [18F]UBI 29-41 (12-17%), whereas no specific binding for [18F]COPCA was found.

Cardiac re-synchronization therapy: effects on myocardial perfusion at rest, after vasodilation and oxygen consumption

AIM

Cardiac resynchronization therapy (CRT) has been shown to improve haemodynamics and clinical symptoms in heart failure patients. The present study evaluated the effects of a 4-month CRT on myocardial blood flow (MBF) at rest, after vasodilation and on myocardial oxygen consumption (MVO(2)).

PATIENTS, METHODS

We studied 16 patients with idiopathic dilated cardiomyopathy prior to and during CRT performed as biventricular pacing. Resting MBF and MVO(2) were determined from an (11)C-acetate PET study and vasodilator MBF from a (13)N-ammonia study.

RESULTS

MBF at rest (0.55 +/- 0.10 ml/min/g), after vasodilation (1.20 +/- 0.45 ml/min/g), and MVO2 (0.082 +/- 0.014/min) did not change by mid-term CRT at a global level (0.57 +/- 0.11 ml/min/g; 1.32 +/- 0.49 ml/min/g; 0.085 +/- 0.018/min), whereas the rate pressure product (RPP) normalised MVO(2) decreased from 0.104 +/- 0.024 to 0.086 +/- 0.018/min (p = 0.02). At baseline, the regional analysis revealed significantly higher values for all parameters in the lateral wall than for those in the other walls. Under CRT the regional differences between the resting parameters equalized and all parameters showed significant lower coefficients of variation.

CONCLUSION

Effects of mid-term CRT on resting MBF, vasodilator MBF and MVO(2) occur at a regional level. The resynchronization is associated with a more homogenous distribution pattern of these parameters among the myocardial walls. Substantial alterations to global MBF at rest, after vasodilation or to MVO(2) are not detectable. Regarding the RPP normalised MVO(2), there is evidence of improved ventricular efficiency through CRT.

[Effect of caffeine on myocardial blood flow during pharmacological vasodilation]

Pharmacologic stress with adenosine is frequently used for noninvasive detection of coronary artery disease. Dietary intake of caffeinated food, beverages or medications might alter adenosine-induced hyperemic blood flow, thereby compromising the diagnostic sensitivity of adenosine stress testing. In this case we report on a male patient with CAD. Myocardial blood flow at rest and during adenosine-induced hyperemia 2 hours after consumption of decaffeinated coffee and again without caffeine intake were quantified by ammonia PET. After caffeine intake there was a clearly diminished increase of myocardial blood flow during adenosine. The average coronary flow reserve in the myocardium was 1.3 after caffeine. In the baseline study without caffeine the coronary flow reserve has been improved to 2.3. Caffeine intake alters the coronary vasodilatory capacity. These findings emphasize the importance of carefully screening patients for intake of caffeinated food prior to adenosine stress testing.

[Myocardial perfusion under H.E.L.P. -apheresis. Objectification by PET]

Due to endothelial dysfunction (ED), coronary vasodilation capacity is reduced in patients with hypercholesterolemia. Cholesterol lowering may largely restore endothelial function. Currently, it is supposed that the onset of this therapeutic effect takes weeks or even months. However, by means of LDL apheresis, a significant LDL reduction may be achieved within hours. Dynamic quantitative positron emission tomography (PET) performed before and after LDL apheresis showed that mean global myocardial perfusion can be measured at rest and after pharmacological vasodilation with dipyridamole using N13 ammonia as tracer.A total of 35 patients (11 women and 24 men) with documented coronary heart disease and hypercholesterolemia underwent PET immediately prior to LDL apheresis and 18-20 hours thereafter. In addition to the decrease in LDL cholesterol (from 175+/-50 to 77+/-25 mg/dl) and fibrinogen (from 287+/-75 to 155+/-52 mg/dl), a significant improvement of myocardial blood flow under dipyridamole (177+/-59 vs 217+/-82 ml/min 100 g, p<0.0001), of coronary flow reserve (2.10+/-0.82 vs 2.62+/-1.02, p<0.0001) and of minimal coronary resistance (0.56+/-0.20 vs 0.44+/-0.17 mmHg 100 g min/ml, p<0.0001) were achieved. Plasma viscosity decreased only by 7.8%. Within 20 hours after single LDL apheresis a 20% improvement of coronary vasodilation capacity was noninvasively demonstrated and quantified.