Partial volume effect estimation and correction in the aortic vascular wall in PET imaging.

We evaluated the impact of partial volume effect (PVE) in the assessment of arterial diseases with (18)FDG PET. An anthropomorphic digital phantom enabling the modeling of aorta related diseases like atherosclerosis and arteritis was used. Based on this phantom, we performed GATE Monte Carlo simulations to produce realistic PET images with a known organ segmentation and ground truth activity values. Images corresponding to 15 different activity-concentration ratios between the aortic wall and the blood and to 7 different wall thicknesses were generated. Using the PET images, we compared the theoretical wall-to-blood activity-concentration ratios (WBRs) with the measured WBRs obtained with five measurement methods: (1) measurement made by a physician (Expert), (2) automated measurement supposed to mimic the physician measurements (Max), (3) simple correction based on a recovery coefficient (Max-RC), (4) measurement based on an ideal VOI segmentation (Mean-VOI) and (5) measurement corrected for PVE using an ideal geometric transfer matrix (GTM) method. We found that Mean-VOI WBRs values were strongly affected by PVE. WBRs obtained by the physician measurement, by the Max method and by the Max-RC method were more accurate than WBRs obtained with the Mean-VOI approach. However Expert, Max and Max-RC WBRs strongly depended on the wall thickness. Only the GTM corrected WBRs did not depend on the wall thickness. Using the GTM method, we obtained more reproducible ratio values that could be compared across wall thickness. Yet, the feasibility of the implementation of a GTM-like method on real data remains to be studied.

A randomized study comparing isotope and echocardiography stress testing in the screening of silent myocardial ischaemia in type 2 diabetic patients.

AIMS: This study aimed to compare the positive predictive value (PPV) of stress myocardial scintigraphy (SPECT) and of dobutamine echocardiography (DE) in the diagnosis of significant coronary artery stenosis (CAD) in asymptomatic type 2 diabetic patients, and to assess long-term clinical outcomes according to silent myocardial ischaemia (SMI) screening. METHODS: A total of 204 asymptomatic type 2 diabetic patients at high cardiovascular (CV) risk were prospectively randomized to undergo either SPECT (n=104) or DE (n=100). Coronary angiography was proposed in cases of SMI, with revascularization of suitable lesions. Intensive treatment of CV risk factors was prescribed for all patients. Death and myocardial infarction (MI) were recorded during the 3-year follow-up. RESULTS: Clinical characteristics were similar in the two testing groups. The prevalence of SMI and significant CAD were 13% and 4%, respectively, in the SPECT group vs 11% and 5%, respectively, in the DE group (not significant [NS]). The PPV for the detection of significant CAD was 29% for SPECT and 45% for DE (NS). Seven patients (3%) underwent initial revascularization. The 3-year rate of CV death and MI was 2.5%, and similar in both groups. CONCLUSION: Rates of SMI and significant CAD in asymptomatic high-risk type 2 diabetic patients receiving intensive care of risk factors are low, and SPECT and DE are similar in the detection of SMI and CAD. Coronary revascularization and intensive CV risk-factor therapy are associated with a low rate of adverse CV events at 3 years, whichever stress test was used.

Clinical and imaging follow-up after exhaustive liver resection of endocrine metastases: a 15-year monocentric experience.

Liver metastases are common in gastroenteropancreatic neuroendocrine tumors and significantly impair survival. Hepatic resection is the only potential curative treatment. The records of 41 consecutive patients undergoing exhaustive resection of liver-only endocrine metastases and followed between 1992 and 2006 were reviewed. Patient's outcome and diagnostic accuracy of somatostatin receptor scintigraphy (SRS) and morphological imaging (MI) for detection of recurrences during post-operative follow-up were assessed. All identified primary had been resected. MI studies including abdominal computed tomography (CT) and/or liver magnetic resonance imaging and thoracic CT if indicated were performed every 6 months; SRS timing was decided by referring clinician. Tumor recurrences were confirmed by pathology or subsequent imaging studies. The results of 136 MI and SRS examinations performed within a 30-day interval from each other were retrospectively compared. Median post-operative follow-up was 51 months (7-165). Recurrences developed in 32 patients (78%), mainly in the liver (n=24) after a median of 19 months (2-79). Five-year overall and disease-free survival rates were 79 and 3% respectively. For recurrence detection, sensitivity, specificity, and accuracy were 89, 94, and 91% for SRS, 68, 91, and 74% for MI respectively. In 11 out of 32 patients (34%), abdominal or extra-abdominal metastases were detected 15.5 months earlier by SRS than MI. In conclusion, despite exhaustive liver surgery for endocrine metastases, hepatic or extra-hepatic recurrences are frequent and develop early. SRS is highly accurate for the detection of recurrences during post-operative follow-up and permitted early diagnosis in one third of patients; therapeutic implications of this early diagnosis remain to be determined.

The use of technetium-99m radiolabeled human antimicrobial peptides for infection specific imaging.

Bacterial resistance to conventional antibiotics poses a challenge medicine to search for alternatives. Cationic antimicrobial peptides (AMPs) are promising for the development of a new class of antibiotics. This review focuses on the use of technetium-99m labeled synthetic AMPs, derived from human natural cationic AMPs, for target-delivery to and in vivo detection of infection sites caused by (drug-resistant) micro-organisms. The scintigraphic approach has proven to be a reliable method for evaluating AMPs in pharmacological studies and for optimizing target-delivery of radiolabeled AMPs to pathological sites in animals and humans. In addition, the effect of alterations in amphipathicity, amino acid substitution, and dimerization on the biological performance of AMPs is reported. Radiolabeled AMPs offer good perspectives for diagnosis of infections, for monitoring therapy, and, most importantly, for the ability to discriminate between infections and sterile inflammatory processes.

Present and future of clinical cardiovascular PET imaging in Europe--a position statement by the European Council of Nuclear Cardiology (ECNC).

This position statement was prepared by the European Council of Nuclear Cardiology and summarises the current and future potential of PET as a clinical cardiovascular diagnostic imaging tool. The first section describes how methodological developments have positively influenced the transition of PET from a research tool towards a clinical diagnostic test. In the second section, evidence in support of its superior diagnostic accuracy, its value to guide decision making and to predict outcome and its cost effectiveness is summarised. The third section finally outlines new PET-based approaches and concepts, which will likely influence clinical cardiovascular medicine in the future. The notion that integration of cardiac PET into healthcare systems and disease management algorithms will advance quality of care is increasingly supported by the literature highlighted in this statement.

Early detection of recurrence by 18FDG-PET in the follow-up of patients with colorectal cancer.

We assessed the potential benefits of including systematic 18fluorodeoxyglucose positron emission tomography (FDG-PET) for detecting tumour recurrence in a prospective randomised trial. Patients (N=130) who had undergone curative therapy were randomised to undergo either conventional (Con) or FDG-PET procedures during follow-up. The two groups were matched at baseline. Recurrence was confirmed histologically. 'Intention-to-treat' analysis revealed a recurrence in 46 patients (25 in the FDG-PET group, and 21 in the Con group; P=0.50), whereas per protocol analysis revealed a recurrence in 44 out of 125 patients (23 and 21, respectively; P=0.60). In another three cases, PET revealed unexpected tumours (one gastric GIST, two primary pulmonary cancers). Three false-positive cases of FDG-PET led to no beneficial procedures (two laparoscopies and one liver MRI that were normal). We failed to identify peritoneal carcinomatosis in two of the patients undergoing FDG-PET. The overall time in detecting a recurrence from the baseline was not significantly different in the two groups. However, recurrences were detected after a shorter time (12.1 vs 15.4 months; P=0.01) in the PET group, in which recurrences were also more frequently (10 vs two patients) cured by surgery (R0). Regular FDG-PET monitoring in the follow up of colorectal cancer patients may permit the earlier detection of recurrence, and influence therapy strategies.

EANM/ESC guidelines for radionuclide imaging of cardiac function.

Radionuclide imaging of cardiac function represents a number of well-validated techniques for accurate determination of right (RV) and left ventricular (LV) ejection fraction (EF) and LV volumes. These first European guidelines give recommendations for how and when to use first-pass and equilibrium radionuclide ventriculography, gated myocardial perfusion scintigraphy, gated PET, and studies with non-imaging devices for the evaluation of cardiac function. The items covered are presented in 11 sections: clinical indications, radiopharmaceuticals and dosimetry, study acquisition, RV EF, LV EF, LV volumes, LV regional function, LV diastolic function, reports and image display and reference values from the literature of RVEF, LVEF and LV volumes. If specific recommendations given cannot be based on evidence from original, scientific studies, referral is given to "prevailing or general consensus". The guidelines are designed to assist in the practice of referral to, performance, interpretation and reporting of nuclear cardiology studies for the evaluation of cardiac performance.

Topology of the fibrinolytic system within the mural thrombus of human abdominal aortic aneurysms.

Development and progression of acquired abdominal aortic aneurysms (AAAs) involve proteolytic activity. In the present study, we investigate the distribution of fibrinolytic system components within mural thrombi of human AAAs. 20 mural thrombi and the remaining AAA walls were dissected. The luminal, intermediate and abluminal thrombus layers, and media and adventitia were separately incubated in cell culture medium. Conditioned media were then analysed for plasminogen activators (PAs), plasminogen activator inhibitor-1 (PAI-1), free-plasmin, plasmin alpha(2)-antiplasmin complexes (PAPs) and D-dimers release. In parallel, PA and PAI-1 mRNA expression analysis was performed by RT-PCR. The study was completed by immunohistochemical localization of these components in AAA, ex vivo functional imaging using (99m)Tc-aprotinin as a ligand and measurement of PAP and D-dimer plasma levels. All fibrinolytic system components were present in each aneurysmal layer. However, the mural thrombus was the main source of active serine-protease release. Interestingly, the luminal layer of the thrombus released greater amounts of PAPs and D-dimers. This paralleled the preferential immunolocalization of plasminogen and PAs, and the (99m)Tc-aprotinin scintigraphic signal observed in the luminal pole of the thrombus. In contrast, mRNA expression analysis showed an exclusive synthesis of tPA and PAI-1 within the wall, whereas uPA mRNA was also expressed within the thrombus. Taken together, these results suggest that the increased plasma concentrations of PAPs and D-dimers found in AAA patients are related to mural thrombus proteolytic activity, thus explaining their known link with AAA progression. Components of the fibrinolytic system could also represent a target for functional imaging of thrombus activities in AAA.

The regulatory background of nuclear cardiology in Europe: a survey by the European Council of Nuclear Cardiology.

PURPOSE: Nuclear cardiology is a well-validated, non-invasive imaging modality that is highly cost-effective as a diagnostic and prognostic tool in the evaluation of patients with known or suspected coronary artery disease. However, the number of procedures in Europe is very far from that which would be expected on the basis of epidemiological data, particularly when comparison is made with the USA. As a preliminary step for future action aimed at improving and increasing nuclear cardiology practice in Europe, the European Council of Nuclear Cardiology performed a survey to identify the regulatory issues and the training components pertaining to the practice of nuclear cardiology. METHODS: a questionnaire was sent to 31 national nuclear medicine societies and to 40 national cardiology societies. The main areas covered by the survey were: (1) the license requirements, (2) the theoretical and practical aspects of training and (3) supervision of the stress test during a nuclear cardiology study. RESULTS: The results show that, in a setting of wide heterogeneity of national regulations, education and professional practice, nuclear medicine is a restricted and closely regulated specialty. This situation guarantees the quality and safe use of radionuclides; at the same time, however, it limits integration of nuclear medicine into the clinical arena. CONCLUSION: Cardiologists should become more involved in nuclear cardiology, to further stimulate the use of this powerful diagnostic and prognostic imaging modality.

Comparative impact of standard approach, FDG PET and FDG dual-head coincidence gamma camera imaging in preoperative staging of patients with non-small-cell lung cancer.

We prospectively compared the impact of the standard approach, of fluorodeoxyglucose positron emission tomography (FDG PET) and of FDG dual-head coincidence gamma camera imaging (DHC) in preoperative staging of patients with non-small-cell lung cancer (NSCLC). In addition to traditional staging, 42 patients were studied with a PET system and a DHC system. The number of lesions detected on DHC and on PET were compared independently of the proof of a tumoural invasion. Then, for the sub-group of lesions with the proof of a tumoural invasion, the sensitivity of the different imaging modalities was compared. Finally, stagings were compared with final staging established by histopathological findings (n=28), additional imaging modalities (n=4), clinical and traditional imaging follow-up over at least 4 months. DHC detected 105 of the 145 lesions considered as pathological on PET (73%, P=0.01), with a concurrence of 89% (NS) in lesions larger than 1.5 cm, and only 17% (P=0.03) in those smaller or equal to 1 cm. Traditional staging detected 87 of the 114 verified tumoural lesions (76%), PET 110/114 (96%, P=0.01 vs traditional staging), DHC 88/114 (77%, NS vs traditional staging, P=0.01 vs PET). PET correctly predicted the N stage in 39/42 (93%) patients, DHC in 38/42 (90%), and computed tomography in 32/42 (76%). PET correctly predicted the M stage in 42/42 (100%) patients, DHC in 41/42 (98%), and traditional staging in 38/42 (90%). Identical NM staging was obtained with DHC and PET in 38/42 (90%) patients. Compared to traditional NM staging, PET correctly up-staged 9/42 (21%) patients and down-staged 3/42 (7%), with one additional false N up-staging. DHC correctly up-staged 7/42 (17%) patients and down-staged 3/42 (7%), with one additional false N down-staging. PET correctly reclassified 4/42 (9.5%) patients from resectable to unresectable and incorrectly reclassified one. DHC correctly reclassified 3/42 (7%) patients without false therapeutic reclassification. Although DHC detected fewer lesions than PET, DHC is a possible alternative to PET since the impact on staging was high as compared with traditional staging and was very similar to that of PET.

[Is coincidence detection emission tomography (CDET) as reliable as positron emission tomography (PET) in head and neck cancer?]. / La tomographie d'emission en détection de coïncidence (CDET) est-elle aussi performante que la tomographie par emission de positons (TEP) en cancérologie ORL?

OBJECTIVE: Positron emission tomography (PET) is becoming more and more useful in head and neck tumour detection, guiding diagnostic and therapeutic decision. However, techniques, similar to PET, but using modified conventional tomography equipment, are used. The most commonly used is the dual-head positron emission tomography using coincidence detection (CDET). This study was aimed at searching if CDET could be as reliable as PET in some of its indications. PATIENTS AND METHODS: Between 1997 and 2001, 19 patients, with head and neck cancer, had a CDET, for 3 indications. We studied retrospectively sensitivity (Se) and specificity (Sp) rates for these 3 indications. RESULTS: 1 degree) Detection of unknown primary head and neck cancers with lymph node manifestation: Se = 100%, Sp = 66,7%. 2 degrees) Detection of body metastasis: Se = 50%, Sp = 33%. 3 degrees) Detection of local recurrent cancer: Se = 100%, Sp = 25%. CONCLUSION: CDET seems to be useful in finding unknown primary cancers with lymph node manifestation but is not reliable to look for metastasis and local recurrences. It cannot be used in all indications for PET. If no other tool is available, this investigation can be used, keeping in mind its limitations.

Myocardial muscarinic receptor upregulation and normal response to isoproterenol in denervated hearts by familial amyloid polyneuropathy.

BACKGROUND: Patients with familial amyloid polyneuropathy, a rare hereditary form of amyloidosis, have progressive autonomic neuropathy. The disease usually does not induce heart failure but is associated with sudden death, conduction disturbances, and an increased risk of complications during anesthesia. Although cardiac sympathetic denervation has been clearly demonstrated, the postsynaptic status of the cardiac autonomic nervous system remains unelucidated. METHODS AND RESULTS: Twenty-one patients were studied (age, 39+/-11 years; normal coronary arteries; left ventricular ejection fraction 68+/-9%). To evaluate the density and affinity constants of myocardial muscarinic receptors, PET with (11)C-MQNB (methylquinuclidinyl benzilate), a specific hydrophilic antagonist, was used. Cardiac beta-receptor functional efficiency was studied by the heart rate (HR) response to intravenous infusion of isoproterenol (5 minutes after 2 mg of atropine, 5, 10, and 15 ng/kg per minute during 5 minutes per step). The mean muscarinic receptor density was higher in patients than in control subjects (B'(max), 35.5+/-8.9 versus 26.1+/-6.7 pmol/mL, P=0.003), without change in receptor affinity. The increase in HR after injection of atropine as well as of MQNB was lower in patients compared with control subjects despite a similar basal HR (DeltaHR after atropine, 11+/-21% versus 62+/-17%; P<0.001), consistent with parasympathetic denervation. Incremental infusion of isoproterenol induced a similar increase in HR in patients and control subjects. CONCLUSIONS: Cardiac autonomic denervation in familial amyloid polyneuropathy results in an upregulation of myocardial muscarinic receptors but without change in cardiac beta-receptor responsiveness to catecholamines.

Myocarditis in patients with clinical presentation of myocardial infarction and normal coronary angiograms.

OBJECTIVES: The aim of this study was to assess the diagnosis of myocarditis in patients presenting with acute myocardial infarction (MI) and normal coronary angiograms. BACKGROUND: Most often in these patients, the etiologic diagnosis remains unclear once they are found to have normal coronary arteries. The diagnosis of myocarditis mimicking MI is clinically relevant, because numerous arguments suggest a relation between myocarditis and dilated cardiomyopathy. Myocardial indium-111 (111In)-antimyosin antibody (AMA)/rest thallium-201 (201Tl) imaging allows noninvasive detection of myocarditis. METHODS: Forty-five patients admitted to three intensive care units for suspicion of acute MI, with normal coronary angiograms, were investigated. Indium-111-AMA planar images and then a dual-isotope rest AMA/201Tl tomographic study were performed. Six-month echocardiographic follow-up was obtained in 80% of the patients with initial left ventricular (LV) wall motion abnormalities. RESULTS: In eight patients, AMA and 201Tl scintigraphy were negative. In two patients, a matched 201Tl defect and focal AMA uptake suggested acute MI (due to prolonged vasospasm or spontaneously reperfused coronary occlusion). In 17 patients, diffuse AMA uptake over the whole LV suggested diffuse myocarditis. In 18 patients, focal AMA uptake with a normal 201Tl scan suggested diffuse but heterogeneous, or focal myocarditis. Complete functional recovery was observed in 81% of the patients with a pattern of myocarditis. CONCLUSIONS: Among 45 patients presenting with acute MI and normal coronary angiograms, 38% had diffuse myocarditis and 40% had a scintigraphic pattern of heterogeneous or focal myocarditis. Short-term follow-up showed complete LV functional recovery in 81% of these patients.

Clinical impact of combination of scatter, attenuation correction, and depth-dependent resolution recovery for (201)Tl studies.

UNLABELLED: A lack of specificity for myocardial perfusion imaging has been widely reported, mostly related to false-positive defects on the inferior wall. The application of depth-dependent resolution recovery (RR), attenuation correction (AC) using external source devices, and scatter correction has been proposed to resolve this pitfall. METHODS: We studied the clinical benefit of depth-dependent RR, nonuniform AC using a scanning line source, and scatter correction (photon energy recovery [PER]) compared with filtered backprojection alone. Eighty-two patients were included: 40 healthy volunteers with a low likelihood of coronary artery disease (control group) and 42 patients with proven right or circumflex coronary artery disease but without involvement of the left anterior descending artery. Among these 82 patients, the images of 33 were also processed with PER. RESULTS: RR did not alter the performance of filtered backprojection alone. AC + RR greatly improved specificity and the rate of normal (201)Tl SPECT findings in the control population (from 56% to 95% and from 53% to 100%, respectively) but significantly decreased sensitivity (from 92% to 54%). AC + RR generated a false anteroapical defect in 21% of patients and reverse redistribution of the apex in 23%. AC + RR significantly decreased the extent of the stress defect (from 4.09 to 3.21 segments, P < 0.003) and increased the perfusion score of the stress defect (from 0.78 +/- 0.72 to 1.47 +/- 1.11, P < 0.00061). Moreover, AC + RR generated overcorrection on the inferior wall, leading to false estimation of viability for 11 of 15 patients with an old inferior myocardial scar without evidence of residual viability. PER decreased overcorrection on the inferior wall, but without improving sensitivity. PER did not significantly reduce the number of anteroapical false-positives or the number of apical reverse distribution cases. CONCLUSION: AC + RR improved the specificity and normalcy rate of (201)Tl SPECT myocardial perfusion imaging but generated overcorrection on the inferior wall, leading to low sensitivity and to false evaluation of myocardial viability in 73% of the patients with inferior infarction. AC + RR also generated anteroapical artifacts. The addition of scatter correction did not significantly reduce these drawbacks.

Electrocardiographically gated blood-pool SPECT and left ventricular function: comparative value of 3 methods for ejection fraction and volume estimation.

UNLABELLED: The current major limitation to development of electrocardiographically (ECG) gated blood-pool SPECT (GBPS) for measurement of the left ventricular (LV) ejection fraction (LVEF) and volumes is the lack of availability of clinically validated automatic processing software. Recently, 2 processing software methods for quantification of the LV function have been described. Their LVEFs have been validated separately, but no validation of the LV volume measurement has been reported. METHODS: We compared 3 processing methods for evaluation of the LVEF (n = 29) and volumes (n = 58) in 29 patients: automatic geometric method (GBPS(G)), semiautomatic activity method (GBPS(M)), and 35% maximal activity manual method (GBPS(35%)). The LVEF provided by the ECG gated equilibrium planar left anterior oblique view (planar(LAO)) and the LV volumes provided by LV digital angiography (Rx) were used as gold standards. RESULTS: Whereas the GBPS(G) and GBPS(M) methods present similar low percentage variabilities, the GBPS(35%) method provided the lowest percentage variabilities for the LVEF and volume measurements (P < 0.04 and P < 0.02, respectively). The LVEF and volume provided by the 3 methods were highly correlated with the gold standard methods (r > 0.98 and r > 0.83, respectively). The LVEFs provided by the GBPS(35%) and GBPS(M) methods are similar and higher than those of the GBPS(G) method and planar(LAO) method, respectively (P < 0.0001). For the LVEF, there is no correlation between the average and paired absolute difference for the 3 GBPS methods against the planar(LAO) method, and the limits of agreement are relatively large. LV volumes are lower when calculated with the GBPS(M), GBPS(G), and Rx methods (P < 0.0001). However, the GBPS(35%) and Rx methods provide LV volumes that are similar. There is no linear correlation between the average and the paired absolute difference of volumes calculated with the GBPS(G) and GBPS(35%) methods against Rx LV volumes. However, a moderate linear correlation was found with the GBPS(M) method (r = 0.6; P = 0.0001). The 95% limits of agreement between the Rx LV volumes and the 3 GBPS methods are relatively large. CONCLUSION: GBPS is a simple, highly reproducible, and accurate technique for the LVEF and volume measurement. The reported findings should be considered when comparing results of different methods (GBPS vs. planar(LAO) LVEF; GBPS vs. Rx volume) and results of different GBPS processing methods.

Optimal 3-dimensional method for right and left ventricular fourier phase analysis in electrocardiography-gated blood-pool SPECT.

BACKGROUND: To overcome some of the limitations imposed by planar imaging, we aimed to optimize the use of first harmonic Fourier phase analysis (FPA) in electrocardiography-gated blood-pool single photon emission computed tomography (GBPS) by comparing different quantitative, 3-dimensional methods. METHODS AND RESULTS: Three groups of patients who underwent GBPS were evaluated: group 1, 8 patients with no heart disease; group 2, 10 patients with left ventricular disease; and group 3, 6 patients with right ventricular disease. Six different methods for FPA were compared: surface, cylindrical, spherical, and hybrid methods with fixed thresholding and spherical and hybrid methods with multiple thresholding. The hybrid method with multiple thresholding for the left ventricle and the spherical method for the right ventricle provided the highest discrimination score (phase) between normal and abnormal ventricles. Among methods with similar discrimination score for these 2 methods, the cylindrical and hybrid methods for the left ventricle and the spherical method for the right ventricle provided the best homogeneity of phase distribution histogram in normal ventricles. These were considered the optimal methods for FPA. CONCLUSIONS: The hybrid or cylindrical method for the left ventricle and the spherical method for the right ventricle with fixed thresholding are the optimal methods for FPA in GBPS.

Prognostic value of radionuclide angiography in patients with right ventricular arrhythmias.

BACKGROUND: The prognosis of patients with right ventricular (RV) arrhythmias remains uncertain. This study prospectively evaluated the prognostic value of RV and left ventricular (LV) involvement assessed by radionuclide angiography (RNA) as predictors for sudden death. METHODS AND RESULTS: Patients (n=188) with severe arrhythmias originating from the RV were followed up for a mean of 45+/-34 months. Data on clinical presentation, resting and stress ECG, signal-averaged ECG, 24-hour Holter monitoring, and programmed stimulation were collected along with RNA. Patients were classified as group I (n=82) with normal RNA or group II (n=106) with an abnormal RV suggestive of arrhythmogenic RV cardiomyopathy, classified as diffuse or localized disease, with or without associated LV abnormalities. During follow-up, 14 patients died suddenly, all in group II. None of the clinical and electrical data were predictive of death. An abnormal RNA study was a highly predictive factor for death (P<0.005), as well as the presence of LV abnormalities (P<0.01). CONCLUSIONS: The present study confirms that arrhythmogenic RV cardiomyopathy is a severe disease with a high risk for cardiac death. Evidence of RV abnormalities in patients presenting with RV arrhythmias is highly predictive for sudden death, as is its association with LV involvement.

Prognostic value of 201Tl myocardial scintigraphy after coronary artery bypass grafting.

BACKGROUND: 201Tl myocardial scintigraphy (201Tl SPECT) is of strong prognostic value in various populations with suspected or known coronary artery disease. However, its value in patients with coronary artery bypass grafting (CABG) is not fully assessed. METHODS: We examined 115 consecutive patients to determine the relation between clinical data/stress 201Tl SPECT performed 5+/-3 years after CABG, and subsequent cardiac events. RESULTS: Thirteen patients (11%) had stress-induced angina, 22 (19%) had electrical positivity, and 97 (84%) had abnormal scintigraphy, including 62 (54%) with reversible defects. During follow-up (35+/-22 months), there were nine cardiac deaths, seven myocardial infarctions, and 20 revascularization procedures. Multivariate Cox analysis identified the delay between CABG and scintigraphy (P<0.01, relative risk (RR) = 1.01), the extent of stress 201Tl defects (P = 0.04, RR = 1.18), and increased stress 201Tl lung uptake (P = 0.03, RR = 3.56) as significant predictors of cardiac deaths/infarctions. Delay between CABG and scintigraphy (P < 0.001, RR = 1.01), the extent of stress 201Tl defects (P = 0.03, RR = 1.15), and that of reversible defects (P = 0.05, RR = 1.13) were the only significant predictors of total events. CONCLUSIONS: Besides the delay between CABG and scintigraphy, the scintigraphic parameters were the only significant and additive predictors of cardiac events in 115 patients with CABG.

[Evaluation of the ejection fraction tomoscintigraphy synchronised with an electrocardiogram]. / Evaluation de la fraction d'éjection par tomoscintigraphie synchronisée à l'électrocardiogramme.

Electrocardiographic gated myocardial scintigraphy (gated SPECT) allows simultaneous evaluation of left ventricular perfusion and contractility. The aim of this study was to assess the impact of the type of tracer and temporal sampling on the measurement of the ejection fraction by gated SPECT. Eighty-six consecutive patients (59 men, 27 women, average age 62 +/- 11 years) with a history of myocardial infarction (anterior N = 50--inferior N = 36) were studied. All had measurement of the isotopic ejection fraction by equilibrium angioscintigraphy and by gated SPECT sampled at 8 (N = 45, 52%) or 16 images/cycle RR (N = 41, 48%). After filtered retroprojection, the ejection fraction was calculated by a validated method (QGS). A better correlation between gated SPECT and equilibrium angioscintigraphy was observed at 16 images/cycle (r = 0.90) compared with 8 (r = 0.80). The Bland-Altman curves showed improved accuracy of the measurement of the ejection fraction by gated SPECT with 16 compared with 8 images/cycles sampling (mean differences of 0.37 +/- 6.06% and 4.3 +/- 7.71%, respectively). Multivariable analysis showed that temporary sampling was the only parameter to significantly affect the difference between the two methods. There was no difference between the use of Thallium and that of 99mTc-sestamibi. Gated SPECT, therefore, provides an accurate measurement of the ejection fraction for routine clinical usage, providing the acquisition is made at 16 images/cycle.

Somatostatin receptor scintigraphy and gallium scintigraphy in patients with sarcoidosis.

UNLABELLED: Somatostatin receptor scintigraphy (SRS) has been shown to reveal sarcoidosis sites. The aim of this study was to prospectively compare SRS and gallium scintigraphy in the evaluation of pulmonary and extrapulmonary involvement in patients with proven sarcoidosis. METHODS: Eighteen patients with biopsy-proven sarcoidosis were included. Nine were or recently had been receiving steroid therapy at the time of the examination. Planar gallium scintigraphy (head, chest, abdomen, and pelvis) and thoracic SPECT were performed at 48-72 h after injection of a mean dose of 138 +/- 21 MBq 67Ga. Planar SRS and thoracic SPECT were performed at 4 and 24 h after injection of a mean dose of 148 +/- 17 MBq 111n-pentetreotide. RESULTS: Gallium scintigraphy found abnormalities in 16 of 18 patients (89%) and detected 64 of 99 clinically involved sites (65%). SRS found abnormalities in 18 of 18 patients and detected 82 of 99 clinically involved sites (83%). Of the 9 treated patients, gallium scintigraphy found abnormalities in 7 (78%), detecting 23 of 39 clinically involved sites (59%), whereas SRS found abnormalities in 9, detecting 32 of 39 clinically involved sites (82%). CONCLUSION: This study suggests that, compared with gallium scintigraphy, SRS appears to be accurate and contributes to a better evaluation of organ involvement in sarcoidosis patients, especially those treated with corticosteroids.