Taux de fixation de la pointe du ventricule gauche et correction d’atténuation TEMP/TDM dans la scintigraphie myocardique de perfusion chez les patients non ischémiques

Introduction

Attenuation correction (AC) has been shown to improve the accuracy of myocardial perfusion single photon emission computed scintigraphy (SPECT). It often reveals a decrease in apical uptake in the AC of the left ventricular (LV) in non-ischemic patients. We aimed to identify the parameters that could affect the apical radiotracer uptake in non-ischemic patients.

Évaluation de l’innervation sympathique cardiaque par la scintigraphie myocardique à la 123I-métaiodobenzylguanidine

Metaiodobenzylguanidine-iode 123 (¹²³I-MIBG) myocardial scintigraphy is one of the few methods available for the objective evaluation of cardiac sympathetic function at the clinical level. Disorders of cardiac sympathetic function play an important role in a variety of heart diseases and particularly in heart failure. MIBG myocardial scintigraphy provides abundance of useful information for evaluation of severity therapeutic effects and prognosis.     

Faisabilité et précision diagnostique d’un protocole de scintigraphie myocardique synchronisée à l’ECG en deux heures : l’étude Myofast

Aim of the studyTo assess the feasibility of early stress and rest myocardial perfusion and function study using a fast 99mTc-tetrofosmin gated-SPECT protocol in patients with known coronary artery disease.Materials and methodsForty-three patients (pts) (37 M, 6 F, mean age 63.8 ± 9.8 years) underwent a 99mTc-Tetrofosmin gated-SPECT (Axis Picker-Philipps^®) myocardial study and a coronary angiography (CA) within 3 months. Images were acquired (LEHR, eight bins, 40 sec per image) after injection of 99mTc-tetrofosmin (200 to 380 MBq) early (15 min) post-stress (36 dipyridamole, two dobutamine and five ergometric stress), and at rest after 99mTc-tetrofosmin reinjection (600 to 1150 MBq), in a total time not exceeding 2 hours. Processing was performed with QGS^® software using the 17-segment model. Pathological study was defined as a summed difference score (SDS) greater than or equal to 4 4, a fixed defect with summed rest score greater than or equal to 4 and/or LV dysfunction defined as myocardial stunning (variation between stress and rest LVEF greater than or equal to 4 5%), stress LVEF less than or equal to 45% or rest LVEF less than or equal to 40%. Results were compared with CA, and stenosis greater than or equal to 4 50% was considered as significant.ResultsFor 100% the quality of SPECT imaging was good or excellent. For six patients gating was impossible because of arrhythmia. The overall sensitivity, specificity and accuracy were 95%, 50%, and 91%, respectively. The concordance between gated SPECT and CA was moderate (kappa = 0.45, SE = 0.15). Interestingly, early-gated acquisition permitted to underline left ventricular dysfunction in 11 cases (30%), of whom eight had polyvascular disease. Stunning was detected in six of 37 cases (16%), of whom six had polyvascular disease.ConclusionA one-day two-hour 99mTc-tetrofosmin gated-SPECT protocol to assess left ventricular perfusion and function is feasible and accurate. Early gated acquisition proves helpful for detecting post-stress stunning, which is a well known crucial prognostic factor of major cardiac events, and could help to speed up clinical management.     

Effets secondaires d’un stress par Régadénoson en scintigraphie myocardique chez les patients traités par Ticagrélor

IntroductionAs an anti-aggregant that has demonstrated its superiority in the management of acute coronary syndrome, Ticagrelor is an inhibitor of adenosine recapture by red blood cells. Regadenoson, an adenosine agonist, is a preferred cardiac pharmacological stress in patients with a history of spastic bronchopathy. A synergistic effect of both drugs is therefore theoretically expected if they are combined during myocardial scintigraphy. In 2015, European Association of Nuclear Medicine did not rule on the use of Regadenoson in patients previously treated with Ticagrelor. The objective of this work is to study the frequency of adverse events in these patients during Regadenoson stress.Materials and methodsWe retrospectively included patients who underwent a myocardial scintigraphy with pharmacological stress by Regadenoson between February 2016 and February 2019. We compared the frequency of expected side effects of Regadenoson in patients treated with Ticagrelor and not treated with Ticagrelor. The data were analysed using a logistic regression model including patient characteristics and side effects.ResultsSeventeen treated patients were included for 49 untreated patients. There was no significant difference in the frequency of each adverse event between treated and untreated patients. However, a higher number of side effects have been reported in treated patients than in untreated patients. No major adverse event was reported.ConclusionIn order to rule about the use of Regadenoson in patients treated with Ticagrelor, a larger study is needed to support the hypothesis of more noted minor side effects and which of them should be more encountered.     

Évaluation de la sidération myocardique post-effort immédiat par tomoscintigraphie myocardique au 99mTc-sestamibi couplée à l’ECG

AimRepeated episodes of myocardial stunning may lead to chronic ventricular dysfunction. We attempted to assess the parameters related to post-exercise stunning in patients undergoing gated SPECT.MethodsSix hundred patients undergoing a one-day stress/rest ^99mTc-sestamibi gated SPECT were studied. Stress imaging was acquired within 15 minutes after injection. Summed perfusion scores (SSS, SRS and SDS) were calculated using QPS, and LV function assessed using QGS. Stunning was defined as the association of ischemia (SSS ≥ 4 and SDS > 0) and a minimum of 5% decrease in post-stress EF.ResultsIschemia was found in 225 (37.5%) patients. Among these, 67 (30%) showed myocardial stunning. Patients with stunning had a lower rest ESV (47 ± 24 mL vs 65 ± 52 mL, p < 0.0003) and EDV (108 ± 35 mL vs 122 ± 66 mL, p = 0.03), an increased rest LVEF (58 ± 10% vs 52 ± 13%, p < 0.0001) and a decreased post-stress LVEF (49 ± 10% vs 53 ± 13%, p < 0.02) compared to patients with no stunning. The number of myocardial segments showing reversible perfusion defects was increased in patients with stunning (2.7 ± 2.6 vs 1.7 ± 2.1, p < 0.02). On logistic regression, an extent of ischemia greater than two segments and a rest EF greater than 45% were independent predictors of the occurrence of myocardial stunning in patients with ischemia.ConclusionsIn patients with ischemia, exercise-induced stunning was associated with an increased extent of ischemia but also preserved rest ventricular function.     

Apports de l’acquisition TDM couplée à la scintigraphie pulmonaire dans l’exploration d’une suspicion d’embolie pulmonaire

Pulmonary embolism is a frequent disease difficult to diagnose because of heterogeneous clinical presentation. Pulmonary embolism diagnosis requires additional examinations, which are guided by clinical probability scores. The ventilation/perfusion scintigraphy is a validated technic in pulmonary embolism diagnosis strategies, which represents one of its most important indications. In the past years, the technique of scintigraphy evolved with the appearance of hybrid cameras, allowing the realization of tomoscintigraphy coupled with computerised tomodensitometry (CT). One of the major interests of this technique is the possibility of considering alternative diagnosis in case of negative result of scintigraphy. The purpose of this article is to offer nuclear medicine physicians a review of the alternative diagnoses that can be found during pulmonary ventilation/perfusion tomoscintigraphy according to the underlying scintigraphic and morphological abnormalities. In this review, we will first on diseases responsible for: a mismatch (pathological perfusion and normal ventilation), an inverted mismatch (normal perfusion and pathological ventilation) and for associated disorders in ventilation and in perfusion patterns (identically abnormal perfusion and ventilation). The final part will address some specific CT features that can be encountered on a low dose CT centered on thorax.     

À propos d’une fixation de l’uncus du pancréas à la scintigraphie des récepteurs de la somatostatine

We report a case of increased Indium 111 pentetreotide (Octreoscan^®) uptake in the processus incinatus of pancreas. 68 Gallium somatostatin analog radiotracer uptake in the head of the pancreas is a common finding, however, this pitfall has never been described with Indium 111 pentetreotide SPECT.     

Émission de rayonnement par les œufs de Discoglosse en cours de développement

Sans résumé     

Application de la technique de PCR en temps réel à l’étude de l’ADN ancien

Real-time Polymerase Chain Reaction (PCR) for the study of ancient DNA. The properties of ancient DNA (aDNA) make difficult the retrieval of DNA sequence. The advantage of Real-Time PCR was exploited, for the first time, in the study of aDNA. We determined the optimal condition to amplify, in one round of PCR, aDNA, which should be directly sequenced. Beside the verification of aDNA authenticity, we compared two cleaning bone methods: scalpel and ethanol. The ethanol specimens showed the best DNA yield. The aDNA was extracted and amplified (mitochondrial hypervariable region I) from five skeletons exhumed from the archaeological site of Notre-Dame-du-Bourg (France), dated from 3rd to 17th century. To cite this article: R. Kefi et al., C. R. Palevol 2 (2003) 125–132.     

Étude CESAR : justification de l’assistance respiratoire extra corporelle pour les graves syndromes de détresse respiratoire de l’adulte

BackgroundSevere acute respiratory failure in adults still has a high mortality in adults despite improvements in ventilation techniques and other treatments. The evidence about the effectiveness of extracorporeal membrane oxygenation (ECMO) was equivocal.MethodNational multi-center pragmatic randomized controlled trial. 180 adults (18-65 years) with severe (Murray score > 3.0 or pH < 7.2) but potentially reversible respiratory failure were randomized to receive either continued conventional management (CM) or to be transferred to Glenfield Hospital, Leicester, UK for consideration of ECMO. Patients were excluded if they had been on high pressure (> 30 cm H₂O of peak inspiratory pressure) and/or high FiO₂ (> 0.8) ventilation for > 7 days; had signs of intra-cranial bleeding ; had any other contra-indication to limited heparinisation ; or had any contra-indication to continuation of active treatment. The primary outcome measure was death or severe disability at six months. Analysis was by intention to treat.Results766 patients were screened. 180 were randomised; 90 to the ECMO arm of whom 68 received ECMO. No cm patients received ECMO. Fewer patients in the ECMO arm than the cm arm had died or were severely disabled 6 months after randomisation, (33/90 (36.7%) vs 46/87 (52.9%) ; RR=0.69 (95%CI 0.50 to 0.97) ; p=0.030). Only one patient (in the cm arm) was known to be severely disabled at 6 months.Randomised controlled trial and economic evaluationControlled Trial of Conventional Ventilatory Support vs Extracorporeal Membrane Oxygenation for Severe Adult Respiratory Failure (CESAR) [ISRCTN47279827].     

Hyperparathyroïdie par autonomisation d’une autogreffe de parathyroïde dans l’avant-bras : le rôle de la scintigraphie

We report the case of a 36-year old patient, referred for parathyroid imaging in a context of hyperparathyroidism. He had a history of congenital bilateral renal hypoplasia treated by four successive transplantations, the last one in July 2011. In 1990, a total parathyroidectomy with autologous parathyroid tissue graft in the right forearm has been performed for secondary hyperparathyroidism. However, hypocalcaemia persisted (2.78 mmol/L), associated with high levels of PTH (1329 pg/mL), even after the last renal transplantation. Neck ultrasound and parathyroid scintigraphy images did not show any cervical or thoracic ectopic parathyroid tissue, while right forearm incidences revealed a high uptake focus corresponding to the autonomisation of the parathyroid transplanted tissue. A brief review of the literature evaluating the benefits of this type of intervention is presented.     

Diagnostic d’une ectopie parathyroïdienne par scintigraphie double traceur

IntroductionA common cause of hyperparathyroidism is the presence of an ectopic parathyroid adenoma. Its diagnostic management remains a challenge and multiple imaging tests exist.Case reportA 39-year-old patient with hyperparathyroidism. At diagnosis, ultrasound and CT were not conclusive. MIBI scintigraphy has objectified a typical parathyroid ectopia in mediastinal position. Surgical resection confirmed parathyroid adenoma allowing standardization of laboratory patient.DiscussionMIBI scintigraphy is the most efficient technique for the diagnosis of hyperparathyroidism, especially in the case of an ectopic parathyroid.     

Facteurs influençant la détectabilité de l’activité myocardique en caméra à semi-conducteurs

Body weight was already shown to be a major factor for the detectability of myocardial activity with conventional cameras and thus, for the optimization of injected activities and or recording times. This study was aimed to identify the factors affecting this detectability on a new solid-state camera showing a high sensitivity of detection (D.SPECT camera Cyclopharma^®).Patients and methodsThe study population involved 101 patients, who underwent myocardial SPECT with Sestamibi on a one-day stress/rest protocol. Each conventional acquisition (DST-XL General Electric Healthcare^® USA) was immediately followed by a D-SPECT^® one. Myocardial activity was determined on each acquisition in counts per seconds and expressed in fraction of the injected activity for assessing the detectability of myocardial activity.ResultsMyocardial activity was on average 12 ± 3 fold higher when recorded with the D-SPECT^® camera than with the DST-XL^® one. Body weight and especially body mass index (BMI) were the most significant correlates of the detectability of myocardial activity for both cameras. According to these correlations, an increase in the BMI from 25 to 35 kg/m was associated with a 47% decrease in the detectability of myocardial activity at stress with the DST-XL^® and of only 30% with the D-SPECT.ConclusionThe detectability of myocardial activity provided by the D.SPECT camera is dramatically higher than that documented for conventional cameras of the DST-XL^® type and is affected by the increase in body weight and in body mass index but at a lower rate than for the Anger camera.