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Background: Relapses upon corticosteroids tapering and immunosuppressive agents are frequent in Takayasu arteritis (TA). Interleukin-6 is highly involved in physiopathology of TA. Many reports showed efficacy of tocilizumab (TCZ) in refractory TA cases. We report four cases and an updated literature review on the TCZ efficacy and safety in patients with TA., Methods: Patients with TA defined by ACR 1990 criteria were included. Clinical, biological and imaging data were retrospectively reported. Disease activity was analyzed before TCZ and during the follow-up. Medline database was searched for systematic literature review., Results: One hundred and five patients (median age 28years [22-38]) were included, mostly refractory cases (76 patients, 72%). Median TCZ duration was 12months [6-20]. Among 105 patients, 90 patients (85.7%) had an initial clinical response within three months [3-6] and 43/66 patients (65.2%) had a radiological improvement. Only seven patients (9%) showed relapse on therapy. Corticosteroid dose reduction was obtained in 75/83 patients (90.4%). Relapse after TCZ discontinuation was observed in six patients (46%), with a median time of five months [2-9]. Twenty-four side-effects were noted in 18 patients (18%), with TCZ interruption in seven cases (7%): 10 infections, five cytopenia, six hepatitis, one pancreatitis, one cutaneous rash and one breast cancer., Conclusions: This review confirms that TCZ is safe and effective in refractory cases of TA and TCZ is a corticosteroid-sparing therapy in patients with or without previous TNFα blockers therapy. However relapses after TCZ discontinuation are frequent., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Aim: To prospectively evaluate the clinical impact and the diagnostic performance of FCH-PET/CT in patients with occult biochemical recurrence of prostate cancer (PCa)., Materials and Methods: Results of 179 patients (mean PSA = 7.5ng/mL) with negative/inconclusive results of pelvic-MRI and of bone-scintigraphy were analysed. To determine the impact of FCH-PET/CT on diagnostic thinking and on patient management, the referring physicians prospectively filled-in a 1st and 2nd questionnaire related to patient's planned management before and after FCH-PET/CT. Based on data from a 6-month follow-up after FCH-PET/CT, an independent assessor blinded to results of FCH-PET/CT determined the adequacy of management changes motivated by FCH-PET/CT., Results: FCH-PET/CT localised foci evocative of recurrent PCa in 59% (105/179) of patients. Results of FCH-PET/CT motivated a change in scheduled patient management in 56% (100/179) of patients; which was considered as adequate in 89% (89/100) of patients. FCH-PET/CT also led to the detection of lung cancer in two patients., Conclusion: FCH PET/CT is a powerful tool to localise the sites of occult biochemical recurrence of PCa, leading to an adequate management change in half of patients.

Background: According to international guidelines, volume expansion with crystalloids is the first-line treatment for hemodynamic management in patients with severe sepsis or septic shock. Compared to balanced crystalloids, 0.9% sodium chloride (0.9% NaCl) induces hyperchloremia and metabolic acidosis and may alter renal hemodynamics and function. We compared the effects of 0.9% NaCl to a less chloride-concentrated fluid, PlasmaLyte ® (PL) in targeted fluid resuscitation in a randomized, double-blind controlled study in an experimental model of severe sepsis in rats., Results: A sepsis with hypotension was induced by cecal ligature and puncture (CLP) in 40 male Wistar rats (20 for each crystalloid). Rats received fluid resuscitation over a period of 200 min for a targeted mean arterial pressure of 90 mm Hg. Animals received similar volumes of 0.9% NaCl or PL. Unlike PL-resuscitated rats, 0.9% NaCl-resuscitated rats experienced hyperchloremia and metabolic acidosis, whereas systemic hemodynamics, renal hemodynamics and renal function were not significantly different between both groups., Conclusion: In our model of rats with severe sepsis resuscitated with large amounts of crystalloids, 0.9% NaCl-induced hyperchloremic acidosis, but balanced crystalloid did not improve systemic and renal hemodynamics or renal function.

Behavioural and psychological symptoms of dementia (BPSD) occur in most patients with dementia. They cause great suffering in patients and caregivers, sometimes more so than the cognitive and functional decline inherent to dementia. The clinical features of BPSD include a wide variety of affective, psychotic and behavioural symptoms and signs. The causes and risk factors for BPSD are multiple and include biological, psychological and environmental variables. Frequently, their combination, rather than any specific factor, explains the occurrence of BPSD in an individual patient. Thus, a sound etiopathogenetic investigation including the patient and the family or care team is essential. The aim is to develop an individualized treatment plan using a therapeutic decision tree modified by the individual and environmental risk profile. Still, treatment may be difficult and challenging. Clinical empiricism often steps in where evidence from controlled studies is lacking. Psychosocial treatment approaches are pivotal for successful treatment of BPSD. Often a combination of different non-pharmacological approaches precedes drug treatment (most of which is off-label). Regular assessments of the treatment plan and any prescriptions must be carried out to detect signs of relapse and to stop any medicines that may have become inappropriate. Even with optimal management, BPSD will not disappear completely in some cases and will remain challenging for all involved parties. This article is a narrative review based closely on the interprofessional Swiss recommendations for the treatment of BPSD. To establish the recommendations, a thorough research of the literature has been carried out. Evidence-based data were provided through searches of Medline, Embase, ISI and Cochrane-Database research. Evidence categories of the World Federation of Biological Societies were used. Additionally, the clinical experience of Swiss medical experts was considered., Competing Interests: Conflict of interest statement: The authors declare that there is no conflict of interest.

See an invited perspective on this article on page 1043.This multicenter phase II study investigated a selective radiotherapy dose increase to tumor areas with significant 18 F-misonidazole ( 18 F-FMISO) uptake in patients with non-small cell lung carcinoma (NSCLC). Methods: Eligible patients had locally advanced NSCLC and no contraindication to concomitant chemoradiotherapy. The 18 F-FMISO uptake on PET/CT was assessed by trained experts. If there was no uptake, 66 Gy were delivered. In 18 F-FMISO-positive patients, the contours of the hypoxic area were transferred to the radiation oncologist. It was necessary for the radiotherapy dose to be as high as possible while fulfilling dose-limiting constraints for the spinal cord and lungs. The primary endpoint was tumor response (complete response plus partial response) at 3 mo. The secondary endpoints were toxicity, disease-free survival (DFS), and overall survival at 1 y. The target sample size was set to demonstrate a response rate of 40% or more (bilateral α = 0.05, power 1-β = 0.95). Results: Seventy-nine patients were preincluded, 54 were included, and 34 were 18 F-FMISO-positive, 24 of whom received escalated doses of up to 86 Gy. The response rate at 3 mo was 31 of 54 (57%; 95% confidence interval [CI], 43%-71%) using RECIST 1.1 (17/34 responders in the 18 F-FMISO-positive group). DFS and overall survival at 1 y were 0.86 (95% CI, 0.77-0.96) and 0.63 (95% CI, 0.49-0.74), respectively. DFS was longer in the 18 F-FMISO-negative patients ( P = 0.004). The radiotherapy dose was not associated with DFS when adjusting for the 18 F-FMISO status. One toxic death (66 Gy) and 1 case of grade 4 pneumonitis (>66 Gy) were reported. Conclusion: Our approach results in a response rate of 40% or more, with acceptable toxicity. 18 F-FMISO uptake in NSCLC patients is strongly associated with poor prognosis features that could not be reversed by radiotherapy doses up to 86 Gy., (© 2017 by the Society of Nuclear Medicine and Molecular Imaging.)

Background: Although morbidity is reduced when sentinel lymph node (SLN) biopsy is performed with dual isotopic and blue dye identification, the effectiveness of adding blue dye to radioisotope remains debated because side effects including anaphylactic reactions., Patients and Methods: Using data from a prospectively maintained database, 1884 lymph node-negative breast cancer patients who underwent partial mastectomy with SLN mapping by a dual-tracer using patent blue dye (PBD) and radioisotope were retrospectively studied between January 2000 and July 2013. Patients with tumors <3 cm and with >1 node detected by one of the two techniques (N = 1024) were included in this real-life cross-sectional study., Results: Among the 1024 patients, 274 had positive SLN detected by isotopic and/or PBD staining. Only 4 patients having no detectable radioactivity in the axilla had SLN identified only by PBD staining (blue-only) while 26 patients had SLN only identified by isotopic detection (hot-only) illustrating failure rates of 9.5% (26/274) and 1.5% (4/274), respectively. Among these four patients, two had negative lymphoscintigraphy. Therefore, the contribution of PBD to metastatic nodes identification was relevant for only 2/274 patients (0.8%). Three patients (0.3%) had an allergic reaction with PBD, and anaphylactic shock occurred in two cases (0.2%)., Conclusions: The added-value of PBD to reduce the false-negative rate of SLN mapping is only limited to the rare cases in which no radioactivity is detectable in the axilla (<1%). When a radioisotope mapping agent is available, the use of PBD should be avoided, because it can induce anaphylaxis., (Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.)

Baclofen, a gamma-aminobutyric acid-B agonist with muscle-relaxant properties, is widely used in patients with severe spasticity. In animals, baclofen has been shown to decrease respiratory drive. In humans, however, use of baclofen at the standard dose did not significantly impair sleep-disordered breathing in a susceptible population of snorers. Recently, there has been increasing interest in the role of baclofen for the treatment of alcohol dependence. We describe severe central sleep apnea (CSA) in four patients with none of the conditions commonly associated with CSA who were receiving chronic baclofen therapy for alcohol withdrawal. In one patient, baclofen withdrawal was associated with a complete resolution of CSA. Three patients were treated by adaptive servo-ventilation while continuing their treatment with baclofen. Given the increasing number of patients receiving baclofen for alcohol withdrawal treatment, physicians should be aware that these patients might be affected by severe CSA. Future studies are required to determine the mechanisms, prevalence, and treatment modalities of sleep-disordered breathing associated with baclofen usage., (Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Purpose: Glioma grading is necessary for prognostic evaluation and optimal treatment decisions. The aims of this study were to establish whether a correlation between F-FDOPA uptake with tumor grade was observed and to determine which of the SUV-derived indices was the best correlated., Patients and Methods: Thirty-one patients were retrospectively included (mean [SD] age, 36.8 [12.1] years) including 21 proven low-grade tumors due to histology, imaging, and clinical follow-up and 10 histologically proven high-grade tumors. Static PET acquisitions were postreconstructed between the 10th and 30th minute after injection of F-FDOPA. Regions of interest of 20 mm were applied to tumors, and isocontoured volumes were defined at levels of 50% and 80% of the peak intensity voxel. Background was quantified with 30-mm-diameter regions of interest on contralateral striatum and centrum semioval. Tumoral uptake was evaluated with the following SUV-derived indices: SUVmax, SUVmean, SUVmax, and SUVmean of isocontoured volume, tumor/striatum ratio (T/S), and tumor/normal brain ratio (T/N)., Results: All the SUV-derived indices tested were significantly correlated with tumor grade, considering low-grade and high-grade groups (P < 0.05), except for the SUVmean 50%. The 2 best-correlated indices were SUVmean T/N and SUVmean T/S, with correlation coefficients of 0.561 and 0.522, respectively. Receiver operating characteristic analysis defined optimal thresholds of 1.33 and 1 for sensitivity and specificity of 71% and 100% and 67% and 100%, respectively., Conclusions: F-FDOPA PET SUV-derived indices are routinely available information that enables accurate discrimination of low-grade and high-grade gliomas. The best-correlated indices were SUVmean T/N and SUVmean T/S with thresholds of 1.33 and 1.

Purpose: Timely identification of septic foci is critical in patients with severe sepsis or septic shock of unknown origin. This prospective pilot study aimed to assess (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET), combined with whole-body computed tomographic angiography (CTA), in patients with suspected severe sepsis and for whom the prior diagnostic workup had been inconclusive., Methods: Patients hospitalized in an intensive care unit with a suspected severe sepsis but no definite diagnosis after 48 h of extensive investigations were prospectively included and referred for a whole body FDG-PET/CTA. Results from FDG-PET/CTA were assessed according to the final diagnosis obtained after follow-up and additional diagnostic workup., Results: Seventeen patients were prospectively included, all on mechanical ventilation and 14 under vasopressor drugs. The FDG-PET/CTA exam 1) was responsible for only one desaturation and one hypotension, both quickly reversible under treatment; 2) led to suspect 16 infectious sites among which 13 (81 %) could be confirmed by further diagnostic procedures; and 3) triggered beneficial changes in the medical management of 12 of the 17 study patients (71 %). The FDG-PET/CTA images showed a single or predominant infectious focus in two cases where CTA was negative and in three cases where CTA exhibited multiple possible foci., Conclusion: Whole-body FDG-PET/CTA appears to be feasible, relatively safe, and provides reliable and useful information, when prospectively planned in patients with suspected severe sepsis and for whom prior diagnostic workup had been inconclusive. The FDG-PET images are particularly helpful when CTA exhibits no or multiple possible sites.

Objective: Bilateral surgery has been largely advocated in premature boys with unilateral inguinal hernia owing to the high incidence of contralateral patent processus vaginalis. Recently, the potential morbidity of herniotomy in low birth-weight babies and the progress in pediatric anesthesia questioned this attitude. This study aims to evaluate the incidence of contralateral metachronous hernia in a large series of premature boys and to compare the morbidity of preventive versus elective surgery., Methods: This retrospective multicenter analysis of 964 premature boys presenting with unilateral inguinal hernia operated from 1998 to 2012 included 557 infants who benefited from a unilateral herniotomy and 407 from a bilateral herniotomy (median follow-up 12months)., Results: Contralateral metachronous hernia after unilateral surgery occurred in 11% (n=60) without significant difference according to the initial symptomatic side (9.5% on right vs 13% on left, p>0.05). Postoperative morbidity on the contralateral side was higher after preventive surgery than elective surgery with metachronous hernia (2.45% versus 0.9%, p=0.05) especially for secondary cryptorchidism (1% vs 0%, p=0.03). Despite the risk of metachronous incarcerated hernia, elective surgery did not increase the rate of testicular hypotrophy on the opposite side (0.7%, vs 0.7%, p>0.05)., Conclusion: Systematic bilateral herniotomy is unnecessary in almost 90% of patients and has a significant morbidity. Secondary surgery for metachronous hernia does not increase the risk of testicular lesion and even reduces the risk of secondary cryptorchidism. These results, along with the risk of hypofertility reported after bilateral surgery, may justify treating only the symptomatic side in premature boys., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Purpose: Combined-modality treatment is standard treatment for patients with clinical stage I/II Hodgkin lymphoma (HL). We hypothesized that an early positron emission tomography (PET) scan could be used to adapt treatment. Therefore, we started the randomized EORTC/LYSA/FIL Intergroup H10 trial evaluating whether involved-node radiotherapy (IN-RT) could be omitted without compromising progression-free survival in patients attaining a negative early PET scan after two cycles of ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) as compared with standard combined-modality treatment., Patients and Methods: Patients age 15 to 70 years with untreated clinical stage I/II HL were eligible. Here we report the clinical outcome of the preplanned interim futility analysis scheduled to occur after documentation of 34 events in the early PET-negative group. Because testing for futility in this noninferiority trial corresponds to testing the hypothesis of no difference, a one-sided superiority test was conducted., Results: The analysis included 1,137 patients. In the favorable subgroup, 85.8% had a negative early PET scan (standard arm, one event v experimental arm, nine events). In the unfavorable subgroup, 74.8% had a negative early PET scan (standard arm, seven events v experimental arm, 16 events). The independent data monitoring committee concluded it was unlikely that we would show noninferiority in the final results for the experimental arm and advised stopping random assignment for early PET-negative patients., Conclusion: On the basis of this analysis, combined-modality treatment resulted in fewer early progressions in clinical stage I/II HL, although early outcome was excellent in both arms. The final analysis will reveal whether this finding is maintained over time.

In daily clinical practice, the esophageal squamous cell cancer (ESCC) is considered to be more (18)F-FDG avid than adenocarcinoma (EAD). To date, the few studies concerning the existence of a real metabolic difference based on esophageal cancer (EC) histology, show divergent and not definitive results. A retrospective analysis of (18)F-FDG PET/CT of 87 patients with ESCC and EAD was performed to investigate the role played by both histopathological subtype and tumor differentiation in the characterization of glucose metabolic profile of EC. Esophageal squamous cell cancer was well differentiated (WD) in 42 cases and poorly differentiated (PD) in 12 patients. Twenty-one of the 33 patients had WD EAD, while 12 had a PD EAD. The (18)F-FDG maximal standardized uptake value (SUV(max)) was determined for all lesions and used for inter and intra-group comparison. In ESCC, the SUV(max) ranged from 4 to 31 with a mean value of 16±6. In EAD, the SUV(max) ranged from 2 to 25 with a mean value of 10±6. A statistically significant difference (P<0.0001) was found between ESCC and EAD. According to histological classification and tumor differentiation, we obtained the following results: a) the SUV(max) values of WD ESCC and WD EAD were 17±5 (range: 7-31) and 7±3 (range: 2-12) respectively (P<0.00001), b) the SUV(max) values of PD ESCC and PD EAD were 11±4 (range: 4-19) and 17±6 (range: 7-25) respectively (P<0.05). Moreover, a statistically significant difference of SUV(max) values was found between WD and PD ESCC (P<0.005) as well as between WD and PD differentiated EAD (P<0.0001). In order to predict tumor histology (ESCC, EAD) from both SUV(max) and lesion location, a multivariate discriminant analysis was performed on the whole population with a resulting diagnostic accuracy equal to 82% (P<0.00001). In conclusion, we provide additional arguments about (18)F-FDG uptake difference between ESCC and EAD as well as between poorly and well-differentiated forms of both EC histological subtypes.

To delineate and compare the isokinetic neck strength profile of senior elite rugby players. One hundred and eighty-nine rugby players (mean; 95% confidence intervals: 24.31; 23.87-24.75 years) were sampled from South African provincial teams and assessed anthropometrically and isokinetically according to a set protocol. Specially designed equipment was used to perform the isokinetic assessment and gathered data were analysed according to positional categories (front, second, back row and backline players). Second row forwards performed the best in the measure of peak flexion (44.04; 40.41-47.67Nm) and lateral flexion right (69.42; 63.36-75.48Nm) and left (66.31; 61.21-71.41Nm) torque, while the front row forwards performed best in peak extension torque (65.60; 62.12-69.08Nm). Few significant differences (p<0.05) existed between the forward positional categories. However, they all proved to be significantly (p<0.05) stronger and more powerful than the backline players. Peak torque values relative to body weight indicated much less variability between all positional categories. Cervical flexor to extensor ratios showed that front row forwards (65; 61.94-68.06%) had significantly (p<0.05) lower ratios than the other positional categories. Absolute peak torque is an important positional prerequisite, especially among the front row forwards. Isokinetic neck strength data presented here provides a benchmark for the effective and quantified comparison of neck strength variables, assisting with preparticipation screening and the effective rehabilitation of injured senior rugby union players.

Unlabelled: Gated SPECT recorded with 16 intervals determines left ventricular (LV) ejection fraction more accurately than does gated SPECT recorded with 8 intervals but produces higher image noise. This study aimed to assess the results from sestamibi and (201)Tl 16-interval gated SPECT when both signal-to-noise ratio and spatial resolution were enhanced with an original method of reconstruction., Methods: Forty patients with coronary artery disease underwent (201)Tl and sestamibi 16-interval gated SPECT and, to be used as a reference, cardiac MRI. Assessments of global and regional LV function provided by ordered-subsets expectation maximization (OSEM) with depth-dependant resolution recovery and temporal Fourier filtering were compared with those from conventional filtered backprojection (FBP) previously optimized by screening various filter frequencies and various temporal smoothing levels., Results: For both tracers, LV ejection fraction was determined best when the association of OSEM with depth-dependant resolution recovery was used alone, with temporal Fourier filtering, or with a slight 2-frame temporal smoothing: Mean absolute values of relative errors ranged from 3.2% to 3.6% (4.0%-7.9% for FBP), and coefficient correlation ranged from 0.91 to 0.93 (0.70-0.91 for FBP). Among these 3 reconstruction methods, the association of OSEM with depth-dependant resolution recovery with temporal Fourier filtering provided the highest signal-to-noise ratio, with mean increases of 54% for sestamibi and 80% for (201)Tl when compared with FBP, and the best analysis of segmental contractility, with exact agreement rates with MRI being 73% for (201)Tl and 79% for sestamibi., Conclusion: OSEM associated with temporal Fourier filtering and depth-dependant resolution recovery filtering enhances the LV function assessment provided by sestamibi and (201)Tl 16-interval gated SPECT and dramatically reduces image noise, a property that enhances and facilitates image interpretation.

Background: Patient displacements and errors in R-wave detection are the main causes of inaccurate acquisition for gated single photon emission computed tomography (SPECT) and equilibrium radionuclide angiography (RNA). This study aimed to compare the influences of both factors between gated SPECT and RNA determinations of left ventricular ejection fraction., Methods and Results: On gated SPECT and RNA acquisitions, recorded in 20 patients with coronary artery disease, we simulated the consequences of (1) 3-dimensional patient displacements of low (6.7 mm), moderate (13.4 mm), and high amplitude (20.1 mm) and (2) an erroneous triggering on T waves in 10% to 40% of recorded beats. Absolute values of left ventricular ejection fraction changes from baseline were higher with gated SPECT compared with RNA for patient displacements of low amplitude (5.0% +/- 3.8% vs 1.2% +/- 0.9%, P < .001) or moderate amplitude (10.0% +/- 6.2% vs 3.0% +/- 2.3%, P = .001) but not for patient displacements of high amplitude (12% +/- 9% vs 9% +/- 7%, P = not significant) and inaccurate triggering (for 20% T-wave triggering, 8.9% +/- 3.6% vs 7.9% +/- 3.0%; P = not significant)., Conclusion: Contrary to RNA, gated SPECT is vulnerable to small patient displacements, and thus, specific efforts might be useful for limiting this potential cause of erroneous results. Both techniques may be affected by low rates of triggering errors, suggesting that small acceptance windows on cycle length should be recommended not only for RNA but also for gated SPECT.

The aim of this study was to determine the contribution of the technique of sentinel lymph node (SLN) biopsy by preoperative lymphoscintigraphy and patent blue injection in management of primary cutaneous melanoma (MM). Sixty three patients with stade I primary MM were operated between March 1999 and January 2003. Preoperative lymphoscintigraphy was performed the day before surgery and peroperative patent blue injection was used to identify SLN. All hot and/or blue lymph nodes were removed and examinated in standard histology and immunohistochemistry. The population was 31 men and 32 women. The MM were distributed between upper extremities (9), lower extremities (24), trunk (19) and head and neck (11). A SLN was identified in 98%. Aberrant drainages were found in 13%. The average number of SLNs removed was 3.6 [0-15]. Fourteen patients (22%) had SLN positive for malignant disease, with micrometastasis in nine cases. The sentinel node was false-negative in 12.5% with a medial follow-up of 14 months. In conclusion, preoperative lymphatic mapping combined used of peroperative detection by a hand-held gamma probe and patent blue injection is a feasible technique to specify the first drainage of MM., (Copyright John Libbey Eurotext 2003.)

Objectives: This study aimed to specifically analyse the impact of low-flow ischaemia on the ability of myocytes to trap and accumulate Tl and sestamibi (MIBI) within myocardial tissue., Methods: In order to reach steady-state conditions for the interstitial/cellular concentration ratios (Ci/Cc) of the tracers and thereby simulate the conditions of cell cultures studies, Tl and MIBI were injected continuously during an 80 min period within the coronary circulation of isolated hearts submitted to normoxia (n=7) or low-flow ischaemia (n=7; >50% reduction in coronary flow). Ci was determined by using interstitial microdialysis and Cc was determined from Ci and myocardial retention values of the tracers., Results: At the end of the experiments, under steady-state conditions, Ci/Cc was equivalent between low-flow ischaemia and normoxia for both Tl (ischaemia, 0.60 +/- 0.25% vs normoxia, 0.63 +/-0.34%; NS) and MIBI (ischaemia, 1.00 +/- 0.68% vs normoxia, 0.76 +/- 0.32%, NS), whereas tissue concentrations of ATP were more than 4-fold lower in ischaemia than in normoxia (5.1 +/- 3.5 nmol.g vs 22.5 +/- 4.8 nmol.g; P< 0.001)., Conclusions: In contrast to the published results concerning the effects of anoxia on cell cultures, low-flow ischaemia within myocardial tissue has no deleterious effects on the ability of the cells to accumulate Tl and MIBI under steady-state conditions. This gives definitive evidence of the negligible impact of cellular metabolic disorders in the decrease in Tl or MIBI uptake, which is documented by stress-SPECT within low-flow ischaemic myocardium.

Unlabelled: This study was aimed at determining whether the (201)Tl SPECT abnormalities documented in patients with dilated cardiomyopathy are related to a local excess in wall stress, which might act against the diastolic perfusion of myocardium., Methods: We included 6 healthy volunteers and 7 patients with idiopathic dilated cardiomyopathy who underwent (201)Tl SPECT at rest. On a 13-segment division of the left ventricle, indices of wall stress and tension were calculated at end-diastole by applying Laplace's law, with thickness and curvature radii being determined for each segment on 2 orthogonal MRI slices., Results: Among all patients, 21 analyzed segments had (201)Tl SPECT defects (D+) and 67 had none (D-). Myocardial thickness was lower in D+ (0.88 +/- 0.30 cm) than in D- (1.23 +/- 0.33 cm, P = 0.0002) or in segments from healthy volunteers (0.99 +/- 0.15 cm, P = 0.04). The index of end-diastolic wall tension was also lower in D+ (2.5 +/- 1.0 N.m(-1).mm Hg(-1)) than in D- (3.3 +/- 1.1 N.m(-1).mm Hg(-1), P = 0.02) or in segments from healthy volunteers (3.2 +/- 1.2 .m(-1).mm Hg(-1)) P = 0.04). Last, the index of end-diastolic wall stress, determined by the ratio of wall tension index to myocardial thickness, was equivalent in D+, in D-, and in segments from healthy volunteers (respectively, 3.0 +/- 1.4, 2.8 +/- 1.2, and 3.2 +/- 1.6 hN.m(-2).mm Hg(-1))., Conclusion: In patients with dilated cardiomyopathy, the abnormalities documented by (201)Tl SPECT at rest are related to a lower than normal wall thickness and not to an excess in wall stress or tension. Therefore, partial-volume effects are likely to induce these abnormalities, and they may be unrelated to any insufficiency of myocardial perfusion.

Unlabelled: It is not known whether cellular metabolic disorders play a role in the decreased tracer uptake that is documented by conventional SPECT during low-flow ischemia or stunning. This study sought to determine the impact of low-flow ischemia and stunning on the kinetics of (201)Tl and MIBI across the plasma membrane of myocytes., Methods: The global myocardial retention (Rf) of (201)Tl and MIBI was determined in isolated working hearts from rabbits, perfused with red blood cell-enhanced solution. Experiments were performed in normoxia, with physiological values of coronary flow (N; n = 16); in low-flow ischemia, with a >50% reduction of coronary flow and a > or =20-mm Hg fall in systolic left ventricle pressure (L; n = 15); and in stunning, with 15 min of acute ischemia followed by reperfusion (S; n = 15). Concentration ratios across the plasma membrane of myocytes were also determined for both tracers and expressed as Ci/Cc, where Ci is interstitial activity determined with microdialysis, and Cc is activity from cellular space determined from Rf and Ci values., Results: There was a slight increase in average values of Ci/Cc in ischemia, but not in stunning, for (201)Tl (L, 0.011 +/- 0.006 vs. N, 0.006 +/- 0.004 [P < 0.05]; S, 0.007 +/- 0.004 vs. N [not significant]) and for MIBI (L, 0.011 +/- 0.008 vs. N, 0.005 +/- 0.004 [P < 0.05]; S, 0.005 +/- 0.003 vs. N [not significant]). Moreover, ischemia and stunning had no deleterious effects on the average values of global myocardial retention for (201)Tl (L, 0.63 +/- 0.09 vs. N, 0.50 +/- 0.14 [P < 0.05]; S, 0.59 +/- 0.10 vs. N [P < 0.05]) or for MIBI (L, 0.45 +/- 0.10 vs. N, 0.31 +/- 0.09 [P < 0.05]; S, 0.41 +/- 0.12 vs. N [P < 0.05]). In fact, these values were significantly enhanced in the 2 situations., Conclusion: The kinetics of (201)Tl and MIBI across the plasma membrane of myocytes were affected only poorly by low-flow ischemia and not at all by stunning, without any deleterious effects on myocardial retention of both tracers. During low-flow ischemia or stunning, therefore, the information provided by (201)Tl or MIBI SPECT is expected to depend on myocardial perfusion but not on cellular metabolic disorders.