RESUMEN
BACKGROUND: One of the main limitations of 99mtechnetium-dimercaptosuccinic acid (DMSA) scan is the long acquisition time. OBJECTIVE: To evaluate the feasibility of short DMSA scan acquisition times using a cadmium-zinc-telluride-based single-photon emission computed tomography (SPECT) system in children. MATERIALS AND METHODS: The data of 27 children (median age: 4 years; 16 girls) who underwent DMSA SPECT were retrospectively analyzed. Both planar and SPECT DMSA were performed. SPECT images were analyzed using coronal-simulated planar two-dimensional images. A reduction in SPECT acquisition time was simulated to provide 4 series (SPECT-15 min, SPECT-10 min, SPECT-5 min and SPECT-2.5 min). A direct comparison of the planar and SPECT series was performed, including semi-quantification reproducibility, image quality (mean quality score on a scale of 0 to 2) and inter- and intra-observer reproducibility of the scintigraphic patterns. RESULTS: The overall image quality score (± standard deviation) was 1.3 (± 0.6) for the planar data set, 1.6 (± 0.5) for the SPECT-15 min data set, 1.4 (± 0.5) for the SPECT-10 min data set, 1.0 (± 0.5) for the SPECT-5 min data set and 0.6 (± 0.6) for the SPECT-2.5 min data set. Median Kappa coefficients for inter-observer agreement between planar and SPECT images were greater than 0.83 for all series and all readers except one reader for the SPECT-2.5 min series (median Kappa coefficient = 0.77). CONCLUSION: Shortening SPECT acquisitions to 5 min is feasible with minimal impact on images in terms of quality and reproducibility.
Asunto(s)
Ácido Dimercaptosuccínico de Tecnecio Tc 99m , Tomografía Computarizada de Emisión de Fotón Único , Niño , Femenino , Humanos , Preescolar , Reproducibilidad de los Resultados , Estudios Retrospectivos , Tomografía Computarizada de Emisión de Fotón Único/métodosRESUMEN
BACKGROUND: Diagnostic and patients' management modifications induced by whole-body 18F-FDG-PET/CT had not been evaluated so far in prosthetic valve (PV) or native valve (NV) infective endocarditis (IE)-suspected patients. METHODS: In sum, 140 consecutive patients in 8 tertiary care hospitals underwent 18F-FDG-PET/CT. ESC-2015-modified Duke criteria and patients' management plan were established jointly by 2 experts before 18F-FDG-PET/CT. The same experts reestablished Duke classification and patients' management plan immediately after qualitative interpretation of 18F-FDG-PET/CT. A 6-month final Duke classification was established. RESULTS: Among the 70 PV and 70 NV patients, 34 and 46 were classified as definite IE before 18F-FDG-PET/CT. Abnormal perivalvular 18F-FDG uptake was recorded in 67.2% PV and 24.3% NV patients respectively (P < .001) and extracardiac uptake in 44.3% PV and 51.4% NV patients. IE classification was modified in 24.3% and 5.7% patients (P = .005) (net reclassification index 20% and 4.3%). Patients' managements were modified in 21.4% PV and 31.4% NV patients (P = .25). It was mainly due to perivalvular uptake in PV patients and to extra-cardiac uptake in NV patients and consisted in surgery plan modifications in 7 patients, antibiotic plan modifications in 22 patients and both in 5 patients. Altogether, 18F-FDG-PET/CT modified classification and/or care in 40% of the patients (95% confidence interval: 32-48), which was most likely to occur in those with a noncontributing echocardiography (P < .001) or IE classified as possible at baseline (P = .04), while there was no difference between NV and PV. CONCLUSIONS: Systematic 18F-FDG-PET/CT did significantly and appropriately impact diagnostic classification and/or IE management in PV and NV-IE suspected patients. CLINICAL TRIALS REGISTRATION: NCT02287792.
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Endocarditis , Prótesis Valvulares Cardíacas , Endocarditis/diagnóstico por imagen , Fluorodesoxiglucosa F18 , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones , Estudios Prospectivos , RadiofármacosRESUMEN
OBJECTIVE: Currently, the diagnosis of bone flap osteomyelitis (BFO) remains a challenge for medical imaging. The present study aimed to identify predictive scintigraphic patterns of BFO. METHODS: This retrospective study reviewed planar bone scan of patients with suspected BFO between 2010, and 2016. A total of 15 patients were included. Final diagnosis of BFO was obtained by histological and bacteriological documentation. Eight scintigraphic signs potentially helpful were reviewed and correlated with the final diagnosis individually or in combination through Fischer exact test. RESULTS: Eight patients out of 15 (53.3%) were diagnosed with BFO. Radionuclide uptake inside the bone flap during blood-pool phase was predictive for BFO (p = 0.007) with 75.0% sensitivity 100% specificity, and 86.7% accuracy. In combination, radionuclide uptake inside the bone flap or a spreading wavefront between blood-pool and delayed phases was associated with BFO (p = 0.007). It did not improve diagnostic performance. CONCLUSION: Using well-defined and reproducible scintigraphic signs, bone scan is helpful for the diagnosis of BFO.
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Osteomielitis/diagnóstico por imagen , Osteomielitis/etiología , Cráneo/diagnóstico por imagen , Cráneo/cirugía , Colgajos Quirúrgicos/efectos adversos , Craneotomía/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Osteomielitis/microbiología , Estudios RetrospectivosRESUMEN
PURPOSE: The aim of this study was to determine the minimum acquisition time without decreasing lesion detectability of bone SPECT using a whole-body cadmium-zinc-telluride camera. METHODS: Patients referred for bone SPECT were retrospectively included. SPECT of 30 patients were reframed from native data (16 s/projection) to produce 10-, 5-, and 3-s/projection data sets. A "critical" acquisition time/projection was defined as that below which the SPECT quality becomes insufficient for interpretation, as determined by 3 reviewers using a 4-point scale (0 = quality insufficient for interpretation, 1 = average, 2 = good, 3 = excellent). Three reviewers (blinded to the acquisition time) evaluated SPECT data sets (n = 79), native and reframed with "critical" acquisition times, in a randomized order. A lesion was defined as any uptake considered pathological by a reviewer. Lesion detectability equivalence between native SPECT and reframed SPECT was assessed by calculating a coefficient (κ) for each reviewer. RESULTS: Image quality of the first sample (n = 30) was significantly and progressively less well graded for the reframed data sets by all reviewers. Only 1 patient was graded 0 by each reviewer for the 5-s/projection data set. For the 3-s/projection data set, 3 patients were graded 0. No patients were graded 0 for 10-s/projection data set. The minimal acquisition time, for each projection, was defined as 5 s/projection. The coefficient κ, between native and reframed, with critical acquisition time/projection SPECT was greater than 0.9 for each reviewer. CONCLUSIONS: The more contrasted images of the cadmium-zinc-telluride camera allow performance of 5-s/projection SPECT without loss of lesion detectability. This suggests the possibility of performing whole-body SPECT in a reasonable time or reducing injected doses, especially in pediatric patients.
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Huesos/diagnóstico por imagen , Cámaras gamma/normas , Imagen de Perfusión Miocárdica/métodos , Tomografía Computarizada de Emisión de Fotón Único/métodos , Adolescente , Cadmio , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Imagen de Perfusión Miocárdica/instrumentación , Sensibilidad y Especificidad , Telurio , Tomografía Computarizada de Emisión de Fotón Único/instrumentación , ZincRESUMEN
BACKGROUND: Considering the distinctive characteristics of CZT detectors, automatic quantification of ischemia using normal limits included with software package may deliver suboptimal results for CAD detection. The present study aims to evaluate the benefits of creating normal limits specific to a local population and laboratory protocol. METHODS AND RESULTS: Two groups were selected from patients who had undergone a CZT MPI. Normal limits were generated with the QPS application based on the population with low likelihood of CAD. Using the vendor-supplied and the population-specific normal limits i-TPD and vessel-specific SDS results obtained for patients who had subsequently undergone coronary angiography were compared with coronary angiography data. A weak correlation was observed for low i-TPD (stress TPD minus rest TPD) and SDS values. Both databases gave similar values for the area under the ROC curve concerning i-TPD (0.75 to 0.74) and SDS results (0.72 to 0.75 for the LAD, 0.62 to 0.64 for the LCx, and 0.63 to 0.67 for the RCA). Sensitivity (60%), specificity (78%), and predictive positive (84%) and negative (52%) values were also similar with a diagnostic and prognostic threshold value. CONCLUSION: The use of a population-specific created database did not influence the diagnostic value of thallium-201 MPI QPS results using a CZT camera.