Technical Note: Impact of impurities on Yttrium-90 glass microsphere activity quantitation.

BACKGROUND: Glass 90 Y microspheres are produced with known radionuclide impurities. These impurities are not independently monitored. Clinical instruments, including ionization chamber dose calibrators and positron emmission tomography (PET) cameras, can be much more sensitive in detecting signals from these impurities than to signals from 90 Y itself. PURPOSE: The "typical" levels of 90 Y impurities have been studied to assess their impact on dosimetry during internal implantation, and for the management of waste. However, unaccounted-for decay spectra of impurities can also have an impact on dose calibrator and PET readings. Thus, even what might be considered negligibly small impurity fractions, can in principle cause substantial overestimates of the amount of 90 Y activity present in a sample. To our knowledge, quantitative effects of radionuclide impurities in glass microspheres on activity measurements have not been documented in the field. As activity quantitation for dosimetry and its correlations with outcome becomes more prevalent, the effects of impurities on measurements may remain unaccounted for in dosimetry studies. METHODS: In this letter, we review theoretical and physical considerations that will result in asymmetric errors in quantitation from 90 Y impurities and estimate their typical and potential impact on clinical utilization. Among the common impurities 88 Y is of particular concern for its impact on 90 Y dose measurements because of its decay characteristics, along with other isotopes 91 Y and 46 Sc which can also impact measurements. RESULTS: The typical level of 88 Y impurities reported by the manufacturer should only cause small errors in dose calibrator and PET measurements made within the 12-day label-specified use-by period, up to 2.0% and 1.6%, respectively. However, the product specification max allowable impurity levels, specified by the manufacturer, leave open the potential for much greater bias from within the 12-day use-by period, potentially as high as 13.2% for dose calibrator measurements and 10.6% for PET from the 88 Y impurities. CONCLUSIONS: While typical levels of impurities appear to have acceptable impact on patient absorbed dose, it should be noted that they can have adverse effects on 90 Y radioactivity measurements. Furthermore, there is currently minimal independent verification and/or monitoring of impurity levels within the field.

Impact of Positron Emission Tomography Viability Imaging: Guided Revascularizations on Clinical Outcomes in Patients With Myocardial Scar on Single-Photon Emission Computed Tomography Scans.

BACKGROUND: Positron emission tomography (PET) viability scan is used to determine whether patients with a myocardial scar on single-photon emission computed tomography (SPECT) may need revascularization. However, the clinical utility of revascularization decision-making guided by PET viability imaging has not been proven yet. The purpose of this study was to investigate the impact of PET to determine revascularization on clinical outcomes. METHODS: Between September 2012 and May 2021, 53 patients (37 males; mean age = 64 ± 11 years) with a myocardial scar on MIBI SPECT who underwent PET viability test were analyzed in this study. The primary outcome was a temporal change in echocardiographic findings. The secondary outcome was all-cause mortality. RESULTS: Viable myocardium was presented by PET imaging in 29 (54.7%) patients. Revascularization was performed in 26 (49.1%) patients, including 18 (34.0%) with percutaneous coronary intervention (PCI) and 8 (15.1%) with coronary artery bypass grafting. There were significant improvements in echocardiographic findings in the revascularization group and the viable myocardium group. All-cause mortality was significantly lower in the revascularization group than in the medical therapy-alone group (19.2% vs. 44.4%, log-rank P = 0.002) irrespective of viable (21.4% vs. 46.7%, log-rank P = 0.025) or non-viable myocardium (16.7% vs. 41.7%, log-rank P = 0.046). All-cause mortality was significantly lower in the PCI group than in the medical therapy-alone group (11.1% vs. 44.4%, log-rank P < 0.001). CONCLUSION: Revascularization improved left ventricular systolic function and survival of patients with a myocardial scar on SPECT scans, irrespective of myocardial viability on PET scans.

Extracranial-Intracranial Bypass and Risk of Stroke and Death in Patients With Symptomatic Artery Occlusion: The CMOSS Randomized Clinical Trial.

Importance: Prior trials of extracranial-intracranial (EC-IC) bypass surgery showed no benefit for stroke prevention in patients with atherosclerotic occlusion of the internal carotid artery (ICA) or middle cerebral artery (MCA), but there have been subsequent improvements in surgical techniques and patient selection. Objective: To evaluate EC-IC bypass surgery in symptomatic patients with atherosclerotic occlusion of the ICA or MCA, using refined patient and operator selection. Design, Setting, and Participants: This was a randomized, open-label, outcome assessor-blinded trial conducted at 13 centers in China. A total of 324 patients with ICA or MCA occlusion with transient ischemic attack or nondisabling ischemic stroke attributed to hemodynamic insufficiency based on computed tomography perfusion imaging were recruited between June 2013 and March 2018 (final follow-up: March 18, 2020). Interventions: EC-IC bypass surgery plus medical therapy (surgical group; n = 161) or medical therapy alone (medical group; n = 163). Medical therapy included antiplatelet therapy and stroke risk factor control. Main Outcomes and Measures: The primary outcome was a composite of stroke or death within 30 days or ipsilateral ischemic stroke beyond 30 days through 2 years after randomization. There were 9 secondary outcomes, including any stroke or death within 2 years and fatal stroke within 2 years. Results: Among 330 patients who were enrolled, 324 patients were confirmed eligible (median age, 52.7 years; 257 men [79.3%]) and 309 (95.4%) completed the trial. For the surgical group vs medical group, no significant difference was found for the composite primary outcome (8.6% [13/151] vs 12.3% [19/155]; incidence difference, -3.6% [95% CI, -10.1% to 2.9%]; hazard ratio [HR], 0.71 [95% CI, 0.33-1.54]; P = .39). The 30-day risk of stroke or death was 6.2% (10/161) in the surgical group and 1.8% (3/163) in the medical group, and the risk of ipsilateral ischemic stroke beyond 30 days through 2 years was 2.0% (3/151) and 10.3% (16/155), respectively. Of the 9 prespecified secondary end points, none showed a significant difference including any stroke or death within 2 years (9.9% [15/152] vs 15.3% [24/157]; incidence difference, -5.4% [95% CI, -12.5% to 1.7%]; HR, 0.69 [95% CI, 0.34-1.39]; P = .30) and fatal stroke within 2 years (2.0% [3/150] vs 0% [0/153]; incidence difference, 1.9% [95% CI, -0.2% to 4.0%]; P = .08). Conclusions and Relevance: Among patients with symptomatic ICA or MCA occlusion and hemodynamic insufficiency, the addition of bypass surgery to medical therapy did not significantly change the risk of the composite outcome of stroke or death within 30 days or ipsilateral ischemic stroke beyond 30 days through 2 years. Trial Registration: ClinicalTrials.gov Identifier: NCT01758614.

Prognostic value of myocardial perfusion imaging by cadmium zinc telluride single-photon emission computed tomography in patients with suspected or known coronary artery disease: a systematic review and meta-analysis.

BACKGROUND: Aim of this study was to define the prognostic value of stress myocardial perfusion imaging by cadmium zinc telluride (CZT) single-photon emission computed tomography (SPECT) for prediction of adverse cardiovascular events in patients with known or suspected coronary artery disease (CAD). METHODS AND RESULTS: Studies published until November 2022 were identified by database search. We included studies using stress myocardial perfusion imaging by CZT-SPECT to evaluate subjects with known or suspected CAD and providing primary data of adverse cardiovascular events. Total of 12 studies were finally included recruiting 36,415 patients. Pooled hazard ratio (HR) for the occurrence of adverse events was 2.17 (95% confidence interval, CI, 1.78-2.65) and heterogeneity was 66.1% (P = 0.001). Five studies reported data on adjusted HR for the occurrence of adverse events. Pooled HR was 1.69 (95% CI, 1.44-1.98) and heterogeneity was 44.9% (P = 0.123). Seven studies reported data on unadjusted HR for the occurrence of adverse events. Pooled HR was 2.72 (95% CI, 2.00-3.70). Nine studies reported data useful to calculate separately the incidence rate of adverse events in patients with abnormal and normal myocardial perfusion. Pooled incidence rate ratio was 2.38 (95% CI, 1.39-4.06) and heterogeneity was 84.6% (P < 0.001). The funnel plot showed no evidence of asymmetry (P = 0.517). At meta-regression analysis, we found an association between HR for adverse events and presence of angina symptoms and family history of CAD. CONCLUSIONS: Stress myocardial perfusion imaging by CZT-SPECT is a valuable noninvasive prognostic indicator for adverse cardiovascular events in patients with known or suspected CAD.

The role of single positron emission computed tomography imaging in the diagnosis of brain death whenever Trans-cranial Doppler fails to support it: A retrospective cohort study.

OBJECTIVE: Although there is widespread acceptance of the concept of brain death/death by neurologic criteria (BD/DNC), there is marked variability in the use of ancillary tests worldwide. Transcranial Doppler (TCD) is a useful ancillary test for brain death confirmation because it is safe, noninvasive, and done at the bedside. However, it is considered less sensitive than Single Photon Emission Computed Tomography (SPECT) Tc-HMPAO (99 m). This study aims to test the yield of brain perfusion SPECT testing after a TCD has demonstrated some level of intracranial blood flow among patients fulfilling clinical criteria for BD/DNC. METHODS: This was a single-center retrospective cohort study of all the patients fulfilling clinical criteria for BD/DNC who underwent brain perfusion SPECT after an intracerebral circulatory arrest was not confirmed by TCD between July 2016 and January 2022. RESULTS: TCD was an initial ancillary test performed in 252 patients (99.6%) fulfilling clinical criteria for BD/DNC. A complete circulatory arrest was demonstrated in 228 (90.5%) patients. Brain perfusion SPECT was performed in the remaining 24 patients. The absence of cerebral perfusion consistent with BD/DNC was found in 21 cases (87.5%). BD/DN could not be confirmed in three patients (12.5%). CONCLUSIONS: SPECT testing has a high diagnostic yield when TCD fails to confirm a suspected diagnosis of BD/DNC. Combining these two modalities may be an optimal strategy for BD/DNC diagnosis when this is required by local regulations or when confounding factors interfere with the performance of a complete clinical assessment.

La atrofia cerebral como hallazgo o factor predictor del deterioro cognitivo en el envejecimiento normal / Cerebral Atrophy as a Finding of Predictive Factor for Cognitive Impairment in Normal Aging

Introducción: En el curso del envejecimiento es conocida la existencia de un patrón complejo de cambios estructurales cerebrales, conductuales y cognitivos, en ocasiones relacionados con enfermedades neurológicas y psiquiátricas. Objetivo: Determinar la posible relación de causalidad de la atrofia cerebral en la aparición del deterioro cognitivo en el curso del envejecimiento normal. Métodos: Se desarrolló un estudio retrospectivo, transversal, descriptivo y observacional. El universo estuvo conformado por el total de los pacientes de ambos sexos con edades comprendidas entre 35-74 años de edad, con indicaciones previas de tomografía computarizada de cráneo y cuyos resultados fueron informados con signos de atrofia cerebral, cuya cifra ascendió a 733. Resultados: El grupo de edad que predomino fue el de 45-54 años (35,3 por ciento), así como las pacientes del sexo femenino (66,3 por ciento). El 27,7 por ciento tenía como nivel de escolaridad el técnico medio superior y 36,2 por ciento fueron pacientes amas de casa. El 99,7 por ciento fueron diestros. Un total de 368 voluntarios presentaron deterioro cognitivo y 365 sujetos no evidenciaron declive en las funciones exploradas. Las funciones de atención y cálculo y retención verbal a corto plazo fueron las que se vieron más afectadas, seguidas de orientación espacial y memoria verbal de fijación. Conclusiones: No se logró establecer una relación de causalidad significativa entre el diagnóstico radiológico de atrofia cerebral y la presencia de deterioro cognitivo(AU)

Introduction: In the course of aging, the existence of a complex pattern of behavioral, cognitive and cerebral structural changes is known, sometimes related to neurological and psychiatric diseases. Objective: To determine the possible causal relationship of cerebral atrophy with the onset of cognitive impairment in the course of normal aging. Methods: A retrospective, cross-sectional, descriptive and observational study was carried out. The study universe consisted of all patients of both sexes aged 35-74 years, with previous indications for cranial computed tomography and whose results were reported with signs of cerebral atrophy, which numbered 733. Results: The predominant age group was 45-54 years old (35.3percent), as well as female patients (66.3percent). The educational level of 27.7percent of the patients was technical high school and 36.2percent were housewife patients. A total of 99.7percent were right-handed. A total of 368 volunteers showed cognitive impairment and 365 subjects showed no decline in the tested functions. The functions of attention and calculation, as well as short-term verbal retention, were the most affected, followed by spatial orientation and speech retention memory. Conclusions: No significant causal relationship was established between the radiological diagnosis of cerebral atrophy and the presence of cognitive impairment(AU)

Artificial Intelligence-based CT Assessment of Bronchiectasis: The COPDGene Study.

Background CT is the standard method used to assess bronchiectasis. A higher airway-to-artery diameter ratio (AAR) is typically used to identify enlarged bronchi and bronchiectasis; however, current imaging methods are limited in assessing the extent of this metric in CT scans. Purpose To determine the extent of AARs using an artificial intelligence-based chest CT and assess the association of AARs with exacerbations over time. Materials and Methods In a secondary analysis of ever-smokers from the prospective, observational, multicenter COPDGene study, AARs were quantified using an artificial intelligence tool. The percentage of airways with AAR greater than 1 (a measure of airway dilatation) in each participant on chest CT scans was determined. Pulmonary exacerbations were prospectively determined through biannual follow-up (from July 2009 to September 2021). Multivariable zero-inflated regression models were used to assess the association between the percentage of airways with AAR greater than 1 and the total number of pulmonary exacerbations over follow-up. Covariates included demographics, lung function, and conventional CT parameters. Results Among 4192 participants (median age, 59 years; IQR, 52-67 years; 1878 men [45%]), 1834 had chronic obstructive pulmonary disease (COPD). During a 10-year follow-up and in adjusted models, the percentage of airways with AARs greater than 1 (quartile 4 vs 1) was associated with a higher total number of exacerbations (risk ratio [RR], 1.08; 95% CI: 1.02, 1.15; P = .01). In participants meeting clinical and imaging criteria of bronchiectasis (ie, clinical manifestations with ≥3% of AARs >1) versus those who did not, the RR was 1.37 (95% CI: 1.31, 1.43; P < .001). Among participants with COPD, the corresponding RRs were 1.10 (95% CI: 1.02, 1.18; P = .02) and 1.32 (95% CI: 1.26, 1.39; P < .001), respectively. Conclusion In ever-smokers with chronic obstructive pulmonary disease, artificial intelligence-based CT measures of bronchiectasis were associated with more exacerbations over time. Clinical trial registration no. NCT00608764 © RSNA, 2022 Supplemental material is available for this article. See also the editorial by Schiebler and Seo in this issue.

British Nuclear Medicine Society Clinical Guideline for bone scintigraphy.

This guideline must be read in conjunction with the British Nuclear Medicine Society (BNMS) Generic guidelines. The purpose of this guideline is to assist specialists in Nuclear Medicine and Radionuclide Radiology in recommending, performing, interpreting and reporting the results of bone scintigraphy studies. This guideline could also be used to help individual departments formulate their own local protocols. This does not aim to be prescriptive regarding technical aspects of individual camera acquisitions, which should be developed in conjunction with the local medical physics expert.

Espina selar, una causa posible de pubertad precoz central / Sellar spine, a possible cause of central precocious puberty

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Além da angiografia. Integrando fisiologia e imagem para tomada de decisão em cenário clínico complexo / In addition to angiography. Integrating physiology and imaging for decision making in a complex clinical setting

Apresentação Clínica • Paciente masculino, 59 anos; • Servente de obras; • Antecedentes: HAS, ex-tabagismo, • Fevereiro de 2021: SCASSST ­ atendido em serviço externo; • Optado por estratificação não invasiva. • Câncer de próstata em programação cirúrgica

Nefrotoxicidad y hematotoxicidad un año después de cuatro ciclos de terapia con péptidos marcados con radionúclidos (PRRT) y su impacto en la planificación del tratamiento futuro. Un análisis retrospectivo / Nephrotoxicity and hematotoxicity one year after four cycles of peptide receptor radionuclide therapy (PRRT) and its impact on future treatment planning. A retrospective analysis

Introducción: La nefrotoxicidad y la hematotoxicidad después de la terapia con péptidos marcados con radionúclidos (PRRT) se han descrito en múltiples estudios usando diferentes actividades acumulativas, número de ciclos o péptidos marcados con radionúclidos. Aunque los tumores neuroendocrinos (NET) altamente diferenciados con metástasis tienen una larga supervivencia libre de progresión, pueden progresar. Analizamos los efectos secundarios a largo plazo en un esquema de tratamiento homogéneo en pacientes con PRRT y su impacto en el futuro tratamiento oncológico en caso de progresión. Métodos: De nuestra base de datos se analizaron 89 de 384 pacientes que recibieron la misma PRRT (Lu-177-DOTATATE o Y-90-DOTATOC) cuatro veces cada 10 a 12 semanas y un seguimiento a los 12 meses. Un paciente recibió tres y 11 pacientes recibieron dos veces cuatro ciclos de PRRT, lo que dio lugar a 102 casos. Se compararon el índice de filtrado glomerular estimado (FGe), la Hb, los glóbulos blancos y las plaquetas antes del primer ciclo de terapia y un año después del cuarto ciclo. La clasificación del FGe se realizó según la clasificación de la enfermedad renal crónica (ERC) y la clasificación de la hematotoxicidad según los Criterios Terminológicos Comunes para Eventos Adversos (CTCAE). También se evaluó el impacto de la edad, el sexo, la actividad acumulada y el tipo de PRRT en la toxicidad a largo plazo. Resultados: El grado 1-2 del FGe se redujo de 87/102 al inicio a 71 casos en el seguimiento (p < 0,001). Antes del tratamiento se encontró grado 3a en 13, grado 3b en 2, y en el seguimiento grado 3a en 25, grado 3b en cinco casos, y grado 4 en 1 caso. La anemia antes de la PRRT y en el seguimiento fue de grado 0 en 63 vs. 48 (p < 0,001), de grado 1 en 36 vs. 48, y de grado 2 en tres vs. seis casos. En el recuento de glóbulos blancos y plaquetas no se produjeron cambios significativos en la clasificación (AU)

Introduction: Nephro- and hematotoxicity after peptide receptor radionuclide therapy (PRRT) have been described in multiple studies with heterogeneous cumulative activities, number of cycles or radiolabelled peptides. Though highly differentiated metastasized neuroendocrine tumours (NET) have long progression free survival, they may progress. We analysed long-term side effects in a homogenous treatment schedule in PRRT-patients and their impact on future oncologic treatment in case of progression. Methods: From our database 89/384 patients receiving the same PRRT (Lu-177-DOTATATE or Y-90-DOTATOC) 4 times every 10 to 12 weeks and a follow-up at 12 months were analysed. One patient had three and 11 patients had two times four PRRT-cycles resulting in 102 cases. eGFR, Hb, WBC and platelets before the first and one year after the fourth therapy cycle were compared. eGFR-Grading was done according to chronic kidney disease classification (CKD) and grading of hematotoxicity according to Common Terminology Criteria for Adverse Events (CTCAE). Impact of age, gender, cumulative activity, type of PRRT on long-term-toxicity was also assessed. Results: eGFR grade 1-2 dropped from 87/102 at the baseline to 71 cases at follow-up (p<0.001). Before treatment grade 3a was found in 13, grade 3b in 2 cases, and at follow-up grade 3a in 25, grade 3b in 5, and grade 4 in 1 case. Anaemia prior to PRRT and at follow-up was grade 0 in 63 versus 48 (p<0.001), grade 1 in 36 versus 48, and grade 2 in three versus six cases. In white blood cell count and platelets, there were no significant changes in grading occurring. Subgroup analysis revealed that only in the age group 65 and older was there a higher incidence for anaemia (p=0.006) (AU)

The spitting stones: a propósito de un caso de broncolitiasis / The Spitting Stones: A Case of Broncholithiasis

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[Translated article] The Spitting Stones: A Case of Broncholithiasis / The spitting stones: a propósito de un caso de broncolitiasis

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Evaluation of Respiratory Mechanics With Dynamic Breathing Magnetic Resonance Imaging in Pleuroparenchymal Fibroelastosis: Limited Lower Chest Wall Motion and Preserved Diaphragm Motion / Evaluación con resonancia magnética dinámica de la mecánica respiratoria en la fibroelastosis pleuroparenquimatosa: movimiento limitado de la pared torácica inferior y movimiento del diafragma conservado

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