Annals of Nuclear Medicine最新文献

Objective

To explore the implementation of low-iodine diets by medical staff caring for patients with differentiated thyroid carcinoma prior to ¹³¹I therapy across 58 hospitals, and offer valuable insights for the development of guidelines on low-iodine diets.

Methods

Convenience sampling was utilized to conduct a survey among 163 medical staff members working in nuclear medicine departments across 58 tertiary hospitals using a self-designed questionnaire.

Results

Concerning the duration of the low-iodine diet prior to treatment, the medical staff’s recommendations were as follows: 58.28% suggested 2–4 weeks, 31.29% recommended more than 4 weeks, 9.2% opted for 7–13 days, and 1.23% favored less than 1 week. Regarding the timing of resuming a normal diet, the respondents’ recommendations ranged from immediately after treatment (1.84%) to 3 months post-treatment (8.58%), with intermediate recommendations of 2 h (8.58%), 24–48 h (14.11%), post-discharge (12.26%), and 1 month (42.94%). Furthermore, the surveyed medical staff unanimously recommended abstaining from seafood, with 90.8% also advising against the consumption of iodized salt, 91.41% recommending avoidance of iodine-containing medications, and 71.17% advising caution with moderately high-iodine foods. Notably, 75.46% of the medical staff evaluated patient compliance with the low-iodine diet. When patients failed to adhere to the diet preparation, 33.74% of healthcare workers chose to proceed with treatment. In terms of guidance sources, 96.93% of respondents relied on relevant guidelines, 66.26% referred to the literature, and 49.69% drew upon their clinical experience. During hospitalization, 58.28% of the medical staff continued to guide patients on the low-iodine diet, while only 8.59% provided such guidance after discharge. Notably, only 20.25% of the staff considered consulting the nutrition department.

Conclusion

This study underscored substantial variations in the duration and selection criteria for low-iodine diets, which were linked to a scarcity of standardized evaluations. Consequently, there is an urgent need for further research to establish detailed, practical, accessible, comprehensive, and dependable implementation programs for low-iodine diets.

Objective

We aimed to establish a practical diagnostic index for Lewy body diseases (LBD), such as Parkinson’s disease and dementia, with Lewy bodies in outpatient settings and criteria for exempting patients from late imaging.

Methods

We acquired early and late ¹²³I-metaiodobenzylguanidine (MIBG) images from 108 consecutive patients with suspected LBD and standardized heart-to-mediastinum (H/M) ratios for collimator conditions. Exclusions included young-onset Parkinson’s disease (age < 50 years) and genetic transthyretin-type amyloidosis. We developed logistic models incorporating H/M ratios with or without age (n = 92). The sympathetic MIBG index for LBD (SMILe index), categorized LBD likelihood from 0 (lowest) to 1 (highest). Diagnostic accuracy was assessed as the area under the receiver operating characteristic (ROC) curve (AUC). The characteristics of the new index were compared with H/M ratios. The need for late imaging was explored using the SMILe index.

Results

Early or late SMILe indexes using a single H/M ratio variable discriminated LBD from non-LBD. The AUC values for early and late SMILe indexes were 0.880 and 0.894 (p < 0.0001 for both), identical to those for early and late H/M ratios. The sensitivity and the specificity of early SMILe indexes with a 0.5 threshold were 76% and 90%, achieving accuracy of accuracy 86%. Similarly, the late SMILe index demonstrated a sensitivity of 76% and specificity of 87%, with an accuracy of 84%. Early SMILe indexes < 0.3 or > 0.7 (representing 84% patients) indicated a diagnosis without a late MIBG study.

Conclusion

The ¹²³I-MIBG-derived SMILe indexes provide likelihood of LBD, and those with a 50% threshold demonstrated optimal diagnostic accuracy for LBD. The index values of either < 0.3 or > 0.7 accurately selected patients who do not need late imaging.

Background:

Cardiac positron emission tomography (PET) can visualize and quantify the molecular and physiological pathways of cardiac function. However, cardiac and respiratory motion can introduce blurring that reduces PET image quality and quantitative accuracy. Dual cardiac- and respiratory-gated PET reconstruction can mitigate motion artifacts but increases noise as only a subset of data are used for each time frame of the cardiac cycle.

Aim:

The objective of this study is to create a zero-shot image denoising framework using a conditional generative adversarial networks (cGANs) for improving image quality and quantitative accuracy in non-gated and dual-gated cardiac PET images.

Methods:

Our study included retrospective list-mode data from 40 patients who underwent an ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) cardiac PET study. We initially trained and evaluated a 3D cGAN—known as Pix2Pix—on simulated non-gated low-count PET data paired with corresponding full-count target data, and then deployed the model on an unseen test set acquired on the same PET/CT system including both non-gated and dual-gated PET data.

Results:

Quantitative analysis demonstrated that the 3D Pix2Pix network architecture achieved significantly (p value<0.05) enhanced image quality and accuracy in both non-gated and gated cardiac PET images. At 5%, 10%, and 15% preserved count statistics, the model increased peak signal-to-noise ratio (PSNR) by 33.7%, 21.2%, and 15.5%, structural similarity index (SSIM) by 7.1%, 3.3%, and 2.2%, and reduced mean absolute error (MAE) by 61.4%, 54.3%, and 49.7%, respectively. When tested on dual-gated PET data, the model consistently reduced noise, irrespective of cardiac/respiratory motion phases, while maintaining image resolution and accuracy. Significant improvements were observed across all gates, including a 34.7% increase in PSNR, a 7.8% improvement in SSIM, and a 60.3% reduction in MAE.

Conclusion:

The findings of this study indicate that dual-gated cardiac PET images, which often have post-reconstruction artifacts potentially affecting diagnostic performance, can be effectively improved using a generative pre-trained denoising network.

Objective

The purpose of this study was to determine the value of sentinel lymph node biopsy (SLNB) in the laryngeal SCC, using intra-operative peri-tumoral injection of Tc-99m-phytate.

Methods

Patients with biopsy-proven squamous cell carcinoma of the larynx were included. On the day of surgery, after anesthesia induction, suspension laryngoscopy was performed to inject 74 MBq/0.4 ml Tc-99m-phytate in four aliquots into the sub-mucosal peri-tumoral location. After a 10-min wait, a portable gamma probe was used to locate sentinel nodes. Subsequently, all patients underwent laryngectomy and neck dissection. Both sentinel nodes and non-sentinel nodes were examined using hematoxylin and eosin (H&E) staining.

Results

Twenty-six patients with a diagnosis of laryngeal carcinoma were included in the study. The SLN detection rate was 65.4%, with a 100% detection rate in the supraglottic region and a 52.6% detection rate for glottis/transglottic patients. Permanent pathology results showed lymph node involvement in four patients, but only one patient had a negative result in the SLNB, resulting in an overall false negative rate of 25%. The sensitivity of the SLN technique was 75% overall, 100% in the supraglottic region, and 67% in the glottis/transglottic region.

Conclusion

The accuracy and feasibility of SLNB may be related to the location of the tumors in the larynx. For supraglottic tumors, the technique seems to be feasible with a low false negative rate. For glottis/transglottic tumors, both the detection rate and false negative rate seem to be suboptimal. Further studies are needed to validate our results.

Purpose

To establish and validate novel predictive models for predicting bone metastasis (BM) in newly diagnosed prostate adenocarcinoma (PCa) via single-photon emission computed tomography radiomics.

Method

In a retrospective review of the clinical single-photon emission computed tomography (SPECT) database, 176 patients (training set: n = 140; validation set: n = 36) who underwent SPECT/CT imaging and were histologically confirmed to have newly diagnosed PCa from June 2016 to June 2022 were enrolled. Radiomic features were extracted from the region of interest (ROI) in a targeted lesion in each patient. Clinical features, including age, total prostate-specific antigen (t-PSA), and Gleason grades, were included. Statistical tests were then employed to eliminate irrelevant and redundant features. Finally, four types of optimized models were constructed for the prediction. Furthermore, fivefold cross-validation was applied to obtain sensitivity, specificity, accuracy, and area under the curve (AUC) for performance evaluation. The clinical usefulness of the multivariate models was estimated through decision curve analysis (DCA).

Results

A radiomics signature consisting of 27 selected features which were obtained by radiomics' LASSO treatment was significantly correlated with bone status (P < 0.01 for both training and validation sets). Collectively, the models showed good predictive efficiency. The AUC values ranged from 0.87 to 0.98 in four models. The AUC values of the human experts were 0.655 and 0.872 in the training and validation groups, respectively. Most radiomic models showed better diagnostic accuracy than human experts in the training and validation groups. DCA also demonstrated the superiority of the radiomics models compared to human experts.

Conclusion

Radiomics models are superior to humans in differentiating between benign bone and prostate cancer bone metastases; it can be used to facilitate personalized prediction of BM in newly diagnosed PCa patients.

Purpose

Information about developed positron emission tomography (PET) tracers and obtained clinical PET images is publicly available in a database. However, findings regarding the kinetic parameters of PET tracers are yet to be summarized. Therefore, in this study, we created an open-access database of central nervous system (CNS) kinetic parameters in the healthy human brain for existing PET tracers (DOCK–PET).

Methods

Our database includes information on the kinetic parameters and compounds of existing CNS–PET tracers. The kinetic parameter dataset comprises the analysis methods, V_T, BP_ND, K parameters, relevant literature, and study details. The list of PET tracers and kinetic parameter information was compiled through keyword-based searches of PubMed and the Molecular Imaging and Contrast Agent Database (MICAD). The kinetic parameters obtained, including V_T, BP_ND, and K parameters, were reorganized based on the defined brain anatomical regions. All data were rigorously double-checked before being summarized in Microsoft Excel and JavaScript Object Notation (JSON) formats.

Results

Of the 247 PET tracers identified through searches using the PubMed and MICAD websites, the kinetic parameters of 120 PET tracers were available. Among the 120 PET tracers, compound structures with chemical and physical properties were obtained from the PubChem website or the ChemDraw software. Furthermore, the affinity information of the 104 PET tracers was gathered from PubChem or extensive literature surveys of the 120 PET tracers.

Conclusions

We developed a comprehensive open-access database, DOCK–PET, that includes both kinetic parameters of healthy humans and compound information for existing CNS–PET tracers.

Objective

This study seeks to evaluate how recent COVID-19 infection affects myocardial perfusion and functional parameters derived from gated myocardial perfusion imaging in patients undergoing evaluation for coronary artery disease. The goal is to enhance our understanding of COVID-19’s influence on the cardiovascular system.

Method

Conducted at Farshchian Heart Hospital from 2022 to 2023, this case–control study enrolled patients suspected of coronary artery disease, stratified into two groups: those with confirmed COVID-19 infection within the past 6 months (study group) and those without prior COVID-19 infection (control group). Employing a 2-day protocol, stress testing and gated SPECT MPI were performed. Statistical analysis included descriptive statistics, Chi-square test, Student’s t test, and Mann–Whitney U test.

Result

Among the 86 patients included, 43 were in each group. Significantly higher summed stress core and summed difference score values were observed in the study group compared to the control group (p < 0.05). In addition, the study group exhibited significantly altered global left ventricular ejection fraction, end-diastolic volume, and end-systolic volume (p < 0.05). Non-perfusion findings, including transient ischemic dilation and transient right ventricular visualization, were more prevalent in the study group.

Conclusion

Recent COVID-19 infection is associated with impaired myocardial perfusion and altered functional parameters as detected by MPI. These findings underscore the intricate interplay between COVID-19 and cardiovascular health, emphasizing the importance of comprehensive evaluation and management strategies to address cardiac complications in affected individuals. Further research is warranted to elucidate the underlying mechanisms and optimize patient care in the context of COVID-19-associated cardiovascular manifestations.

Purpose

Predicting the malignancy of pure ground-glass nodules (GGNs) using CT is challenging. The optimal role of [¹⁸F]FDG PET/CT in this context has not been clarified. We compared the performance of [¹⁸F]FDG PET/CT in evaluating GGNs for predicting invasive adenocarcinomas (IACs) with CT.

Methods

From June 2012 to December 2020, we retrospectively enrolled patients with pure GGNs on CT who underwent [¹⁸F]FDG PET/CT within 90 days. Overall, 38 patients with 40 ≥ 1–cm GGNs were pathologically confirmed. CT images were analyzed for size, attenuation, uniformity, shape, margin, tumor–lung interface, and internal/surrounding characteristics. Visual [¹⁸F]FDG positivity, maximum standardized uptake value (SUV_max), and tissue fraction-corrected SUV_max (SUV_maxTF) were evaluated on PET/CT.

Results

The histopathology of the 40 GGNs were: 25 IACs (62.5%), 9 minimally invasive adenocarcinomas (MIA, 22.5%), and 6 adenocarcinomas in situ (AIS, 15.0%). No significant differences were found in CT findings according to histopathology, whereas visual [¹⁸F]FDG positivity, SUV_max, and SUV_maxTF were significantly different (P=0.001, 0.033, and 0.018, respectively). The size, visual [¹⁸F]FDG positivity, SUV_max, and SUV_maxTF showed significant diagnostic performance to predict IACs (area under the curve=0.693, 0.773, 0.717, and 0.723, respectively; P=0.029, 0.001, 0.018, and 0.013, respectively). In the multivariate logistic regression analysis, visual [¹⁸F]FDG positivity discriminated IACs among GGNs among various CT and PET findings (P=0.008).

Conclusions

[¹⁸F]FDG PET/CT demonstrated superior diagnostic performance compared to CT in differentiating IAC from AIS/MIA among pure GGNs, thus it has the potential to guide the proper management of patients with pure GGNs.

Objective

Tc-99m N-pyridoxyl-5-methyl-tryptophan (PMT) hepatobiliary scintigraphy has high diagnostic performance for biliary atresia. Our hospital implements standard Tc-99m PMT administration followed by a 6 h static imaging review; booster doses are given in cases requiring 24 h delayed scans. This study aimed to evaluate the diagnostic performance of this method.

Methods

A total of 37 pediatric patients who underwent Tc-99m PMT biliary scintigraphy were classified into the surgically-diagnosed biliary atresia or non-biliary atresia groups. The absence of tracer accumulation in the small bowel was considered a hepatobiliary scintigraphic diagnosis of biliary atresia. The Clopper–Pearson method was used to calculate the 95% confidence intervals (CIs) for determining the diagnostic accuracy, negative predictive value, positive predictive value, sensitivity, and specificity of Tc-99m PMT biliary scintigraphy.

Results

Among the 37 patients, 12 were classified into the diagnosis of biliary atresia group. Regarding biliary scintigraphy findings, 16 of 37 patients demonstrated tracer accumulation in the small bowel within 6 h of testing. These cases were diagnosed as non-biliary atresia, requiring no further testing or booster administration. In contrast, 21 patients underwent delayed testing requiring booster administration, which revealed 13 without tracer excretion and 11 who were diagnosed with biliary atresia. Among the eight patients with tracer accumulation, only one was diagnosed with biliary atresia. Furthermore, two cases without tracer excretion and seven cases with tracer excretion were clinically diagnosed as non-biliary atresia. The diagnostic performance of our examination was as follows: a diagnostic accuracy of 91.9% (34/37; 95% CIs 78.0–98.3%), sensitivity of 91.6% (11/12; 95% CIs 61.5–99.8%), specificity of 92.0% (23/25; 95% CIs 74.0–99.0%), a positive predictive value of 84.6% (11/13; 95% CIs 54.6–98.0%), and a negative predictive value of 95.8% (23/24; 95% CIs 78.9–99.9%).

Conclusions

Our protocol for Tc-99m PMT biliary scintigraphy using tracer booster administration demonstrated reliable diagnostic performance for biliary atresia. Notably, 43% of cases did not require booster administration, indicating that lesser radiation exposure may still yield comparable diagnostic accuracy.

Objective

Radioiodine (I-131) therapy for hyperthyroidism is a well-established and safe treatment option. This study aimed to investigate the relationship between the computed tomography (CT) value and the function and volume of the thyroid gland by identifying the factors that induce changes in the CT value of patients with hyperthyroidism.

Methods

This retrospective study evaluated 38 patients with Graves’ disease and 10 patients with Plummer disease. To obtain the mean CT value and volume of the thyroid gland, the entire thyroid gland was set as the region of interest. A test dose of 3.7 MBq I-131 was administered before initiating I-131 therapy, and the radioiodine uptake (RIU) rate was assessed after 3, 24, 96, and 168 h. An approximate curve was plotted based on the RIU values obtained, and the effective half-life (EHL) was calculated. The correlation between the mean CT value and the volume of the thyroid gland, 24-h RIU, EHL, and the free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), and TSH receptor antibody (TRAb) levels was evaluated.

Results

The CT value exhibited a significant positive correlation with EHL in patients with Graves’ disease (r = 0.62, p < 0.0001) as well as patients with Plummer disease (r = 0.74, p < 0.05). However, it did not display any correlation with the remaining parameters.

Conclusion

The CT value is significantly correlated with EHL, suggesting that it reflects thyroid function and is mainly related to the factors associated with iodine discharge.