Annals of Nuclear Medicine最新文献

Objective: To determine the role of whole-body dynamic (WBD)/Patlak parametric ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with alveolar echinococcosis (AE). This technique allows separating metabolized from unmetabolized FDG in the blood pool and tissue, potentially providing complementary qualitative information and superior quantification to standard static PET/CT images.

Methods: We prospectively analyzed 20 PET/CT datasets performed for staging or therapy monitoring in patients with confirmed AE. Dynamic and standard static PET/CT datasets were acquired in all patients, and quantitative imaging parameters were measured in the lesion with the highest uptake (i.e., maximum standardized uptake value (SUVmax) and Patlak parameters) and compared to normal liver tissue (SUVratio and Patlak ratio).

Results: Mean SUVmax in AE manifestations was 5.7 ± 3.1 (3.2-13.9), compared to 3.2 ± 0.4 (2.5-4.2) in non-infected liver tissue, respective values for Patlak were 13.0 ± 8.6 (2.7-35.5) and 4.9 ± 2.8 (0.6-12.1). SUVratio (1.8 ± 1.1; 1.0-5.2) was significantly lower (P < 0.001) than Patlak ratio (3.2 ± 3.2; 1.1-15.6). Both ratios correlated significantly with E. granulosus hydatid fluid (EgHF) antibodies (SUVratio r = 0.73, P < 0.001; Patlak ratio r = 0.85, P < 0.001).

Conclusion: WBD PET/CT yields higher lesion-to-background contrast and may, therefore, have the potential to increase sensitivity in the assessment of hepatic AE.

Objective: To investigate the relationship between striatal asymmetry indices-namely the High/Low Ratio and Asymmetry Index (AI)-derived from dopamine transporter single-photon emission computed tomography (DAT-SPECT) using ^99mTc-TRODAT-1, and the subscale scores of the Unified Parkinson's Disease Rating Scale (UPDRS), with the aim of evaluating their utility in clinical phenotyping and symptom assessment in Parkinson's disease (PD).

Methods: Fifty-six patients with clinically diagnosed PD underwent ^99mTc-TRODAT-1 SPECT imaging and UPDRS evaluation. Radiotracer uptake in the caudate nucleus, putamen, and whole striatum was quantified bilaterally, and corresponding High/Low Ratios and AIs were calculated. These asymmetry measures were analyzed in relation to UPDRS subscale scores and Hoehn-Yahr stages.

Results: Putaminal asymmetry was significantly greater in early-stage PD patients (Hoehn-Yahr ≤ 2; p = 0.010), suggesting early lateralized dopaminergic degeneration. The AI of the caudate nucleus was strongly correlated with UPDRS Part I (non-motor symptoms; r = 0.690, p < 0.001), while putaminal asymmetry was significantly associated with UPDRS Part III (motor symptoms; r = 0.497, p < 0.001).

Conclusion: Region-specific DAT-SPECT asymmetry shows domain-specific correlations in PD (caudate-non-motor; putamen-motor). These findings may support the use of TRODAT-1-based imaging biomarkers for precision assessment and individualized management; however, they are hypothesis-generating and require confirmation in larger, better-balanced prospective cohorts.

Objective: This study aimed to demonstrate the differences in Technetium-99 m albumin scintigraphy findings for patients with protein-losing enteropathy (PLE) associated with their characteristics and laboratory data.

Methods: Eighteen patients with PLE were grouped into two based on two mechanisms: direct mucosal damage and failed lymph drainage. Scintigraphy images were divided based on the timing of acquisition: images obtained at 1, 2, 4, 6, and 24 h after starting the examination. The intensity of tracer uptake was graded as follows: 3 (marked uptake equal to or greater than the liver level), 2 (moderate uptake less than liver and greater than kidney levels), 1 (mild uptake less than kidney level), and 0 (negative). The grades at each timepoint for the two groups were compared using the Mann-Whitney U test. The associations between the grades and fecal alpha-1-antitrypsin and serum total protein concentrations were evaluated using Pearson correlation coefficients.

Results: Of 18 patients, 7 had PLE due to failed lymph drainage. The direct mucosal damage and failed lymph drainage groups had significantly different fecal alpha-1-antitrypsin concentrations [43.5 ± 29.6 (range 11-115) vs. 208.7 ± 66.0 (range 124-311), respectively; P < 0.001] and scintigraphy-based severity at 24 h [1.2 ± 0.8 (range 1-3) vs. 2.8 ± 0.4 (range 2-3), respectively; P = 0.007]. The fecal alpha-1-antitrypsin concentration was positively correlated with the scintigraphy-based severity at 6 h (r = 0.499, P = 0.049) and 24 h (r = 0.747, P = 0.002). However, the serum protein concentration was negatively correlated with the scintigraphy-based severity at 6 h (r = - 0.587, P = 0.017).

Conclusions: The scintigraphy-based severity at 6 and 24 h and the fecal alpha-1-antitrypsin concentrations were higher for patients with PLE due to failed lymph drainage mechanisms than for those with PLE due to direct mucosal damage. Scintigraphy can help localize the leakage point and determine disease severity to guide PLE management.

Objective: To evaluate the prognostic values of ¹⁸F-FDG PET-derived whole-body imaging features in patients with metastatic lung adenocarcinoma treated with EGFR-targeted therapies.

Methods: We retrospectively analyzed 249 patients with lung adenocarcinoma who underwent pre-treatment ¹⁸F-FDG PET and were treated with EGFR-targeted agents. The patients were divided into analog (n = 150) and digital (n = 99) PET cohorts. Whole-body and primary tumor respiratory-stable imaging features were extracted. The prognostic values of the study variables for progression-free (PFS) and overall survival (OS) were assessed using univariate and multivariate Cox regression analyses across the analog and digital PET cohorts.

Results: Total sphericity and primary tumor inverse difference normalized were independent predictors of both PFS and OS. The total metabolic tumor volume was another independent predictor of OS. Combined models integrating these imaging biomarkers with clinical variables outperformed the traditional staging system (c-indices for PFS: 0.649 versus 0.550 for analog and 0.668 versus 0.583 for digital PET cohorts; for OS: 0.694 versus 0.562 for analog and 0.728 versus 0.579 for digital PET cohorts). Our models showed consistent predictive values across subgroups based on sex, EGFR mutation subtype, and clinical stage.

Conclusions: Our results indicate that models integrating whole-body ¹⁸F-FDG PET features with traditional variables can enhance survival prediction and may support personalized treatment strategies for patients with lung adenocarcinoma treated with EGFR-targeted therapies.