European Journal of Nuclear Medicine and Molecular Imaging最新文献

Purpose: Inflammatory Bowel Diseases (IBD) comprise ulcerative colitis (UC) and Crohn's disease (CD). Management of IBD requires assessment of disease activity, severity, extent and complications. Here, we describe the signal behavior of both CD and UC in ⁶⁸Gallium- fibroblast activation protein inhibitor-based radiopharmaceuticals-46-positron emission tomography (⁶⁸Ga-FAPI-46-PET) and evaluate the potential of ⁶⁸Ga-FAPI-46-PET for activity assessment in IBD.

Patients and methods: This analysis includes data of 43 IBD patients and 43 control patients examined by ⁶⁸Ga-FAPI-46-PET/computed tomography (CT). Disease activity of IBD patients was assessed by colonoscopy. FAPI-positive gastrointestinal tract (GIT)-findings and healthy appearing GI structures were contoured. Non-IBD related FAPI-positive GIT-findings were ruled out by interdisciplinary consensus. Static and dynamic PET-parameters of FAPI-positive IBD lesions and healthy appearing GI structures were extracted and PET signalling was analyzed with respect to IBD subtype and disease activity.

Results: We examined 20 CD patients and 23 UC patients (29 with active, 14 with inactive disease). FAPI-uptake in most healthy appearing GI structures of IBD patients was significantly increased compared to controls. Of 80 FAPI-positive GIT-findings, 14 were ruled out as non-IBD related and 66 FAPI-positive IBD lesions were analyzed. We observed equally high lesional FAPI-uptake in CD and UC. All patients with active disease showed at least one intensively FAPI-positive IBD lesion, while only 4/14 patients with inactive disease showed any FAPI-positive IBD lesion. Lesional and patientwise FAPI-uptake was significantly higher in active than in inactive disease. FAPI-positive IBD lesions showed a characteristic kinetic behaviour with two types of uptake patterns - one showing a continuous increase and the other an early peak followed by a plateau.

Conclusion: ⁶⁸Ga-FAPI-46-PET/CT appears promising for assessing disease activity in terms of fibroblast activation in both CD and UC.

Purpose: To assess machine learning (ML) classifiers trained on harmonised multicentre ¹²³I-mIBG planar scintigraphy for differentiating Parkinson's disease (PD) from non-PD parkinsonian syndromes and to determine whether early imaging alone may ensure accurate discrimination.

Methods: This retrospective study included patients with suspected PD who underwent early (~ 15 min) and delayed (~ 240 min) imaging and received a definitive diagnosis after ≥ 12 months. Harmonised region of interest (ROI) placement and ComBat correction were applied. Early and late heart-to-mediastinum (H/M) ratios and washout rate (WR) were calculated. Differences were tested by Mann-Whitney U test, and cut-points identified by ROC analysis. Logistic regression, Gaussian naïve Bayes, and support vector machine were trained on these features with Z-score normalisation and synthetic minority oversampling technique (SMOTE).

Results: 127 patients were analysed (85 PD, 42 non-PD). Early and late H/M ratios were significantly lower in PD than non-PD (early H/M 1.45 ± 0.20 vs. 1.80 ± 0.20; late H/M 1.33 ± 0.22 vs. 1.68 ± 0.21; both p < 0.001). WR was modestly higher in PD (8.74 ± 5.76% vs. 6.49 ± 6.19%, p = 0.024). Optimal cut-points for PD were: early H/M ≤ 1.62 (accuracy 80.3%, sensitivity 83.3%, specificity 78.8%, and AUC 0.878), late H/M ≤ 1.52 (83.5%, 83.3%, 83.5% and 0.866) and WR ≥ 6.03% (70.1%, 70.6%, 69.0% and 0.645). ML achieved mean accuracy 78.9-80.7%, sensitivity 81.9-84.0%, specificity 68.6-78.0%, and AUC 0.850-0.875.

Conclusion: Classifiers trained on ¹²³I-mIBG semi-quantitative indices accurately distinguished PD from non-PD. Early H/M ratio alone provided excellent discrimination, supporting early-imaging; prospective validation is warranted.

Purpose: Recent advancements in autoimmune encephalitis (AE) have enhanced diagnosis and management, but predicting long-term outcomes remains challenging. This study aims to evaluate longitudinal changes in brain [¹⁸F]FDG PET patterns in AE patients to identify specific regional metabolic variations and predict clinical outcomes.

Methods: This longitudinal study compared brain [¹⁸F]FDG PET scans of 22 AE patients at baseline (BS) and after treatment follow-up (FU) using voxel-wise paired t-tests. Significant clusters with at least 100 voxels and p < 0.05 were identified and designated as volumes of interest (VOIs). The VOI values were correlated with main clinical outcomes using partial Spearman's tests, and their prognostic significance was assessed through regression models.

Results: Three VOIs showed significant metabolic changes between baseline (BS) and follow-up (FU) assessments. VOI-A, which was relatively hypermetabolic at BS, included the caudate-thalamus-parahippocampal region, right amygdala, and anterior cingulate cortex. VOI-B1 and VOI-B2, relatively hypometabolic at BS, corresponded to the right fusiform gyrus, precuneus, and temporo-parietal cortex, respectively. Poorer metabolic recovery in all VOIs to normalcy correlated with greater disability (mRS) in both acute and post-therapy phases. Lower metabolism in BS VOI-B1 predicted higher Clinical Assessment Scale in Autoimmune Encephalitis (CASE) score at FU and relapses, while lower age was a significant predictor of escalation to second-line treatment.

Conclusions: Longitudinal [¹⁸F]FDG PET reveals distinct regional metabolic changes paralleling clinical recovery post-treatment in AE. Temporo-parietal metabolism correlates with relapses, clinical severity, and functional impairment, highlighting [¹⁸F]FDG PET as a biological tracker of disease activity throughout AE and its prognostic value.

Objective: Multiple system atrophy (MSA) is a progressive neurodegenerative disorder with complex clinical manifestations, which is essential for patient management and mechanistic understanding of MSA. In this study, we aimed to use disease progression modeling (SuStaIn model) to elucidate the in vivo spatiotemporal progression patterns of brain glucose metabolism in MSA patients, and investigate the differential profiles of clinical characteristics and dopaminergic function among the identified progression-related subtypes.

Methods: A total of 192 participants (117 MSA patients [70 MSA-P, 47 MSA-C] and 75 healthy controls) who underwent [¹⁸F]FDG PET scans, with 82 MSA patients additionally receiving [¹⁸F]FP-CIT PET imaging were retrospectively enrolled. [¹⁸F]FDG PET-based SuStaIn model was established to illustrate spatiotemporal evolutionary patterns of brain glucose metabolism using the cross-sectional data, and identified distinct metabolic subtypes. Metabolic subtypes and stages were correlated with motor function (UPDRS-III), cognitive function (MMSE, MoCA), autonomic symptoms, and dopamine transporter (DAT) activity.

Results: The [¹⁸F]FDG PET-based SuStaIn model identified two robust spatiotemporal metabolic progression subtypes, with Subtype 1 enriched in MSA-C (52.0%, 39/75) and Subtype 2 in MSA-P (78.8%, 26/33). Subtype 1 was characterized by initial hypometabolism in the cerebellum, sequentially progressing to brainstem, striatum, and cortical regions. Subtype 2 demostrated a striatal-onset pattern, progressing sequentially to the brainstem, cerebellum, and frontal lobe. Despite comparable disease duration, subtype 1 patients exhibited significantly poorer cognitive performance (MMSE, FDR q = 0.013; MoCA, FDR q = 0.032) and reduced anterior-to-posterior putamen DAT ratios (FDR q < 0.001) compared to subtype 2. Conversely, subtype 2 patients showed more obvious motor deficits (UPDRS-III, FDR q = 0.042). Significant correlations were observed between SuStaIn progression stages and clinical features across all patients, including UPDRS-III (r = 0.322, p = 0.001), MMSE (r = -0.263, p = 0.009), and MoCA scores (r = -0.292, p = 0.004). These results were confirmed in an independent validation cohort.

Conclusion: This study for the first time used [¹⁸F]FDG PET-based SuStaIn model to elucidate spatiotemporal dynamic progression of MSA, and identified novel metabolic subtypes. These findings provided metabolic evidence of the biological heterogeneity in MSA, which maybe helpful for patients managment and the understanding of mechanisms.

Clinical trial number: Not applicable.

Purpose: To identify predictors of complete response (CR) following induction therapy in lupus nephritis (LN) and comparatively evaluate the predictive value of baseline [18 F]F-FAPI PET/CT versus [18 F]F-FDG PET/CT for treatment short-term outcomes.

Materials and methods: Twenty biopsy-proven LN patients were prospectively enrolled and underwent dual-tracer PET/CT imaging, using both [18 F]F-FAPI and [18 F]F-FDG imaging prior to standardized induction therapy. Treatment response was assessed at 6 months, categorizing into CR, partial response (PR), and non-response (NR) groups. Associations between PET metrics, clinical biomarkers and treatment response were analyzed. Semiquantitative PET parameters including renal standardized uptake values (SUVmax) and target-to-background ratio (TBR) were calculated.

Results: Baseline renal FAPI SUVmax was inversely correlated with estimated glomerular filtration rate (eGFR) and positively with erythrocyte sedimentation rate (ESR) (P < 0.05 for both), whereas FDG SUVmax showed no significant correlation with either parameter. At 6 months, 50% of patients achieved CR, 25% PR, and 25% NR. Patients with CR exhibited significantly lower baseline renal FAPI SUVmax and TBR compared to those with non-CR (PR + NR) (P < 0.01). Visual assessment of FAPI uptake outperformed FDG in predicting CR, with higher accuracy (85% vs. 70%), specificity (90% vs. 50%), and positive predictive value (PPV, 89% vs. 64%), while sensitivity and negative predictive value (NPV) were comparable. Univariate logistic regression identified age > 35 years (P < 0.05) and negative baseline FAPI uptake (P < 0.01) as significant predictors of CR. In multivariate analysis, negative FAPI uptake remained the only independent predictor (P < 0.01).

Conclusion: [18 F]F-FAPI PET/CT demonstrates superior predictive performance over [18 F]F-FDG PET/CT for short-term treatment response in lupus nephritis. It holds promise as a noninvasive imaging biomarker to guide clinical decision-making and optimize individualized therapy.

Purpose: To investigate the feasibility of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) radiomics in preoperative prediction of visceral pleural invasion (VPI) status in invasive adenocarcinoma (IAC) with a maximum diameter ≤ 3 cm.

Materials and methods: A total of 590 IAC patients with a maximum diameter ≤ 3 cm were enrolled and divided into training set (n = 364), validations set 1 (n = 156) and validation set 2 (n = 70). A conventional model was built based on clinical and PET/CT imaging features by logistic regression. Radiomics features extracted from CT and PET images were screened using interclass correlation coefficients, Pearson correlation analysis and the least absolute shrinkage and selection operator. These selected features were used to calculate the CT and PET rad-scores. Finally, a combined model was constructed using multivariate logistic regression.

Results: Tumor type [odds ratio (OR): 3.258, P = 0.012], distance between tumor and pleura (OR: 0.464, P = 0.001), and maximum standardized uptake value (SUVmax) (OR: 1.109, P = 0.002) were used to construct the conventional model. Ten CT radiomics features and six PET radiomics features were used to establish the CT and PET rad-score models. The area under the curve (AUC) value of the combined model (0.824) was higher than conventional model (0.734), CT rad-score model (0.790) and PET rad-score model (0.748) in the training set, and the differences were statistically significant as tested by Delong test (P < 0.05). In the validation set 1 and validation set 2, the combined model exhibited the highest AUC values (0.835 and 0.787), and the difference between the combined model and PET rad-score model (validation set 1: 0.835 vs. 0.747, P = 0.028; validation set 2: 0.787 vs. 0.657, P = 0.043) and CT rad-score model (validation set 2: 0.787 vs. 0.694, P = 0.025) was statistically significant.

Conclusion: The combined model based on PET/CT radiomics is an effective and non-invasive tool for preoperative predicting VPI status in IAC patients.

Crohn's disease (CD) is a chronic and relapsing inflammatory disease of the gastrointestinal tract. Diagnostics and follow-up are difficult in small bowel, that can be only partially evaluated by conventional endoscopy. Combined positron emission tomography magnetic resonance enterography (PET-MRE) has shown potential in diagnosing small bowel CD, but its role in monitoring treatment response has not been previously established. This study aimed to evaluate whether PET-MRE can be used to assess the efficacy of medical therapy. We hypothesized that standardized uptake values (SUV) in inflamed small bowel segments would decrease following initiation of standard therapy. A total of 35 volunteer patients with clinically suspected small bowel CD were recruited. All patients underwent ileocolonoscopy and laboratory testing, followed by [¹⁸F]-FDG PET-MRE. CD diagnosis was confirmed by small bowel capsule endoscopy. Clinicians initiated treatment based on standard diagnostics, blinded to the PET results. Eighteen patients completed follow-up [¹⁸F]-FDG PET-MRE at three months. Maximum SUV (SUV_Max) was measured in the small intestine and compared with MRE findings. The median SUV_Max decreased significantly from baseline to follow-up (3.2 vs. 2.1, p = 0.0025). The Simplified Magnetic Resonance Index of Activity (sMARIA) was also significantly lower at follow-up (p = 0.001). Representatively, median fecal calprotectin declined (451 µg/g vs. 163 µg/g, p = 0.004). This preliminary prospective study suggests that [¹⁸F]-FDG PET-MRE may be a useful tool for assessing biochemical response to treatment in newly diagnosed small bowel CD.Trial registration number: NCT06796959 (ClinicalTrials.gov). Retrospectively registered on 21.1.2025. Enrollment of first participant on 1.8.2020.

Purpose: To determine the efficacy of [¹⁷⁷Lu]Lu-Hydroxyapatite radiosynovectomy (RSV) in patients with refractory chronic inflammatory arthritis of the knee joint.

Materials and methods: Overall, 24 knees in 22 patients with refractory chronic inflammatory arthritis were enrolled in this prospective study. All patients were assessed clinically for pain, tenderness, range of motion, analgesic intake, Oxford Knee Score, and scintigraphically based on blood pool activity on three-phase bone scan. Various scores were assigned to clinical these parameters. RSV of the knee joint was done using intra-articular injection of [¹⁷⁷Lu]Lu-Hydroxyapatite. Patients were assessed clinically at 1 and 3 months, and scintigraphically at 3 months using blood pool index on three-phase bone scan. Patients were categorised as responders and non-responders on the basis of change in percentage of cumulative scores.

Results: Out of 24 knees, 18 knees were responders and 6 knees were non-responders at 3 months. There was a significant improvement in clinical scores at 1 month post-RSV, which persisted at 3 months post-RSV (p < 0.05). However, the change in blood pool activity on three-phase bone scan was not significant. Reported adverse effects were mild and not significant.

Conclusion: This study confirmed the safety and efficacy of [¹⁷⁷Lu]Lu-Hydroxyapatite radiosynovectomy for patients with chronic inflammatory knee joint arthritis refractory to conventional medical treatment.