Clinical Nuclear Medicine最新文献

A 58-year-old woman was referred for right wrist pain, with suspicion of stress fracture of the radial styloid. 99m Tc-HDP bone scintigraphy, using new 3D-ring CZT system, was performed. Blood pool SPECT/CT revealed intense hyperemia along the first extensor compartment of the right wrist, suggesting De Quervain tenosynovitis, while late-phase SPECT/CT showed right thumb arthritis. Ultrasound imaging confirmed De Quervain tenosynovitis. Our case highlights the potential of blood pool SPECT/CT using new 3D-ring CZT system to detect relevant extraosseous findings, especially common tendinopathies such as De Quervain tenosynovitis.

A 13-year-old girl with severe Cushingoid features had ectopic ACTH-dependent Cushing syndrome. 18 F-FDG PET/CT demonstrated diffusely FDG-avid bilateral adrenal hyperplasia, confirming ectopic ACTH stimulation, and detected a presacral mass with mild uptake. 68 Ga-DOTA-NOC PET/MRI revealed intense somatostatin-receptor activity (SUVmax: 56.1), and MRI identified fat and cystic elements, suggesting teratoma. Surgery proved a mature teratoma harboring an ACTH-secreting NET (G1). This rare case demonstrates that in pediatric patients with aggressive-appearing presacral masses and life-threatening hypercortisolism, complementary imaging modalities may be necessary to exclude malignancy while identifying the functional tumor source.

Purpose: Imaging protocols for progressive supranuclear palsy (PSP) are increasingly incorporating different PET modalities-including 18 F-fluorodeoxyglucose ( 18 F-FDG; cerebral glucose metabolism), 18 F-FP-CIT (dopamine transporter [DAT] activity), and 18 F-Florzolotau (tau pathology) PET-to improve diagnostic accuracy. In this cross-sectional study, we characterized tracer-specific imaging patterns and evaluated their interrelationships in patients with PSP to clarify the underlying pathophysiological mechanisms.

Materials and methods: Twenty-eight patients with clinically diagnosed PSP underwent 18 F-FDG, 18 F-FP-CIT, and 18 F-Florzolotau PET imaging. Quantitative voxel-based and region-of-interest analyses were conducted. Standardized uptake value ratios (SUVRs) were calculated and compared with sex-matched controls (n=20 per PET modality).

Results: In patients with PSP compared with controls, 18 F-FDG PET revealed significant glucose hypometabolism in frontal, parietal, cerebellar, and subcortical regions. 18 F-FP-CIT PET demonstrated reduced DAT availability in the striatum and midbrain. Finally, 18 F-Florzolotau PET showed elevated tau deposition in the thalamus, midbrain, pons, and precentral gyrus. An inverse correlation linked midbrain tau burden with local glucose metabolism ( r =-0.39, P =0.04). Frontal hypometabolism correlated strongly with subcortical metabolic deficits ( r =0.61, P <0.001). Only the left putamen showed a moderate negative association between DAT loss and tau accumulation ( r =-0.42, P =0.03).

Conclusions: Patients with PSP exhibit metabolic deficits in cortical-subcortical networks, dopaminergic denervation in striatal-midbrain regions, and tau pathology localized to brainstem and thalamic areas. Tracer-specific SUVRs correlations revealed specific interplay among glucose hypometabolism, DAT deficiency, and tau accumulation.

A 5-year-old boy with right-sided chest pain and fever was diagnosed with pleuropulmonary blastoma, confirmed by thoracoscopic biopsy. Initial imaging showed a large hypermetabolic mass in the right lower lobe. After 2 cycles of chemotherapy, FDG PET/CT demonstrated significant solid component shrinkage and increased cystic airspaces with decreased hypermetabolic activity. After surgery, pathology confirmed type II pleuropulmonary blastoma. Nine months later, recurrent disease was detected on follow-up FDG PET/CT. Patient underwent further tumor resection, followed by radiation and chemotherapy. This case illustrates the evolving FDG PET/CT findings, and recurrence of pleuropulmonary blastoma after treatment.

Takayasu arteritis (TAK) is a large-vessel vasculitis characterized by granulomatous inflammation of the aorta and its primary branches. The clinical presentation of TAK is heterogeneous. Intracranial vascular involvement in TAK is uncommon and is understudied. Clinical, biochemical, and imaging data always do not correspond, making it difficult to evaluate disease activity in TAK. FAPI PET/CT is a noninvasive whole-body imaging modality that could potentially aid in diagnosis, therapy monitoring, and identifying disease relapse when 18 F-FDG-PET/CT is inconclusive. The authors in this research demonstrate intracranial and extracranial vascular involvement in a patient of TAK on 68 Ga-FAPI-04 PET/CT.

Neuroendocrine prostate cancer (NEPC) is an aggressive subtype of prostate cancer, often developing from androgen receptor (AR) independence, characterized by neuroendocrine molecular markers and nonresponsiveness to standard treatments of prostate adenocarcinoma. The evolution of adenocarcinoma to NEPC is characterized by epigenetic changes, leading to the downregulation of the PSMA transmembrane protein, as well as the upregulation of FDG-uptake pathways and somatostatin receptor expression. We present a case of NEPC that depicts a significant metastatic intertumoral heterogeneity as depicted on PSMA, FDG, and DOTATATE PET/CT scans. Such multiprobe PET evaluation of NEPC may assist in sampling the most aggressive disease and guide an appropriate management strategy. It also provides a cellular-level insight into this dreadful disease with very limited treatment options.

We report a thyroid-shaped iodine uptake in the scrotum incidentally detected on an 131 I whole-body scan (WBS). A 62-year-old man with papillary thyroid carcinoma underwent 131 I ablation therapy after total thyroidectomy. A postablation whole-body scan after 7 days revealed a butterfly-shaped uptake in the lower pelvic region on the anterior image, which was suspected to be an unusual form of urinary contamination. However, additional lateral images demonstrated that the tracer activity was not superficial. Computed tomography revealed a bilateral scrotal hydrocele that corresponded to the 131 I uptake in the lower pelvis on WBS. This case presents a previously unreported hydrocele incidentally detected on 131 I WBS, with iodine uptake in the bilateral scrotal regions, shaped like a thyroid gland.

A 68-year-old man with a history of 2 primary tumors (prostate adenocarcinoma and colon adenocarcinoma) underwent 18 F-DCFPyL PET/CT for biochemical recurrence after prostate cancer treatment. A hypogastric nodular lesion with avid PSMA uptake was observed, interpreted as a possible implant. Surgical excision revealed a benign spindle cell proliferation compatible with a desmoid tumor (fibromatosis). This case highlights the potential pitfall of desmoid tumors mimicking malignancy on 18 F-DCFPyL PET/CT, emphasizing the importance of awareness and correlation with clinical and histopathologic findings.

A 70-year-old man with primary hyperparathyroidism underwent 18F-choline PET/CT to localize a parathyroid adenoma before surgery. 18F-choline PET/CT confirmed the right superior parathyroid adenoma but also revealed skin uptake corresponding to an inflammatory epidermoid cyst of the left neck. Two months later, the patient underwent successful minimally invasive parathyroidectomy. The epidermoid cyst was also excised. Inflammatory epidermoid cysts can be a cause of false-positive 18F-choline skin uptake.

Purpose: Primary hyperparathyroidism is one of the most common endocrine disorders and it is only curable by surgery. This study aimed to accurately localize parathyroid adenomas (PTAs) in patients with negative results from conventional diagnostics, consisting of MIBI SPECT/CT and ultrasound, by utilizing F-18-ethylcholine-PET/ultrasound real-time fusion imaging. Fusion ultrasound is a well-established diagnostic tool that enables precise identification and localization of target structures by superimposing MRI, CT, or PET/CT with real-time B-mode ultrasound. The goal was to detect occult PTAs and enable curative targeted parathyroidectomy.

Methods: A total of 49 patients with primary hyperparathyroidism were consecutively recruited from routine clinical workflows. Given negative standard diagnostics, patients were referred for FEC-PET/CT followed by FEC-PET/ultrasound. PTAs were categorized as positive, ambiguous, or negative based on FEC-PET/ultrasound findings. A retrospective data analysis was performed, examining PTA volume (ml) based on ultrasound results, SUVmax of PTAs and locoregional lymph nodes, as well as parathyroid hormone, calcium, and phosphate levels. Maximal, minimal, median, mean values, and SDs were reported.

Results: Forty-nine PTAs were identified, of which 45 were solitary, whereas 2 patients had double adenomas each. The study showed relatively high rates of ectopic PTAs (28%). No significant differences were observed in FUS-based detection rates between ectopic and orthotopic lesions. PTAs, exhibited significantly higher ( P <0.05) tracer uptake [SUVmax 4.5±2.7 (4, 1.4-11.9)] compared with lymph nodes [SUVmax 2.7±1.7 (2.5, 1.2-11.8)]. SUVmax was significantly higher in positive lesions compared with ambiguous cases ( P <0.05). No significant SUVmax difference was found for lymph nodes in ambiguous cases. FUS-based PTA volume ranged from 0.2 to 2.6 ml (mean 0.5±0.5 ml). Twenty-seven patients underwent surgery, and the diagnosis was confirmed in 90% of cases.

Conclusions: This study shows that FEC-PET/ultrasound offers valuable support for preoperative localization and thus can be considered as an effective and precise method for detecting parathyroid adenomas in primary hyperparathyroidism. Because of its high time and technical demands, it is reserved for challenging cases unresolved by standard diagnostics. Future technical advances may increase its accessibility.