Pulmonary artery imaging with 68 Ga-FAPI-04 in patients with chronic thromboembolic pulmonary hypertension.

BACKGROUND: The feasibility and significance of imaging pulmonary artery (PA) remodeling with 68 Ga-fibroblast activating protein inhibitor (FAPI) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) have not yet been addressed. METHODS: 68 Ga-FAPI-04 uptake in the PA and ascending artery was evaluated in 13 patients with CTEPH and 13 matched non-CTEPH controls. The correlations of PA 68 Ga-FAPI-04 uptake and remodeling parameters derived from right heart catheterization (RHC) were analyzed. RESULTS: Of the 13 patients with CTEPH, nine (69%) showed visually enhanced 68 Ga-FAPI-04 uptake, whereas none of the control subjects had increased 68 Ga-FAPI-04 uptake in the PA. The prevalence of enhanced uptake in the main, lobar, and segmental PAs was 45% (17/38), 33% (16/48), and 28% (44/159), respectively. 68 Ga-FAPI-04 activity in the PA was positively correlated with pulmonary arterial diastolic pressure (r = 0.571, P = 0.041). CONCLUSION: 68 Ga-FAPI-04 has the potential for imaging fibroblast activation in the PA wall, and 68 Ga-FAPI-04 activity in PA is positively correlated with pulmonary arterial diastolic pressure.

Imaging of cardiac fibroblast activation in patients with chronic thromboembolic pulmonary hypertension.

PURPOSE: The aim of this study was to explore the association of cardiac fibroblast activation with clinical parameters and cardiovascular magnetic resonance (CMR) imaging parameters in patients with chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: Thirteen CTEPH patients were prospectively enrolled. All of the patients underwent cardiac 68Gallium-labelled fibroblast activation protein inhibitor (68 Ga-FAPI-04)-positron emission tomography/computed tomography (PET/CT), right heart catheterisation, and echocardiography, and 11 of them additionally underwent CMR. Thirteen control subjects were selected to establish the normal range of cardiac 68 Ga-FAPI-04 uptake. Cardiac 68 Ga-FAPI-04 uptake higher than that in the blood pool was defined as abnormal. The global and segmental maximum standardised uptake values (SUVmax) of the right ventricle (RV) were measured and further expressed as target-to-background ratio (TBRRV) with left ventricular lateral wall activity as background. Late gadolinium enhancement (LGE) was visually evaluated, and native-T1 times, enhanced-T1 times, and extracellular volume (ECV) were quantitatively measured. RESULTS: Ten CTEPH patients (77%) had abnormal 68 Ga-FAPI-04 uptake in RV, mainly located in the free wall, which was significantly higher than that in controls (TBRRV: 2.4 ± 0.9 vs 1.0 ± 0.1, P < 0.001). The TBRRV correlated positively with the thickness of RV wall (r = 0.815, P = 0.001) and inversely with RV fraction area change (RVFAC) (r = - 0.804, P = 0.001) and tricuspid annular plane systolic excursion (TAPSE) (r = - 0.678, P = 0.011). No correlation was found between 68 Ga-FAPI-04 activity and CMR imaging parameters. CONCLUSION: Fibroblast activation in CTEPH, measured by 68 Ga-FAPI-04 imaging, is mainly localised in the RV free wall. Enhanced fibroblast activation reflects the thickening of the RV wall and decreased RV contractile function.

[Correlations of 18F-Fluorodeoxyglucose Positron Emission Tomography/Magnetic Resonance Imaging Parameters with the Pathological Differentiation of Head and Neck Squamous Cell Carcinoma and Their Diagnostic Efficiencies].

Objective To evaluate the correlation of the positron emission tomography/magnetic resonance imaging (PET/MR) parameters with the pathological differentiation of head and neck squamous cell carcinoma(HNSCC) and the diagnostic efficiencies of PET/MR parameters. Methods Patients with clinical suspicion of HNSCC were included and underwent PET/MR scan. HNSCC was pathologically confirmed in all these patients. The PET/MR examination included PET and MR sequences of diffusion-weighted imaging (DWI) and T2-and T1-weighted imaging. The multiple parameters of PET/MR included the mean values of apparent diffusion coefficient(ADCmean) and the maximum and mean values of standardized uptake value (SUVmax and SUVmean) were measured and estimated. The correlations of all the parameters and distribution between the different tumor differentiation groups were analyzed. Logistic regression was utilized to build the model as the PET/MR combined parameter for predicting the differentiation by multiple parameters of PET/MR. The receiver operating characteristic curve was calculated for each parameter and the combination. Results Totally 23 patients were included in this study:9 patients (9 males and 0 female) had well-differentiated tumor,with an average age of (61.0±6.8)years;14 cases had moderately-differentiated (n=10) or poorly-differentiated tumors (n=4),with an average age of (62.0±9.1) years. All the patients were males. There was statistical correlation between SUVmean and SUVmax (P<0.001);however,ADCmean showed no statistical correlation with SUVmax and with SUVmean (P=0.42,P=0.13). ADCmean and SUVmean showed significant difference between well-differentiated group and moderately-poorly-differentiated group (P=0.005,P=0.007). Compared with the individual parameters,the combination of PET/MR parameters with SUVmean and ADCmean had higher efficacy in predicting tumor differentiation,with an area under curve of 0.84. Conclusions The distributions of ADCmean,SUVmax and SUVmean differ among HNSCC with different pathological differentiation. Compared with the individual parameters,the combination of the PET/MR parameters has higher efficiency in predicting tumor differentiation.

[Value of 68Ga-DOTA-TATE Positron Emission Tomography/Computed Tomography in the Localization of Culprit Tumors Causing Osteomalacia with Negative 99mTc-HYNIC-TOC Single Photo Emission Computed Tomography].

Objective To analyze 68Ga-DOTA-TATE positron emission tomography/computed tomography (PET/CT) imaging features of tumor-indud osteomalacia (TIO) patients with negative 99mTc-HYNIC-TOC single photo emission computed tomography (SPECT) findings and to investigate the value of 68Ga-DOTA-TATE PET/CT in accurate localization of culprit tumors.Methods We retrospectively analyzed 68Ga-DOTA-TATE PET/CT imaging features including location,size,density,the maximum and mean standardized uptake value in 37 TIO patients with negative 99mTc-HYNIC-TOC SPECT findings.Results Totally 37 solitary TIO tumors,including 35 phosphaturic mesenchymal tumors and 2 spindle cell tumors confirmed by pathological examinations,were detected via 68Ga-DOTA-TATE PET/CT scans in the included 37 cases. These 37 TIO tumors showed obviously increased activities,with an maximum standardized uptake value of 7.2±4.3 and mean standardized uptake value of 4.3±2.4. The average maximum diameter was (1.9±0.7) cm. The majority of the tumors occurred in the lower extremities (19/37),followed by the trunk (11/37),maxillary/mandibular bone (5/37),and upper extremities (2/37). In addition,24 bone lesions were located in long bones of lower extremities (13/24),most of which demonstrated eccentric growth (8/13). Osteolytic changes (14/24) were observed mainly in the lesions via the corresponding CT imaging;meanwhile,sclerotic changes presented in nine cases. Of the 13 soft-tissue lesions,the majority (10/13) showed well-circumscribed isodense or hypodense nodules on the CT images,with spot calcification in one lesion located in the pleura.Conclusions 68Ga-DOTA-TATE PET/CT scans can detect the TIO culprit tumors miss-diagnosed by 99mTc-HYNIC-TOC SPECT. Somatostatin-receptors highly expressed lesions with focal osteolytic or osteosclerotic change in bone and isodense or hypodense nodules in soft tissue will favor the diagnosis of TIO tumors.

Potential application of neogalactosylalbumin in positron emission tomography evaluation of liver function.

AIM: To investigate the evaluation of neogalactosylalbumin (NGA) for liver function assessment based on positron emission tomography technology. METHODS: Female Kunming mice were assigned randomly to two groups: fibrosis group and normal control group. A murine hepatic fibrosis model was generated by intraperitoneal injection of 10% carbon tetrachloride (CCl4) at 0.4 mL every 48 h for 42 d. 18F-labeled NGA ([18F]FNGA) was synthesized and administered at a dosage of 3.7 MBq/mouse to both fibrosis mice and normal control mice. Distribution of [18F]FNGA amongst organs was examined, and dynamic scanning was performed. Parameters were set up to compare the uptake of tracers by fibrotic liver and healthy liver. Serologic tests for liver function were also performed. RESULTS: The liver function of the fibrosis model mice was significantly impaired by the use of CCl4. In the fibrosis model mice, hepatic fibrosis was verified by naked eye assessment and pathological analysis. [18F]FNGA was found to predominantly accumulate in liver and kidneys in both control group (n = 21) and fibrosis group (n = 23). The liver uptake ability (LUA), peak time (Tp), and uptake rate (LUR) of [18F]FNGA between healthy liver (n = 8) and fibrosis liver (n = 10) were significantly different (P < 0.05, < 0.01, and < 0.05, respectively). LUA was significantly correlated with total serum protein level (TP) (P < 0.05). Tp was significantly correlated with both TP and glucose (Glu) concentration (P < 0.05 both), and LUR was significantly correlated with both total bile acid and Glu concentration (P < 0.01 and < 0.05, respectively). CONCLUSION: [18F]FNGA mainly accumulated in liver and remained for sufficient time. Functionally-impaired liver showed a significant different uptake pattern of [18F]FNGA compared to the controls.

[Features of Acquired Immunodeficiency Syndrome-related Lymphoma on (18)F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography].

OBJECTIVE: To analyze the imaging features of (18)F-fluorodeoxyglucose (¹8F-FDG) positron emission tomography(PET)/computed tomography (CT) in acquired immune deficiency syndrome-related lymphoma (ARL) patients correlated with their clinical signs, symptoms, and treatments. METHODS: Five ARL patients underwent ¹8F-FDG PET/CT at Peking Union Medical College Hospital from October 2008 to January 2013. Two patients received two additional follow-up studies 6 months later. RESULTS: Among these 5 patients, ¹8FDG-PET/CT helped in diagnosis of two patient and changed therapeutic strategy in other two patients. In two patients underwent ¹8F-FDG PET/CT brain scans, low-metabolism lesion was newly found in cerebral cortex. Of 4 patients receiving highly active antiretroviral therapy, PET/CT also demonstrated diffusely elevated ¹8F-FDG uptake in subcutaneous adipose tissue in two patients. CONCLUSION: ¹8F-FDG PET/CT is a highly useful tool in the diagnosis and treatment of ARL patients, in particular in the identification of associated encephalopathy and lipodystrophy.

[Clinical application of radionuclide bone scintigraphy in diagnosis of avascular osteonecrosis in patients with severe acute respiratory syndrome in convalescence].

OBJECTIVE: To evaluate the clinical value of radionuclide bone scintigraphy in diagnosis of avascular osteonecrosis in patients with severe acute respiratory syndrome (SARS) in convalescence. METHODS: We performed three-phase bone scintigraphy of femoral head regions and whole-body bone scan in SARS patients 4-6 months after they recovered from the syndrome, and then compared the results with simultaneous MRI. RESULTS: Typical avascular necrosis at different stages and severities was found on bone scintigraphy at 31 femoral heads of 16 SARS patients, 97% of which were MRI positive. Suspicious necrosis was found at 42 femoral heads of 23 patients, 67% of which were MRI negative. Among 30 patients with normal three-phase scintigraphic results, 10% of whom were suspicious on MRI. In addition, abnormal distributions of radioactivity were observed in other bones on the whole-body bone scans of 29 patients, including osteonecrosis of knees in 15 patients. CONCLUSIONS: Radionuclide bone scintigraphy is valuable in early diagnosis of osteonecrosis in SARS patients in convalescence. It provides a mutually supplementary tool for MRI.