Correlations of F-Fluorodeoxyglucose Positron Emission Tomography/Magnetic Resonance Imaging Parameters with the Pathological Differentiation of Head and Neck Squamous Cell Carcinoma and Their Diagnostic Efficiencies / 中国医学科学院学报

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(ADC) and the maximum and mean values of standardized uptake value (SUV and SUV) 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 SUV and SUV (P<0.001);however,ADC showed no statistical correlation with SUV and with SUV (P=0.42,P=0.13). ADC and SUV 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 SUV and ADC had higher efficacy in predicting tumor differentiation,with an area under curve of 0.84. Conclusions The distributions of ADC,SUV and SUV 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 Ga-DOTA-TATE Positron Emission Tomography/Computed Tomography in the Localization of Culprit Tumors Causing Osteomalacia with Negative Tc-HYNIC-TOC Single Photo Emission Computed Tomography / 中国医学科学院学报

Objective To analyze Ga-DOTA-TATE positron emission tomography/computed tomography (PET/CT) imaging features of tumor-indud osteomalacia (TIO) patients with negative Tc-HYNIC-TOC single photo emission computed tomography (SPECT) findings and to investigate the value of Ga-DOTA-TATE PET/CT in accurate localization of culprit tumors.Methods We retrospectively analyzed Ga-DOTA-TATE PET/CT imaging features including location,size,density,the maximum and mean standardized uptake value in 37 TIO patients with negative Tc-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 Ga-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 Ga-DOTA-TATE PET/CT scans can detect the TIO culprit tumors miss-diagnosed by Tc-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.

Features of Acquired Immunodeficiency Syndrome-related Lymphoma on (18)F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography / 中国医学科学院学报

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Clinical application of radionuclide bone scintigraphy in diagnosis of avascular osteonecrosis in patients with severe acute respiratory syndrome in convalescence / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the clinical value of radionuclide bone scintigraphy in diagnosis of avascular osteonecrosis in patients with severe acute respiratory syndrome (SARS) in convalescence.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>Radionuclide bone scintigraphy is valuable in early diagnosis of osteonecrosis in SARS patients in convalescence. It provides a mutually supplementary tool for MRI.</p>