Comparison of integrated PET/MRI with PET/CT in evaluation of endometrial cancer: a retrospective analysis of 81 cases.

BACKGROUND: The objective of this study was to compare the diagnostic value of integrated PET/MRI with PET/CT for assessment of regional lymph node metastasis and deep myometrial invasion detection of endometrial cancer. METHODS: Eighty-one patients with biopsy-proven endometrial cancer underwent preoperative PET/CT (n = 37) and integrated PET/MRI (n = 44) for initial staging. The diagnostic performance of PET/CT and integrated PET/MRI for assessing the extent of the primary tumor and metastasis to the regional lymph nodes was evaluated by two experienced readers. Histopathological and follow-up imaging results were used as the gold standard. McNemar's test was employed for statistical analysis. RESULTS: Integrated PET/MRI and PET/CT both detected 100% of the primary tumors. Integrated PET/MRI proved significantly more sensitivity and specificity than PET/CT in regional lymph node metastasis detection (P = 0.015 and P < 0.001, respectively). The overall accuracy of myometrial invasion detection for PET/CT and Integrated PET/MRI was 45.9% and 81.8%, respectively. Integrated PET/MRI proved significantly more accurate than PET/CT (P < 0.001). CONCLUSION: Integrated PET/MRI, which complements the individual advantages of MRI and PET, is a valuable technique for the assessment of the lymph node metastasis and myometrial invasion in patients with endometrial cancer.

Comparing PET/MRI with PET/CT for Pretreatment Staging of Gastric Cancer.

18F-FDG PET/MRI has been applied to the diagnosis and preoperative staging in various tumor types; however, reports using PET/MRI in gastric cancer are rare because of motion artifacts. We investigated the value of PET/MRI for preoperative staging compared with PET/CT in gastric cancer (GC). Thirty patients with confirmed GC underwent PET/CT and PET/MRI. TNM staging for each patient was determined from the PET/MRI and PET/CT images. The diagnostic performance of PET/MRI and PET/CT was calculated compared with the pathologic TNM stage. The two methods were compared using statistical analyses. The accuracy for T staging between PET/MRI and PET/CT was 76.9% vs. 57.7%, respectively. In T1 and T4a staging, the sensitivity and specificity for PET/MRI vs. PET/CT was 1.0 vs. 0.6 and 1.0 vs. 0.8, respectively. The area under the curve (AUC) for PET/MRI vs. PET/CT was 1.00 vs. 0.78 in the T1 stage, 0.73 vs. 0.66 in the T2 stage, 0.72 vs. 0.57 in the T3 stage, and 0.86 vs. 0.83 in the T4 stage. The accuracy for N staging of PET/MRI vs. PET/CT was 53.9% vs. 34.0%, and that for N0 vs. N+ was 85.0% vs. 77.0%. The sensitivity for PET/MRI in N3 staging was 0.67 and 0 for PET/CT. There was a statistically significant difference in the AUC for N1 staging (PET/MRI vs. PET/CT, 0.63 vs. 0.53, p = 0.03). SUVmax/ADC positively correlated with tumor volume and Ki-67. PET/MRI performs more accurately in TNM staging compared with PET/CT and is optimal for accurate N staging. SUVmax/ADC has positive correlations with tumor volume and Ki-67.

Partial improvement in performance of patients with severe Alzheimer's disease at an early stage of fornix deep brain stimulation.

Deep brain stimulation is a therapy for Alzheimer's disease (AD) that has previously been used for mainly mild to moderate cases. This study provides the first evidence of early alterations in performance induced by stimulation targeted at the fornix in severe AD patients. The performance of the five cases enrolled in this study was scored with specialized assessments including the Mini-Mental State Examination and Clinical Dementia Rating, both before and at an early stage after deep brain stimulation. The burden of caregivers was also evaluated using the Zarit Caregiver Burden Interview. As a whole, the cognitive performance of patients remained stable or improved to varying degrees, and caregiver burden was decreased. Individually, an improved mental state or social performance was observed in three patients, and one of these three patients showed remarkable improvement in long-term memory. The conditions of another patient deteriorated because of inappropriate antipsychotic medications that were administered by his caregivers. Taken together, deep brain stimulation was capable of improving some cognitive aspects in patients with severe AD, and of ameliorating their emotional and social performance, at least at an early stage. However, long-term effects induced by deep brain stimulation in patients with severe AD need to be further validated. More research should focus on clarifying the mechanism of deep brain stimulation. This study was registered with ClinicalTrials.gov (NCT03115814) on April 14, 2017.

Multi-modality molecular imaging characteristics of dementia with Lewy bodies.

Objective Dementia with Lewy bodies (DLB) is a common type of neurodegenerative dementia. Molecular neuroimaging using dopamine transporter (DaT), Pittsburgh compound B (PIB), and fluorodeoxyglucose (FDG) positron emission tomography (PET) has advantages in detecting dopaminergic neuron loss, abnormal amyloid ß-protein deposition, and glucose metabolism changes in patients with neurodegenerative disorders. However, the multi-modality molecular imaging features of patients with DLB have rarely been reported. Methods Five patients with a probable diagnosis of DLB were enrolled. PET/magnetic resonance imaging was performed with three tracers: 11C-ß-CFT, 11C-PIB, and 18F-FDG. Clinical and imaging characteristics were analyzed. Results All patients with DLB showed reduced uptake in the bilateral putamen on DaT PET, increased uptake throughout the cerebral cortex on PIB PET, and intact metabolism of the posterior cingulate gyrus on FDG PET. Conclusion Multimodal molecular imaging is helpful for early diagnosis of DLB. Studies with larger sample sizes are needed to confirm the molecular imaging differences between DLB and Alzheimer's disease and Parkinson's disease dementia.

Can Carrier-Mediated Delivery System Promote the Development of Antisense Imaging?

PURPOSE: We aimed to explore the feasibility of transfection methods for antisense imaging. PROCEDURES: Antisense oligonucleotides (ASON) targeted to the mRNA of hTERT gene were synthesized and labeled with Technetium-99m and fluorescein isothiocyanate (FITC), respectively. Then, ASON was combined with transfection reagent Lipofectamine 2000 and Xfect(TM), named Lipo-ASON and Xfect-ASON, respectively. After transfection, the labeled ASON was characterized in hNPCs-G3 and hRPE cells. Reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were performed to assay the hTERT mRNA and protein levels after hNPCs-G3 cells were incubated with Lipo-ASON, Xfect-ASON, and naked ASON. In addition, Lipo-ASON, Xfect-ASON, and naked ASON were injected into tumor-bearing mice, and the biodistribution in vivo was performed. RESULTS: The presence of two transfection reagents significantly increased intracellular uptake of radiolabeled ASON in both cell lines compared with naked ASON (p < 0.05). However, there was no significant difference in cellular uptake rates of Lipo-ASON and Xfect-ASON between hNPCs-G3 and hRPE cells. In comparison with naked ASON, the fluorescence intensity was strongly enhanced after binding to transfection reagents. Furthermore, the levels of hTERT mRNA and protein were significantly reduced in cells treated with Lipo-ASON and Xfect-ASON (p < 0.05), but naked ASON had no significant effect on hTERT expression level. The biodistribution study indicated that tumor radioactivity uptake of radiolabeled ASON for naked ASON, Lipo-ASON, and Xfect-ASON group was low and shown no significant difference in vivo. CONCLUSIONS: Lipofectamine transfection and Xfect(TM) transfection were not effective delivery methods of ASON for antisense imaging.

Hyperaccumulation of (18)F-FDG in order to differentiate solid pseudopapillary tumors from adenocarcinomas and from neuroendocrine pancreatic tumors and review of the literature.

Solid pseudopapillary tumors (SPT) are rare, unique pancreatic tumors with benign entity and low malignant potential. Limited information is available in the literature reporting their accumulation of fluorine-18 fluoro deoxyglucose ((18)F-FDG) using positron emission tomography/computed tomography (PET/CT). The aim of this retrospective study was to define t he uptake-accumulation of (18)F-FDG PET/CT in a comparatively large cohort of SPT, and to compare their uptake with the uptake of (18)F-FDG in pancreatic ductal adenocarcinomas (PAC) and neuroendocrine tumors (PNET). Between June 2007 and January 2013, 18 pathologically proven SPT were identified from the total of patients studied by PET/CT in our Center, including 13 women and 5 men, aging from 23 to 56 years old (mean age, 38.5 years). Malignant SPT was histologically classified using the WHO criteria. Eighty-six PAC patients and 28 PNET patients were also identified and included in this study for comparison. Positron emission tomography results were considered as positive if focal accumulation of (18)F-FDG exceeded the surrounding normal pancreatic tissue. Regions of interest were drawn on the pancreatic lesions, and the maximal standardized uptake values (SUVmax values) were calculated. The mean values of SUVmax were compared with independent-samples t test or with the nonparametric Mann-Whitney U method. Correlation of SUVmax values and tumor size were analyzed in cases of SPT. Receiver operating characteristics (ROC curve) were used to study the efficiency of SUV values for the differential diagnosis between SPT versus (vs) PAC and SPT vs PNET. A value of P<0.05 was considered statistically significant. All SPT cases were (18)F-FDG-PET positive, with SUVmax values ranging from 3.5-18.3. The SUVmax values of SPT had poor correlation with tumor size, and no significant difference by gender and age. Areas under the curve ROC were 0.619 and 0.526, respectively for the differentiation of SPT from PNET and PAC tumors. Five SPT tumors were malignant, and exhibited relatively low (18)F-FDG uptake (SUVmax range, 3.0-4.5) except a tumor after recurrence (SUVmax 17.7). Images of CT were of low dose and thus were not evaluated. In conclusion, our results suggest that SPT benign or malignant are consistently hyperaccumulating (18)F-FDG above SUVmax 3. Differentiation from PAC and PNET if only based on the higher SUVmax values was not possible but if based on lower SUVmax, of ≤2.6 (in 14%) and ≤2.5 (in 21,4%) of PAC and PNET, respectively, these pancreatic tumors could be differentiated from SPT.

The influence of interpreters' professional background and experience on the interpretation of multimodality imaging of pulmonary lesions using 18F-3'-deoxy-fluorothymidine and 18F-fluorodeoxyglucose PET/CT.

OBJECTIVE: Based on the results of a recently accomplished multicenter clinical trial for the incremental value of a dual-tracer (18F-FDG and 18F-FLT), dual-modality (PET and CT) imaging in the differential diagnosis of pulmonary lesions, we investigate some issues that might affect the image interpretation and result reporting. METHODS: The images were read in two separate sessions. Firstly the images were read and reported by physician(s) of the imaging center on completion of each PET/CT scanning. By the end of MCCT, all images collected during the trial were re-read by a collective of readers in an isolated, blinded, and independent way. RESULTS: One hundred sixty two patients successfully passed the data verification and entered into the final analysis. The primary reporting result showed adding 18F-FDG image information did not change the clinical performance much in sensitivity, specifity and accuracy, but the ratio between SUVFLT and SUVFDG did help the differentiation efficacy among the three subgroups of patients. The collective reviewing result showed the diagnostic achievement varied with reading strategies. ANOVA indicated significant differences among (18)F-FDG, (18)F-FLT in SUV (F = 14.239, p = 0.004). CT had almost the same diagnostic performance as 18F-FLT. When the 18F-FDG, 18F-FLT and CT images read in pair, both diagnostic sensitivity and specificity improved. The best diagnostic figures were obtained in full-modality strategy, when dual-tracer PET worked in combination with CT. CONCLUSIONS: With certain experience and training both radiologists and nuclear physicians are qualified to read and to achieve the similar diagnostic accuracy in PET/CT study. Making full use of modality combination and selecting right criteria seems more practical than professional back ground and personal experience in the new hybrid imaging technology, at least when novel tracer or application is concerned.

Solid pseudopapillary tumor of the pancreas and concomitant urogenital malformations in a young woman.

Solid pseudopapillary tumor (SPT) of the pancreas is a rare pancreatic tumor with low malignant potential. It occurs characteristically more often in young women. SPT associated with extra- and pancreatic anomalies are occasionally reported. Here we report a case of pancreatic SPT with concomitant urogenital malformations including solitary kidney and uterus didelphys in a 25-year-old woman. The patient underwent central pancreatectomy, and SPT was confirmed with pathological results. Recurrence or metastasis was not found after 14 months of follow-up.

[Value of combined CT coronary angiography and adenosine stress myocardial perfusion scintigraphy for diagnosis of coronary artery disease].

OBJECTIVE: To assess the accuracy and feasibility of combination of CT coronary angiography (CTCA) and adenosine stress myocardial perfusion scintigraphy (MPS) for diagnosis of coronary artery disease (CAD). METHODS: CTCA, MPS were performed in 105 patients with suspected or diagnosed CAD within 4 weeks before coronary angiography (CAG) examination. RESULTS: The sensibility, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were 97.1%, 75.0%, 88.2%, 93.1% and 89.5%, respectively, for CTCA; 79.7%, 63.9%, 80.9%, 62.2% and 74.3%, respectively, for MPS and 97.2%, 98.5%, 98.5%, 89.7% and 95.2%, respectively, for CTCA + MPS. CONCLUSION: Combination of CTCA and adenosine stress MPS, which provided both anatomical and functional information of coronary vessels, could significantly increase the specificity and PPV of diagnosing CAD with CTCA.

The Use of CT Perfusion to Determine Microvessel Density in Lung Cancer: Comparison with FDG-PET and Pathology.

OBJECTIVE: To investigate the validity of CT perfusion in assessing angiogenic activity of lung cancer. METHODS: Fifty-six patients with lung cancer scheduled for elective surgical resection received 16-slice helical CT perfusion imaging. Time-density curve (TDC), blood flow (BF), blood volume (BV), mean transmit time (MTT) and permeability surface area product (PS) were calculated. 18F-deoxyglucose-positron emission tomography (FGD-PET) was carried out in 14 out of the 56 patients to calculate standardized uptake values (SUVs). Tumor microvessel density (MVD) was examined using CD34 immunohistochemical staining of the resected tumor tissue. Pearson's correlation analysis was used to evaluate potential correlation between CT perfusion parameters and MVD or SUV. RESULTS: Average time to peak height (TPH) of the TDCs (including two types of TDC) was 24.38±5.69 seconds. Average BF, BV, MTT and PS were 93.42±53.45 ml/100g/min,93.42±53.45 ml/100g,6.83±4.51 s and 31.92±18.73 ml/100g/min, respectively. Average MVD was 62.04±29.06/HPF. The mean SUV was 6.33±3.26. BF was positively correlated with MVD (r=0.620,P<0.01) and SUV (r=0.891, P<0.01). PS was also positively correlated with SUV (r=0.720, P<0.05). A positive correlation was also observed between tumor MVD and SUV (r=0.915, P<0.01). CONCLUSIONS: CT perfusion imaging is a reliable tool to evaluate the tumor neovascularity of lung cancer.

Monitoring early responses to irradiation with dual-tracer micro-PET in dual-tumor bearing mice.

AIM: To monitor the early responses to irradiation in primary and metastatic colorectal cancer (CRC) with (18)F-fluorothymidine ((18)F-FLT) and (18)F-fluorodeoxyglucose ((18)F-FDG) small-animal position emission tomography (micro-PET). METHODS: The primary and metastatic CRC cell lines, SW480 and SW620, were irradiated with 5, 10 and 20 Gy. After 24 h, the cell cycle phases were analyzed. A dual-tumor-bearing mouse model of primary and metastatic cancer was established by injecting SW480 and SW620 cells into mice. micro-PET with (18)F-FLT and (18)F-FDG was performed before and 24 h after irradiation with 5, 10 and 20 Gy. The region of interest (ROI) was drawn over the tumor and background to calculate the ratio of tumor to non-tumor (T/NT) in tissues. Immunohistochemical assay and Western blotting were used to examine the levels of integrin ß(3,) Ki-67, vascular endothelial growth factor receptor 2 (VEGFR2) and heat shock protein 27 (HSP27). RESULTS: The proportion of SW480 and SW620 cells in the G(2)-M phase was decreased with an increasing radiation dose. The proportion of SW480 cells in the G(0)-G(1) phase was increased from 48.33% ± 4.55% to 87.09% ± 7.43% (P < 0.001) and that of SW620 cells in the S-phase was elevated from 43.57% ± 2.65% to 66.59% ± 7.37% (P = 0.021). In micro-PET study, with increasing dose of radiation, (18)F-FLT uptake was significantly reduced from 3.65 ± 0.51 to 2.87 ± 0.47 (P = 0.008) in SW480 tumors and from 2.22 ± 0.42 to 1.76 ± 0.45 (P = 0.026) in SW620 tumors. (18)F-FDG uptake in SW480 and SW620 tumors was reduced but not significantly (F = 0.582, P = 0.633 vs F = 0.273, P = 0.845). Dose of radiation was negatively correlated with (18)F-FLT uptake in both SW480 and SW620 tumors (r = -0.727, P = 0.004; and r = -0.664, P = 0.009). No significant correlation was found between (18)F-FDG uptake and radiation dose in SW480 or SW620 tumors. HSP27 and integrin ß(3) expression was higher in SW480 than in SW620 tumors. The T/NT ratio for (18)F-FLT uptake was positively correlated with HSP27 and integrin ß(3) expression (r = 0.924, P = 0.004; and r = 0.813, P = 0.025). CONCLUSION: (18)F-FLT is more suitable than (18)F-FDG in monitoring early responses to irradiation in both primary and metastatic lesions of colorectal cancer.

Feasibility of whole body diffusion weighted imaging in detecting bone metastasis on 3.0T MR scanner.

OBJECTIVE: To evaluate the feasibility of whole body diffusion weighted imaging (DWI) in bone metastasis detection using bone scintigraphy as comparison. METHODS: Forty-five patients with malignancy history were enrolled in our study. All the patients received the whole body DWI and bone scintigraphy scan within 1 week. The magnetic resonance (MR) examination was performed on 3.0T MR scanner using embedded body coil. The images were reviewed separately by two radiologists and two nuclear medicine physicians, who were blinded to the results of the other imaging modality. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the two techniques for detecting bone metastasis were analyzed. RESULTS: A total of 181 metastatic lesions in 77 regions of 34 patients were detected by whole body DWI, and 167 metastatic lesions in 76 regions of 31 patients were identified by bone scintigraphy. The patient-based sensitivity and PPV of whole body DWI and bone scintigraphy were similar (89.5% vs. 81.6%, 97.1% vs. 91.2%), whereas, the patient-based specificity and NPV of whole body DWI were obviously higher than those of bone scintigraphy (85.7% vs. 57.1%, 60.0% vs. 36.4%). Ten regions negative in scintigraphy but positive in whole body DWI, mainly located in spine, pelvis, and femur; nine regions only detected by scintigraphy, mainly located in skull, sternum, clavicle, and scapula. The region-based sensitivity and specificity of whole body DWI were slightly higher than those of bone scintigraphy (89.5% vs. 88.4%, 95.6% vs. 87.6%). CONCLUSION: Whole body DWI reveals excellent concordance with bone scintigraphy regarding detection of bone metastasis, and the two techniques are complementary for each other.