Multimodality imaging in the diagnosis of bioprosthetic aortic valve endocarditis: A case report.

Introduction: Prosthetic valve infective endocarditis (PVE) is a diagnostic challenge even in the era of multimodality cardiovascular imaging. Case presentation: The patient was a 67-year-old male with a three-year history of bioprosthetic aortic valve replacement who presented with persistent fever and negative blood cultures. The initial transthoracic echocardiography revealed a thickened aortic root. An abscess formation was visualized upon subsequent three-dimensional transesophageal echocardiography and positron emission tomography/computerized tomography (PET/CT). The patient underwent an urgent necrotic tissue debridement and a redo Bentall surgery. The real-time polymerase chain reaction of excised tissues was positive for Streptococcus. Clinical discussion: The diagnosis of PVE and its complications requires the integration of clinical, microbiological, and serial imaging data. Although advanced imaging modalities like PET/CT allow a timely diagnosis and management, their routine use in resource-limited scenarios is difficult. Conclusion: Multimodality cardiovascular imaging plays an important role in the diagnosis of PVE. Serial echocardiographic and clinical assessments are possible alternatives when the access to advanced cardiovascular imaging modalities is limited.

Predictive value of serological factors, maximal standardized uptake value and ratio of Ki67 in patients diagnosed with non-Hodgkin's lymphoma.

The present study aimed to determine the prognostic value of serological factors, positron emission tomography/computed tomography maximal standardized uptake value (SUVmax) and the immunohistochemical index ratio of Ki67 (Ki67%) for patients diagnosed with non-Hodgkin's lymphoma (NHL). A total of 120 patients with NHL who received regular chemotherapy and underwent serological, radiological and pathological examinations at Shanghai Tongji Hospital between July 2015 and March 2019 were retrospectively analyzed. Spearman's correlation analysis was preformed to describe the associations between different categories of indicators. Kaplan-Meier analysis and log-rank test were used to compare the survival of different subgroups. Receiver operating characteristic curves were generated to assess the predictive value of prominent indicators derived from Cox regression analysis. The results indicated that inflammatory cytokines were strongly associated with tumor burden indicators. The correlation between SUVmax and Ki67% was significant, and SUVmax of the biopsy site exhibited a stronger association with Ki67% (Ρ=0.529, P<0.001) compared with SUVmax of the whole body (Ρ=0.395, P=0.017). C-reactive protein (CRP), lactate dehydrogenase (LDH) and interleukin-6 could differentiate the survival status of patients with NHL, whereas no statistical significance in the estimation of overall survival (OS) was obtained for SUVmax and Ki67%. SUVmax of the biopsy site had only a limited value in the estimation of progression-free survival (PFS), whereas LDH, ß2-microglobulin (ß2-mg) and CRP were independent predictors of both OS and PFS with high sensitivity and specificity. Among all indicators, CRP and ß2-mg could predict both survival status and complete remission of patients with NHL, whereas the prognostic value of SUVmax and Ki67% requires further study and discussion.

Study of the relationship between brain injury and glucose metabolism in rat model of cardiac arrest / 中华急诊医学杂志

Objective To determine the relationship between brain injury and cerebral glucose metabolism in rat model of cardiac arrest. Methods Asphyxia-induced cardiac arrest model was established. Forty-two male Wistar rats were randomly assigned to sham or experimental groups. Rats in the CA4,CA6 and CA8 group were treated with cardiopulmonary resuscitation(CPR) 4 min, 6 min and 8 min after cardiac arrest, respectively. The maximum standardized uptake value (SUVmax) of glucose was detected by PET, and neural defi cit score (NDS) were evaluated at 24 h and 72 h after ROSC. The numbers of injured neurons and apoptotic cells and the protein level of hexokinase I (HXK I) were measured at 72 h after ROSC. Results SUVmax, NDS and the level of HXK I were all decreased after ROSC, and interestingly, this declination of these markers was correlated with the prolongation of the duration of CA, the longer duration of CA the more declination of these biomarkers. Accordingly, the number of injured neurons and apoptotic cells increased were correlated with duration of CA, and thus CA8 group had greater numbers of those cells than CA6 group and CA4 group (P<0.05),and CA6 group had greater numbers of those cells than CA4 group(P<0.05). In addition, the SUVmaxwas positively correlated with NDS(P<0.05), and negatively correlated with the numbers of injured neurons and apoptotic index(P<0.05). Conclusions The degree of brain injury is associated with cerebral glucose metabolism, and PET may become a novel method to assess the severity of brain damage after CA.

Optimization of scan initiation timing after 11C-methionine administration for the diagnosis of suspected recurrent brain tumors.

OBJECTIVE: 11C-Methionine (MET) positron emission tomography (PET) imaging is a valuable technique for the evaluation of primary and recurrent brain tumors. Many studies have used MET-PET for data acquisition starting at 20 min after the tracer injection, while others have used scan initiation times at 5-15 min postinjection. No previous studies have identified the best acquisition timing during MET-PET imaging for suspected recurrent brain tumors. Here we sought to determine the optimal scan initiating timing after MET administration for the detection of recurrent brain tumors. MATERIALS AND METHODS: Twenty-three consecutive patients with suspected recurrent brain tumors underwent MET-PET examinations. Brain PET images were reconstructed from the four serial data sets (10-15, 15-20, 20-25, and 25-30 min postinjection) that were obtained using the list-mode acquisition technique. We determined the maximal standardized uptake values (SUVmax) of the target lesions and the target-to-normal-tissue ratios (TNRs), calculated as the SUVmax to the SUVmean of a region of interest placed on the normal contralateral frontal cortex. Target lesions without significant MET uptake were excluded. RESULTS: Thirty-one lesions from 23 patients were enrolled. There were no significant differences in MET SUVmax or TNR values among the PET images that were reconstructed with the data extracted from the four phases postinjection. CONCLUSION: The MET uptake in the suspected recurrent brain tumors was comparable among all data extraction time phases from 10 to 30 min postinjection. The scan initiation time of MET-PET at 10 min after the injection is allowable for the detection of recurrent brain tumors. The registration identification number of the original study is 1002.

Imaging manifestation of elastofibroma dorsi in18F-FDG PET-CT / 中国医学装备

Objective:To explore the imaging manifestation of elastofibroma dorsi in18F-FDG PET-CT.Methods: The back soft tissue mass of abnormal metabolism was found by18F-FDG PET-CT scan, and then delayed imaging for the mass was performed.Results: Surgical pathology confirmed it was elastofibroma. The tumor showed clear boundary, there was no damage to adjacent ribs, and this method was mild radioactivity uptake, besides, metabolism was decreased at delayed imaging in18F-FDG PET-CT; the patient had no correlated clinical symptomatic and apparent positive physical signs.Conclusion: Tumor detection rate of18F-FDG PET-CT for elastofibroma dorsi is higher than normal CT detection. And the delayed manifestation for metabolism were decrease. Therefore, these situation accordance to benign tumor metabolism changes.

Ga-68 DOTANOC PET/CT imaging in detection of primary site in patients with metastatic neuroendocrine tumours of unknown origin and its impact on clinical decision making: experience from a tertiary care centre in India.

BACKGROUND: Neuroendocrine tumours (NETs) are rare, heterogeneous group of tumours which usually originate from small, occult primary sites and are characterized by over-expression of somatostatin receptors (SSTRs). Positron emission tomography/computed tomography (PET/CT) using Ga-68-labeled-somatostatin-analogues have shown superiority over other modalities for imaging of NETs. The objective of the study was to retrospectively evaluate the efficacy of Ga-68 DOTANOC PET/CT imaging in detecting the primary site in patients with metastatic NETs of unknown origin and its impact on clinical decision making in such patients. METHODS: Between December 2011 and September 2014, a total of 263 patients underwent Ga-68 DOTANOC PET/CT study in our department for various indications. Out of them, 68 patients (45 males, 23 females; mean age, 54.9±10.7 years; range, 31-78 years) with histopathologically proven metastatic NETs and unknown primary site (CUP-NET) on conventional imaging, who underwent Ga-68 DOTANOC PET/CT scan as part of their clinical work-up were included for analyses. Histopathology (wherever available) and/or follow-up imaging were taken as reference standard. Quantitative estimation of SSTR expression in the form of maximal standardized uptake value (SUVmax) of detected primary and metastatic sites was calculated. Follow-up data of individual patients was collected through careful survey of hospital medical records and telephonic interviews. RESULTS: Maximum patients presented to our department with hepatic metastasis (50 out of 68 patients) and grade I NETs (>50%). Ga-68 DOTANOC PET/CT scan identified primary sites in 40 out of these 68 patients i.e., in approximately 59% patients. Identified primary sites were: small intestine [19], rectum [8], pancreas [7], stomach [4], lung [1] and one each in rare sites in kidney and prostate. In one patient, 2 primary sites were identified (one each in stomach and duodenum). Mean SUVmax of the detected primary sites was 25.1±18.0 (median: 16.25; range, 2.1-150). Significant positive correlation was found between SUVmax of detected primary site and SUVmax of the histopathologically proven sites of metastasis (r=0.662; P<0.0001). Based on the findings of the Ga-68 DOTANOC PET/CT scan, 3 out of 40 patients underwent definitive treatment for their primary tumour (1 gastric, 1 ileal and 1 prostatic tumour). One patient was being planned for resection of primary rectal lesion at the time of data-collection. Thirty-six out of 68 patients were started on long-acting somatostatin analogues or chemotherapy or targeted therapy. Two patients underwent multiple cycles of peptide receptor radionuclide therapy (PRRNT) using (90)Y and (177)Lu labeled somatostatin analogues. CONCLUSIONS: Our findings indicate that Ga-68 DOTANOC PET/CT is a promising imaging modality in patients with metastatic NETs of unknown origin for detection of the primary site and in guiding their therapeutic management.

Value of (18)F-FDG PET/CT in the Detection of Ovarian Malignancy.

PURPOSE: Ovarian cancer is a leading cause of gynecologic malignancy. As symptoms of ovarian cancer are nonspecific, only 20 % of ovarian cancers are diagnosed while they are still limited to the ovaries. Thus, early and accurate detection of disease is important for an improved prognosis. For the accurate and effective diagnosis of ovarian malignancy on (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT), we analyzed several parameters, including visual assessment. METHOD: A total of 51 peritoneal lesions in 19 patients who showed ovarian masses with diffuse peritoneal infiltration were enrolled. Twelve patients were confirmed to have ovarian malignancy and seven patients with benign disease by pathologic examination. All patients were examined by (18)F-FDG PET/CT, and an additional 2-h delayed (18)F-FDG PET/CT was also performed for 15 patients with 42 peritoneal lesions. We measured semiquantitative parameters including maximum and mean standardized uptake values (SUVmax, SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) on a 1-h initial (18)F-FDG PET/CT image (Parameter1) and on a 2-h delayed image (Parameter2). Additionally, retention indices of each parameter were calculated, and each parameter among the malignant and benign lesions was compared by Mann-Whitney U test. We also assessed the visual characteristics of each peritoneal lesion, including metabolic extent, intensity, shape, heterogeneity, and total visual score. Associations between visual grades and malignancy were analyzed using linear by linear association methods. Moreover, a receiver operating characteristic (ROC) curve was analyzed to compare the effectiveness of significant parameters. RESULT: In a comparison between the malignant and benign groups in the analysis of 51 total peritoneal lesions, SUVmax1, SUVmean1, and TLG1 showed significant differences. Also, in the analysis of 42 peritoneal lesions that underwent an additional 2-h (18)F-FDG PET/CT examination, SUVmax1,2, SUVmean1,2, TLG2, and the RI of TLG showed significant differences between the malignant and benign groups. MTV did not show significant differences in either the analysis of 51 peritoneal lesions or of 42 lesions. Regarding visual assessments, metabolic intensity, shape, heterogeneity, and total visual score showed an association with malignancy. In the ROC analysis, the AUC of the visual score was larger than the AUC of other parameters in both the analyses of 51 peritoneal lesions and of 42 lesions. CONCLUSION: Although further study with a larger patient population is needed, the visual assessment of (18)F-FDG PET/CT imaging has a primary role in the detection of malignancy in ovarian cancer patients with assistance from other semi-quantitative parameters.

Does the intensity of diffuse thyroid gland uptake on F-18 fluorodeoxyglucose positron emission tomography/computed tomography scan predict the severity of hypothyroidism? Correlation between maximal standardized uptake value and serum thyroid stimulating hormone levels.

CONTEXT: F-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) scan and hypothyroidism. AIMS: The aim was to determine whether the intensity of diffuse thyroid gland uptake on F-18 FDG PET/CT scans predicts the severity of hypothyroidism. MATERIALS AND METHODS: A retrospective analysis of 3868 patients who underwent F-18 FDG PET/CT scans, between October 2012 and June 2013 in our institution for various oncological indications was done. Out of them, 106 (2.7%) patients (79 females, 27 males) presented with bilateral diffuse thyroid gland uptake as an incidental finding. These patients were investigated retrospectively and various parameters such as age, sex, primary cancer site, maximal standardized uptake value (SUVmax), results of thyroid function tests (TFTs) and fine-needle aspiration cytology results were noted. The SUVmax values were correlated with serum thyroid stimulating hormone (S. TSH) levels using Pearson's correlation analysis. STATISTICAL ANALYSIS USED: Pearson's correlation analysis. RESULTS: Clinical information and TFT (serum FT3, FT4 and TSH levels) results were available for 31 of the 106 patients (27 females, 4 males; mean age 51.5 years). Twenty-six out of 31 patients (84%) were having abnormal TFTs with abnormal TSH levels in 24/31 patients (mean S. TSH: 22.35 µIU/ml, median: 7.37 µIU/ml, range: 0.074-211 µIU/ml). Among 7 patients with normal TSH levels, 2 patients demonstrated low FT3 and FT4 levels. No significant correlation was found between maximum standardized uptake value and TSH levels (r = 0.115, P > 0.05). CONCLUSIONS: Incidentally detected diffuse thyroid gland uptake on F-18 FDG PET/CT scan was usually associated with hypothyroidism probably caused by autoimmune thyroiditis. Patients should be investigated promptly irrespective of the intensity of FDG uptake with TFTs to initiate replacement therapy and a USG examination to look for any suspicious nodules.

Relationship Between PET/CT Maximum Standardized Uptake Value, Tumor Markers and Prognosis of Lung Cancer / 中国医学影像学杂志

Purpose To compare the relationship between the maximum standardized uptake value (SUVmax) of PET/CT imaging and tumor markers in lung cancer, and to provide evidence for the comprehensive assessment of non small cell lung cancer. Materials and Methods The results of PET/CT imaging, serum carcinoembryonic antigen (CEA), cytokeratin-19 fragment antigen 21-1 (CYFRA21-1) and neuronspecific enolase (NSE) of 179 patients with non small cell lung cancer were analyzed, subjects were then divided into different groups according to their clinical features and pathological types, the differences of SUVmax and tumor markers'' level were compared between different groups, and their correlations with tumor histological type, differentiation and the clinical stages were also analyzed.Results SUVmax of the tumor was related with lesion size,≥3 cm tumors'' SUVmax were significantly higher than that of 0.05).Conclusion SUVmax and NSE have a certain relationship with tumor differentiation in non small cell lung cancer patients, thus can be used as a reference index for prognosis of indirect prediction of lung cancer.

Sunlight may increase the FDG uptake value in primary tumors of patients with non-small cell lung cancer.

Currently, positron emission tomography with computerized tomography (PET-CT) is the most sensitive technique for detecting extracranial metastases in non-small cell lung cancer (NSCLC). It has been reported that there is a correlation between the maximal standardized uptake value (SUV(max)) of primary tumors and prognosis in patients with NSCLC. The effect of sunlight exposure on PET-CT SUV(max) value is not known. Therefore, we aimed to evaluate the effect of sunlight exposure on PET-CT SUV(max) value in patients with NSCLC. A total of 290 patients with NSCLC from two different regions of Turkey (Kayseri, n=168 and Adana, n=122) that have different climate and sunlight exposure intensity, were included in the study. Age, gender, histology of cancer, cancer stage, smoking status, comorbidity and SUV(max) of the primary tumor area at the time of staging were evaluated as prognostic factors. In the multivariate analysis, we detected that the region was the only independent factor affecting SUV(max) (P=0.019). We identified that warmer climate and more sunlight exposure significantly increases the SUV(max) value of the primary tumor area in patients with NSCLC. Further studies are warranted to clarify the issue.