18F-FDGPET/CT in fever of unknown origin and inflammation of unknown origin: a Chinese multi-center study.

PURPOSE: To evaluate the clinical value of 18F-FDG-PET/CT for the diagnosis of fever of unknown origin (FUO) and inflammation of unknown origin (IUO) in Chinese population, as well as the characteristics of PET/CT in different category of etiological disease. METHODS: A total of 376 consecutive patients with FUO/IUO who underwent FDG-PET/CT at 12 hospitals were retrospectively studied. FDG uptake was quantitatively and visually evaluated, by using SUVmax and a 4-grade scale respectively. A questionnaire survey to the clinicians was used to evaluate the significance of PET/CT in diagnosing of FUO/IUO. Data analysis included the etiological distribution in the study population, image characteristics in different category of diseases, and clinical significance of PET/CT. RESULTS: In 376 studied patients, the infectious diseases accounted for 33.0% of patients, rheumatologic diseases for 32.4%, malignancies for 19.1%, miscellaneous causes for 6.6%, and cause unknown for 8.8%. However, the etiological distribution among hospitals was varied. In addition, the etiological disease composition ratio has changed over time in China. On PET/CT examinations, 358 (95.2%) of the patients had a positive finding. Within them, local high uptake lesion was found in 219 cases, and nonspecific abnormal uptake (NAU) was found in 187 cases. FDG uptake in malignant diseases was significantly higher than in other category diseases both on SUVmax and visual scores (t-value range from 4.098 to 5.612, all P value < 0.001). Based on a clinical questionnaire survey, PET/CT provided additional diagnostic information for 77.4% of patients, and 89.6% of patients benefited from PET/CT examination. CONCLUSIONS: FDG PET/CT is a valuable tool for clinical diagnosis of FUO/IUO, and it is of great significance in further investigating the usefulness of PET/CT in non-neoplastic diseases.

[A comparison of ventilation/perfusion single photon emission CT and CT pulmonary angiography for diagnosis of pulmonary embolism].

OBJECTIVE: To assess the diagnostic accuracy of ventilation/perfusion (V/Q) single photon emission CT (SPECT) as compared to computed tomographic pulmonary angiography (CTPA) for pulmonary embolism (PE). METHODS: In this prospective multicenter study, 111 patients in whom acute or sub-acute PE was clinically confirmed or suspected were enrolled. The patients underwent one-day method V/Q lung scan (including SPECT and planar imaging) within 3 days before and after completion of CTPA. The European Association of Nuclear Medicine (EANM) guidelines for ventilation/perfusion scintigraphy (2009) reference was used as the evaluation criteria of V/Q SPECT imaging. The refined modified prospective investigation of pulmonary embolism diagnosis (RM-PIOPED) criteria was used for evaluation of planar imaging. According to the direct and indirect signs of PE, the imaging of CTPA was evaluated. All patients were followed for at least 6 months. A diagnosis was finally made by consensus of respiratory physicians, radiologists and nuclear medicine physicians based on the clinical data, laboratory tests, imaging features and follow-up results. The difference among diagnostic methods was evaluated for significance using chi-square test. The receiver operator characteristic (ROC) curve was drawn according to the results of the 3 diagnostic tests. The area under ROC curve (AUC) was calculated and compared. P < 0.05 was considered statistically significant. RESULTS: Among the 111 patients, PE was confirmed in 80, and excluded in 31. The diagnostic sensitivity/specificity/accuracy of V/Q SPECT, planar imaging, and CTPA were 85.9%/93.5%/88.1%, 75.7%/92.9%/81.4%, and 85.5%/90.0%/86.8%, respectively. By ROC curve analysis, the AUC values of V/Q SPECT, planar imaging and CTPA were 0.898, 0.838, and 0.877, respectively; with 95% confidence intervals [CI] 0.831 to 0.966, 0.759 to 0.917, and 0.801 to 0.954, respectively. The area of the fitted smooth ROC curve was statistically significant (P < 0.05) as compared with the area under the reference line. CONCLUSION: The results indicate that SPECT V/Q imaging is superior to V/Q planar scan and CTPA in the diagnosis of PE.

[Prognostic value of adenosine triphosphate myocardial perfusion tomography in octogenarians.].

OBJECTIVE: To evaluate the prognostic value of (99m)Tc-MIBI myocardial perfusion single-photon emission computed tomography (MPS) with adenosine triphosphate in patients aged 80 years or older. METHODS: A total of 265 patients [mean age (84.2 +/- 3.6) years old] who underwent adenosine triphosphate and rest (99m)Tc-MIBI myocardial SPECT imaging were followed-up for (36.7 +/- 22.8) months. RESULTS: During the period of follow-up, 57 patients (20.4%) suffered from cardiac events, including 20 major events: 5 cardiac death and 15 acute non-fatal myocardial infarction, 14 unstable angina pectoris, 7 heart failure and 16 cases undergoing PCI. The cardiac event rate in patients with fixed or mixed perfusion defects (n = 54) was 50%, which was significantly higher than that in patients with reversible perfusion defects (n = 67, 31.3%, P < 0.05) and normal perfusion imaging (n = 144, 6.2%, P < 0.01). The major cardiac event rate in patients with fixed or mixed perfusion defects was 27.8%, which was significantly higher than that in those with reversible perfusion defects (6.0%, P < 0.05) and normal perfusion imaging (0.7%, P < 0.01). Cox multivariate analysis revealed that an abnormal MPS was the most important independent predictor of major or total cardiac events. CONCLUSIONS: (99m)Tc-MIBI MPS with ATP is demonstrated to be a powerful tool for the prognostic evaluation in octogenarian population. Octogenarians with a normal MPS have a low risk of major or total cardiac events, but when an abnormal MPS is present, the risk is significantly higher, being highest in patients with fixed or mixed perfusion defects.

[Study of serum thyroid hormone levels changes in perioperation patients accepted coronary artery bypass grafts].

OBJECTIVE: To clarify the change of serum thyroid hormone levels during perioperation period of coronary artery bypass grafts (CABG). METHODS: The levels of serum thyroid hormones (TT(3), TT(4), FT(3), FT(4), TSH, rT(3)) were measured by chemical-luminal and RIA in 62 patients at certain time in perioperation period, as well as 30 normal volunteers on a fasting basis. SPSS 10.0 was used for statistic analysis. RESULTS: The levels of serum thyroid hormones had no significant difference between controls and patients before CABG. At 10 min and 60 min after giving heparin, serum TT(4), FT(4) levels in patients during operation elevated significantly than before (P < 0.01), however, at 2 h after operation, serum TT(3), TT(4), FT(3), FT(4), rT(3), TSH levels had no significant changes. Serum TT(3), TT(4), FT(3), FT(4), TSH levels at 24 h and 72 h after operation were significantly lower in patients than before CABG (P < 0.01). Especially at 24 h, serum TT(3), FT(3) levels decreased by 52.7% and 46.6% than before respectively, while serum rT(3) levels increased significantly (P < 0.01) and serum TT(3), rT(3) levels decreased significantly (P < 0.01). The serum TT(4), FT(3), FT(4), TSH levels didn't return to normal at 7 d after operation. CONCLUSION: Elevated serum TT(4), FT(4) levels are present in acute period in patients accepted CABG. Decreased serum T(3) and FT(3) levels after CABG may indicate a bad prediction.

[Evaluation of cerebral hemodynamics in geriatric carotid stenosis pre- and post-carotid artery stenting].

OBJECTIVES: To explore influencing factors of regional cerebral blood flow (rCBF) in geriatric carotid stenosis, and to analyze changes of rCBF and clinical symptoms after carotid stenting. METHODS: During August 2005 and April 2008, 68 geriatric patients of carotid stenosis having SPECT examination in our hospital were retrospectively studied, whose diagnosis was approved by angiography. Correlated rCBF was compared separately in different stenotic degrees of carotid stenosis, in unilateral or bilateral stenosis, accompanied with vertebrobasilar stenosis (VBS) or not, with collateral circulation or not, before and after carotid stenting. RESULTS: When patients of unilateral carotid stenosis were grouped by different clinical factors, cases of patients with reduced rCBF were compared using chi(2) test: the P value was 0.046 and 0.020 when comparing group of stenotic degree 90% - 99% with group 70% - 89% and group 50% - 69%; the P value was 0.927 between group accompanied with VBS and group without; the P value was 0.222 between group with collateral circulation and group without. When comparing reduced rCBF cases between unilateral and bilateral carotid stenosis, the P value was 0.046. After carotid stenting, 76% of patients had their rCBF improved, and also the scores of presenting symptoms evaluated by modified Rankin scale were elevated from 1.4 +/- 0.7 on admission to 0.4 +/- 0.3 postoperatively (P < 0.001). CONCLUSIONS: The research indicates that higher stenotic degree and bilateral carotid stenosis may cause rCBF decrease in geriatric carotid stenosis. Carotid stenting may improve rCBF and change clinical symptoms significantly.

Role of SPECT/CT in diagnosis of hepatic hemangiomas.

AIM: To investigate the role of SPECT/CT in the diagnosis of hepatic hemangiomas whose anatomical positions are not ideal, situated adjacent to the heart, the inferior cava, hepatic vessels or abdominal aorta, etc. METHODS: The hepatic perfusion, blood pool, and fusion imaging were carried out using SPECT/CT in 54 patients, who were suspected for hepatic hemangiomas. When the anatomical positions were not ideal, the diagnosis was difficult by SPECT only. So the information of computed tomography (CT) was applied to help in diagnosing. The results were recorded as hemangiomas or not. RESULTS: Of the 54 patients, 31 patients were diagnosed as suffering from hepatic hemangiomas. The anatomical positions of eight patients' hepatic hemangiomas (25.81%) were not ideal. Among these lesions of the eight patients, three patients' hepatic lesions were located near to the abdominal aorta, one to the heart, and four to the inferior cava. In addition, six abnormal radioactivity accumulation regions, adjacent to the heart and inferior cava, with the help of CT, were confirmed to be the imaging of inferior cava other than hepatic hemangiomas. CONCLUSION: When the anatomical positions of hepatic hemangiomas are not good enough for diagnosis, the fusion imaging of SPECT/CT is a simple and efficient method for differential diagnosis.

[Diagnostic value of adenosine (99m)Tc-MIBI myocardial perfusion imaging for detecting coronary artery disease].

OBJECTIVE: The aim of this study was to assess the accuracy of adenosine (99m)Tc-MIBI myocardial perfusion SPECT for the diagnosis of coronary artery disease. METHODS: A total of 89 patients [mean age (57 +/- 9) years,62 men, 27 women] were included in this study. Adenosine was infused intravenously at a rate of 140 microg.kg(-1).min(-1) for 6 minutes. At the end of 3 minute of adenosine infusion, 925MBq of (99m)Tc-MIBI was injected intravenously. SPECT myocardial imaging acquisition was obtained 1 hour after adenosine infusion. Coronary angiography was performed in all patients. RESULTS: Thirty-one patients had significant coronary artery stenosis and 58 had normal coronary angiography. Adenosine myocardial perfusion imaging was abnormal in twenty-two out of the 31 patients with significant coronary artery stenosis (sensitivity, 71%). Fifty-three out of the 58 patients with normal angiography had a normal adenosine myocardial perfusion imaging (specificity, 91%). The positive predictive value and negative predictive value of adenosine (99m)Tc-MIBI myocardial perfusion imaging for detection of coronary artery disease was 81% and 84% respectively. CONCLUSION: Adenosine myocardial perfusion imaging is probably an accurate method for detecting coronary artery disease.

Comparison of (99)mTc-methoxyisobutylisonitrile myocardial single-photon emission computed tomography and electron beam computed tomography for detecting coronary artery disease in patients with no myocardial infarction.

BACKGROUND: Previous studies have compared single-photon emission computed tomography (SPECT) and electron beam computed tomography (EBCT) in detection of coronary artery disease (CAD) in patients with myocardial infarction (MI). The purpose of this study was to compare SPECT with EBCT in detection of CAD in patients with no MI. METHODS: One hundred and forty-seven patients with suspected CAD underwent stress-rest (99)mTc-methoxyisobutylisonitrile ((99)mTc-MIBI) myocardial SPECT, cardiac EBCT and coronary angiography (CAG) within one month. Of them, 73 patients (aged 52.6 +/- 10.6 years old) with no history of MI were included in this study. Coronary artery calcium (CAC) was defined as a CT value >or= 130 HU within the boundary of coronary artery on EBCT. RESULTS: There were 35 and 38 patients with or without CAD according to CAG. Ninety-six percent of the patients with abnormal SPECT and CAC had a coronary arteries stenosis >or= 50%, and 90.9% patients with normal SPECT and EBCT showed no CAD. The sensitivity of SPECT and EBCT in detection of CAD was comparable, and the specificity of SPECT (92.1%) was significantly higher than that of EBCT (55.3%) (P < 0.005). For the detection of individual coronary artery stenosis, both sensitivity and specificity of SPECT (75.0% and 93.7%) were significantly higher than those of EBCT (53.3% and 76.7%) (P < 0.025 and P < 0.005, respectively). In patients without chest pain, the sensitivity and specificity of SPECT (76.9% and 91.4%) were significantly higher than those of EBCT (23.1% and 69.0%) in detection of a coronary artery stenosis of >or= 50% (P < 0.01 and P < 0.005, respectively). However, in patients with chest pain, both sensitivity and specificity of SPECT were comparable to those of EBCT. In patients or= 50% (P < 0.005), and the specificity of SPECT was comparable to that of EBCT. In patients > 45 years old, the specificity of SPECT (94.3%) was significantly higher than that of EBCT (70.5%) (P < 0.005), and the sensitivity of SPECT was comparable to that of EBCT. CONCLUSION: (99)mTc-MIBI myocardial perfusion SPECT has higher accuracy than that of EBCT in detection of CAD in patients without MI.