Objective To analyze the pitfalls of 18F fluorodeoxyglucose (FDG) positron emission tomography/computer tomography (PET-CT) scan in the diagnosis of 60 patients of tuberculosis mimicking malignancy.Methods The study included 60 patients with PET-CT diagnosis of probable malignancy.Fifty patients were proved to be tuberculosis by pathological examinations and 10 were diagnosed by clinical followup.The images of whole body were acquired at 60 min after administration of 222-555 MBq 18F-FDG.The PET-CT imaging characteristics and clinical data,including lesion size,distribution,standardized uptake value (SUV) were retrospectively analyzed.After the whole body scan of PET-CT,each patient had a chest spiral CT scan for detailed observation of lung lesions.Contrast enhanced CT (CECT) was performed in 8 patients.Results (1)Thirty patients were misdiagnosed as lung cancer,14 patients as malignant lymphoma,6 patients as malignant mesothelioma,3 as intestine carcinoma,2 as bone malignancy,1 patient as hepatocarcinoma,spleen malignancy,ovarian cancer,laryngocarcinoma and nasopharyngeal carcinoma respectively.(2) 90.9％ (20/22) of patients showed normal level of serum CEA and 100％ (13/13) of patients showed normal level of CA199.Increasing serum CA125 was found in all patients (6/6) with activeTB patients accompanied with ascites,pleural fluid and (or) pericardial effusion.(3) 93.3％ (28/30)active tuberculosis showed accumulated 18F-FDG which was incorrectly interpreted as malignancy.The most common sites of TB lymphadenopathy were bilateral cervical tissues,which was accounted for 85.7％(12/14).CECT revealed characteristics of peripheral enhancement and central necrosis in tubercular lymphadenopathy,which was 87.5％ (7/8).Conclusions The diverse manifestations of TB on imaging and high uptake of 18F-FDG on PET imaging result in misdiagnosis of malignancy.It is important for radiologists and nuclear medicine physicians to identify the common imaging features and patterns of TB to make a correct diagnosis.Integration of reconstruction HR CT,PET-CT and lab examinations may improve the diagnostic accuracy.

Purpose To investigate the diagnostic value of ~(18)F-flurorodeoxyglucose (~(18)F-FDG) PET/CT (positron emission tomography/computed tomography) on multiple myeloma.Materials and Method ~(18)FDG PET/CT imaging findings were retrospectively analyzed in 31cases with multiple myeloma proved by bone marrow aspiration or biopsy from August 2005 to June 2009. Results The PET/CT imaging characteristics were categorized into three types: ① osseous destruction (n=28): Osseous destruction with active metabolism was found in this type combined with no extramedullary organs involvement. The SUV_(max) ranged from 2.5 to 15.4, and the SUV_(arg) ranged from 2.0 to 11.3. ② Extramedullary organ involvement (n=2): Besides osseous destruction, extramedullary organs involvement were detected in this type demonstrating active metabolism in varying degrees. The SUV_(max) ranged from 2.2 to 8.3 and the SUV_(avg) ranged from 1.7 to 6.5. ③ Diffuse bone marrow infiltration (n=1): Diffuse hypermetabolism without osseous destruction was found in the whole body bone marrow with the SUV_(max) of 13.4 and SUV_(avg) of 8.8.Conclusions ~(18)FDG PET/CT can accurately demonstrate the morphology, extent and activity of multiple myeloma, thus facilitating the clinical staging, whereas multiple osteolytic osseous metastases and osseous lymphoma should be excluded for certain cases.

OBJECTIVETo assess the value of (18)F-FDG PET/CT in the diagnosis of solitary nodular-type bronchoalveolar carcinoma (BAC).

METHODSThe clinical and radiographic data were analyzed retrospectively in 30 patients with pathologically confirmed solitary nodular-type BAC who underwent (18)F-FDG PET/CT examinations between August, 2005 and December, 2006. The morphological and radioactive findings of the lesions were reviewed, and the maximum standard uptake values (SUVmax) were measured. The diagnostic accuracy of PET, PET/CT, and HRCT were analyzed.

RESULTSThe (18)F-FDG SUV was markedly lower in BAC than in other well differentiated adenocarcinoma. In 19 of the BAC cases, PET showed a SUVmax of no less than 2.5, demonstrating positive changes. Of the total of 30 cases, 5 had ground glass opacity (GGO) changes, 3 exhibited mixed nodules with GGO changes around the lesions, and 22 cases presented with solid nodules. HRCT showed that BAC located often in the superior lobes of the bilateral lungs, mostly below the pleura in the surrounding lung field; the lesions were patchy or nodular with irregular shapes, showing lobulation in 22 cases, spiculation in 15 cases, pleural indentation in 21 cases, and vacuolar changes in 4 cases. The diagnostic accuracy of PET, PET/CT and HRCT for solitary nodular-type BAC was 36.67%, 93.33%, and 93.33%, respectively.

CONCLUSIONThe SUVmax of BAC provides only limited value for defining the nature of the lesions, but can serve as a general reference for assessing the disease activity. PET/CT, which allows both functional and imaging assessment, can be a valuable modality to reduce the misdiagnosis rate of BAC.

Adenocarcinoma, Bronchiolo-Alveolar ; diagnostic imaging ; Adult ; Aged ; Female ; Fluorodeoxyglucose F18 ; Humans ; Lung Neoplasms ; diagnostic imaging ; Male ; Middle Aged ; Positron-Emission Tomography ; Retrospective Studies ; Tomography, X-Ray Computed

Objectives: To propose a novel clinical classification system of gallbladder cancer, and to investigate the differences of clinicopathological characteristics and prognosis based on patients who underwent radical resection with different types of gallbladder cancer. Methods: The clinical data of 1 059 patients with gallbladder cancer underwent radical resection in 12 institutions in China from January 2013 to December 2017 were retrospectively collected and analyzed.There were 389 males and 670 females, aged (62.0±10.5)years(range:22-88 years).According to the location of tumor and the mode of invasion,the tumors were divided into peritoneal type, hepatic type, hepatic hilum type and mixed type, the surgical procedures were divided into regional radical resection and extended radical resection.The correlation between different types and T stage, N stage, vascular invasion, neural invasion, median survival time and surgical procedures were analyzed.Rates were compared by χ² test, survival analysis was carried by Kaplan-Meier and Log-rank test. Results: Regional radical resection was performed in 940 cases,including 81 cases in T1 stage,859 cases in T2-T4 stage,119 cases underwent extended radical resection;R0 resection was achieved in 990 cases(93.5%).The overall median survival time was 28 months.There were 81 patients in Tis-T1 stage and 978 patients in T2-T4 stage.The classification of gallbladder cancer in patients with T2-T4 stage: 345 cases(35.3%)of peritoneal type, 331 cases(33.8%) of hepatic type, 122 cases(12.5%) of hepatic hilum type and 180 cases(18.4%) of mixed type.T stage(χ²=288.60,P<0.01),N stage(χ²=68.10, P<0.01), vascular invasion(χ²=128.70, P<0.01)and neural invasion(χ²=54.30, P<0.01)were significantly correlated with the classification.The median survival time of peritoneal type,hepatic type,hepatic hilum type and mixed type was 48 months,21 months,16 months and 11 months,respectively(χ²=80.60,P<0.01).There was no significant difference in median survival time between regional radical resection and extended radical resection in the peritoneal type,hepatic type,hepatic hilum type and mixed type(all P>0.05). Conclusion With application of new clinical classification, different types of gallbladder cancer are proved to be correlated with TNM stage, malignant biological behavior and prognosis, which will facilitate us in preoperative evaluation,surgical planning and prognosis evaluation.