Beilei Li

Differential diagnostic value of single-photon emission computed tomography/spiral computed tomography with Tc-99m-methylene diphosphonate in patients with spinal lesions.

PurposeThe objective of this study was to compare the diagnostic value obtained using single-photon emission computed tomography (SPECT)/spiral computed tomography (CT) with Tc-99m methylene-diphosphonate with that obtained using SPECT alone in patients with spinal lesions. MethodsThis was a retrospective study of 56 patients who underwent planar whole-body scintigraphy because of bone pain or osseous lesions that had been detected by other imaging techniques, or for the investigation of bone metastasis in patients with extraskeletal malignancies. Only patients who had hot spots detected in their spine and who had undergone single-photon emission computed tomography/computed tomography (SPECT/CT) imaging were included. One lesion from each patient was resected or biopsied for pathological diagnosis, and lesions for which a pathological diagnosis could be made were included in this study. Single-photon emission computed tomography (SPECT) and SPECT/CT images were independently interpreted by two experienced nuclear medicine physicians who had not been involved in the selection of data for the study. The physicians were aware of patients’ sex, age, history of histologically confirmed extraskeletal malignancy, and whole-body scintigraphy results, but were unaware of the results of other investigations, such as X-ray, MRI, and laboratory tests. SPECT images were analyzed first, followed by SPECT/CT images. Each lesion was graded on a 4-point diagnostic scale (1, benign; 2, likely benign; 3, likely malignant; 4, malignant), and the inter-reviewer agreement and the agreement of the SPECT and SPECT/CT diagnoses with the pathology results were evaluated by &kgr; scores. ResultsThe pathology results revealed 39 malignant bone tumors and 17 benign lesions. In the malignant cases, 20 were bone metastases and 19 were malignant tumors of another histological type. The reviewers rated 67.9% of lesions as equivocal (grade 2–3) by SPECT, but only 19.6% as equivocal by SPECT/CT. The &kgr; scores for inter-reviewer agreement were 0.467 for SPECT and 0.905 for SPECT/CT (both P<0.0001). The &kgr; scores for the agreement of the interpretation of SPECT and SPECT/CT with the pathology results were 0.493 and 0.689, respectively (both P<0.0001). ConclusionCompared with SPECT imaging, SPECT/spiral CT hybrid imaging significantly reduced the number of lesions judged to be equivocal. This reduction allowed for a definitive diagnosis to be made by imaging in the majority of patients.

Added value of SPECT/spiral CT versus SPECT in diagnosing solitary spinal lesions in patients with extraskeletal malignancies.

PurposeThe aim of this study was to investigate the added value of single-photon emission computed tomography (SPECT)/spiral computed tomography (CT) versus SPECT alone in the differential diagnosis of solitary spinal lesions in patients with extraskeletal malignancies. Materials and methodsA total of 90 patients who had a solitary spine ‘hot spot’ that could not be definitively diagnosed using planar scintigraphy were enrolled in the study. SPECT/spiral CT was performed on the indeterminate lesions in the spine. Images were independently interpreted by two experienced nuclear medicine physicians. Each spinal lesion was graded on a four-point diagnostic scale (1, benign; 2, likely benign; 3, likely bone metastasis; 4, bone metastasis). The final diagnosis of each lesion was based on pathological confirmation or follow-up. &kgr; scores were used to evaluate inter-reviewer agreement and agreement of the SPECT and SPECT/spiral CT diagnoses with the final diagnosis. ResultsFinal diagnoses revealed 25 bone metastases and 65 benign lesions. Forty percent (36/90) of the solitary spinal lesions were diagnosed as equivocal (likely benign or likely bone metastasis) according to SPECT, whereas only 5.6% (5/90) were diagnosed as equivocal according to SPECT/spiral CT. For SPECT/spiral CT-based and SPECT-based diagnoses, the &kgr; scores for inter-reviewer agreement were 0.889 (P<0.001, 95% confidence interval 0.824–0.954) and 0.504 (P<0.001, 95% confidence interval 0.401–0.607). The diagnostic accuracies of SPECT/spiral CT and SPECT images were 91.1% (82/90) and 58.9% (53/90), respectively (&khgr;2=24.919, P<0.001). ConclusionCompared with SPECT imaging alone, SPECT/spiral CT imaging was more accurate and valuable in the differential diagnosis of solitary spinal lesions in patients with extraskeletal malignancies.

Sarcomatoid carcinoma of the lung mimics aspergilloma on ¹⁸F-FDG PET/CT.

Primary PSC in the lung is a rare malignant cancer that represents a particularly aggressive subtype of non-small cell lung carcinomas (NSCLC) containing sarcoma or sarcoma-like components with spindle or giant cell features. The medical literature referring to imaging characteristics by fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) of these tumors is very limited. We present a case of PSC with air crescent and halo signs that resemble aspergilloma on the ¹⁸F-FDG PET/CT, scan.

Gastric Carcinosarcoma and 18F-FDG PET/CT.

Gastric carcinosarcoma is a rare, malignant neoplasm that simultaneously comprises mixed epithelial and mesenchymal elements. In the present study, we report a case of gastric carcinosarcoma composed of rhabdomyosarcoma and adenocarcinoma on F-FDG PET/CT.

Diagnostic value of 99mTc-MDP SPECT/spiral CT combined with three-phase bone scintigraphy in assessing suspected bone tumors in patients with no malignant history.

IntroductionThree-phase bone scintigraphy using technetium-99m-methylene diphosphonate is used to diagnose skeletal lesions, whereas single-photon emission computed tomography/computed tomography (SPECT/CT) improves the diagnostic accuracy of bone disease. We investigated the usefulness of SPECT/CT combined with three-phase bone scintigraphy over three-phase bone scintigraphy alone in assessing suspected bone tumors in patients with no malignant history. Materials and methodsForty-eight patients (30 men and 18 women; mean age, 43.3±20.1 years; age range, 11–82 years) with suspected bone tumors who underwent technetium-99m-methylene diphosphonate three-phase bone scintigraphy and SPECT/CT between July 2008 and August 2013 were retrospectively reviewed. The lesion from each patient was resected or biopsied for pathological confirmation of the diagnosis within 3 weeks of the bone scan. All images were interpreted by two experienced nuclear medicine physicians who had not been involved in the selection of data for the present study. The reviewers were aware of the patient’s sex, age, and the lesion’s site but were unaware of the results of other imaging modalities, such as radiography, MRI, and laboratory tests. In cases of discrepancy regarding the interpretations, a consensus was reached after mutual discussion. The diagnostic ability of three-phase bone scintigraphy and SPECT/CT combined with three-phase bone scintigraphy was compared with pathological results using the &khgr;2-test, with P-values less than 0.05 indicating significant differences. Agreement between three-phase bone scintigraphy alone or SPECT/CT combined with three-phase bone scintigraphy with pathological results was evaluated using &kgr; scores. ResultsPathological results from the 48 lesions of all patients revealed 32 malignant bone tumors and 16 benign lesions. On using three-phase bone scintigraphy and SPECT/CT combined with three-phase bone scintigraphy for the differential diagnosis of bone lesions, we found sensitivities to be 96.9 and 100%, specificities to be 31.2 and 81.3%, positive predictive values to be 73.8 and 91.4%, and negative predictive values to be 83.3 and 100%, respectively. The diagnostic accuracies of three-phase bone scintigraphy alone and SPECT/CT combined with three-phase bone scintigraphy were 75.0 and 93.8%, respectively (&khgr;2=5.057; P=0.025). &kgr; scores for the agreement of three-phase bone scintigraphy and SPECT/CT combined with three-phase bone scintigraphy with pathological results were 0.333 (P=0.005) and 0.850 (P<0.0001), respectively. ConclusionCompared with three-phase bone scintigraphy, the diagnostic accuracy of SPECT/CT combined with three-phase bone scintigraphy was higher. SPECT/CT combined with three-phase bone scintigraphy is beneficial over three-phase bone scintigraphy for the differential diagnosis of suspected bone tumors in patients with no malignant history.

18F-FDG PET/CT in gastric lymphoepithelioma-like carcinoma

Gastric lymphoepithelioma-like carcinoma (GLLC), which is also nown as Epstein-Barr virus (EBV)-associated gastric carcinoma, s a rare and peculiar type of gastric carcinoma, constitutes about –4% of all gastric carcinomas.1 GLLCs frequently affect the proxmal stomach or gastric stump and are more common in old age ith a male predominance, while >80% are associated with infecion with EBV. The prognosis for patients with GLLCs is reportedly etter than that for patients with typical gastric malignancies. So ar, there are few published cases of lymphoepithelioma-like carinoma evaluated by 18F-FDG PET in liver and lungs, but no reports f stomach. In general, lymphoepithelioma-like carcinomas are DG-avid, the tumor SUVmax in the published reports varied from .0 to 34.5.2,3 In the present study, we report a case of gastric ymphoepithelioma-like carcinoma also FDG-avid with SUVmax of 1.9. The case involves a 74-year-old woman diagnosed with a gastric

Primary Liver Carcinosarcoma and 18F-FDG PET/CT.

Primary liver carcinosarcoma is a very rare, malignant neoplasm that is concomitantly composed of a mixture of sarcomatous and carcinomatous elements. In the present study, an initial staging FDG PET/CT showed intense FDG uptake in a patient with liver carcinosarcoma composed of hepatocellular carcinoma and rhabdomyosarcoma. Two months after surgical resection, a restaging PET/CT showed rapid progression of the disease with abdominal and lung metastases, indicating aggressive feature of the disease. The case shows the importance to repeat a restaging PET/CT at early time after surgery for a patient with liver carcinosarcoma to monitor disease progression.

Primary pulmonary artery sarcoma differentiated from pulmonary thromboembolism by ventilation-perfusion scan. Long survival of the patient.

UNLABELLED Primary pulmonary artery sarcoma (PAS) is a rare and highly lethal tumor. Here, we report a case of a 53-year-old female with PAS who was initially diagnosed with chronic pulmonary thromboembolism (PTE) based on the results of a transthoracic Doppler echocardiogram, a contrast-enhanced computed tomography angiography, and a ventilation/perfusion lung scan. CONCLUSION We emphasize the difficulties in diagnosing PAS, the need to investigate this neoplasm in the differential diagnosis of PTE, the diagnostic value of different imaging techniques in the identification of the the tumor, and the efficacy of adjuvant chemotherapy in prolonging survival.

18F-FDG PET/CT of common hepatic duct lymphoepithelioma-like carcinoma

Lymphoepithelioma-like carcinoma (LELC) is an undifferentiaed carcinoma composed of malignant epithelial cells with an ssociated background of lymphocytes. Most LELCs are strongly ssociated with EBV infection and are found primarily in Asia. LELCs an arise in different anatomical sites including the head and neck egion, thymus, breast, lung, gastrointestinal tract,1 liver, biliary ystem, genitourinary tract, and skin. Primary LELC of the extraheatic bile duct is extremely rare. Only one case of LELC arising from he common bile duct appeared in the English medical literature in 011.2 This is the first report of 18F-FDG PET/CT imaging of LELC of the ommon hepatic duct. LELCs usually show strong 18F-FDG uptake. he reported SUVmax of LELCs of various organs ranges from 7.6 o 34.5. In our case, the 18F-FDG-avid tumor showed an SUVmax of 20.4. Although the features of LELCs on 18F-FDG PET/CT are not specific, PET/CT is advantageous in accurately staging the primary tumor, monitoring the efficacy of treatment, and detecting tumor recurrence.3 There are no obvious histopathological differences between EBV-positive and -negative LELCs of the biliary system. The prognosis of LELCs of the biliary tract is thought to be better than that of conventional biliary tract carcinomas. A 34-year-old man presented our hospital with 2-month history of right upper quadrant pain. Abdominal MRI revealed a large tumor in the common hepatic duct (Fig. 1A). The levels of the tumor markers -fetoprotein (AFP), carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were 10.9 ng/mL, 0.4 ng/mL and 5.7 U/Ml, respectively (normal AFP <20 ng/mL, CEA <5 ng/mL, CA 19-9 <37 U/mL). The patient was referred for 18F-FDG PET/CT

Vertebral Hemangiolymphangioma Mimics Bone Metastases on 99mTc-MDP SPECT/CT.

Hemangiolymphangioma is a very rare, congenital malformation of both lymphatic and blood vessels. In the present study, we report a case of vertebral hemangiolymphangioma that was misdiagnosed as bone metastasis on 99mTc-MDP SPECT/CT.