Meftune Ozhan

F-18 FDG PET/CT Findings of a Patient with Takayasu Arteritis Before and After Therapy

Vasculitis is defined as inflammation and necrosis with leukocytic infiltration of the blood vessel wall. Takayasu arteritis is a chronic inflammatory arteritis that primarily involves the aorta and its main branches. A 64-year-old female patient with a 2-month history of fever of unknown origin was presented to our clinic for F-18 FDG PET/CT imaging. Baseline PET/CT images demonstrated intense F-18 FDG uptake in the aorta, bilateral subclavian and brachiocephalic arteries consistent with Takayasu arteritis. After 2 months of immunosuppressive therapy, she was asymptomatic and follow-up FDG PET/CT scan showed almost complete disappearance of large vessels’ F-18 FDG uptake. FDG PET/CT is a sensitive technique for assessing presence of large-vessel vasculitis such as Takayasu arteritis, extent of large-vessel inflammation and disease activity after therapy. Conflict of interest:None declared.

FDG PET/CT in the detection of metastases in a patient with Tg and 131I WBS negative follicular thyroid cancer.

After a total or near total thyroidectomy and radioiodine ablation therapy for differential thyroid cancer (DTC), routine follow-up methods are (131)I or (131)I whole-body scanning (WBS) as well as serum thyroglobulin (Tg) and anti-thyroglobulin (anti-Tg) levels. We describe a case of a 41-year-old woman with follicular thyroid cancer. Although serum Tg level and (131)I WBS were negative after radioiodine ablation therapy, she had pain around her left medial clavicle. FDG PET/CT was performed for any undetected metastases. FDG PET/CT showed hypermetabolic bone metastases in the left medial clavicle. Biopsy confirmed metastases of the thyroid follicular carcinoma.

Appearance of recurrent cardiac myxofibrosarcoma on FDG PET/CT.

Primary cardiac sarcomas are extremely rare tumors. In this case report, we presented the condition of a 37-year-old male patient diagnosed with myxofibrosarcoma after histopathologic evaluation of the left atrium mass excision. FDG PET/CT was performed and showed recurrent hypermetabolic lesions in the left atrial wall and right anterior mediastinal region.

The different distribution patterns of FDG and FDG-labelled WBC in inflammatory and infectious lesions

A 56-year-old woman with a 1 year history of right knee prosthesis and right ankle cyst resection was referred for right ankle pain and skin lesion on the right ankle. The patient also had an iliac bone graft operation for talar bone defect. The patient underwent whole-body fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT and FDG-labelled white blood cell (WBC) scan for diagnosis of the infection. The interval between the two studies was 1 day. FDG PET/CT images showed a soft tissue lesion

Cardiac hydatid cyst mimicking malignancy.

A 50-year-old man presented with chest pain symptoms for 7 years. He did not report any other complaints. The diagnostic tests including physical examination, routine laboratory tests, chest x-ray, and electrocardiography were reported as normal. Cardiac MRI, however, revealed a 64 × 66 mm mass lesion in the left myocardium. He was referred to our unit for further tests. A PET/CT was carried out which demonstrated a minimally increased fluorodeoxyglucose uptake at the peripheral margins of the mass, which deemed to be suspicious for malignancy. The patient underwent a thoracotomy and the cardiac mass was excised. Histopathologic examination reported this lesion as a hydatid cyst.

Primary spinal leptomeningeal gliomatosis in a 3-year-old boy revealed with MRI and FDG PET/CT mimicking tuberculosis meningitis.

A 3-year-old boy was referred to neurologist for inward devition of his left eye, weakness, lack of appetite, headache and ehavioral change. On physical examination, the findings of ilateral abducens nerve paralysis were noted. Cranial magnetic esonance imaging (MRI) revealed diffuse leptomeningeal contrast nhancement at the supra-infratentorial regions predominantly nvolving the basal cisterns and also hydrocephalus and initially uggesting basilar meningitis. Cerebrospinal fluid (CSF) studies howed normal glucose and elevated protein levels but no tumor ells. No growth was detected in any of the bacterial cultures ncluding acid-resistant bacteria. The patient was started on oral nti-tuberculosis medication and corticosteroid treatment with he presumed diagnosis of tuberculosis meningitis and a ventricuoperitoneal (VP) shunt was inserted due to hydrocephalus. After months of treatment, the patient was re-admitted to hospial with vomiting, convulsion and confusion. Cranial MRI showed he similar findings to previous one, and spinal MRI depicted iffuse leptomeningeal contrast enhancement as well as microystic changes along the spinal cord (Fig. 1). Histopathology of the ural biopsy material revealed widespread glioma infiltration of he subarachnoid space suggestive of leptomeningeal gliomatosis. his patient with unknown primary was referred for FDG PET/CT. nder child sedation, brain and whole body non-contrast enhanced ET/CT images were obtained 90 min after the intravenous injecion of 148MBq (4mCi) 18F FDG using a Biograph 6 PET/CT. The can depicted slightly increased FDG uptake (SUVmax 2.1)along the pinal cord without any other FDG-avid primary tumor. The patient as started on chemotherapy including vincristine and carboplatin Figs. 2 and 3). His symptoms were relieved after completion of hemo. Primary diffuse leptomeningeal gliomatosis (PDLG) is a rare isease thought to arise from isolated astrocytic cell nests also nown as heterotropic neuroglial tissue within the leptomeninges HLNT) in the subarachnoid space. The HLNT can transform into two

FDG PET-CT Finding in Bilateral Renal and Bone Involvement of Diffuse Large B-Cell Lymphoma.

Thirty-six year old male patient with pathological fracture of the left tibia underwent intramedullary and soft tissue curettage. The histopathological examination revealed diffuse large B cell lymphoma. The patient underwent F18-FDG PET-CT scanning for initial staging. FDG PET-CT scan revealed hypermetabolic lesions at the left tibia and in bilateral kidneys. After the systemic chemotherapy and local radiotherapy to the tibia, repeated FDG PET/CT scan showed improvement of the previous hypermetabolic lesions, suggesting good response to therapy. Bone and renal involvement is an uncommon variant of diffuse large B-cell lymphoma and FDG PET-CT is an useful whole body imaging modality in these cases.

FDG PET/CT in monitoring treatment of retroperitoneal fibrosis

Retroperitoneal fibrosis is an uncommon disease characterized by inflammatory fibrosis typically surrounding abdominal aorta and iliac arteries. The glucose analogue F18-fluorodeoxyglucose can be used to image inflammatory cell activity non-invasively by PET. In this report we investigated the usefulness of the FDG PET/CT in the disease activity and therapy response evaluation of retroperitoneal fibrosis.

Metformin-Induced Intense Bowel Uptake Observed on Restaging FDG PET/CT Study in a Patient with Gastric Lymphoma.

A 53-year-old man with a diagnosis of gastric non-Hodgkin lymphoma (NHL) underwent PET/CT scans both prior to starting chemotherapy and immediately following completion of chemotherapy to evaluate the response to therapy. Pre-therapy PET/CT images showed intense FDG uptake in the antral region of the stomach. Biodistribution of FDG was otherwise unremarkable. The patient was started on metformin in the middle of his therapy period to provide glycemic control. Post-therapy PET/CT study performed after 6 courses of chemotherapy showed complete resolution of the disease with no evidence of residual FDG uptake. However, intense and diffuse FDG accumulation is observed in the bowel, which was interpreted as physiological and most probably due to metformin administration. It should be borne in mind that there are a number of physiological variants of FDG biodistribution seen on PET/CT imaging. Recognizing physiologic bowel activity is crucial for the accuracy of PET image interpretation. Conflict of interest:None declared.

Detection of Hodgkin Transformation in a Case of Chronic Lymphocytic Leukemia by PET/CT.

Richter’s transformation (RT) represents the development of high grade lymphoma, most commonly diffuse large B-cell lymphoma, in patients with chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL). CLL/SLL may convert also to Hodgkin’s lymphoma, the so-called Hodgkin’s variant of Richter transformation. Histopathological proof is needed to confirm a definitive diagnosis. Patients with RT generally have a poor prognosis, with prompt recognition optimise clinical management. Whole-body PET scan with 18F-FDG can be used for detection of RT of CLL/SLL. We describe the case of 64-year-old woman with CLL/SLL who developed Hodgkin lymphoma detected with PET/CT.