Can a penalized-likelihood estimation algorithm be used to reduce the injected dose or the acquisition time in Ga-DOTATATE PET/CT studies?

Background: Image quality and quantitative accuracy of positron emission tomography (PET) depend on several factors such as uptake time, scanner characteristics and image reconstruction methods. Ordered subset expectation maximization (OSEM) is considered the gold standard for image reconstruction. Penalized-likelihood estimation (PL) algorithms have been recently developed for PET reconstruction to improve quantitation accuracy while maintaining or even improving image quality.

PET/CT in Disease Detection and Follow-up of Subcutaneous Involvement in Marginal Zone Lymphoma.

Background: The value of positron emission tomography/computed tomography (PET/CT) in the staging and assessment of treatment response in marginal zone lymphoma (MZL) lymphomas remains controversial. We investigated radiologic characteristics of subcutaneous MZL as imaged on PET/CT scans.

Patients And Methods: From the records of a single medical center, for the years 2008 and 2017, we identified subcutaneous lesions in PET/CT scans of patients with histopathologically confirmed MZL in sites other than subcutaneous tissue.

Gallium-68 prostate-specific membrane antigen PET-CT and the clinical management of prostate cancer.

Objectives: The purpose of this study was to evaluate the use of Gallium-68 prostatic-specific membrane antigen (PSMA) PET-computerized tomography (CT) in patients with prostate cancer undergoing imaging for initial staging, biochemical failure or the evaluation of metastatic disease.

Methods: This is a single institution retrospective study of 95 patients with prostate cancer who were referred for PSMA PET-CT scans. The National Comprehensive Cancer Network guidelines were used to generate treatment recommendations.

68Ga-PSMA PET/CT in prostate cancer patients - patterns of disease, benign findings and pitfalls.

Background: 68Ga-PSMA PET/CT has an important role in assessment of prostate cancer patients with biochemical recurrence and is evolving in staging high- and intermediate risk disease. The aim of present study was to describe the metastatic patterns and frequency of involved sites of prostate cancer and to assess the incidence of benign Ga68-PSMA avid PET/CT findings in a large patient population.

Methods: 68Ga-PSMA PET/CT studies performed in two tertiary medical centers over a period of 24 months were retrospectively reviewed.

Feasibility study of a novel general purpose CZT-based digital SPECT camera: initial clinical results.

Background: The performance of a prototype novel digital single-photon emission computed tomography (SPECT) camera with multiple pixelated CZT detectors and high sensitivity collimators (Digital SPECT; Valiance X12 prototype, Molecular Dynamics) was evaluated in various clinical settings. Images obtained in the prototype system were compared to images from an analog camera fitted with high-resolution collimators. Clinical feasibility, image quality, and diagnostic performance of the prototype were evaluated in 36 SPECT studies in 35 patients including bone (n = 21), brain (n = 5), lung perfusion (n = 3), and parathyroid (n = 3) and one study each of sentinel node and labeled white blood cells.

Low rate of spleen involvement in sporadic Burkitt lymphoma at staging on PET-CT.

Background: Burkitt lymphoma is a highly aggressive B cell non-Hodgkin lymphoma. Cross-sectional imaging techniques that are used to detect liver and spleen involvement by lymphoma have high rates of false negative and false positive findings, and as such may reduce the accuracy of staging.

Purpose: This retrospective study evaluated the use of FDG PET-CT in determining splenic involvement at staging, in a relatively large cohort of adult patients with the sporadic form of Burkitt lymphoma (SBL).

Fat necrosis after abdominal surgery: A pitfall in interpretation of FDG-PET/CT.

Objective: We describe FDG-PET/CT findings of postoperative fat necrosis in patients following abdominal surgery, and evaluate their changes in size and FDG uptake over time.

Methods: FDG-PET/CT scans from January 2007-January 2016 containing the term 'fat necrosis' were reviewed. Lesions meeting radiological criteria of fat necrosis in patients with prior abdominal surgery were included.

Clinical Problem Solving: A Tobacco Merchant Who Can't Spit.

A 47 year old man presented with a combination of dry mouth and lightheadedness while standing. His medical background was unremarkable except for cigarette smoking and hyperlipidemia. Sjögren's syndrome was ruled out, and he was referred for evaluation of orthostatic hypotension, which by then included syncopal episodes and injuries.

The PET-CT Radiological Appearance of Facial Cosmetic Injections: A Pitfall in the Evaluation of the Oncological Patient.

Background: Facial rejuvenation using different dermal and sub-dermal injectable compounds is a popular cosmetic procedure which may pose a diagnostic dilemma to the radiologist.

Objectives: To describe the appearance of cosmetic facial fillers on PET-CT.

Methods: All PET-CT exams performed between January 2015 and May 2017 in which findings suggestive of prior facial filler procedures was evident and where anamnestic confirmation with the patient was possible were reviewed.

Use of F-FDG PET-CT imaging to determine internal mammary lymph node location for radiation therapy treatment planning in breast cancer patients.

Purpose: Adjuvant internal mammary lymph node (IMN) radiation is often delivered with 2-dimensional techniques that use anatomic landmarks and predetermined depths for field placement and dose specification. In contrast, 3-dimensional planning uses the internal mammary vessels (IMVs) to localize the IMNs for planning. Our purpose was to determine if localization of the involved IMN (i-IMN) by F-labeled fluorodeoxyglucose positron emission tomography-computed tomography (F-FDG PET-CT) offers opportunities to improve treatment.

FDG PET-CT evaluation in neurolymphomatosis: imaging characteristics and clinical outcomes.

Neurolymphomatosis (NL) often represents unidentified non-Hodgkin lymphoma relapses. Considering its severity, early detection and treatment are crucial. We outline one hospital's F-FDG-PET-CT imaging findings of NL, along with the patients' clinical characteristics.

Focal fluorine-18 fluorodeoxyglucose-avid parotid findings in patients with lung cancer: prevalence and characteristics.

Objective: Correct interpretation of incidental tumors is important to plan an appropriate treatment. We assessed the incidence and imaging characteristics of fluorine-18 fluorodeoxyglucose (F-FDG)-avid focal parotid findings (FPFs) in patients with lung cancer.

Patients And Methods: FPFs in PET-computed tomography reports of cancer patients were searched.

Metabolic assessment of Merkel cell carcinoma: the role of 18F-FDG PET/CT.

Objectives: Merkel cell carcinoma (MCC) is a rare aggressive skin tumor associated with a high mortality rate. The present study evaluated the role of fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) in subsequent management of patients with MCC.

Methods: A total of 101 consecutive F-FDG PET/CT studies of 46 patients with MCC (28 men, 68±15.

Incidental detection of elastofibroma dorsi on PET-CT: initial findings and changes in tumor size and standardized uptake value on serial scans.

Objective: We describe changes in elastofibroma dorsi (EFD) as observed in serial fluorine-18 fluorodeoxyglucose (F-FDG) PET-computed tomography (CT) imaging studies.

Materials And Methods: F-FDG PET-CT studies carried out between January 2006 and January 2015 at a single institution were reviewed by an experienced radiologist and nuclear medicine specialist. When available, previous or subsequent imaging studies were reviewed to evaluate changes in EFD.

The impact of R-VACOP-B and interim FDG-PET/CT on outcome in primary mediastinal large B cell lymphoma.

The choice of a rituximab-based regimen and the prognostic significance of interim 2-[fluorine-18]fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) in primary mediastinal large B cell lymphoma (PMBCL) are debatable. We evaluated the clinical features and outcomes of 95 consecutive patients with PMBCL who were treated between 1985 and 2009. Forty-three patients received rituximab-based chemotherapy, R-VACOP-B (N = 30) or R-CHOP21 (N = 13), whereas 52 patients were treated with VACOP-B (N = 47) or CHOP21 (N = 5).

Is there a role for therapy response assessment with 2-[fluorine-18] fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography in mantle cell lymphoma?

2-[Fluorine-18] fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) scanning is used for response assessment in mantle cell lymphoma (MCL). However, its ability to predict outcome is debatable. We retrospectively evaluated the prognostic impact of interim and post therapy FDG-PET/CT scan on outcome of 58 consecutive MCL patients.

18F- FDG-PET/CT for the diagnosis of tumor thrombosis.

Background: Venous thromboembolism is a well-recognized and relatively frequent complication of malignancy, whereas tumor thrombosis is a rare complication of solid cancers. The correct diagnosis of tumor thrombosis and its differentiation from VTE can alter patient management and prevent unnecessary long-term anticoagulation treatment.

Objectives: To evaluate the contribution of 18F-fluorodeoxyglucose positron emission tomography/computed tomography to the diagnosis of tumor thrombosis and its differentiation from VTE.

Diffuse lymphangiomatosis--a fatal case with atypical skeletal features.

Diffuse lymphangiomatosis is a rare idiopathic condition that occurs mostly in children, is characterized by a non-neoplastic proliferation of lymphatic vessels, leading to organ dysfunction, chylous effusions, and death. A closely related condition-the Gorham-Stout syndrome-is also characterized by lymphangiomatosis and chylous effusions, but also with massive osteolytic changes ("vanishing bone disease"). A 33-year-old woman presented with a 5-year history of worsening chylous effusions and organomegaly.

PET/CT in the evaluation of lymphoma in patients with HIV-1 with suppressed viral loads.

Objective: Positron emission tomography (PET) with F-18 fluorodeoxyglucose detects active lymphoid tissue during HIV-1 infection, with distinct patterns of lymphoid activation correlating to various stages of disease activity. Patients with HIV-1 are at risk for lymphoma, making the differential diagnosis between benign and malignant lymphadenopathy imperative. This study retrospectively evaluated the role of PET/computed tomography (CT) in differentiating active lymphoma from persistent generalized lymphadenopathy in patients with HIV-1.

Combined increased and decreased skeletal uptake of F-18 FDG.

Increased uptake of F-18 FDG is the general mainstay of diagnosis, because it indicates hypermetabolic foci of pathology. This case, describing a patient with relapsing lymphoma, represents the diagnostic dilemmas of both locally decreased and diffusely increased uptake in the skeleton.

Anterograde and retrograde amnesia in a person with bilateral fornix lesions following removal of a colloid cyst.

AD, a 45-year-old man, presented with a severe and global anterograde amnesia following surgery for removal of a colloid cyst. Structural neuroimaging confirmed bilateral lesions to the fornix and a small lesion in the basal forebrain. Testing for remote episodic memory of autobiographical events, and for remote semantic memory of personal and public events, and of famous people, revealed that AD had a severe retrograde amnesia for autobiographical episodes that covered his entire lifetime, and a time-limited retrograde amnesia for semantic memory.

Experience with somatostatin receptor scintigraphy in the management of pulmonary carcinoid tumors.

Background: Somatostatin receptor scintigraphy has been used widely for the evaluation of neuroendocrine tumors in the gastrointestinal tract. Its use for detecting and staging thoracic carcinoids is only sporadically reported.

Objectives: To evaluate the possible roles of SRS in the management of proven or suspected pulmonary carcinoids.

Moyamoya disease--diagnosis and treatment: indirect cerebral revascularization at the Sheba Medical Center.

Moyamoya disease is a cerebral vasculopathy characterized mainly by progressive narrowing of the major intracranial vessels. While more common and having a familial predilection in the Far East, it can also develop in association with some common hereditary diseases and can be acquired after environmental exposure. In the young its manifestations are the result of cerebral ischemia.