Effect of PSMA PET/CT on the Use of Bone Scintigraphy for Prostate Cancer at a University Hospital System.

We observed at our university-based imaging centers that when prostate-specific membrane antigen (PSMA) PET/CT became available for staging and restaging prostate cancer, the volume of bone scanning on patients with prostate cancer (BS-P) markedly decreased. We aimed to study use patterns of PSMA PET/CT and BS-P at our imaging centers during the 4-y period around U.S.

Nuclear Medicine Imaging Tools in Fever of Unknown Origin: Time for a Revisit and Appropriate Use Criteria.

Fever of unknown origin (FUO) is a clinical conundrum for patients and clinicians alike, and imaging studies are often performed as part of the diagnostic workup of these patients. Recently, the Society of Nuclear Medicine and Molecular Imaging convened and approved a guideline on the use of nuclear medicine tools for FUO. The guidelines support the use of 2-18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) in adults and children with FUO.

Musculoskeletal Infection: Role of Molecular Imaging in Diagnosis and Monitoring Treatment Response.

Molecular imaging tests frequently are performed as part of the diagnostic workup of musculoskeletal infection. Three-phase bone scintigraphy reliably diagnoses osteomyelitis in bones not affected by underlying conditions. The test is less useful, because of decreased specificity, in patients with underlying bony abnormalities or alterations such as fractures, orthopaedic hardware, arthritic changes, and tumors.

ACR Appropriateness Criteria® Imaging After Total Hip Arthroplasty.

This article reviews evidence for performing various imaging studies in patients with total hip prostheses. Routine follow-up is generally performed with radiography. Radiographs are also usually the initial imaging modality for patients with symptoms related to the prosthesis.

A Brief History of Nuclear Medicine Imaging of Infection.

For nearly 50 years, nuclear medicine has played an important role in the diagnosis of infection. Gallium citrate Ga 67 was one of the first, if not the first, radionuclide used for this purpose. Unfavorable imaging characteristics, a lack of specificity, and the long interval (2-3 days) between administration and imaging spurred the search for alternatives.

Appearance of aseptic vascular grafts after endovascular aortic repair on [(18)F]fluorodeoxyglucose positron emission tomography/computed tomography.

Background: Diagnosis of prosthetic vascular graft infection with [(18)F]fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) allows for early detection of functional changes associated with infection, based on increased glucose utilization by activated macrophages and granulocytes. Aseptic vascular grafts, like all foreign bodies, can stimulate an inflammatory response, which can present as increased activity on 18F-FDG PET/CT. Consequently, distinguishing aseptic inflammation from graft infection, though important, can be difficult.

1-hour versus 3-hour 99mTc-PYP imaging to evaluate suspected cardiac transthyretin amyloidosis.

The diagnosis of cardiac transthyretin amyloidosis can involve early or delayed 99mTc-pyrophosphate planar, single photon emission computed tomography (SPECT), and/or SPECT/CT imaging. We investigated whether image interpretations differed among modalities and time points. In this observational study, data were reviewed for 173 patients with suspected transthyretin amyloidosis who underwent planar and SPECT/CT 1 and 3 hours after radiopharmaceutical injection.

FDG PET in Evaluation of Patients With Fever of Unknown Origin: Expert Panel Narrative Review.

Fever of unknown origin (FUO) is a diagnostic challenge, with its cause remaining undiagnosed in approximately half of patients. Nuclear medicine tests typically are performed after a negative or inconclusive initial workup. Gallium-67 citrate and labeled leukocytes were previous mainstays of radionuclide imaging for FUO, although they had limited diagnostic performance.

Indicators of abnormal PET coronary flow capacity in detecting cardiac ischemia.

Coronary flow capacity (CFC) categorizes severity of left ventricular (LV) ischemia by PET myocardial blood flow (MBF). Our objective was to correlate abnormal CFC with other indicators of regional ischemia. Data were examined retrospectively for 231 patients evaluated for known/suspected CAD who underwent rest and regadenoson-stress Rb PET/CT.

Imaging of Spondylodiscitis: An Update.

Spondylodiscitis is an infection of the vertebral body and/or intervertebral disc, which can also involve the epidural space, posterior elements, and paraspinal soft tissues. Due to high morbidity and mortality, prompt diagnosis and treatment of spondylodiscitis is critical. However, diagnosis can be challenging due to nonspecific signs and symptoms.

Molecular Imaging of Periprosthetic Joint Infections.

Infection is an infrequent complication of lower extremity prosthetic joint surgery. Approximately one third develop within 3 months (early), another third within 1 year (delayed), and the remainder more than 1 year (late) after surgery. The diagnosis of periprosthetic joint infection is not always straightforward.

Tc-PYP SPECT and SPECT/CT quantitation for diagnosing cardiac transthyretin amyloidosis.

Background: We investigated quantitative Tc-pyrophosphate (PYP) SPECT/CT reproducibility and accuracy for diagnosing cardiac transthyretin amyloidosis (ATTR), and whether SPECT/CT improved visual and quantitative results compared to SPECT-only.

Methods: Data were reviewed for 318 patients with suspected ATTR who underwent PYP SPECT/CT. Myocardial-to-blood pool count (MBP) ratios were computed and repeated independently > 1 month later.

Computational approaches to detect small lesions in F-FDG PET/CT scans.

Purpose: When physicians interpret F-FDG PET/CT scans, they rely on their subjective visual impression of the presence of small lesions, the criteria for which may vary among readers. Our investigation used physical phantom scans to evaluate whether image texture analysis metrics reliably correspond to visual criteria used to identify lesions and accurately differentiate background regions from sub-centimeter simulated lesions.

Methods: Routinely collected quality assurance test data were processed retrospectively for 65 different F-FDG PET scans performed of standardized phantoms on eight different PET/CT systems.

Clinical implications of compromised Rb PET data acquisition.

Background: We wished to document the prevalence and quantitative effects of compromised Rb PET data acquisitions on myocardial flow reserve (MFR).

Methods And Results: Data were analyzed retrospectively for 246 rest and regadenoson-stress studies of 123 patients evaluated for known or suspected CAD. An automated injector delivered pre-determined activities of Rb.

Comparison and validation of automated scoring of SPECT phantom cold rod visibility.

Purpose: Evaluation of phantom image quality is an integral component of the quality assurance of SPECT systems. This evaluation often is done by visual assessment of the resolution of known structures of a specified size, such as arrays of cold rods in a warm background. Although this method is rapid and convenient, it is qualitative and is subject to inter- and intraobserver variability.

A pilot study treatment of malignant tumors using low-dose F-fluorodeoxyglucose (F-FDG).

Photons, electrons and protons have therapeutic use however positrons have only been used for diagnostic imaging purposes. The energies of positrons (β) from F-18 (0.633 MeV) and electrons (β) from I-131 (0.

The Role of Imaging Techniques to Define a Peri-Prosthetic Hip and Knee Joint Infection: Multidisciplinary Consensus Statements.

Diagnosing a peri-prosthetic joint infection (PJI) remains challenging despite the availability of a variety of clinical signs, serum and synovial markers, imaging techniques, microbiological and histological findings. Moreover, the one and only true definition of PJI does not exist, which is reflected by the existence of at least six different definitions by independent societies. These definitions are composed of major and minor criteria for defining a PJI, but most of them do not include imaging techniques.

Early onset of left ventricular regional asynchrony in arteries with sub-clinical stenosis.

Background: Asynchrony has been reported to be a marker of ischemic-induced left ventricular dysfunction, the magnitude of which correlates with extent of epicardial coronary disease. We wished to determine whether normal-appearing arterial territories with mild degrees of asynchrony have lower Rb PET absolute myocardial blood flow (MBF) and/or lower myocardial flow reserve (MFR).

Methods And Results: Data were examined retrospectively for 105 patients evaluated for known/suspected CAD who underwent rest/regadenoson-stress Rb PET/CT and quantitative coronary angiography.