PET biodistribution study of subcutaneous and intravenous administration of adalimumab in an inflammatory bowel disease model.

Monoclonal antibodies targeting tumor necrosis factor-alpha (antiTNF-α) are used for patients with immuno-mediated illness as inflammatory bowel disease (IBD). However, 20-40 % of IBD patients do not respond to these therapies, and increasing knowledge of biodistribution could optimize their use and consequently their effectiveness. The aim of this study is to compare the biodistribution of adalimumab after intravenous (IV) and subcutaneous (SC) administration using Positron Emission Tomography (PET) imaging in IBD animal models.

First week of life respiratory management and pulmonary ventilation/perfusion matching in infants with bronchopulmonary dysplasia: a retrospective observational study.

Objective: To investigate the association between early neonatal respiratory management in infants with bronchopulmonary dysplasia (BPD) and the degree of pulmonary ventilation perfusion-matching (V/Q) at term.

Methods: 30 preterm infants with a diagnosis of BPD who were initially treated with either controlled mechanical ventilation/continuous positive airway pressure (CMV/CPAP) (n = 14) or high-frequency oscillatory ventilation (HFOV) using a high lung-volume strategy (n = 16) were retrospectively included in this study. All infants underwent pulmonary V/Q single photon emission computed tomography at a median postmenstrual age of 37 weeks.

Primary hyperparathyroidism, a machine learning approach to identify multiglandular disease in patients with a single adenoma found at preoperative Sestamibi-SPECT/CT.

Objective: Successful preoperative image localisation of all parathyroid adenomas (PTA) in patients with primary hyperparathyroidism (pHPT) and multiglandular disease (MGD) remains challenging. We investigate whether a machine learning classifier (MLC) could predict the presence of overlooked PTA at preoperative localisation with 99mTc-Sestamibi-SPECT/CT in MGD patients.

Design: This study is a retrospective study from a single tertiary referral hospital initially including 349 patients with biochemically confirmed pHPT and cured after surgical parathyroidectomy.

Pulmonary translocation of ultrafine carbon particles in COPD and IPF patients.

Objective: Epidemiological studies indicate association between elevated air pollution and adverse health effects. Several mechanisms have been suggested, including translocation of inhaled ultrafine carbon (UFC) particles into the bloodstream. Previous studies in healthy subjects have shown no significant pulmonary translocation of UFC-particles.

The preoperative localisation of small parathyroid adenomas improves when adding Tc-99m-Sestamibi SPECT to multiphase contrast-enhanced CT.

Objectives: To investigate the incremental value of Sestamibi SPECT combined with a non-enhanced and contrast-enhanced CT, using SPECT/CT, for the preoperative localisation of small parathyroid adenomas (PTA).

Methods: Retrospectively, 147 patients surgically cured from primary hyperparathyroidism, as verified by biochemistry 6 months postoperatively, were included. All patients had preoperatively undergone a dual time Technetium-Sestamibi SPECT (S) with multiphase CT including native (N), arterial (A) and venous (V) phases.

Multiphase Iodine Contrast-Enhanced SPECT/CT Outperforms Nonenhanced SPECT/CT for Preoperative Localization of Small Parathyroid Adenomas.

Purpose: The aim of this study was to assess the value of intravenously contrast-enhanced CT in conjunction with Tc-MIBI SPECT for preoperative localization of parathyroid adenoma.

Methods: One hundred ninety-two patients with primary hyperparathyroidism were enrolled in the study between May 2015 and May 2017. The patients underwent a preoperative "one-stop shop" examination with Tc-MIBI SPECT/CT by using dual time-point (10 and 90 minutes) protocol and both nonenhanced CT and contrast-enhanced CT acquisition in the arterial and venous phase, 35 and 75 seconds, respectively, after contrast medium injection start.

Comparison of acquisition protocols for ventilation/perfusion SPECT-a Monte Carlo study.

One of the most commonly used imaging techniques for diagnosing pulmonary embolism (PE) is ventilation/perfusion (V/P) scintigraphy. The aim of this study was to evaluate the performance of the currently used imaging protocols for V/P single photon emission computed tomography (V/P SPECT) at two nuclear medicine department sites and to investigate the effect of altering important protocol parameters. The Monte Carlo technique was used to simulate 4D digital phantoms with perfusion defects.

Ten-year-old children with a history of bronchopulmonary dysplasia have regional abnormalities in ventilation perfusion matching.

Aim: The ratio of ventilation to blood flow is an important determinant for regional gas exchange in the lung and hypoxemia is one of the clinical hallmarks in infants with bronchopulmonary dysplasia (BPD). We have previously demonstrated ventilation/perfusion ratio (V/Q) abnormalities in infants with BPD at 36 weekś postconceptional age. The status of V/Q matching in older children with a history of BPD in infancy is unknown.

Lung Scintigraphy in the Assessment of Aerosol Deposition and Clearance.

Environmental and occupational exposure to particulate aerosols is known to have negative health effects. However little is known about how these aerosols trigger the development of pathophysiological mechanisms in the body or the fate of ultrafine particles in the lungs after inhalation. The development of aerosols of different origin that can be labeled to a large variety with radionuclides compatible with clinical gamma camera systems opens the possibility of using lung scintigraphy imaging to study these causalities in detail.

Lung Ventilation/Perfusion Single Photon Emission Computed Tomography (SPECT) in Infants and Children with Nonembolic Chronic Pulmonary Disorders.

Single photon emission computed tomography (SPECT) provides high contrast three dimensional images of the regional distribution of a radiotracer. SPECT is a widely used technique in pulmonary investigations of the ventilation (V) and perfusion (Q) in the adult patient, mainly in the diagnosis of pulmonary embolism. However, safety concerns among practitioners due to radiation exposure and the use of macroaggregate albumin for the perfusion scan have historically precluded the use of SPECT in pediatric patients with nonembolic pulmonary disorders.

18F FDG-PET/CT evaluation of histological response after neoadjuvant treatment in patients with cancer of the esophagus or gastroesophageal junction.

Background: In most parts of the world, curatively intended treatment for esophageal cancer includes neoadjuvant therapy, either with chemoradiotherapy or chemotherapy alone, followed by esophagectomy. Currently 18F-FDG positron emission tomography/computed tomography (PET/CT) is used for preoperative disease staging, but is not well established in the evaluation of neoadjuvant treatment.

Purpose: To evaluate changes in PET parameters in relation to the histological primary tumor response in the surgical specimen in patients randomized to neoadjuvant chemoradiotherapy or chemotherapy.

Hallmarks in prostate cancer imaging with Ga68-PSMA-11-PET/CT with reference to detection limits and quantitative properties.

Background: Gallium-68-labeled prostate-specific antigen positron emission tomography/computed tomography imaging (Ga68-PSMA-11-PET/CT) has emerged as a potential gold standard for prostate cancer (PCa) diagnosis. However, the imaging limitations of this technique at the early state of PCa recurrence/metastatic spread are still not well characterized. The aim of this study was to determine the quantitative properties and the fundamental imaging limits of Ga68-PSMA-11-PET/CT in localizing small PCa cell deposits.

Diagnostic accuracy of C-methionine PET in detecting neuropathologically confirmed recurrent brain tumor after radiation therapy.

Objective: This study aims to determine the diagnostic test accuracy (DTA) of C-methionine (MET) PET in the discrimination between recurrent tumor and radiation-induced injury in neuropathologically confirmed cases.

Methods: A retrospective cohort of 30 patients with previously irradiated intracranial tumors (23 gliomas, 6 metastases, and 1 meningioma) was included. All patients underwent a preoperative MET PET and postoperative neuropathological analysis.

SPECT/CT's Advantage for Preoperative Localization of Small Parathyroid Adenomas in Primary Hyperparathyroidism.

Purposes: The aims of this study were to assess the performance of Tc-sestamibi SPECT/CT, with diagnostic CT quality, compared with SPECT alone for preoperative localization of parathyroid adenomas and to assess the influence of adenoma weight on the correct adenoma lateralization with SPECT/CT and with SPECT alone.

Methods: Two hundred forty-nine consecutive patients, biochemically diagnosed with primary hyperparathyroidism, were examined with a combined SPECT/CT scanner. Subsequently, 200 patients with confirmed histopathology and biochemical cure after parathyroidectomy were included in this study (16 with multiglandular disease).

Predictive value of [F]-fluoride PET for monitoring bone remodeling in patients with orthopedic conditions treated with a Taylor spatial frame.

Purpose: The Taylor Spatial Frame (TSF) is used to correct orthopedic conditions such as correction osteotomies in delayed fracture healing and pseudarthrosis. Long-term TSF-treatments are common and may lead to complications. Current conventional radiological methods are often unsatisfactory for therapy monitoring.

18F-FDG PET/CT Diagnosis of Bronchopulmonary Carcinoids Versus Pulmonary Hamartomas.

Purpose: Radiological characterization of pulmonary tumors may be difficult and invasive. Needle biopsy may produce false-negative results. 18F-FDG PET/CT is an established noninvasive procedure for lung tumor characterization and staging.

Repeatability of the Maximum Standard Uptake Value (SUVmax) in FDG PET.

Objective: SUVmax is often calculated at FDG PET examinations in systematic studies as well as at clinical examinations. Since SUVmax represents a very small portion of a lesion it may be questioned how statistically reliable the figure is. This was studied by assessing the repeatability of SUVmax between two FDG acquisitions acquired immediately upon each other in patients with chest lesions.

Bronchopulmonary dysplasia: clinical grading in relation to ventilation/perfusion mismatch measured by single photon emission computed tomography.

Bronchopulmonary dysplasia (BPD) is a significant cause of morbidity in the preterm population. Clinical severity grading based on the need for supplemental oxygen and/or need for positive airway pressure at 36 weeks postmenstrual age does not yield reproducible predictive values for later pulmonary morbidity. Single photon emission computed tomography (SPECT) was used to measure the distribution of lung ventilation (V) and perfusion (Q) in 30 BPD preterm infants at a median age of 37 weeks postmenstrual age.

Comparison of Gallium-68 and Fluorine-18 imaging characteristics in positron emission tomography.

This review article compares PET imaging performance with Gallium-68 ((68)Ga) and Fluorine-18 ((18)F). The literature on this topic is scarce; hence in order to complete the published data, Monte Carlo calculations, as well as phantom measurements, were carried out. The qualitative and quantitative differences between (68)Ga and (18)F imaging were evaluated in terms of spatial resolution, sensitivity, contrast and activity recovery coefficients for both human PET systems and small animal PET scanners.

The pulmonary deposition and retention of indium-111 labeled ultrafine carbon particles in healthy individuals.

Context: Particulate air pollution, for example, from ultrafine (UF) particles, has negative health effects. However, there is still limited knowledge regarding the fate of inhaled particles in the human body.

Objectives: To describe the normal lung deposition and 1 week particle retention of indium-111 labeled UF carbon particles in healthy subjects.

A revision of the organ radiation doses from 2-fluoro-2-deoxy-D-glucose with reference to tumour presence.

Absorbed radiation doses to major human organs after intravenous bolus administration of 2-[(18)F]fluoro-2-deoxy-d-glucose (FDG) were reviewed. Absorbed doses were calculated using the medical internal radiation dose (MIRD) formalism from experimental activity-time curves. Thirty patients (22 with macroscopic lung tumour and 8 without observable disease) were investigated using a state-of-the-art combined positron emission tomography/computer tomography system (Siemens Biograph 64).

Postoperative regional distribution of pulmonary ventilation and perfusion in infants with congenital diaphragmatic hernia.

Background/purpose: Advances in management of patients with congenital diaphragmatic hernia (CDH) have improved mortality rates but with a risk of increased pulmonary morbidity. The prognosis for CDH survivors remains difficult to predict owing to the lack of adequate methods. We used single photon emission computed tomography (SPECT) to measure the regional distribution of ventilation and perfusion in CDH infants to quantify the degree of lung function impairment and relate it to neonatal clinical disease severity.

¹¹¹Indium-labeled ultrafine carbon particles; a novel aerosol for pulmonary deposition and retention studies.

Continuous environmental or occupational exposure to airborne particulate pollution is believed to be a major hazard for human health. A technique to characterize their deposition and clearance from the lungs is fundamental to understand the underlying mechanisms behind their negative health effects. In this work, we describe a method for production and follow up of ultrafine carbon particles labeled with radioactive ¹¹¹Indium (¹¹¹In).

Inhalation anesthesia increases V/Q regional heterogeneity during spontaneous breathing in healthy subjects.

Background: The underlying mechanism for the increased alveolar-arterial oxygen tension difference resulting from almost all forms of general anesthesia is unknown. We hypothesized that inhalation anesthesia influences the intrapulmonary distribution of ventilation (V) and perfusion (Q), leading to less advantageous V/Q matching.

Methods: Ten healthy volunteers were studied in supine position on two separate occasions, once awake and once during mild anesthesia (sevoflurane inhalation) with maintained spontaneous breathing.

Positive end-expiratory pressure redistributes regional blood flow and ventilation differently in supine and prone humans.

Background: Animal studies have demonstrated an interaction between posture and the effect of positive end-expiratory pressure (PEEP) on regional ventilation and lung blood flow. The aim of this study was to explore this interaction in humans.

Methods: Regional lung blood flow and ventilation were compared between mechanical ventilation with and without PEEP in the supine and prone postures.