Citations

Abstract Up to 50% of patients with Hodgkin lymphoma and diffuse large B-cell lymphoma will relapse, requiring additional therapy. Although surveillance imaging is commonly performed in clinical practice, its ability to identify asymptomatic relapses and improve survival for patients is not well defined. We evaluated the surveillance imaging role in relapse detection and reviewed its impact on survival for relapsed patients, and found that current imaging approaches do not detect most relapses prior to clinical signs and symptoms or improve survival.

Abstract Physicians performing x-ray guided interventional procedures have a keen interest in radiation safety. Radiation dose to tissues and organs of the head and neck are of particular interest because they are not routinely protected by wearable radiation safety devices. This study was conducted to facilitate estimation of radiation dose to tissues of the head and neck of interventional physicians based on the dose recorded by a personal dosimeter worn on the left collar. Scatter beam qualities maximum energy and HVL were measured for 40 scatter beams emitting from an anthropomorphic patient phantom. Variables of the scatter beams included scatter angle (35° and 90°), primary beam peak tube potential (60, 80, 100, and 120 kVp), and 5 Cu spectral filter thicknesses (0–0.9 mm). Four reference scatter beam qualities were selected to represent the range of scatter beams realized in a typical practice. A general radiographic x-ray tube was tuned to produce scatter-equivalent radiographic beams and used to simultaneously expose the head and neck of an anthropomorphic operator phantom and radiochromic film. The geometric relationship between the x-ray source of the scatter-equivalent beams and the operator phantom was set to mimic that between a patient and physician performing an invasive cardiovascular procedure. Dose to the exterior surface of the operator phantom was measured with both 3 × 3 cm 2 pieces of film and personal dosimeters positioned at the location of the left collar. All films were scanned with a calibrated flatbed scanner, which converted the film’s reflective density to dose. Films from the transverse planes of the operator phantom provided 2D maps of the dose distribution within the phantom. These dose maps were normalized by the dose at the left collar, providing 2D percent of left collar dose (LCD) maps. The percent LCD maps were overlain with bony anatomy CT images of the operator phantom and estimates of percent LCD to the left, right and whole brain, brain stem, lenses of the eyes, and carotid arteries were calculated. Per expectation, results indicated greater percent dose to superficial versus deep tissues and increasing percent dose to deep tissues with increasing scatter-equivalent beam energy and HVL. The results enable estimation of the scatter dose to tissues of the head and neck of interventional physicians based on occupational dose measured by a personal dosimeter worn at the collar outside the protective apron.

BackgroundEchocardiographically detected patent foramen ovale (PFO) has been associated with stroke/transient ischemic attack (TIA) in patients with cardiac implantable electronic devices (CIEDs). We sought to evaluate the relationship between echocardiographic characteristics and risk of stroke/TIA and mortality in CIED patients with PFO.MethodsIn 6,086 device patients, PFO was detected in 319 patients. A baseline echocardiogram was present in 250 patients, with 186 having a follow‐up echocardiogram.ResultsOf 250 patients with a baseline echocardiogram, 9.6% (n = 24) had a stroke/TIA during mean follow‐up of 5.3 ± 3.1 years; and 42% (n = 105) died over 7.1 ± 3.7 years. Atrial septal aneurysm, prominent Eustachian valve, visible shunting across PFO, baseline or change in estimated right ventricular systolic pressure (RVSP)/tricuspid regurgitation (TR), or maximum RVSP were not associated with postimplant stroke/TIA (P > 0.05). An exploratory multivariate analysis using time‐dependent Cox models showed increased hazard of death in patients with increase in TR ≥2 grades (hazard ratio [HR] 1.780, 95% confidence interval [CI] 1.447–2.189, P < 0.0001), or increase in RVSP by >10 mm Hg (HR 2.018, 95% CI 1.593–2.556, P < 0.0001), or maximum RVSP in follow‐up (HR 1.432, 95% CI 1.351–1.516, P < 0.0001). A significant increase (P < 0.001) in TR was also noted during follow‐up.ConclusionsIn patients with CIED and PFO, structural and hemodynamic echocardiographic markers did not predict future stroke/TIA. However, a significantly higher TR or RVSP was associated with higher mortality.

AbstractRationale, aims, and objectivesNovel health care delivery models are needed to reduce health care use while delivering effective and safe care. We developed a model of a neurologist integrated and colocated in primary care leveraging “curbside,” electronic, and traditional consultations. Our objective was to examine the impact on health care resource use of diagnostic testing and referrals for face‐to‐face neurological consultation and adverse outcomes associated with electronic and curbside consultations.MethodsConsecutive patients from December 1, 2014, to March 13, 2015, were included in the analysis about whom contact was made between a primary care clinician and a colocated neurologist.ResultsOver 3.5 months of the pilot, 359 unique patients generated 429 consultations (179 curbsides, 68 electronic consultations, and 182 face‐to‐face visits). The integrated model resulted in avoidance of 78 face‐to‐face tertiary neurology consultations, 39 brain magnetic resonance imaging, 50 electromyograms, and 53 other advanced imaging studies. Earlier curbside consultation may have prevented unnecessary testing or face‐to‐face tertiary neurology consultations in 40 (22%) patients. Earlier face‐to‐face consultation may have avoided expensive testing in 31 (17%) patients. No cases met criteria for an adverse outcome. The number of referrals to tertiary neurology declined by 64%, and the total number of face‐to‐face visits per month declined by 25%.ConclusionColocated neurology in a primary care medical home offers a promising intervention to deliver high‐value care.

PurposeThe purpose of this study was to perform a pilot evaluation of an integrated molecular breast imaging/ultrasound (MBI/US) system designed to enable, in real‐time, the registration of US to MBI and diagnostic evaluation of breast lesions detected on MBI.MethodsThe MBI/US system was constructed by modifying an existing dual‐head cadmium zinc telluride (CZT)‐based MBI gamma camera. The upper MBI detector head was replaced with a mesh panel, which allowed an ultrasound probe to access the breast. An optical tracking system was used to monitor the location of the ultrasound transducer, referenced to the MBI detector. The lesion depth at which ultrasound was targeted was estimated from analysis of previously acquired dual‐head MBI datasets. A software tool was developed to project the US field of view onto the current MBI image. Correlation of lesion location between both modalities with real‐time MBI/US scanning was confirmed in a breast phantom model and assessed in 12 patients with a breast lesion detected on MBI.ResultsCombined MBI/US scanning allowed for registration of lesions detected on US and MBI as validated in phantom experiments. In patient studies, successful registration was achieved in 8 of 12 (67%) patients, with complete registration achieved in seven and partial registration achieved in one patient. In 4 of 12 (37%) patients, lesion registration was not achieved, partially attributed to uncertainty in lesion depth estimates from MBI.ConclusionThe MBI/US system enabled successful registration of US to MBI in over half of patients studied in this pilot evaluation. Future studies are needed to determine if real‐time, registered US imaging of MBI‐detected lesions may obviate the need to proceed to more expensive procedures such as contrast‐enhanced breast MRI for diagnostic workup or biopsy of MBI findings.

Abnormalities in zinc homeostasis are indicated in many human diseases, including Alzheimer disease (AD). 63 Zn-zinc citrate was developed as a positron emission tomography (PET) imaging probe of zinc transport and used in a first-in-human study in 6 healthy elderly individuals and 6 patients with clinically confirmed AD. Dynamic PET imaging of the brain was performed for 30 minutes following intravenous administration of 63 Zn-zinc citrate (∼330 MBq). Subsequently, body PET images were acquired. Urine and venous blood were analyzed to give information on urinary excretion and pharmacokinetics. Regional cerebral 63 Zn clearances were compared with 11 C-Pittsburgh Compound B ( 11 C-PiB) and 18 F-fluorodeoxyglucose ( 18 F-FDG) imaging data. 63 Zn-zinc citrate was well tolerated in human participants with no adverse events monitored. Tissues of highest uptake were liver, pancreas, and kidney, with moderate uptake being seen in intestines, prostate (in males), thyroid, spleen, stomach, pituitary, and salivary glands. Moderate brain uptake was observed, and regional dependencies were observed in 63 Zn clearance kinetics in relationship with regions of high amyloid-β plaque burden ( 11 C-PiB) and 18 F-FDG hypometabolism. In conclusion, zinc transport was successfully imaged in human participants using the PET probe 63 Zn-zinc citrate. Primary sites of uptake in the digestive system accent the role of zinc in gastrointestinal function. Preliminary information on zinc kinetics in patients with AD evidenced regional differences in clearance rates in correspondence with regional amyloid-β pathology, warranting further imaging studies of zinc homeostasis in patients with AD.