Repurposing the Microsoft Kinect for Windows v2 for external head motion tracking for brain PET.

Medical imaging systems such as those used in positron emission tomography (PET) are capable of spatial resolutions that enable the imaging of small, functionally important brain structures. However, the quality of data from PET brain studies is often limited by subject motion during acquisition. This is particularly challenging for patients with neurological disorders or with dynamic research studies that can last 90 min or more. Restraining head movement during the scan does not eliminate motion entirely and can be unpleasant for the subject. Head motion can be detected and measured using a variety of techniques that either use the PET data itself or an external tracking system. Advances in computer vision arising from the video gaming industry could offer significant benefits when re-purposed for medical applications. A method for measuring rigid body type head motion using the Microsoft Kinect v2 is described with results presenting ⩽0.5 mm spatial accuracy. Motion data is measured in real-time at 30 Hz using the KinectFusion algorithm. Non-rigid motion is detected using the residual alignment energy data of the KinectFusion algorithm allowing for unreliable motion to be discarded. Motion data is aligned to PET listmode data using injected pulse sequences into the PET/CT gantry allowing for correction of rigid body motion. Pilot data from a clinical dynamic PET/CT examination is shown.

Percutaneous coronary intervention in a 3-year-old with hypoplastic left heart syndrome.

Mortality outcomes associated with surgical palliation for hypoplastic left heart syndrome (HLHS) have continued to improve with time. Despite these advances, interstage mortality continues to be difficult to predict and prevent. This case report details a 3-year-old boy with HLHS palliated with a Glenn shunt who presented with acute myocardial infarction due to near total occlusion of the distal right coronary artery. He was treated by thrombus aspiration with good clinical response. This is the first report of thrombus aspiration in complex pediatric congenital heart disease and demonstrates the utility of collaboration between congenital and adult cardiologists.

Single scan parameterization of space-variant point spread functions in image space via a printed array: the impact for two PET/CT scanners.

Incorporation of a resolution model during statistical image reconstruction often produces images of improved resolution and signal-to-noise ratio. A novel and practical methodology to rapidly and accurately determine the overall emission and detection blurring component of the system matrix using a printed point source array within a custom-made Perspex phantom is presented. The array was scanned at different positions and orientations within the field of view (FOV) to examine the feasibility of extrapolating the measured point source blurring to other locations in the FOV and the robustness of measurements from a single point source array scan. We measured the spatially-variant image-based blurring on two PET/CT scanners, the B-Hi-Rez and the TruePoint TrueV. These measured spatially-variant kernels and the spatially-invariant kernel at the FOV centre were then incorporated within an ordinary Poisson ordered subset expectation maximization (OP-OSEM) algorithm and compared to the manufacturer's implementation using projection space resolution modelling (RM). Comparisons were based on a point source array, the NEMA IEC image quality phantom, the Cologne resolution phantom and two clinical studies (carbon-11 labelled anti-sense oligonucleotide [(11)C]-ASO and fluorine-18 labelled fluoro-l-thymidine [(18)F]-FLT). Robust and accurate measurements of spatially-variant image blurring were successfully obtained from a single scan. Spatially-variant resolution modelling resulted in notable resolution improvements away from the centre of the FOV. Comparison between spatially-variant image-space methods and the projection-space approach (the first such report, using a range of studies) demonstrated very similar performance with our image-based implementation producing slightly better contrast recovery (CR) for the same level of image roughness (IR). These results demonstrate that image-based resolution modelling within reconstruction is a valid alternative to projection-based modelling, and that, when using the proposed practical methodology, the necessary resolution measurements can be obtained from a single scan. This approach avoids the relatively time-consuming and involved procedures previously proposed in the literature.

Use of the assessment of discomfort in dementia protocol.

The Assessment of Discomfort in Dementia (ADD) Protocol was developed to improve recognition and treatment of physical pain and affective discomfort in people with dementia who are no longer able to clearly or consistently report on their internal states. The purpose of this study was to describe use of each step of the ADD protocol with 143 residents of long-term care facilities. Of the subjects who received nonpharmacological comfort interventions, 37% showed improved symptoms. Of the 91 protocols in which an analgesic was administered, 83.5% showed improved symptoms. People who complained verbally received considerably more analgesics and other comfort interventions. Limitations inherent in this descriptive exploratory study do not permit conclusions regarding the effectiveness of the ADD protocol. Research with a control group, random assignment, and objective measures of discomfort level is planned.

Nurses' perceptions of pain assessment and treatment in the cognitively impaired elderly. It's not a guessing game.

The purpose of the study was to describe nurses' perceptions regarding the assessment and treatment of pain in patients with late-stage dementia. Thirty nurses from six long-term care facilities were interviewed using a semistructured format for this qualitative study. Initial results were presented to a second group for validation and refinement of findings. The most commonly cited behaviors used to indicate discomfort were facial grimacing, restless body movement, change in behavior, moaning, and tense muscles. Psychotropic drugs were perceived to be commonly misused because behavior changes were seen as a psychiatric problem rather than a representation of the patient's unmet need. Nurses had positive feelings about using both narcotics and nonnarcotic analgesics with this population but believed both types of analgesics were underused. The most common concerns regarding the administration of narcotic analgesics to this population were falls, sedation, and constipation.

Condensing osteitis of the clavicle in a man.

Condensing osteitis of the clavicle is a rare, benign, usually painful condition leading to sclerosis of the medial end of the clavicle. In the English language literature, this has only been reported in women since its original description by Brower et al. in 1974 [1]. We report a clavicular lesion occurring in a man that is clinically, radiographically, and histologically identical to described cases of condensing osteitis.

Regional subacute cranial neuropathies following internal carotid cisplatin infusion.

The inferolateral trunk arises from the internal carotid artery at C-4 and provides vascular supply to cranial nerves III to VI. We report a patient who developed neuropathies of cranial nerves III, V1-3, and VI, 48 hours after infusion of cisplatin into the right internal carotid artery for an anaplastic oligoastrocytoma. The clinical and radiographic findings implicated direct toxicity to nerves in the distribution of the inferolateral trunk. We found additional cases by review of published brain tumor chemotherapy trials, thus identifying a novel, toxic neurovascular mechanism for injury to cranial nerves III to VI.

Recent advances in the treatment of cystinosis.

Cysteamine bitartrate capsules (Cystagon) have been approved by the US Food and Drug Administration for use in patients with nephropathic cystinosis. Plasma cysteamine concentrations were virtually identical at various times following ingestion of either cysteamine hydrochloride or Cystagon capsules in 24 normal control subjects. A transfer study was done with eight cystinosis patients who had been receiving either cysteamine hydrochloride or phosphocysteamine for many years. The plasma cysteamine concentration was significantly higher 2h after Cystagon and the leukocyte cystine content was significantly lower at all times after Cystagon compared to older forms of the drug. These differences are probably the result of greater patient compliance in taking the capsules compared to the older, liquid forms of the drug. A new method for following the course of renal glomerular deterioration in diseases such as cystinosis has been published recently. This method was used to re-analyse data on the efficacy of cysteamine treatment and to re-analyse new data on treating cystinosis patients with either of two doses of cysteamine (1.30 g/m2 per day and 1.95 g/m2 per day). This new method agrees well with other methods and shows that both doses of drug are equally effective in maintaining glomerular function.

Bioequivalence of two methotrexate formulations in psoriatic and cancer patients.

OBJECTIVE: To compare the bioequivalence of a generic methotrexate (MTX) tablet (Mylan) with that of a brand-name (Lederle) product. DESIGN: A single-dose, randomized, crossover study. SETTING: Clinical Research Center (CRC) at a university hospital. PATIENTS: Men and women who had a diagnosis of malignancy or psoriasis who were at least 21 years old. METHODOLOGY: Two overnight study periods were scheduled at the CRC at least one week, but not more than two weeks apart. Each period consisted of a 10-hour fast prior to and 4 hours following oral MTX 15 mg administered as six 2.5-mg tablets. Blood samples were collected over 48 hours. Plasma MTX concentrations were determined using an HPLC assay. Area under the curve from zero to infinity (AUC0-infinity) was calculated by the log-trapezoidal method. RESULTS: Twenty-two patients (21 psoriasis, 1 colon cancer) aged 23-61 years completed both study periods. Mean values for peak concentration, time to peak concentration, and AUC0-infinity were 0.80 mumol/L, 1.2 hours, and 3.0 mumol.h/L, respectively, for Mylan's MTX tablets and 0.81 mumol/L, 1.4 hours, 3.0 mumol.h/L, respectively, for Lederle's MTX. Normalization for weight or body surface area did not affect interpatient variability. Relative bioavailability of generic MTX was 99.2 percent. Rate and extent of absorption were not significantly different and the confidence intervals were within the range of 80-120 percent required by the Food and Drug Administration. CONCLUSIONS: Mylan's MTX tablet is bioequivalent to Lederle's product.

The impact of lag time on the estimation of pharmacokinetic parameters. I. One-compartment open model.

Lag time in pharmacokinetics corresponds to the finite time taken for a drug to appear in systemic circulation following extravascular administration. Lag time is a reflection of the processes associated with the absorption phase such as drug dissolution and/or release from the delivery system and drug migration to the absorbing surface. Failure to specify the lag time can lead to inappropriate or erroneous estimates of pharmacokinetic parameters. This has been demonstrated in the case of a one-compartment open model by the pharmacokinetic analysis of bioequivalence data from a study involving the administration of propoxyphene napsylate to human volunteers. Subsequently, pharmacokinetic and statistical analyses of data obtained from a series of 49 simulations involving a wide range of absorption and elimination rate constants (0.05 to 5.00 and 0.01 to 0.95 hr-1, respectively) showed that lag time has a substantial effect on several primary and secondary pharmacokinetic parameters.

Dose proportionality of transdermal nitroglycerin.

The FDA Cooperative Efficacy Study of transdermal nitroglycerin utilized a combination of marketed products over a wide dose range. Unfortunately, plasma nitroglycerin concentrations were not determined. The current study was conducted to assess plasma nitrate concentrations after transdermal doses of 15, 30, 60, and 105 mg/24 hr employing the FDA Cooperative Study design. Plasma concentrations of nitroglycerin, 1,3-glyceryl dinitrate, and 1,2-glyceryl dinitrate were determined during the 24 hr of application and for 1 hr after transdermal system removal. Dose proportionality was assessed after normalizing the data by theoretical dose. For nitroglycerin, dose-normalized AUC(0-infinity) and Cmax were higher for the 105 mg/24 hr dose than for the other doses. For the metabolites, 1,3-glyceryl dinitrate and 1,2-glyceryl dinitrate, there were no differences in dose-normalized AUC(0-infinity) and dose-normalized Cmax between the dose levels. No differences were seen in Tmax between the dose levels for all three species. Based on the dinitrate metabolites, dose proportionality was seen over the 15 to 105 mg/24 hr dose range. Nitroglycerin, however, was found to be linear only between 15 and 60 mg/24 hr.

Pilot study for the development of a monitoring device for ventilated children.

Airway pressure and air flow were measured at the endotracheal tube in 13 children on a variety of ventilators. These signals were stored for analysis on a computer. Further data sets were obtained after 24 hours or following major interventions. Air flow rate was integrated to give volume. Pulmonary resistance and elastance were obtained by multiple linear regression. Pressure-volume, pressure-flow and flow-volume loops were plotted. "Closed" pressure-volume and pressure-flow loops (by subtraction of the resistive or elastic pressure components, respectively) were also displayed, giving compliance and resistance loops. The loops from the initial data set were taken as the baseline, and loops from later data sets were superimposed to provide visual comparisons. Change in clinical status was reflected by the change in slope of compliance and resistance loops. A 30% change in compliance or resistance was easily observed. There was minimal interference with patient care. This pilot study demonstrates that changes in respiratory mechanics can be displayed safely and easily in ventilated patients using resistance and compliance loops. Further work is necessary to confirm the usefulness of real time of these displays.

Product matrix: materiel management information systems. A look into the 90s: software catches up with hardware.

As always, you'll have to fight for the dollars to buy systems, competing with departments who produce revenue. Financial managers and hospital boards respond most favorably to a good return on investment (ROI) presentation. Join forces with your software vendor of choice and give your board the best ROI argument they'll hear this year. Keep two things in mind: 1) today's innovations, particularly in reducing inventory, interfacing and lower hardware costs will help you make your case and 2) make sure the system is growing consistent with the industry to ensure you won't be asking for a similar purchase three years from now.

Gas chromatographic determination of gallopamil and norgallopamil in human plasma.

A highly sensitive gas chromatographic assay is described for the simultaneous determination of gallopamil, a calcium channel blocking agent, and its major metabolite, norgallopamil. A multi-step extraction procedure is employed followed by on-column capillary gas chromatographic analysis using nitrogen-selective detection. Acetylation of norgallopamil is performed to enable accurate quantification of the metabolite. Linearity was achieved over the range 1-50 ng/ml for both analytes. Assay specificity, precision and accuracy were investigated.

Variable glyceryl dinitrate formation as a function of route of nitroglycerin administration.

Plasma concentrations of 1,2- and 1,3-glyceryl dinitrates were measured in each of four healthy volunteers who received intravenous infusions (10, 20, and 40 micrograms/min), topical ointment (20 mg/200 cm2), and oral solution (6.5 mg) doses of nitroglycerin and from two subjects who received sublingual (0.4 mg) nitroglycerin. The ratio of 1,2-glyceryl dinitrate to 1,3-glyceryl dinitrate (dinitrate ratio) was determined for each subject after each dose and was found to vary with route of administration. Dinitrate ratios were 7.36, 4.60, 3.86, and 1.99 for intravenous, sublingual, topical, and oral doses, respectively. Nonspecific metabolism of nitroglycerin would result in twice as much of the 1,2-dinitrate as the 1,3-dinitrate (i.e., a dinitrate ratio of 2.0, such as that produced after oral administration). A high ratio (e.g., after intravenous administration) indicates that the metabolism was more specific. These results indicate that metabolite formation depends on route of administration, implying different metabolic specificity of enzymes in the gut, liver, skin, sublingual mucosa, and blood vessels.

High-performance liquid chromatographic (HPLC) assay using fluorescence detection for the simultaneous determination of gallopamil and norgallopamil in human plasma.

Gallopamil is a calcium-channel antagonist with reported activity in experimental animals three to five times higher than that of verapamil. An automated high-performance liquid chromatographic (HPLC) method with fluorescence detection is described for the simultaneous determination of gallopamil and its metabolite norgallopamil in plasma. Gallopamil was well resolved from norgallopamil and other metabolites, allowing simultaneous quantitation of both drugs. The detection limit for both gallopamil and norgallopamil was 0.9 ng/ml. This method has been successfully used for the determination of gallopamil and norgallopamil following the administration of 25-, 37.5-, and 50-mg oral doses of drug.