How Best to Estimate Insertion Length of Multichannel Intraluminal Impedance pH Probes in Children.

Objective: To assess the reliability of the KidZ Health Castle formula (KHC-F) to determine the correct probe position of a multichannel intraluminal impedance pH.

Study Design: A retrospective cohort study was performed on 222 children between 1 month and 18 years of age undergoing multichannel intraluminal impedance pH. The primary outcome was the comparison of the pH sensor location determined by the KHC-F with the radiological target position.

Limitations of quantitative radionuclide bone scanning in the evaluation of total knee replacement.

To establish the value of quantitative radionuclide bone scanning after total knee replacement, 21 patients were scheduled for examination. Eight patients were scanned more than 1 year after surgery (group 1), and 13 within the first postsurgical year (group 2). Ratios were calculated for three regions of interest.

Visualization and characterization of gastric contractions using a radionuclide technique.

With the use of the radionuclide gastric-emptying test and a new data processing method, the contraction characteristics of the stomach were analyzed. After ingestion of a radiolabeled test meal, dynamic images of the stomach were acquired and analyzed to determine the frequency, amplitude, and rate of gastric contractions in healthy subjects. The frequency of antral contractions was found to be inversely related with food retention in the stomach; in contrast, the amplitude of the contractions decreased progressively during the course of gastric emptying.

Background correction in factor analysis of dynamic scintigraphic studies: necessity and implementation.

In factor analysis, structures are separated on the basis of their temporal behaviour, even if there is a partial overlap. Usually, the temporal behaviour of the system under study cannot be sampled in its true form due to a total overlap by the background. In the ROI (region of interest) method, background subtraction is used as a means to correct the problem.

Thrombus imaging with an I-123-labeled F(ab')2 fragment of an anti-human fibrin monoclonal antibody in a rabbit model.

The murine monoclonal antibody MA-15C5 binds to cross-linked fibrin but not to fibrinogen. Fab or F(ab')2 fragments of MA-15C5, labeled with iodine-123, were injected intravenously into nine rabbits with a nonocclusive 0.2-mL human plasma clot in the jugular vein and into eight control rabbits.

Comparison of quantification methods of 111In-labelled platelet deposition in peripheral bypass grafts.

The action of antithrombotic drugs can be evaluated by measuring the deposition of 111In-labelled platelets on peripheral bypass grafts several days after injection. This evaluation can be performed qualitatively (visual interpretation on the daily images) or quantitatively. Four different methods which calculate the ratio of platelet uptake with a reference region are compared: two methods use a gamma camera and two a detector.

Comparison of 133Xe washout curves after bolus inhalation, perfusion, and equilibration.

In 6 healthy subjects and 13 patients with chronic obstructive lung disease, 133Xe washout curves after bolus inhalation, perfusion and equilibration were compared, using a gamma camera and computerized data handling. In healthy subjects the washout after equilibration was significantly slower than after the two other procedures. As this phenomenon occurred at the basal zones, it was attributed to the presence of airway closure in some units.

Horizontal gradient in ventilation distribution due to a localized chest wall abnormality.

Horizontal gradients in the distribution of ventilation and of regional vital capacities, as well as a reversed vertical, esophageal pressure gradient, were observed in a patient with a unilateral painful chest wall lesion. The distribution abnormalities disappeared after surgical treatment. These findings suggest that the interdependency between chest wall and lungs, and within the latter, between lobes, is an important factor determining the regional distribution of ventilation and the pleural pressure gradient in man.