Cardiogenic motion of right lung parenchyma in anesthetized intact dogs

Abstract

Cardiogenic motion of the right lung parenchyma (CGLM) was measured in six morphine-pentobarbital-anesthetized dogs (11-16 kg) under conditions of varying paced and spontaneous sinus heart rates. Motion of 1-mm-diameter percutaneously implanted radiopaque lung parenchymal markers were measured using a computer-based biplane video-roentgenographic assembly. Correlation of the amplitudes and phases of marker motions to the R wave of the electrocardiogram (ECG) were determined utilizing a modified fast Fourier transform algorithm. Of initial importance was the observation that CGLM was significantly greater than the variability of repeated measurements. The total amplitudes of motion of the markers (where AT = square root A2X + A2Y + A2Z and AX, AY, AZ are the amplitudes of marker motion along the orthogonal X, Y, and Z body axes) in the right apical, cardiac, and diaphragmatic lobes were 0.025 +/- 0.005 (SE), 0.046 +/- 0.005, and 0.023 +/- 0.025 cm, respectively, (P less than 0.01, cardiac lobe vs. others). The total amplitude of motion observed in the cardiac lobe was equivalent to earlier observations of total amplitude (0.045 +/- 0.004 cm) of marker motion in response to high frequency airway oscillation at a pump stroke volume of 22-26 ml. An analysis of the higher harmonics of marker oscillation suggested that the second harmonic of CGLM is also larger than the variability of our measurements.

Reproducibility and Validity of Lung Density Measures from Cardiac CT Scans—The Multi-Ethnic Study of Atherosclerosis (MESA) Lung Study1

“…Images acquired below TLC provide an inaccurate representation of the amount of emphysema in the lung,15 and not holding the breath for the entire scan can introduce motion artifact. On the other hand, cardiac motion can affect lung density measures,33 so the cardiac gating in the MESA protocol may have improved reproducibility, and MESA employed extensive QC procedures 16…”

First-pass scintigraphy with 99mTc macroaggregated albumin: a method for evaluating pulmonary arterial flow pulsatility

“…Lung parenchyma moves through mechanical transmission of cardiac motion, but heart induced motion is almost negligible in the right lung [20]. Breathing motion has a large amplitude, and could cause significant artifacts (specially at single heartbeats and to a lesser extent in the average heartbeat).…”

Rule-based detection of intrathoracic airway trees

“…There are several major limitations of HRCT which make the extraction of the entire airway trees from CT image sets difficult [4], [24], [25]: 1) in-plane image resolution is insufficient to visualize airways with a diameter smaller than 1 mm and to quantify changes in airway dimensions in airways smaller than 1.5 mm; 2) greater slice thickness dimensions relative to in-plane pixel dimension cause some discontinuity of bronchi between slices; and 3) the 3-D image data sets may not consist of perfectly contiguous slices if care has not been taken to assure a constant lung volume during scanning. Additionally, if image acquisition is not ECG-triggered, cardiogenic motion can significantly alter position of the lung parenchyma and thus alter the position of airways throughout the cardiac cycle [26].…”