Related Experiment Video
Updated: Aug 14, 2026
Pulmonary Structural MRI using Free-Breathing, Self-Gated Ultra-short Echo Time Imaging
Published on: September 6, 2024
Renal mobility during uncoached quiet respiration: an analysis of 4DCT scans
John R van Sörnsen de Koste1, Suresh Senan, Catharina E Kleynen
1Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands. j.vansornsendekoste@vumc.nl
Purpose:
Data on organ mobility is required for optimizing radiotherapy. Renal mobility was studied in four-dimensional computed tomography (4DCT) scans acquired during uncoached respiration.
Methods And Materials:
The 4DCT scans of 54 patients, in whom at least the upper pole of both kidneys were visualized in all 10 respiratory phases, were analyzed. Scans were performed on a 16-slice CT scanner (slice index and reconstruction, 2.5 mm) during quiet, uncoached respiration. Mobility of the renal apex was evaluated in all patients by use of the z-position on CT slices. Reproducibility of mobility was studied in 8 patients who underwent 1 or 2 repeat 4DCT scans.
Results:
Mobility was predominantly craniocaudal, with a mean of 9.8 mm for the left kidney and 9.0 mm for the right kidney. Large interpatient variations were observed that ranged from 2.5 to 30 mm (left) and 2.5 to 20 mm (right), and mobility of 1 kidney did not predict for mobility of the contralateral organ. Reproducibility of renal mobility and position at end-expiration was poor, with positional variations in repeat scans appearing to correlate with changes in the amplitude of respiratory waveform and total lung volume.
Conclusions:
Large interpatient variations in renal movement occur during uncoached respiration, which indicates that respiratory coaching is useful for 4DCT imaging and treatment delivery.
Related Concept Videos
01:27Physical Assessment of the Respiratory Tract II: Inspection
Chest Configuration
The chest configuration can...
01:20Assessment of Ventilation I: Respiratory Rate
A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma.
Critical Guidelines for Assessing Ventilation:
01:29Assessment of Ventilation II: Respiratory Depth and Rhythm
Respiratory depth measures the volume of air inhaled or exhaled during a breath. It can vary from shallow to deep and typically remains consistent when a person is at rest or asleep. Occasionally, individuals will automatically inhale deeply, known as sighing, which inflates the lungs with more air than normal breathing.
To assess respiratory depth, observe the degree of chest excursion or movement:
01:15Respiratory Volumes
Tidal Volume (TV) Tidal volume (TV) is the air inhaled or exhaled in a...
01:23Assessment of Respiration
Subjective Assessment: Nurses interview the patient to gather information directly during the subjective assessment. It includes questions about the individual's medical history, medications, and symptoms, focusing on past respiratory conditions like asthma or COPD,...