CT evaluation of suspected tracheal stenosis is routinely performed at end-inspiration during a single breath hold.
An additional sequence during dynamic expiration may be helpful to assess for tracheomalacia,
which may coexist with tracheobronchial stenoses,
especially among patients who have relapsing polychondritis,
and airway narrowing secondary to long-standing extrinsic compression.
The 640-slice dynamic volume CT was a useful method for diagnosing center airway narrowing.
A relative disadvantage of this new technology is its higher radiation dose compared with routine end-inspiration CT.
Methods and Materials
Sixteen patients with small BMI (BMI < 25) underwent 640-slice dynamic volume CTscan (80 or 100kV; 50 mA; collimation,
320×0.5 mm; gantry rotation,
0.5 second; acquisition time,
Eight patients employed 100kv protocol,
5.1 seconds; and remaining8 objects employed 80kv protocol,
During the coaching period,
expiratory time (Texp) taken from maximal end-inspiration to the end of forceful exhalation was measured,
and acquisition time was selected according to Texp time.
Multiplanar reformation and 3D reconstruction images were created from...
The multiplanar reformation image noise level was consistently ranked higher for CT images of 80 KV protocol than for CT images of 100 KV protocol (P < 0.05).
The level of confidence in tracheal lumen measurement was high,
regardless of respiratory phase and dose.
There was no significant difference in confidence level between 80KV and 100 KV protocol,
and among each respiratory phase,
respectively (P > 0.05).
Excessive central airway collapse (expiratory reduction in cross-sectional area > 30%) was seen in 3 patients with tracheomalacia...
The 640 slice dynamic volume CT is a promising method for diagnosing central airways narrowing with short acquisition time.
The 80KV protocol performs as well as the 100 KV protocol for the 4D dynamic imaging in small BMI objects during common Asia populations,
with a similar degree of confidence for measuring the tracheal lumen.
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Acquired tracheomalacia: detection...