Application Of64-Slice Spiral Ct In The Classification Of The Segmengtal Bronchial Patterns Of The Right Middle And Lower Lobes

PurposeTo display the right middle and lower lobar bronchi, to classify their segmental bronchial patterns as well as to calculate the rate of different segmental bronchial patterns by three post-processing techniques of three-dimensional reconstruction of bronchial tree, CT virtual endoscopy （VE）, and transverse thin-section reformation from64-slice spiral CT.MethodsIn this work,300individuals, who presented with no obvious lesions in right middle and lower lobar segmental bronchia, were randomly selected from patients, who underwent routine CT scan in our institute. The images of bronchial tree and virtual endoscopy were reconstructed using the following parameters, i.e., section thickness_{1.0millimeter}, reconstruction interval_{0.7millimeter}, and standardized medium window setting. The transverse thin-section CT images were reconstructed using the following parameters, section thickness_{2.0millimeter}, reconstruction interval_{1.5millimeter}, bone algorithms, and standardized lung window setting.Firstly, we clearly demonstrated the right middle and lower lobar bronchial images of three hundred patients with CT thorax scans by three-dimensional reconstruction of bronchial tree and virtual endoscopy. Secondly, integrating with transverse thin-section images, we classified the segmental bronchial patterns of the right middle and lower lobes, and analyzed different effects in displaying different segmental bronchial patterns. Lastly, combining three post-processing techniques, we classified and calculated the segmental bronchial patterns and the rate of subsuperior segmental bronchus of the right middle and lower lobes. Bronchial tree three-dimensional images can stereoscopically show every segmental bronchus, which arises one by one, and the long common stem of bifurcation and theirs number and directions. VE demonstrates segmental bronchial images from inside of lumen, and can easily show the short common stem of bifurcation and trifurcation of bronchi. We identified the subsuperior segmental bronchus or the pattern that had two medial basal segmental bronchial by combining the transverse thin-section CT images, and identified the right lower lobar common stem of lateral and posterior basal segmental bronchi or the common stem of anterior and lateral basal segmental bronchi. Two experienced radiologist observed all images of bronchial tree, virtual endoscopy, and transverse thin-section reformation.ResultsThree kinds of images can display all of the right middle and lower lobar segmental bronchial, and more than80%subsegmental bronchial. The segmental bronchial ramifications of the right middle lobar were classified into two types, i.e., bifurcation in289patients （96.3%） and trifurcation in11patients （3.7%）. The right lower lobes were classified into two major types, i.e., the common stem of lateral and posterior basal segmental bronchi in230patients （76.7%）, the common stem of anterior and lateral basal segmental bronchi in31patients （10.3%）, no medial basal segmental bronchus in18patients （6.0%）, and others in21patients （7.0%） arising from subsuperior segmental bronchus in113patients （37.7%） in which12patients （4.0%） had two segmental bronchi.ConclusionBronchial tree three-dimensional images can clearly show every segmental bronchus and the long common stem of bifurcation. VE demonstrates segmental bronchial images from inside of lumen, and can easily identify the short common stem of bifurcation and trifurcation of bronchi. Transverse thin-section images identify subsuperior segmental bronchus. Combining these three-dimensional reconstruction of bronchial tree, virtual endoscopy, and transverse thin-section reformation three post-processing techniques, we can classify the segmental bronchial patterns of the right middle and lower lobes perfectly.ApplicationThe combination of the aforementioned three post-processing techniques can stereoscopically show branching patterns of bronchi and their distributions in the transverse, and, also, calculate the segmental bronchial patterns and the rate of subsuperior segmental bronchus, which is a useful complementary to anatomic study. The branching patterns of segmental bronchi are complex and various, and the most common pattern which is known to all kinds of doctors, is described only. Moreover, the detailed bronchial anatomy of every patient can provide accurate and plentiful information in positioning lesions, minimally invasive surgery of thyroid benign lesions, fiberoptic bronchoscopic biopsy, and treatment.