ABSTRACT
To investigate the computed tomography (CT) image characteristics, adjacent tissues, and related measurement indices of the sternal foramina and provide an anatomical basis for the safety of minimally invasive sternum surgery. The data from 2500 thoracic multi-slice computed tomography (MSCT) cases from January 2020 to June 2021 were analyzed retrospectively. The number and location of the sternal foramina and adjacent tissues (mediastinal adipose tissue, lung, pericardium) were observed. The size of the sternal foramina, CT value of the tissue inside the foramina, subcutaneous adipose tissue thickness, distance from skin to lung, distance from skin to the pericardium, and manubrio-foraminal distance were measured. Sex differences were compared for each indicator performed. The incidence of sternal foramina was 4.44% (111/2500), with 83 males and 28 females. All sternal foramina were located at the mesosternum's fourth to sixth costal cartilage level. The transverse diameter of the sternal foramina was (0.60 ± 0.29) cm, and the vertical diameter was (0.68 ± 0.39) cm, which was greater in males than females (p > 0.01). The CT value of the tissue in the sternal foramina was (-77.05 ± 32.26) Hu, and there was no statistical difference between male and female patients (t = -1.780, p = 0.078). The adjacent tissues of the sternal foramina were only adjacent to adipose tissue in 41 cases (36.94%), pericardium in 18 patients (16.22%), lung tissue in 37 cases (33.33%), and both kinds of tissue in 15 cases (13.51%). The sternal foramina were not adjacent to the left lung in the female patients. In the sternal foramina region, the thickness of subcutaneous adipose tissue was (1.13 ± 0.51) cm, the distance from skin to lung was (1.86 ± 0.57) cm, the distance from skin to pericardium was (3.07 ± 0.72) cm, the manubrio-foraminal distance was (12.68 ± 1.31) cm, which was significantly greater in males than in females (p < 0.05). The sternal foramina are closely related to the heart and lungs. The size and location of sternal foramina, the thickness of subcutaneous adipose tissue, and the distance from skin to heart and lung are all crucial factors in evaluating the safety of sternal puncture biopsy.
ABSTRACT
PURPOSE: Multislice spiral CT (MSCT) was used to investigate the anatomical characteristics of sternal development, and to provide anatomical basis for sternal puncture in children. METHODS: We retrospectively analyzed the thoracic MSCT data of 600 children who received thoracic MSCT from January to June 2020 with their age ranging from 1 month to 19 years. The distribution of sternal ossification centers and adjacent tissues and organs was observed. Subcutaneous soft tissue thickness and the distance between the skin and the posterior margin of the sternum were measured in the central areas of sternal manubrium and mesosternum (segments I and II), and the correlation between the two was calculated using linear correlation. RESULTS: A total of 600 patients were enrolled, the mean age was 9.87 years and the standard deviation was 8.28 years. The sternal manubrium and ossification centers at the I and II segments of the mesosternum were visible in all cases (100%). There was no ossification in segment III of the mesosternum in 15 cases (2.5%), including 12 cases (80%) adjacent to the posterior pericardium and 7 cases (46.7%) of lung tissue. There were 274 cases (45.7%) of segment IV without ossification, including 204 cases (74.5%) of adjacent pericardium and 95 cases (32.8%) of lung tissue. The xiphoid process was not ossified in 258 cases (43%), including 190 cases (73.6%) adjacent to the pericardium and 97 cases (37.6%) adjacent to the lung tissue. Correspondingly, the thickness of subcutaneous soft tissue of the sternal manubrium and the central region of the I and II segments of the mesosternum had a low positive correlation with age (P < 0.001), the distance between the skin and the posterior margin of the sternum showed a moderate positive correlation with age (P < 0.001), and the distance between the skin and the posterior margin of the sternum showed a high positive correlation with the thickness of subcutaneous soft tissue (P < 0.001). CONCLUSIONS: Nonossification of the sternal ossification center usually occurs below segment III of the mesosternum and is usually adjacent to heart and lung tissue. Pediatric sternal puncture should be performed at the sternal manubrium and the mesosternum of segments I and II. However, attention should be paid to the space between multiple ossification centers. The thickness of subcutaneous soft tissue is a critical factor that determines the depth of the puncture.
