Roentgenographic Parameters Research Articles

Natural History of Congenital Hip Dislocation (CDH) and Hip Dysplasia

For normal development of the hip joint to occur, there must be a delicate, genetically determined balance between growth of the acetabular and triradiate cartilages and a well-centered femoral head. This balance may be profoundly affected by the intrauterine environment. Without treatment, it is uncertain how many dysplastic, unstable hips will retain their dysplastic features throughout life. The natural history of untreated complete dislocation varies considerably and is affected by societal considerations. There may be little, if any, functional disability in many cases. Significant roentgenographic degenerative disease and poor clinical results, however, may develop in completely dislocated hips with well developed false acetabulae. In unilateral cases, ipsilateral knee deformity and pain may develop. Congenital subluxations have a particularly poor long-term outcome. A significant percentage of these patients have roentgenographic degenerative joint disease and clinical disability. The age of symptom onset and roentgenographic degenerative joint disease is related to the amount of subluxation and dysplasia. The natural history of acetabular dysplasia in the absence of subluxation is difficult to predict. Physical signs may be absent, and the diagnosis only established with symptom onset or as an incidental roentgenographic finding. While degenerative joint disease may ensue, current roentgenographic parameters are not predictive.

Normal and abnormal motion of the shoulder

The roentgenographic parameters of motion in normal and abnormal shoulders, including the movement of the scapula, arm angle, glenohumeral angle, scapulothoracic angle, excursion of the humeral head, and instant center of motion for abduction in the plane of the scapula, were determined in twelve normal subjects and fifteen patients. The scapula rotated externally with abduction. The ratio of glenohumeral to scapulothoracic movement was 5:4 after about 30 degrees of abduction. The center of rotation of the glenohumeral joint for abduction in the plane of the scapula was located within six millimeters of the geometric center of the humeral ball. The average excursion of the humeral ball on the face of the glenoid in the superoinferior plane between each 30-degree arc of motion was less than 1.5 millimeters in normal subjects. Significant previous injury resulting in abnormal mechanics of the shoulder joint was associated with abnormal values for excursion of the instant center and of the humeral head. An abnormal glenohumeral-to-scapulothoracic ratio was associated with significant pain in the shoulder. The fact that these various parameters were sensitive indicators of normal and abnormal motion raises the possibility of diagnostic clinical application.

The computer evaluation and diagnosis of congenital heart disease, using roentgenographic findings.

Many roentgenographic signs have been described (2,4,8, 9, 11, 13, 18) which are considered characteristic of specific congenital heart abnormalities, but no single study has examined the frequencies with which each of these signs is distributed over a broad spectrum of congenital defects. This study evaluates the occurrence of 20 roentgenographic parameters as found in 9 uncomplicated congenital heart lesions. The 9 lesions include secundum type of interatrial septal defect (IASD), primum type of interatrial septal defect, interventricular septal defect (IVSD), patent ductus arteriosus (PDA), tertralogy of Fallot, coarctation of the aorta, pulmonary valve stenosis, aortic valve stenosis, and complete transposition of the great vessels. These defects comprise about 87 per cent of all congenital heart deformities (10). An accurate evaluation of the 20 roentgenographic parameters and their occurrence in different congenital heart lesions required a rapid and uniformly consistent method of handling data. The digital computer was utilized to compile and analyze over 3,000 bits of information collected during this study. The computer analysis has included absolute and relative frequency distributions for the various radiographic signs. From this data a frequency distribution matrix (Fig. 3) has been constructed from which the computer, using Bayes' theorem of inverse probability (14, 22), or a radiologist by visual inspection, can diagnose one of the 9 different cardiac lesions. A discussion of the Bayesian method as applied to computer diagnosis is presented. Computers are finding increased and varied applications in radiology (5, 15–17, 20, 23). But before a computer can be intelligently programed to perform a task or solve a problem, the radiologist must objectively identify and methodically analyze all the roentgenographic information used in his decision-making processes. Then the computer can evaluate this information statistically and determine its validity. The results obtained may cause the radiologist to reassess and reorganize his pattern recognition. Thus, not only is the computer fast and consistent, but the exacting, systematic manner of film analysis imposed is an excellent tool for teaching and research. Once instructed, the computer will go completely through the programed sequence and consider each roentgenographic parameter in relation to every diagnosis for which it has information; it is tireless and never has mental lapses. Material and Methods A total of 231 cases have been reviewed. Figure 2, A shows the number of cases evaluated for each of the 9 different “pure” congenital heart defects. The lack of sufficient case material necessitated omission of the rarer cardiac lesions from the study at this time. Every case has been proved at autopsy, surgery, or by cardiac catheterization and angiography. The different roentgenographic parameters recorded for each patient are illustrated by the worksheet in Figure 1.