1. Prospective Study of the Natural History of Thoracic Aortic Aneurysms
Tatu Juvonen, MD, PhD, M.Arisan Ergin, MD, PhD, Jan D Galla, MD, PhD, Steven L Lansman, MD, PhD, Khanh H Nguyen, MD, Jock N McCullough, MD, Dale Levy, MD, Richard A de Asla, BA, Carol A Bodian, DrPH, Randall B Griepp, MD 
The Annals of Thoracic Surgery 
Volume 63, Issue 6, Pages (June 1997)
DOI: /S (97)

2. Fig. 1
Diagram of factors to be balanced when making a decision whether or not to operate on a descending thoracic or thoracoabdominal aneurysm. Aneurysm size is usually the only factor used to estimate risk of rupture.
The Annals of Thoracic Surgery  , DOI: ( /S (97) )

3. Fig. 2
A computer-generated three-dimensional reconstruction of the last preoperative computed tomographic scan in a patient with a descending thoracic aortic aneurysm that had been under surveillance for almost 4 years before operation. Elective aneurysm resection was carried out when the patient was 60 years old, prompted by an increase in the maximal diameter of the aneurysm to 7.3 cm and a diameter growth rate of 1.55 cm per year. In addition to showing the configuration of the aorta and the diameter of each slice, with the maximal diameter of each aortic segment in italics (as seen on the left and explained in detail in the text), the computer also generates a linear graph of the diameter and the cross-sectional area of each slice. These data are presented as though the entire aorta were stretched with its axis along a straight line (longitudinal axis of the aorta), beginning with the ascending aorta (−15 to −5), skipping the arch (in which measurements are very unreliable), and continuing in the descending aorta (5 to 35). Each study is represented by a line of a different color, allowing easy comparisons of serial studies in the same patient: in this case, the growth of the aneurysm in the proximal descending thoracic aorta and then its return to normal size after operation are clearly shown.
The Annals of Thoracic Surgery  , DOI: ( /S (97) )

4. Fig. 3
Diagram illustrating several aortic slices that might be obtained from a typical computer-generated three-dimensional reconstruction of the aorta, and how the maximal aortic diameter would be determined from them. Although the largest measured diameters of these elliptical cross-sections occur low in the descending aorta, the true maximal diameter of 5.5 cm would be selected by the computer because it most closely approximates the diameter that would be measured if the slice were perpendicular to the aortic wall, and most accurately reflects the distance over which outward forces on the aortic wall are exerted.
The Annals of Thoracic Surgery  , DOI: ( /S (97) )

5. Fig. 4
Diagram illustrating how the computer measures all possible diameters and selects the smallest of them to report as the slice diameter.
The Annals of Thoracic Surgery  , DOI: ( /S (97) )

6. Fig. 5
Graphs enabling estimation of the probability of aneurysm rupture within 1 year when particular combinations of risk factors are present: a more exact figure for the probability of rupture for an individual patient can be calculated by substituting the relevant information for each risk factor in the equation for probability given in the text. The graphs limit input about abdominal diameter to whether or not it exceeds 5 cm; age input is also limited to 10-year intervals. (Abd. Dia. = abdominal aortic diameter; COPD = chronic obstructive pulmonary disease.)
The Annals of Thoracic Surgery  , DOI: ( /S (97) )

7. Fig. 6
Diagram of factors to be considered in deciding whether or not to operate on a patient with a descending thoracic or thoracoabdominal aneurysm. With the aid of the equation for determination of probability of rupture, the balancing of risk of operation and risk of rupture can be much more precise. (COPD = chronic obstructive pulmonary disease.)
The Annals of Thoracic Surgery  , DOI: ( /S (97) )