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(Radiology. 2000;217:461-465.)
© RSNA, 2000

Cardiac Imaging

Tracking Coronary Calcification by Using Dual-Section Spiral CT: A 3-Year Follow-up1

Joseph Shemesh, MD, Sara Apter, MD, Chaim I. Stroh, MD, Yacov Itzchak, MD and Michael Motro, MD

1 From the Cardiac Rehabilitation Institute (J.S., C.I.S., M.M.) and Department of Diagnostic Imaging (S.A., Y.I.), Chaim Sheba Medical Center, Tel-Hashomer 52621, Israel. From the 1999 RSNA scientific assembly. Received January 12, 2000; revision requested February 9; revision received March 21; accepted April 4. Address correspondence to J.S. (e-mail: dshemesh@netvision.net.il).


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 MATERIALS AND METHODS
RESULTS
DISCUSSION
 REFERENCES
 
PURPOSE: To investigate the accuracy of dual-section spiral computed tomography (CT) in tracking the progression of coronary calcification, as measured during a 3-year follow-up.

MATERIALS AND METHODS: Two hundred forty-six patients with hypertension (mean age, 66 years ± 6 [SD]) were preselected in accordance with the International Nifedipine Study Intervention as a Goal for Hypertension Therapy protocol. Subjects had no clinical coronary arterial disease prior to the study and no cardiovascular events during follow-up. All participants underwent baseline CT (3.2-mm section thickness; reconstruction increment, 1.5 mm) and follow-up CT after 3 years. Calcification progression was defined as any increase in total calcification score (TCS) and analyzed in accordance with five baseline TCS categories: 1–9, 10–35, 36–100, 101–250, and greater than 250.

RESULTS: At baseline CT, 152 patients had a TCS greater than 0, and 106 (70%) showed progression after 3 years, while 94 had a baseline TCS of 0; of these, 26 (28%) showed progression (P < .01 between groups). The mean TCS was significantly higher in each baseline TCS category after 3 years. The percentage increase was negatively correlated with baseline TCS (P < .01) and ranged from 466% in the lowest category to 38% in the highest.

CONCLUSION: Dual-section spiral CT depicts significant change in TCS over time and is useful in tracking calcified coronary atherosclerosis.

Index terms: Arteriosclerosis, 51.81, 54.81 • Computed tomography (CT), 51.12115, 54.12115 • Computed tomography (CT), helical, 51.12115 • Coronary vessels, calcification, 54.81 • Heart, CT, 51.12115


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
 REFERENCES
 
Coronary arterial calcification is a well-accepted marker of coronary atherosclerosis (1,2). In the early stages of disease, atherosclerotic plaques are in the walls of the arteries and do not protrude into the lumen. With simple progression, these fatty plaques protrude slightly into the lumen, which creates the angiographic appearance of irregularity and mildly obstructive lesions (3). These lesions occur frequently in apparently healthy individuals (4–6). Prone to rupture, the lesions provide the background for an acute coronary event, which results in sudden death or acute myocardial infarction (7). Since these nonobstructive plaques have no limiting effect on the coronary arterial flow, patients remain asymptomatic and cannot receive a diagnosis with standard stress testing procedures. As a result, primary preventive therapy is often delayed, leaving these subjects vulnerable to the danger of an acute coronary event. One proposed treatment involves lipid-lowering agent ß-hydroxy-ß-methylglutaryl-CoA, or HMG-CoA, reductase inhibitors. These compounds have significantly reduced the incidence of acute coronary events in asymptomatic high-risk populations in well-designed clinical trials (8). This kind of intervention and other primary preventative measures are dependent on simple techniques to measure the progression or regression of the atherosclerotic process. Studies of the progression of coronary atherosclerosis (9–12) have hitherto been limited to invasive angiographic techniques in patients with symptoms.

Limited data exist with regard to the use of fast computed tomographic (CT) techniques for documenting the atherosclerotic process (13–15). Dual-section spiral CT is one of the noninvasive techniques that can be used to diagnose and measure the calcified atherosclerosis. Its accuracy (16), reproducibility (17), and diagnostic contributions in different clinical conditions (18–21) have been documented. However, to the best of our knowledge, measurement of the progression of the calcific atherosclerotic process by using this technique has yet to be validated. The purpose of this study was to investigate the accuracy of dual-section spiral CT in the measurement of calcification progression during a 3-year period in a group of patients with hypertension.


   MATERIALS AND METHODS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS
DISCUSSION
 REFERENCES
 
Patients
Patients were selected from participants in the International Nifedipine Study Intervention as a Goal for Hypertension Therapy (INSIGHT) calcification study, which was designed to compare the effect of the calcium channel blocker nifedipine (Gastrointestinal Therapeutic System, or GITS; Bayer, Leverkusen, Germany) versus that of a diuretic on the progression of coronary calcification in high-risk patients with hypertension (21). The main inclusion criteria in the INSIGHT protocol applied to men and women aged 50–80 years who had hypertension and at least one of the following: diabetes mellitus, a history of smoking, a positive family history of coronary arterial disease at an age younger than 50 years, left ventricular hypertrophy, or documented coronary arterial disease. To analyze calcification progression in a homogeneous group, we included all 246 participants (mean age, 66 years ± 6 [SD]) who were free of clinical coronary arterial disease prior to the study and during the entire follow-up period. Thus, patients with previous myocardial infarction, coronary angioplasty, coronary bypass surgery, at least one obstructive lesion of more than 50% luminal obstruction at coronary angiography, anginal syndrome, or positive thallium stress test findings were excluded.

All patients underwent baseline CT and were followed up for 3 years, at the end of which repeat CT was performed. At the end of the 1st and 2nd years of follow-up, additional CT was performed and evaluated in patients with a baseline total calcification score (TCS) of greater than 9, in accordance with the INSIGHT calcification protocol requirement. Written informed consent was obtained from all patients, and the entire study protocol was approved by the Helsinki institutional review board.

Definition of Coronary Calcification Progression
We defined progression as any increase in TCS measured at follow-up as TCS minus the baseline level and as percentage increase from the baseline ([{follow-up TCS - baseline TCS} / baseline TCS] x 100). To accommodate the wide distribution of TCS levels, we divided patients into categories in accordance with their baseline TCS: A TCS of 0 indicated that no calcification was detected (n = 94); a TCS of 1–9 indicated that minimal calcification was detected (n = 33); a TCS greater than 9 indicated that the minimum amount of calcification required by the INSIGHT calcification protocol for annual CT to be performed was detected (n = 119). The patients with a TCS greater than 9 were divided into four categories by TCS quartile level: 10–35, 36–100, 101–250, and greater than 250.

CT Protocol
We used the previously described protocol, which includes the modified Agatston method, for dual-section CT, with a calcification threshold of 90 HU instead of the traditional 130 HU. Use of this threshold yielded a better sensitivity with equal specificity, as compared with angiographic methods of investigating obstructive coronary disease (16,17).

Image Acquisition
CT was performed by using a commercially available double-spiral scanner (Twin; Marconi, Cleveland, Ohio) and spiral scanning mode, without electrocardiographic triggering or the injection of contrast material. The scanning time was 1 second for two contiguous 2.5 mm sections and was 15–22 seconds for the entire zone of interest, which encompassed the heart. CT was performed during a single unforced withheld inspiration. During helical scanning, with the tube rotating once per second and with the table moving at 5 mm/sec, with a 1:1 pitch, images were obtained with an effective section thickness of 3.2 mm (nominal section width, 2.5 mm) and a reconstruction increment of 1.5 mm (overlapping section method). Scanning was performed with 120 kVp and 210 mAs, standard resolution, and a 43-cm field of view. The total duration of the procedure was 10 minutes.

For the scoring of calcification, only the 40 most cephalic contiguous sections were selected; selection started at the level of the first visible coronary artery (the left main or left anterior descending coronary artery). This provided 6-cm coverage of the proximal portion of the coronary tree, as measured along the longitudinal axis of the patient.

Determination of Coronary Calcification
A calcific lesion was defined as an area within a coronary artery that had an attenuation above a threshold of 90 HU and covered at least 0.5 mm2. Regions of interest were placed around all lesions by the same experienced reader (J.S.) in all instances and were automatically analyzed by using the Marconi software. By applying a modification of the Agatston scoring method, with a threshold of 90 HU instead of 130 HU, an attenuation factor was determined for each lesion: A factor of 1 was assigned for 90–199 HU; a factor of 2, for 200–299 HU; a factor of 3, for 300–399 HU; and a factor of 4, for at least 400 HU. A score was calculated automatically for each region of interest by multiplying the attenuation factor by the area. The TCS was the sum of the lesion scores for all 40 sections. All 40 sections were printed on film and included traces of all regions of interest. This enabled the reader to fix the starting level at the same level as in the baseline scan and to accurately identify all baseline calcified lesions.

Statistical Methods
The {chi}2 test was performed to evaluate differences between the two study groups (with and without coronary calcification) and for the categoric parameters (Table 1). The two-sample Student t test and nonparametric test were performed to test the differences between the study groups for baseline quantitative parameters (Table 1). The paired Student t test and nonparametric signed rank test were performed to assess differences between baseline and 3-year follow-up assessments for quantitative parameters. All tests were two-tailed, and a P value of .05 or less was considered to indicate a significant difference. The data were analyzed by using SAS software version 6 (SAS Institute, Cary, NC).


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  		TABLE 1. Clinical Characteristics of Patients With or Without Coronary Arterial Calcification at Baseline CT
 

   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS
DISCUSSION
 REFERENCES
 
Baseline TCS
Ninety-four of the 246 patients who entered the study had no calcification (TCS = 0). Among the 152 with calcification (TCS > 0), 33 had a minimal amount of calcification (TCS = 1–9), and 119 had a TCS greater than 9. Sixty-seven (56%) of 119 had a baseline TCS of 100 or less (median), 28 (24%) had a TCS of 101–250 (3rd quartile), and 24 (20%) had a TCS greater than 250 (4th quartile).

The clinical characteristics of the patients, in accordance with the presence of calcification, are given in Table 1. Patients with calcification were slightly older (mean age, 65 years ± 5 vs 62 years ± 6; P = .003) and included more men (80 [53%] of 152 vs 30 [32%] of 94, P < .01) than the patients without calcification. The prevalence of all other clinical parameters was not significantly different. The prevalence of coronary calcification in our study group was 80 (73%) of 110 men and 72 (53%) of 136 women. This did not reflect the prevalence of coronary calcification in the general hypertensive population, since all patients with coronary arterial disease were excluded.

Increase in TCS
The mean TCS in the patients with calcification increased significantly each year from 245 at baseline CT to 288, 322, and 349 at the end of the 1st, 2nd, and 3rd years of follow-up, respectively (for trend, P < .01). This corresponds with the percentage change from the baseline TCS of 33%, 71%, and 117%, respectively. This progression of calcification was not related to age, sex, or any other risk factor at univariate analysis. Moreover, none of these factors influenced the baseline TCS category.

The incidence of 3 years progression of calcification was almost three times higher among patients with calcification at baseline CT, as compared with that in patients without calcification: 70% (106 of 152) versus 28% (26 of 94; (P < .001), respectively. All 33 patients with the minimal amount of calcification at baseline CT (TCS < 9) had detectable calcification at follow-up, with a mean TCS increasing from 3.8 ± 0.45 to 14.9 ± 2.7 (P = <.001). A significant increase in the mean TCS was observed in each of the baseline TCS categories after 3 years, as shown in Figure 1. During this period, the mean TCS had at least doubled in patients with a baseline TCS of less than 250. Table 2 describes the TCS changes after 3 years by baseline TCS category. A significant opposite trend (P < .01) was found between the baseline levels of TCS and the ratio of 3rd-year to baseline TCS levels. Patients in the category of minimal baseline TCS (score 1–9) had significantly higher calcification progression, with a ratio of 5.66, as compared with patients in all other categories (P < .01). This ratio was as low as 1.38 among patients with the highest baseline quartile. Figure 2 demonstrates the mean percentage change of calcification score after 3 years, in accordance with the baseline TCS category. Figure 3 shows the typical progression of calcification at the left anterior descending coronary artery, with an increase in the TCS from 30 to 108. Figure 4a shows a minimally calcific lesion with a baseline TCS of one. The same lesion was detected at follow-up CT, with a TCS of 2 (Fig 4b).



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  		Figure 1. Graph shows the mean TCS in patients with calcification at baseline CT and at the end of the 3rd year, in accordance with baseline TCS categories. A significant increase in the mean TCS was observed in each of the baseline TCS categories after 3 years. The last four categories are quartiles. P values are for differences between the baseline and follow-up means for each category. White bars = baseline, black bars = 3-year follow-up.

 

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  		TABLE 2. Changes in TCS After 3 Years in Accordance with Baseline TCS Category
 


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  		Figure 2. Graph shows the mean percentage increase in TCS from baseline to the 3rd year, in accordance with TCS category. The opposite trend is shown for the relationship between the baseline TCS and percentage change.

 


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  		Figure 3a. Dual-section spiral CT scans show a calcific lesion within the proximal part (a) of the left anterior descending (LAD) coronary artery at (a) baseline and (b) 3-year follow-up. TCS at this level increased from 31 to 108. MLCA = main left coronary artery; RCA = right coronary artery.

 


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  		Figure 3b. Dual-section spiral CT scans show a calcific lesion within the proximal part (a) of the left anterior descending (LAD) coronary artery at (a) baseline and (b) 3-year follow-up. TCS at this level increased from 31 to 108. MLCA = main left coronary artery; RCA = right coronary artery.

 


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  		Figure 4a. Dual-section spiral CT scans show a typical minimally calcific lesion (arrow) at (a) baseline and (b) 3-year follow-up. In b, the lesion’s area has doubled and its TCS has increased from 1 to 2. To enable identification of the minimally calcific lesions, automatic highlighting of the calcification was used, which gave a gray coloration to the calcification.

 


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  		Figure 4b. Dual-section spiral CT scans show a typical minimally calcific lesion (arrow) at (a) baseline and (b) 3-year follow-up. In b, the lesion’s area has doubled and its TCS has increased from 1 to 2. To enable identification of the minimally calcific lesions, automatic highlighting of the calcification was used, which gave a gray coloration to the calcification.

 

   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS
DISCUSSION
REFERENCES
 
The main finding of this prospective study was that dual-section spiral CT can be used to measure the progression of coronary calcification over time. Furthermore, this significant increase in the mean TCS was observed for each category of baseline TCS. In this study, reproducibility was not measured directly to avoid performing CT examinations in addition to the four planned for each participant. However, using the same method and algorithm, we have demonstrated (22) that the mean interstudy variability, expressed as a percentage, was 32% (from 23% for a TCS > 100 to 54% for a TCS = 1–10). In the present study, the mean percentage increase was 117% after 3 years, which was higher than the variability range.

Dual-section spiral CT is a simple noninvasive examination that provides an alternative to quantitative coronary angiography, which is the method currently used to track the coronary atherosclerotic process (9–12). This is so for a number of reasons. First, angiography is invasive and thus is not widely applicable. Second, angiography is used to measure only the degree of luminal obstruction at measurable levels of measurable focal stenoses. This means that much of the atherosclerotic burden not protruding into the lumen—as demonstrated by the results of intravascular comparative ultrasonographic studies (3,4)—is neglected. Finally, the remodeling process may increase the luminal diameter of the atherosclerotic vessels (23,24) and thus interferes with the correct interpretation of serial angiographic studies. Assessment of coronary calcification by using new-generation fast CT techniques can overcome all of these drawbacks, although it must be pointed out that these techniques are limited to the calcific atherosclerotic lesions and cannot depict the noncalcified fatty and fibrous plaques. Nonetheless, as Rumberger et al (25) report, the calcific area indicates the presence of five times higher of the noncalcific area of atherosclerosis along the vessel; therefore, coronary calcification should be regarded as a reliable correlate of total coronary atherosclerosis.

Another contribution of this study is the demonstration of dual-section spiral CT for detecting and tracking minor calcific lesions (Fig 4a, 4b). At the end of the 3rd year, calcification was detected in all 33 patients with baseline minor calcification (TCS = 1–9), with a mean increase of TCS from 3.8 to 14.90 (P < .001). Moreover, at follow-up, all 36 spotty lesions on the left anterior descending coronary artery were detected again, and only one of four baseline lesions at the right coronary artery and one of seven at the left circumflex coronary artery (both with a score of 2) were not detected.

The use of dual-section spiral CT to depict lesions with a minimum area of 0.5 mm2 and an attenuation threshold of 90 HU is due to its high resolution and the use of overlapping reconstruction images. The use of dual-section CT to track minor lesions has been reported recently (26). In that study, it was used to track newly developed coronary atherosclerosis in cardiac transplant recipients. Forty-two (eight of 20) percent of the patients in that study developed minor calcific lesions between the 2nd and 4th year after transplantation, with a mean TCS of 6.7 ± 4.0. Such minor lesions could not be detected and tracked by Callister et al (13), who used electron-beam CT to investigate the effect of lipid-lowering drugs on the 1-year progression of coronary calcification. These authors demonstrated a measurable increase in the TCS, as calculated by using the volume method. With this method, the minimally calcific lesion was defined as an area greater than 2.24 mm2 with an attenuation of more than 130 HU. Moreover, patients with an initial calcification volume score of less than 30 were excluded because of the modality’s limitation in reproducing these minor calcium deposits. However, these minor lesions should not be ignored, since they indicate newly developed atherosclerosis and noncalcific fibro-fatty plaques and thus essential features for studying the progression of this process (12). The importance of minor calcification is further emphasized by the results of another study (27), in which dual-section spiral CT was used to compare the prevalence and morphology of coronary calcification in patients who had had their first acute myocardial infarction versus those who had stable chronic angina pectoris. Results showed that minor spotty calcific lesions were prevalent in patients who had had their first acute myocardial infarction; of these, 51 (50%) of 102 had a TCS of less than 41.3, which serves to emphasize the association between such lesions and acute coronary syndrome.

The use of new-generation CT devices and better scoring algorithms may further improve the measurement of the progression of coronary calcification. Particular efforts should be made to improve the detection and reproducibility of minimal calcium deposits.

In conclusion, the results of this study demonstrate that the progression of coronary calcification can be measured by using dual-section spiral CT. Dual-section spiral CT can be used to detect and measure significant progression of minimally calcific lesions.


   ACKNOWLEDGMENTS
 
The authors acknowledge Gil Harari from "Medistat Statistic in Medicine" for his statistical support in the processing of data for this study.


   FOOTNOTES
 
Abbreviations: INSIGHT = International Nifedipine Study Intervention as a Goal for Hypertension Therapy, TCS = total calcification score

Author contributions: Guarantor of integrity of entire study, J.S.; study concepts, J.S., M.M.; study design, J.S., C.I.S.; definition of intellectual content, Y.I., M.M.; literature research, C.I.S., S.A.; clinical studies, C.I.S., J.S.; data acquisition, J.S.; data analysis, J.S.; statistical analysis, J.S., S.A.; manuscript preparation, S.A.; manuscript editing, M.M., Y.I.; manuscript review, M.M.


   REFERENCES
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS
DISCUSSION
 REFERENCES
 

  1. Blankenhorn DH. Coronary arterial calcification: a review. Am J Med Sci 1961; 242:1-9.
  2. Wexler L, Brundage B, Crouse J, et al. Coronary artery calcification: pathophysiology, epidemiology, imaging methods, and clinical implications—A statement for health professionals from the American Heart Association Writing Group. Circulation 1996; 94:1175-1192.[Free Full Text]
  3. Mintz GS, Popma JJ, Pichard AD, et al. Patterns of calcification in coronary artery disease: a statistical analysis of intravascular ultrasound and coronary angiography in 1,155 lesions. Circulation 1995; 91:1959-1965.[Abstract/Free Full Text]
  4. Nissen SE, Gurley JC, Grines CL, et al. Coronary atherosclerosis is frequently present at angiographically normal sites: evidence from intravascular ultrasound in man (abstr). Circulation 1990; 82:459.
  5. Nissen SE, Gurley JC, Grines CL, et al. Intravascular ultrasound assessment of lumen size and wall morphology in normal subjects and patients with coronary artery disease. Circulation 1991; 84:1087-1099.[Abstract/Free Full Text]
  6. Tutar H, Kapadia SR, Ziada KM, et al. Coronary atherosclerosis begins at young age: intravascular ultrasound evidence of disease in individual <20 years old (abstr). Circulation 1999; 100(suppl 1):524.
  7. Little WC, Constantinescu M, Applegate RJ, et al. Can coronary angiography predict the site of subsequent myocardial infarction in patients with mild-to-moderate coronary artery disease?. Circulation 1988; 78:1157-1166.[Abstract/Free Full Text]
  8. Shepherd J, Cobbe SM, Ford I, et al. Prevention of coronary heart disease with pravastatin in men with hypercholesterolemia: West of Scotland Coronary Prevention Study Group. N Engl J Med 1995; 333:1301-1307.[Abstract/Free Full Text]
  9. Waters D, Higginson L, Gladstone P, et al. Effects of monotherapy with an HMG-CoA reductase inhibitor on the progression of coronary atherosclerosis as assessed by serial quantitative arteriography: the Canadian Coronary Atherosclerosis Intervention Trial. Circulation 1994; 89:959-968.[Abstract/Free Full Text]
  10. Brown BG, Hillger L, Zhao XQ, Poulin D, Albert JJ. Types of change in coronary stenosis severity and their relative importance in overall progression and regression of coronary disease: observations from the FATS Trial. Familial Atherosclerosis Treatment Study. Ann N Y Acad Sci 1995; 748:407-417.
  11. Blekenhorn DH, Azen SP, Kramsch DM, et al. Coronary angiographic changes with lovastatin therapy: the Monitored Atherosclerosis Regression Study (MARS). Ann Intern Med 1993; 119:969-976.[Abstract/Free Full Text]
  12. Lichtlen PR, Nikutta P, Jost S, Deckers J, Wiese B, Rafflenbeul W. Anatomical progression of coronary artery disease in humans as seen by prospective, repeated, quantitated coronary angiography: relation to clinical events and risk factors. The INTACT Study Group. Circulation 1992; 86:828-838.
  13. Callister TQ, Raggi P, Cooil B, Lippolis NJ, Russo DJ. Effect of HMG-CoA reductase inhibitors on coronary artery disease as assessed by electron-beam computed tomography. N Engl J Med 1998; 339:1972-1978.[Abstract/Free Full Text]
  14. Maher JE, Bielak FB, Raz JA, Sheedy PF, II, Schartz RS, Peyester PA. Progression of coronary artery calcification: a pilot study. Mayo Clin Proc 1999; 74:347-355.[Medline]
  15. Shemesh J, Apter S, Itzchak Y, Motro M. Progression of coronary calcification in patients with and without coronary artery disease by double helix computerized tomography: one-year follow-up (abstr). Eur Heart J 1995; 16:228.
  16. Shemesh J, Apter S, Rozenman J, et al. Calcification of coronary arteries: detection and quantification with double helix CT. Radiology 1995; 197:779-783.[Abstract/Free Full Text]
  17. Broderick LS, Shemesh J, Wilensky RL, et al. Measurement of coronary artery calcium with double helical CT compared to coronary angiography: evaluation of CT scoring methods, interobserver variation, and reproducibility. Am J Radiol 1996; 167:439-444.[Abstract/Free Full Text]
  18. Shemesh J, Tenenbaum A, Fisman EZ, et al. Coronary calcium as a reliable tool for differentiating ischemic from nonischemic cardiomyopathy. Am J Cardiol 1995; 77:191-194.
  19. Shemesh J, Tenenbaum A, Fisman EZ, et al. Absence of coronary calcification on double helical CT scans: predictor of angiographic normal coronary arteries in elderly women?. Radiology 1996; 199:665-668.[Abstract/Free Full Text]
  20. Shemesh J, Fisman EZ, Tenenbaum A, et al. Coronary artery calcification in women with syndrome X: usefulness of double-helical CT for detection. Radiology 1997; 205:697-700.[Abstract/Free Full Text]
  21. Motro M, Shemesh J. Effect of nifedipine on progression of coronary artery calcification: a three years inquiry (suppl). J Cardiovasc Pharmacol 1996; 28:33-35.
  22. Shemesh J, Tenenbaum A, Kopecky KK, et al. Coronary calcium measurements by double helical computed tomography: using the average instead of peak density algorithm improves reproducibility. Invest Radiol 1997; 32:503-506.[Medline]
  23. Glagov S, Weisenberg E, Zarins CK, Stankunavicius R, Kolletis GJ. Compensatory enlargement of human atherosclerotic coronary arteries. N Engl J Med 1987; 316:1371-1375.[Abstract]
  24. Gibbons GH, Dzau VJ. The emerging concept of vascular remodeling. N Engl J Med 1994; 330:1431-1438.[Free Full Text]
  25. Rumberger JA, Simons DB, Fitzpatrick LA, et al. Coronary artery calcium areas by electron beam computed tomography and coronary atherosclerotic plaque area: a histopathologic correlative study. Circulation 1995; 92:2157-2162.[Abstract/Free Full Text]
  26. Shemesh J, Tenenbaum A, Stroh CI, et al. Double helical CT as a new tool for tracking of allograft atherosclerosis in heart transplant recipients. Invest Radiol 1999; 32:503-506.
  27. Shemesh J, Stroh CI, Tenenbaum A, et al. Comparison of coronary calcium in stable angina pectoris and in first acute myocardial infarction utilizing double helical computerized tomography. Am J Cardiol 1998; 81:271-275.[Medline]



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Radiology, February 1, 2002; 222(2): 474 - 482.
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