Coronary CT calcium scan: Difference between revisions

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Coronary CT Calcium Scan

A Coronary CT Calcium Scan is a specialized medical imaging technique used to assess the presence of coronary artery disease (CAD) by detecting calcium deposits in the coronary arteries. This non-invasive test helps in evaluating the risk of future cardiovascular events such as myocardial infarction (heart attack).

Overview

The coronary CT calcium scan, also known as a cardiac CT for calcium scoring, utilizes computed tomography (CT) technology to create detailed images of the heart. The primary purpose of this scan is to measure the amount of calcified plaque in the coronary arteries. Calcified plaque is an indicator of atherosclerosis, which can lead to narrowing of the arteries and increased risk of heart disease.

Procedure

The procedure for a coronary CT calcium scan is relatively quick and painless. It involves the following steps:

Preparation: Patients may be asked to avoid caffeine and smoking for a few hours before the test. They should wear comfortable clothing and remove any metal objects.
Positioning: The patient lies on a table that slides into the CT scanner. Electrodes are attached to the chest to monitor the heart's activity.
Scanning: The CT scanner takes multiple images of the heart, which are then used to calculate the calcium score.

Calcium Score

The calcium score is a numerical value that reflects the amount of calcified plaque in the coronary arteries. It is calculated using specialized software that analyzes the CT images. The score is used to estimate the risk of coronary artery disease:

0: No detectable plaque. Low risk of CAD.
1-99: Mild plaque. Low to moderate risk.
100-399: Moderate plaque. Moderate to high risk.
400 and above: Extensive plaque. High risk of CAD.

Clinical Significance

A coronary CT calcium scan is particularly useful for individuals with intermediate risk of heart disease. It provides additional information that can guide treatment decisions, such as the need for lifestyle changes or medication. The test is not typically recommended for individuals with very low or very high risk, as it may not change the management strategy.

Limitations

While the coronary CT calcium scan is a valuable tool, it has limitations:

It does not detect non-calcified plaque, which can also contribute to heart disease.
It involves exposure to a small amount of ionizing radiation.
It is not suitable for individuals with certain medical conditions, such as severe kidney disease.

Conclusion

The coronary CT calcium scan is an important diagnostic tool in the assessment of coronary artery disease. By providing a calcium score, it helps in stratifying the risk of cardiovascular events and guiding preventive measures. However, it should be used in conjunction with other clinical assessments and diagnostic tests.

Cardiovascular disease A-Z

Most common cardiac diseases

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A

B

Brown atrophy of the heart

C

D

E

H

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

I

K

Keshan disease

L

Loeffler endocarditis

M

N

Nonbacterial thrombotic endocarditis

O

P

R

S

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

T

Traumatic cardiac arrest

V

W

Waon therapy

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-== Coronary CT Calcium Scan: An Insight into Heart Health ==
+==Coronary CT Calcium Scan==
-A '''coronary CT calcium scan''' is a specialized [[computed tomography (CT)]] imaging procedure primarily aimed at evaluating the extent of coronary artery disease. By specifically identifying calcium deposits within the coronary arteries, the scan aids in determining arterial blockages which can escalate the threat of a [[heart attack]].
+A '''Coronary CT Calcium Scan''' is a specialized medical imaging technique used to assess the presence of [[coronary artery disease]] (CAD) by detecting [[calcium]] deposits in the [[coronary arteries]]. This non-invasive test helps in evaluating the risk of future [[cardiovascular events]] such as [[myocardial infarction]] (heart attack).
-[[File:Bandfoermige Verkalkung Ligamentum transversum atlantis 91W - CT axial sagittal und Volumen Rendering - 001 - Annotation.jpg|thumb|right|700px|Coronary CT calcium scan showcasing calcium deposits in coronary arteries.]]
+===Overview===
-== Principle and Indication ==
+The coronary CT calcium scan, also known as a cardiac CT for calcium scoring, utilizes [[computed tomography]] (CT) technology to create detailed images of the heart. The primary purpose of this scan is to measure the amount of calcified plaque in the coronary arteries. Calcified plaque is an indicator of atherosclerosis, which can lead to narrowing of the arteries and increased risk of heart disease.
-The central principle of the coronary CT calcium scan is to detect and quantify calcium deposits in the [[coronary arteries]]. The presence of these deposits can lead to arterial narrowing, thereby posing a potential risk for cardiac events.
-== Scoring and Its Significance ==
+===Procedure===
-The outcome of the scan can be presented in terms of:
-* '''Agatston Score'''
+The procedure for a coronary CT calcium scan is relatively quick and painless. It involves the following steps:
-* '''Coronary Artery Calcium (CAC) Score'''
-The CAC score, in particular, stands out as a crucial marker, serving multiple functions:
+# '''Preparation''': Patients may be asked to avoid caffeine and smoking for a few hours before the test. They should wear comfortable clothing and remove any metal objects.
+# '''Positioning''': The patient lies on a table that slides into the CT scanner. Electrodes are attached to the chest to monitor the heart's activity.
+# '''Scanning''': The CT scanner takes multiple images of the heart, which are then used to calculate the calcium score.
-* Independent predictor of impending [[cardiac events]]
+===Calcium Score===
-* Indicative of cardiac mortality risk
-* Suggestive of all-cause mortality risk<ref name="ref2"></ref>
-In addition, the CAC score complements other cardiovascular risk markers, offering a more comprehensive prognostic picture.<ref name="ref2"></ref>
+The calcium score is a numerical value that reflects the amount of calcified plaque in the coronary arteries. It is calculated using specialized software that analyzes the CT images. The score is used to estimate the risk of coronary artery disease:
-==Indications==
+* '''0''': No detectable plaque. Low risk of CAD.
-The well-established indications for the use of the CAC score include stratification of global cardiovascular risk for asymptomatic patients: intermediate risk based on the Framingham risk score (class I); low risk based on a family history of early CAD (class IIa); and low-risk patients with diabetes (class IIa).<ref name="NevesAndrade2017"/>
+* '''1-99''': Mild plaque. Low to moderate risk.
+* '''100-399''': Moderate plaque. Moderate to high risk.
+* '''400 and above''': Extensive plaque. High risk of CAD.
-In symptomatic patients, the pre-test probability should always be given weight in the interpretation of the CAC score as a filter or tool to indicate the best method to facilitate the diagnosis. Therefore, the use of the CAC score alone is limited in symptomatic patients.<ref name="NevesAndrade2017"/>
+===Clinical Significance===
-In patients with diabetes, the CAC score helps identify the individuals most at risk, who could benefit from screening for silent ischemia and from more aggressive clinical treatment.<ref name="NevesAndrade2017"/>
+A coronary CT calcium scan is particularly useful for individuals with intermediate risk of heart disease. It provides additional information that can guide treatment decisions, such as the need for lifestyle changes or medication. The test is not typically recommended for individuals with very low or very high risk, as it may not change the management strategy.
-However, [[coronary CT angiography]] (CTA) is superior to coronary CT calcium scanning in determining the risk of Major Adverse Cardiac Events (MACE).<ref>{{cite journal |url=http://imaging.onlinejacc.org/article.aspx?articleid=1377205 |title=Prognostic Value of Coronary CT Angiography and Calcium Score for Major Adverse Cardiac Events in Outpatients |journal=Jacc: Cardiovascular Imaging |volume=5 |issue=10 |pages=990–999 |author1=Zhi-hui Hou |author2=Bin Lu |author3=Yang Gao |author4=Shi-liang Jiang |author5=Yang Wang |author6=Wei Li |author7=Matthew J. Budoff |access-date=April 9, 2015|doi=10.1016/j.jcmg.2012.06.006 |pmid=23058065 |year=2012 }}</ref>
+===Limitations===
-There is potential to measure CAC on chest radiographs taken for other indications, possibly allowing some primary screening for [[coronary artery disease]] without adding to radiation exposure and with minimal marginal cost.<ref name="pmid_26777213">{{cite journal | vauthors = Hughes-Austin JM, Dominguez A, Allison MA, Wassel CL, Rifkin DE, Morgan CG, Daniels MR, Ikram U, Knox JB, Wright CM, Criqui MH, Ix JH | title = Relationship of Coronary Calcium on Standard Chest CT Scans With Mortality | journal = JACC. Cardiovascular Imaging | volume = 9 | issue = 2 | pages = 152–9 | date = February 2016 | pmid = 26777213 | pmc = 4744104 | doi = 10.1016/j.jcmg.2015.06.030 }}</ref>
+While the coronary CT calcium scan is a valuable tool, it has limitations:
-==Agatston score==
+* It does not detect non-calcified plaque, which can also contribute to heart disease.
-[[Image:Lesionspecificcalciumscore.png|thumb|Lesion specific calcium score]]
+* It involves exposure to a small amount of [[ionizing radiation]].
-The ''Agatston score'', named after its developer [[Arthur Agatston]], is a measure of calcium on a coronary CT calcium scan.<ref>{{cite journal | vauthors = Hoffmann U, Brady TJ, Muller J | title = Cardiology patient page. Use of new imaging techniques to screen for coronary artery disease | journal = Circulation | volume = 108 | issue = 8 | pages = e50-3 | date = August 2003 | pmid = 12939244 | doi = 10.1161/01.CIR.0000085363.88377.F2 }}</ref> The original work was based on [[Electron beam tomography|electron beam computed tomography]] (also known as ultrafast CT or EBCT). The score is calculated using a weighted value assigned to the highest density of calcification in a given coronary artery. The density is measured in [[Hounsfield scale|Hounsfield units]], and score of 1 for 130–199 HU, 2 for 200–299 HU, 3 for 300–399 HU, and 4 for 400 HU and greater. This weighted score is then multiplied by the area (in square millimeters) of the coronary calcification. For example, a "speck" of coronary calcification in the left anterior descending artery measures 4 square millimeters and has a peak density of 270 HU. The score is therefore 8 (4 square millimeters × weighted score of 2).  The tomographic slices of the heart are 3 millimeters thick and average about 50–60 slices from the coronary artery ostia to the inferior wall of the heart. The calcium score of every calcification in each coronary artery for all of the tomographic slices is then summed up to give the total coronary artery calcium score (CAC score).
+* It is not suitable for individuals with certain medical conditions, such as severe [[kidney disease]].
-Several variations of the Agatston score have been described, including mass-based calcium scoring, volume-based calcium scoring, or lesion-specific calcium-scoring have been developed.<ref name="QianAnderson2010" />
+===Conclusion===
-==Lesion-specific calcium score==
+The coronary CT calcium scan is an important diagnostic tool in the assessment of coronary artery disease. By providing a calcium score, it helps in stratifying the risk of cardiovascular events and guiding preventive measures. However, it should be used in conjunction with other clinical assessments and diagnostic tests.
-A lesion-specific calcium score has been developed.<ref>{{cite journal | vauthors = Akram K, Voros S | title = Absolute coronary artery calcium scores are superior to MESA percentile rank in predicting obstructive coronary artery disease | journal = The International Journal of Cardiovascular Imaging | volume = 24 | issue = 7 | pages = 743–9 | date = October 2008 | pmid = 18351440 | doi = 10.1007/s10554-008-9305-5 }}</ref> Each individual calcified lesion is characterized and measured using parameters including the width, length, density, and distance from the entrance of the major coronary arteries.<ref>{{cite journal | vauthors = Qian Z, Marvasty I, Anderson H, Rinehart S, Voros S | title = Lesion-specific coronary artery calcium quantification better predicts cardiac events. | journal = InBiomedical Imaging: From Nano to Macro | date = June 2009 | issue = ISBI'09. IEEE International Symposium | pages = 237–240 | publisher = IEEE | doi = 10.1109/ISBI.2009.5193027 | isbn = 978-1-4244-3931-7 }}</ref> Research has shown that the lesion-specific calcium scoring method is superior to the traditional [[Agatston score]] for the prediction of significant blockages in the heart.<ref name="QianAnderson2010">{{cite journal | vauthors = Qian Z, Anderson H, Marvasty I, Akram K, Vazquez G, Rinehart S, Voros S | title = Lesion- and vessel-specific coronary artery calcium scores are superior to whole-heart Agatston and volume scores in the diagnosis of obstructive coronary artery disease | journal = Journal of Cardiovascular Computed Tomography | volume = 4 | issue = 6 | pages = 391–9 | year = 2010 | pmid = 21035423 | doi = 10.1016/j.jcct.2010.09.001 }}</ref> A patent application protecting this method has been filed.<ref>{{cite patent |country= US |number= 2010156898 |status= application |title= System and method for lesion-specific coronary artery calcium quantification |pubdate= 24 June 2010 |gdate= |fdate= |pridate= 19 December 2008 |inventor= Szilard V, Zhen Q |assign1= Piedmont Healthcare Inc }}</ref>
+{{Cardiology}}
+{{Radiology}}
-==Radiation dosage==
-On average a single scan will expose a patient to about 2.3 millisieverts of radiation, equivalent to 23 chest x-rays (front and side views).<ref name="pmid19597067" /><ref>[https://www.radiologyinfo.org/en/info.cfm?pg=safety-xray] Radiation Dose in X-Ray and CT Exams, Radiologyinfo.org</ref> That average covers a wide range of doses depending on equipment type and scanning protocol. Using modern equipment and protocols a 1 millisievert exposure is possible.<ref>{{cite journal | last=Patel | first=Amish | last2=Budoff | first2=Matthew | last3=Fine | first3=Jeffrey J. | title=Coronary Calcium Scans And Radiation Exposure In The Society For Heart Attack Prevention And Eradication Cohort | journal=Journal of the American College of Cardiology | publisher=Elsevier BV | volume=67 | issue=13 | year=2016 | issn=0735-1097 | doi=10.1016/s0735-1097(16)31734-x | page=1733}}</ref> Because the exact radiation exposure for a specific patient depends on the equipment type in use, the patients build and a variety of scanning options (such as retrospective vs prospective gating) it is difficult for a patient to know what their radiation exposure will be.
-A 2009 study indicated that for every 100,000 people screened with CAC testing every 5 years between ages 45 to 75 years (men) or 55 to 75 years (women), there would be 42 (men) or 62 (women) additional radiation induced cancer cases.<ref name="pmid19597067">{{cite journal | last = Kim | first = Kwang Pyo | last2 = Einstein | first2 = Andrew J. | last3 = Berrington de González | first3 = Amy | title = Coronary Artery Calcification Screening | journal = Archives of Internal Medicine | publisher = American Medical Association (AMA) | volume = 169 | issue = 13 | pages = 1188–94 | date = 2009-07-13 | issn = 0003-9926 | doi = 10.1001/archinternmed.2009.162 | pmid = 19597067 | pmc = 2765044 }}</ref>
-== Methodology ==
-Typically, the coronary CT calcium scan is conducted without the use of [[radiocontrast]]. However, in some cases, it might be derived from contrast-enhanced images, as seen in '''coronary CT angiography'''<ref name="ref3"></ref>.
-== Benefits of the Scan ==
-* Early Detection: The scan can detect coronary artery disease even before symptoms start manifesting.
-* Risk Assessment: It aids in gauging the risk level of severe cardiac events.
-* Treatment Guidance: Depending on the severity, doctors can tailor interventions and treatment plans.
-== See Also ==
-* [[Computed tomography (CT)]]
-* [[Coronary arteries]]
-* [[Cardiovascular diseases]]
-== References ==
-<references>
- name="ref3">[3] Source detailing coronary CT angiography and its relation to coronary CT calcium scan
-</references>
-==External links==
-*[https://www.nlm.nih.gov/medlineplus/ency/article/007344.htm Medline article on heart scans]
-*[http://www.webmd.com/heart-disease/guide/ct-heart-scan WebMD article on heart scans]
-*[http://www.radiologyinfo.org/en/info.cfm?pg=ct_calscoring RadiologyInfo.org article on heart scans]
-[[Category:Medical Imaging]]
 [[Category:Cardiology]]
-[[Category:Diagnostic Procedures]]
+[[Category:Medical imaging]]
-[[Category:Cardiac imaging]]
+[[Category:Diagnostic tests]]
-{{stub}}