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Study rates heart scan techniques
“Magnetic resonance imaging (MRI) scans ought to be used to assess patients with suspected heart disease, instead of commonplace checks,” reports BBC News these days.
This story relies on an oversized, well-designed study comparing a brand new technique referred to as cardiovascular magnetic resonance (CMR) imaging against the commonly used various check, single-photon emission computed tomography (SPECT). The researchers tested the scan’s ability to diagnose vital coronary heart disease, conjointly observing how they compared against commonplace angiography, where dye is introduced into the blood vessels to spotlight any blockage or narrowing. The study found that CMR performed furthermore or higher than SPECT on variety of key diagnostic measures. in conjunction with the actual fact that CMR doesn't expose patients to ionising radiation, the researchers say the results show that CMR ought to be a lot of widely adopted.
However, CMR won't be appropriate for all patients, together with some with medical implants and people who may expertise claustrophobia within the scanner. any analysis also will be required to demonstrate that improved diagnosis through techniques like CMR really improves patient outcomes. That said, these results do counsel the technique has benefit.
Where did the story come back from?
The study was distributed by researchers from the University of Leeds and was funded by the British Heart Foundation. The study was revealed within the peer-reviewed journal The Lancet.
The coverage by the BBC on this story was correct, and featured comments from freelance consultants and explanations of the necessity for confirmation in alternative centres, population teams and for an assessment of price.
What quite analysis was this?
This was a randomised trial comparing how well 2 forms of non-invasive scanning techniques may diagnose coronary heart disease: a more recent check referred to as cardiovascular magnetic resonance (CMR) versus the widely used technique of single-photon emission computed tomography (SPECT).
CMR uses magnetic fields and radio waves to provide pictures of the within of the body. It doesn't use ionising radiation. SPECT needs a radiation-emitting chemical (a radioisotope) to be injected into the bloodstream. The radioactive emissions are detected and used to make a picture. this system exposes patients to tiny amounts of ionising radiation. each ways give useful tests for angina, in that heart operate or perfusion is detected when an injection of a chemical that stresses the center.
Both of those techniques were compared with another imaging technique referred to as X-ray coronary angiography, that acted because the reference commonplace. during this method, the researchers may directly compare the results of the 2 scans in an exceedingly single patient and then flip to X-ray scanning to substantiate that was most correct.
In X-ray coronary angiography, a distinction agent is introduced into the coronary artery and X-ray pictures are taken. Again, the patient is exposed to ionising radiation and additionally the technique used to introduce the distinction agent is invasive. this can be an anatomical check that shows where any narrowed arteries may be.
Patients with suspected disease were randomised into 2 teams, receiving either CMR before SPECT (prior to confirmation with angiography) or SPECT before CMR (prior to confirmation with angiography). providing CMR and SPECT in an exceedingly random order reduces the probabilities of the results being influenced by bias: as an example, the method of performing a scan may probably influence the results seen in any subsequent scan, and thus continually performing a selected variety of scan 1st might skew the results.
This study style provides an acceptable thanks to check the diagnostic accuracy of a brand new technique, because it compares CMR with each the widely used SPECT and also the ‘gold standard’ X-ray angiography.
What did the analysis involve?
The trial enrolled 752 patients with angina (chest pain owing to lack of blood to the heart) that required any investigation and a minimum of one alternative risk issue for coronary heart disease. Patients were excluded if that they had previously undergone heart bypass surgery.
All patients were scheduled to receive all 3 tests. The patients’ hearts were imaged using CMR, SPECT and X-ray angiography and also the pictures analysed by folks experienced in decoding the results, to form a diagnosis. The order of CMR and SPECT imaging was randomised and people reading the results of the tests were unaware of the results of previous testing, except at the tip when the results can be revealed to the treating clinician to see treatment.
What were the fundamental results?
The overall results urged that thirty ninth of the recruited patients had vital coronary heart disease identified using X-ray angiography.
The researchers found the subsequent for CMR:
A sensitivity of eighty six.5% [95% confidence interval (CI) eighty one.8% to 90.1%]. this suggests that eighty six.5% of patients with the disease identified using X-ray angiography had a positive result on CMR. Therefore, these folks were properly identified as having coronary heart disease.
A specificity of eighty three.4% [95% CI seventy nine.5% to 86.7%]. this suggests that eighty three.4% of patients while not coronary heart disease throughout X-ray angiography properly received a negative result using CMR. These folks were properly identified as not having coronary heart disease.
A positive predictive price of seventy seven.2% [95% CI seventy two.1% to 81.6%]. this suggests that seventy seven.2% of patients who were diagnosed as having coronary heart disease by CMR did if truth be told have coronary heart disease. But, conversely, 22.8% of patients would be incorrectly identified.
A negative predictive price of ninety.5% [95% CI eighty seven.1% to 93.0%]. this suggests that ninety.5% of patients who had a negative result by CMR didn't have coronary heart disease. But, conversely nine.5% of patients would be incorrectly reassured.
The sensitivity and negative predictive price for CMR was considerably higher than those for the widely used SPECT technique. The specificity and positive predictive price of the 2 techniques were similar.
How did the researchers interpret the results?
The researchers conclude that this trial has shown “CMR’s high diagnostic accuracy in coronary heart disease and CMR’s superiority over SPECT”. they assert it ought to be adopted a lot of widely for the investigation of coronary heart disease.
Conclusion
This analysis has demonstrated the diagnostic accuracy of CMR in diagnosing coronary heart disease. CMR conjointly has the advantage that it's a non-invasive technique that doesn't expose patients to ionising radiation. However, CMR won't be appropriate for all patients, as owing to the high magnetic fields concerned, patients with some medical implants won't be ready to use it. owing to the confined nature several|of the many} scanners it's conjointly not appropriate for patients that suffer from claustrophobia (although this can be conjointly the case with many SPECT scanners).
Some points to note:
The tests were wiped out a bunch of patients at comparatively high risk of coronary heart disease, with nearly four-hundredth having the disease. The accuracy of the check in an exceedingly community sample of lower-risk patients can have to be compelled to be tested.
The analysis was conducted by skilled, experienced operators, that means that its accuracy may not be an equivalent in units where fewer procedures are performed.
X-ray angiography itself isn't itself an ideal check and thus may not are ideal as a reference commonplace.
Further analysis are required to check if improved diagnosis, using techniques like CMR, really improves patient outcomes. Cost, cost-effectiveness and also the availability of scanners also will have to be compelled to be evaluated.
“Magnetic resonance imaging (MRI) scans ought to be used to assess patients with suspected heart disease, instead of commonplace checks,” reports BBC News these days.
This story relies on an oversized, well-designed study comparing a brand new technique referred to as cardiovascular magnetic resonance (CMR) imaging against the commonly used various check, single-photon emission computed tomography (SPECT). The researchers tested the scan’s ability to diagnose vital coronary heart disease, conjointly observing how they compared against commonplace angiography, where dye is introduced into the blood vessels to spotlight any blockage or narrowing. The study found that CMR performed furthermore or higher than SPECT on variety of key diagnostic measures. in conjunction with the actual fact that CMR doesn't expose patients to ionising radiation, the researchers say the results show that CMR ought to be a lot of widely adopted.
However, CMR won't be appropriate for all patients, together with some with medical implants and people who may expertise claustrophobia within the scanner. any analysis also will be required to demonstrate that improved diagnosis through techniques like CMR really improves patient outcomes. That said, these results do counsel the technique has benefit.
Where did the story come back from?
The study was distributed by researchers from the University of Leeds and was funded by the British Heart Foundation. The study was revealed within the peer-reviewed journal The Lancet.
The coverage by the BBC on this story was correct, and featured comments from freelance consultants and explanations of the necessity for confirmation in alternative centres, population teams and for an assessment of price.
What quite analysis was this?
This was a randomised trial comparing how well 2 forms of non-invasive scanning techniques may diagnose coronary heart disease: a more recent check referred to as cardiovascular magnetic resonance (CMR) versus the widely used technique of single-photon emission computed tomography (SPECT).
CMR uses magnetic fields and radio waves to provide pictures of the within of the body. It doesn't use ionising radiation. SPECT needs a radiation-emitting chemical (a radioisotope) to be injected into the bloodstream. The radioactive emissions are detected and used to make a picture. this system exposes patients to tiny amounts of ionising radiation. each ways give useful tests for angina, in that heart operate or perfusion is detected when an injection of a chemical that stresses the center.
Both of those techniques were compared with another imaging technique referred to as X-ray coronary angiography, that acted because the reference commonplace. during this method, the researchers may directly compare the results of the 2 scans in an exceedingly single patient and then flip to X-ray scanning to substantiate that was most correct.
In X-ray coronary angiography, a distinction agent is introduced into the coronary artery and X-ray pictures are taken. Again, the patient is exposed to ionising radiation and additionally the technique used to introduce the distinction agent is invasive. this can be an anatomical check that shows where any narrowed arteries may be.
Patients with suspected disease were randomised into 2 teams, receiving either CMR before SPECT (prior to confirmation with angiography) or SPECT before CMR (prior to confirmation with angiography). providing CMR and SPECT in an exceedingly random order reduces the probabilities of the results being influenced by bias: as an example, the method of performing a scan may probably influence the results seen in any subsequent scan, and thus continually performing a selected variety of scan 1st might skew the results.
This study style provides an acceptable thanks to check the diagnostic accuracy of a brand new technique, because it compares CMR with each the widely used SPECT and also the ‘gold standard’ X-ray angiography.
What did the analysis involve?
The trial enrolled 752 patients with angina (chest pain owing to lack of blood to the heart) that required any investigation and a minimum of one alternative risk issue for coronary heart disease. Patients were excluded if that they had previously undergone heart bypass surgery.
All patients were scheduled to receive all 3 tests. The patients’ hearts were imaged using CMR, SPECT and X-ray angiography and also the pictures analysed by folks experienced in decoding the results, to form a diagnosis. The order of CMR and SPECT imaging was randomised and people reading the results of the tests were unaware of the results of previous testing, except at the tip when the results can be revealed to the treating clinician to see treatment.
What were the fundamental results?
The overall results urged that thirty ninth of the recruited patients had vital coronary heart disease identified using X-ray angiography.
The researchers found the subsequent for CMR:
A sensitivity of eighty six.5% [95% confidence interval (CI) eighty one.8% to 90.1%]. this suggests that eighty six.5% of patients with the disease identified using X-ray angiography had a positive result on CMR. Therefore, these folks were properly identified as having coronary heart disease.
A specificity of eighty three.4% [95% CI seventy nine.5% to 86.7%]. this suggests that eighty three.4% of patients while not coronary heart disease throughout X-ray angiography properly received a negative result using CMR. These folks were properly identified as not having coronary heart disease.
A positive predictive price of seventy seven.2% [95% CI seventy two.1% to 81.6%]. this suggests that seventy seven.2% of patients who were diagnosed as having coronary heart disease by CMR did if truth be told have coronary heart disease. But, conversely, 22.8% of patients would be incorrectly identified.
A negative predictive price of ninety.5% [95% CI eighty seven.1% to 93.0%]. this suggests that ninety.5% of patients who had a negative result by CMR didn't have coronary heart disease. But, conversely nine.5% of patients would be incorrectly reassured.
The sensitivity and negative predictive price for CMR was considerably higher than those for the widely used SPECT technique. The specificity and positive predictive price of the 2 techniques were similar.
How did the researchers interpret the results?
The researchers conclude that this trial has shown “CMR’s high diagnostic accuracy in coronary heart disease and CMR’s superiority over SPECT”. they assert it ought to be adopted a lot of widely for the investigation of coronary heart disease.
Conclusion
This analysis has demonstrated the diagnostic accuracy of CMR in diagnosing coronary heart disease. CMR conjointly has the advantage that it's a non-invasive technique that doesn't expose patients to ionising radiation. However, CMR won't be appropriate for all patients, as owing to the high magnetic fields concerned, patients with some medical implants won't be ready to use it. owing to the confined nature several|of the many} scanners it's conjointly not appropriate for patients that suffer from claustrophobia (although this can be conjointly the case with many SPECT scanners).
Some points to note:
The tests were wiped out a bunch of patients at comparatively high risk of coronary heart disease, with nearly four-hundredth having the disease. The accuracy of the check in an exceedingly community sample of lower-risk patients can have to be compelled to be tested.
The analysis was conducted by skilled, experienced operators, that means that its accuracy may not be an equivalent in units where fewer procedures are performed.
X-ray angiography itself isn't itself an ideal check and thus may not are ideal as a reference commonplace.
Further analysis are required to check if improved diagnosis, using techniques like CMR, really improves patient outcomes. Cost, cost-effectiveness and also the availability of scanners also will have to be compelled to be evaluated.
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