MRI safe for most patients with Pacemakers or Defibrillators

A study by Russo et al published in the NEJM found that MRI scans for patients with older not FDA approved pacemakers and implantable cardioverter-defibrillators (ICD) are safe even if the scan focuses on the chest area.

The researchers performed 1000 MRI in which patients had a pacemaker and in 500 MRI in which patients had an ICD in a 1.5T MRI scanner. No deaths, lead failures, losses of capture, or ventricular arrhythmias occurred during MRI. One ICD generator could not be interrogated after MRI and required immediate replacement; the device had not been appropriately programmed per protocol before the MRI.  Nine of the implants were disrupted but reset themselves to backup mode.  In all but one instance the effect was temporary.

Neither MRI performed on chest or in other parts of the body produced significant complications.   The concerns of potential magnetic field–induced cardiac lead heating, which could result in myocardial thermal injury and/or disrupt pacing properties of the devices were noted in this study.

The authors concluded that in their study, device or lead failure did not occur in any patient who was appropriately screened, and had the device reprogrammed in accordance with the pre-specified protocol.

Top Three

In the past four years I uploaded 113 posts in Radiology Weekly.  The top three in order of viewing frequency were:

Risk of Stroke due to Intracranial Atherosclerosis

http://radiologyweekly.blogspot.com/2014/05/risk-of-stroke-due-to-intracranial.html

iPad is Accurate in the Diagnosis of Bone Fractures

http://radiologyweekly.blogspot.com/2014/08/ipad-is-accurate-in-diagnosis-of-bone.html

Circulating Tumor Cells Culture Promises Individualized Testing and Treatment 

http://radiologyweekly.blogspot.com/2014/07/circulating-tumor-cells-culture.html

Most visitors to my blog were from United States, Greece, Russia, France, South Korea, Poland, Ukraine, Turkey, United Kingdom, and Ireland in that order.  

I am sure some of you have noticed that since January 1st 2017 I post on the 1^st of each month only. 

I wish you all and your families a Happy New Year.

American Women Prefer Annual Mammograms

The US Preventive ServicesTask Force (USPSTF) reaffirmed its recommendations to screen women ages 50-74 for breast cancer every two years stating that the harms of annual screening outweighed the benefits.  It also says the decision on frequency of screening should be individualized for women ages 40-49 based on risk.  The USPSTF found insufficient evidence to recommend for or against screening for women 75 or older.

Several professional societies like the American College of Radiology and Society of Breast Imaging advocate annual screening mammography starting at age 40.

A survey of 731 women indicated that 71% of the women who were 59 years old on average said they’d prefer a screening mammogram every year. Only 17% of participants felt having biennial screening would cause less anxiety. Of the patients who reported a prior abnormal mammogram, 13% believe biennial screening would cause less anxiety

The study was presented at the 103th annual meeting of the Radiological Society of North America.

Carotid endarterectomy versus stenting, 1999-2014

Lichtman et al in their article published in JAMA address the issue of carotid endarterectomy and stenting outcomes in the U.S. in the years 1999 to 2014.

In their study that included Medicare beneficiaries, the national annualized rate of carotid endarterectomy per 100 000 beneficiary-years decreased from 298 in 1999-2000 to 128 in 2013-2014, whereas the rate of carotid artery stenting initially 40 in 1999-2000 increased to 75 in 2005-2006 followed by a decline to 38 in 2013-2014.

During the study, 937 111 unique patients underwent carotid endarterectomy (mean age, 75.8 years) and 231 077 underwent carotid artery stenting (mean age, 75.4 years).

Outcomes improved over time despite increases in vascular risk factors such as hypertension prevalence that increased from 67% to 81% among patients who underwent endarterectomy and from 61% to 70% among patients who underwent stenting.  The adjusted annual decreases in 30-day ischemic stroke or death of 2.90% among patients who underwent endarterectomy and 1.13% among patients who underwent stenting.  The 1-year ischemic stroke decreased to 3.5% after endarterectomy and 1.6% after stenting. Additional improvements were noted for in-hospital mortality, 30-day stroke, myocardial infarction, or death, and 30-day all-cause mortality.

Carotid endarterectomies declined from 1999 to 2014, whereas carotid artery stenting increased until 2006 and then declined from 2007 to 2014. Outcomes improved despite increases in vascular risk factors.

Coronary Artery Calcium on Chest CTs and Mortality Risk.

A study by Hughes-Austin et al published in the Journalof the American College of Cardiology: Cardiovascular Imaging reported on the correlation between coronary artery calcium (CAC) scores on 3 mm electrocardiography (ECG)-gated computed tomography (CT) scans and standard 6 mm chest CT scans, and compared their associations of CAC on each scan type with mortality risk.

The investigators analyzed CT studies of 4,544 patients (mean age 68), who had standard 6mm CT that were followed with 3mm EKG gated CTs.  The Agatston method quantified CAC on both scans.  The median CAC scores were lower on 6 mm CTs compared to 3 mm CTs (22 vs.104 Agatston units, p < 0.001).

During the study period 157 deaths were recorded.  Adjusted for traditional CVD risk factors, when CAC scores were evaluated as a continuous variable each standard deviation higher CAC score on both 6 mm and 3 mm CTs was associated with 1.5-fold or 50% higher odds of mortality. 

The authors concluded that CAC scores on standard 6 mm chest CTs correlate well with 3 mm ECG-gated CTs and can predict mortality risk similarly in patients whose CTs were performed for other clinical indications without additional radiation exposure or expense.