Wednesday, December 21, 2011

Reinterpretation on Negative Findings for CAD in Mammography

I have recently published an article in the Journal of the National Cancer Institute (Oxford University Press) a leading medical journal. It is a letter in reply to a recently published and highly publicized study on the use of computer-aided detection (CAD) technologies in breast cancer screening via mammography. That study, published late last summer was the world's largest study on the effects of computer-aided detection technologies in breast cancer screening (in terms of the number of examinations incorporated into the analysis - 1.6 million screening examinations). The study reported largely negative findings for the performance of breast cancer screening with the help of computer-aided detection technologies.

Thursday, October 6, 2011

Site Update: Nature Blogs

This website was originally founded under the name With A Grain of Salt and was eventually listed with Nature Publishing Group's network of independent science themed blogs / websites (you can check out their network over at More recently I have revamped this website to look more professional and renamed it Spotlight on Science. Under the new name, this website has been re-included into Nature Publishing Group's network of high quality independent blogs.

Tuesday, October 4, 2011

Detecting Breast Cancer by Assessing the Lesion's Margin

I recently published an article with the journal Academic Radiology. The paper presents a method for assessing a tumour's margin towards the detection of breast cancer from state-of-the-art MRI examinations. Malignant margins tend to appear diffuse and variable by virtue of cancerous lesions being characterized by invading into neighbouring tissues. Margin measurements also have potential applications in the assessment of whether a lumpectomy (removing a lesion via surgery)   actually successfully removed the entire tissue of interest, however, this article is focused on using the margin measurement towards a more accurate diagnosis of breast cancer from MRI examinations. 

Thursday, September 29, 2011

Statistical Significance and the Publication Process

In theory if you have an original presentation of data, or an original collective argument on a given scientific topic then, in order to get your ideas "out there" and heard among other scientists you submit your work to the peer review process. If the peer reviewers agree that the work holds merit then the work will be published. Unfortunately this publishing paradigm is an idealization - with journals commonly making subjective decisions as to what should be sent out for peer review.

Friday, September 9, 2011

On Digital Infrared Thermal Imaging for Breast Cancer Detection

I recently got a letter published in the British Medical Journal on Digital Infrared Thermal Imaging for the detection of breast cancer. Since no copyright is taken out on these letters, I am reproducing it here:

Tuesday, August 23, 2011

Update: News on the Nature Front

I have good news, I am now part of the editorial board for Nature's Scientific Reports. I will be in charge of the peer review process for research papers in biophysical and computational methods in cancer research (etc.). The journal removes the subjective decision of how significant a research study appears to be in order to be worthy of publication (which is great!). Instead the publication of papers is contingent upon being technically and scientifically sound as well as original.

The journal is put out by the extremely successful Nature Publishing Group and is also open access - of which I am also very supportive. This allows all research studies published at the journal to be read by anyone in the world (who has the luxury of an internet connection). I look forward to performing my duties as an editorial board member and also look forward to publishing some of my work with them.

Jacob Levman, PhD
Imaging Research
Sunnybrook Research Institute
University of Toronto

Wednesday, August 10, 2011

Not All Computer Aided Detection Methods Are Equal

A recent publication in the Journal of the National Cancer Institute has indicated that computer-aided detection (CAD) technologies do not aid in improving breast cancer detection via x-ray mammography based screening (here is a news article on the publication). The conclusions reached in this study may be flawed and this article explores some of the issues of why this may have occurred.

Wednesday, June 1, 2011

Chronic and Recent Starvation and Malnourishment

I recently got a relatively short article published on malnourishment with the European Journal of Public Health which is published by the Oxford University Press. The article is titled "Chronic and Recent Starvation and Malnourishment" and is accessible from the journal's website here. If you would like to read the article, I am reprinting it below:

Monday, April 25, 2011

Comparing Screening Methods in Long Term Analyses

I recently got an article published with the European Journal of Public Health, which is put out by Oxford University Press. The article comments on methods for evaluating disease detection (or screening) methods after many years in a longitudinal analysis. Disease detection rates are one of the most common evaluative methods in this scenario and my article explains why that can be an unsafe evaluative method that can lead to the dismissal of newer and beneficial technologies.

You can read the article by clicking here.

Wednesday, March 9, 2011

Humorous Aside: Trust Me I'm a Doctor

When I was a little boy I had a favourite T-shirt. I remember being an idealistic little kid and when asked what I was going to do with my life I said: "I'm going to cure cancer". Now I'm 32 and I'm a doctor - incidentally I earned my doctorate in breast cancer detection - one of a gazillion possible research areas that can theoretically help with the fight against cancer. 

Monday, March 7, 2011

The Problems with Evaluating Detection Technologies with Disease Caught in the First Round of Screening

My research is focused on breast cancer screening methods, however, the ideas presented here apply to the detection of most diseases.

Friday, February 11, 2011

Humorous Aside: Chutzpah in Science, part 2

Chutzpah is a Yiddish word meaning: impressive cheekiness, brash, informal shameless audacity.

Thursday, February 10, 2011

Malnutrition and HIV in Ugandan Children

I recently read a Nutrition Journal study from 2006 on severely malnourished children with and without HIV. It was a very interesting study on an extremely important topic. I am not only particularly interested in the subject of malnourishment but I’m also particularly interested in Uganda, a country where I have visited with my wife who did some of her health professional training (in Occupational Therapy from the University of Toronto) at a hospital in Mbarara.

Sunday, February 6, 2011

Humorous Aside: Chutzpah in Science

Chutzpah is a Yiddish word meaning: impressive cheekiness, brash, informal shameless audacity

Monday, January 24, 2011

Site Update: Nature Publishing Group Network

This website (formerly With a Grain of Salt) has been added as part of the Nature Publishing Group's network of science-themed independent websites (blogs). Entry is dependent on the opinion of Nature Publishing Group along with the results of an election where existing bloggers admitted into Nature's network are given a vote on new entries. I have since renamed this website Spotlight on Science and given it a more professional layout.

Friday, January 21, 2011

The Ideal Scientific Journal

In the world of science, a journal's quality is typically measured with what's called an Impact Factor. The impact factor is really a measurement of how often any given article published in a particular journal gets cited in other scientific contributions. Journals with high impact factors tend to generate a lot of citations for each of their articles and tend to be quite prestigious.

Thursday, January 13, 2011

The impact of the impact factor on the scientific publication process

The impact factor is a measure of how often articles published in a given scientific journal get cited by other research articles. Scientists tend to use the impact factor as the main method for evaluating the quality of a given journal publication. Because the impact factor is the main source of respectability for a given journal publication among scientists, journal editors are naturally biased towards achieving as high an impact factor as possible for their journal. This bias leads to a connected bias: the rejection of studies for which the journal editor qualitatively believes that the study is not likely to generate citations from other scientific research in the near future.

Tuesday, January 11, 2011

Challenges in estimating the increase in the death rate among the malnourished

A 10-year-old and largely ignored United Nations report estimated that malnourished people die at a rate of about 36 million people per year, accounting for about 58% of worldwide deaths. Proper statistics aren't kept in many of the world's countries, so we don't know if this estimate is correct. However, even if the true value is quite substantially lower, this problem is still of massive proportions. I previously published an article that helps to wrap your head around the scope of the problem by comparing the number of deaths of malnourished people with the number of deaths due to World War II (by these estimates there are about 3 times as many deaths among the malnourished as compared with deaths due to World War II).

Saturday, January 8, 2011

Humorous Aside: Peer-reviewed rejection

Peer reviewed rejection can be one of the most frustrating things about being a scientist. Here's some peer reviewed rejection humour with the hope that it can be cathartic for some scientists out there.

Thursday, January 6, 2011

The old food crisis, the chronic food crisis and the coming food crisis?

In 2008 the price for many basic foods increased dramatically. This led to rioting in many countries such as Haiti, Bangladesh, Egypt and many African countries. This chaos and the strains that the food price increases have caused on the world's poor were dubbed a "food crisis", which it surely was. However, older reports from the United Nations claim that the death rate for malnourished people is ridiculously high - 3 times higher than the death rate due to World War II. Even if this is an exaggeration, then this is still a ridiculously large problem, large enough that it deserved the title "food crisis" long before we were using that term in 2008. As such I refer to the ongoing problem as the chronic food crisis.

Tuesday, January 4, 2011

There are more benefits from breast cancer screening than simply saving a woman's life

This past year saw the eruption of a fresh controversy in breast cancer screening. The United States Preventive Services Task Force (USPSTF) issued a report to the Obama administration advising against x-ray mammographic screening for women in their forties. The journal Science reported on the controversy and published a reply letter which was also published here at Spotlight-on-Science. The article pointed out that the USPSTF task force accepted a particular conservative estimate about the number of women in their forties that needed to be screened by x-ray mammography in order to save one life (1900 need to be screened by this estimate). I pointed out that when a fully developed screening program is applied to a large population such as the United States, the use of screening still adds up to many lives saved.

Saturday, January 1, 2011

P=NP and the million dollar mathematics prize

The Clay Mathematics Institute in Cambridge Massachusetts is providing a one million dollar prize for the first person who can prove or disprove the P=NP problem. A variety of descriptions of the P=NP problem are available. Simply put, computer scientists have divided computer problems into a series of categories which include P (problems that are relatively easy to solve) and NP (problems that are relatively challenging to solve). The majority of computer scientists believe that P != NP (P is not equal to NP - this expression is repeated below) indicating that many believe problems exist which are too complex to solve for them to ever be classified as P type problems. Recently Vinay Deolalikar of HP labs released a possible proof that P != NP. His work has been subject to some criticisms, however, I am inclined to agree with his goal of proving that P != NP and good luck to him in responding effectively to his critics - that million dollar prize would sure be sweet!