Mayo Patent Watch: Aneurysm Detection And Tissue Wall Ultrasound

Mayo Patent Watch: Aneurysm Detection And Tissue Wall Ultrasound

The latest and most innovative patents coming out of the Rochester medical powerhouse.

The Mayo Foundation for Medical Education and Research, the nonprofit parent entity of the Mayo Clinic, is a worldwide research powerhouse that is assigned numerous U.S. patents each year. Mayo scientists and doctors are at the scientific forefront of many medical specialties, and the breadth of their activities is widely varied.

As part of its healthcare industry coverage, TCB is taking occasional looks at recent patents awarded to the Mayo Foundation and its inventors in a feature called Mayo Patent Watch. This is the second installment of series, looking at patents assigned to Mayo during the week of May 23-27, 2016.

Patent No.: 9,349,176
Title: Computer-aided detection (CAD) of intracranial aneurysms
Inventors: Xiaojiang Yang, Bradley Erickson, M.D., Daniel Blezek, David Kallmes, M.D.

Dr. David Kallmes, chief of the Mayo Clinic’s Applied Neuroradiology Laboratory, and Dr. Bradley Erickson, head of its Radiology Informatics Lab, led a team of Mayo researchers who last week were awarded a patent for a new kind of magnetic imaging method that can more accurately detect brain aneurysms.
Also credited as inventors on the patent were Daniel Blezek, an assistant professor of biomedical engineering, and Xiaojiang Yang, a Mayo computer scientist.
The team’s invention is described as a fully automated computer-aided detection (CAD) way of identifying aneurysms through 3D “time-of-flight” images generated via the use of magnetic resonance angiography, a kind of MRI technology used to look at blood vessels.
In the detection of brain aneurysms, invasive surgical methods remain the gold standard. However, in recent years, magnetic resonance angiography (MRA) has emerged as a useful non-invasive alternative. But even when used by experienced neuroradiologists, its success in finding smaller aneurysms is poor, on the order of 30 to 60 percent.
That situation is addressed by the Mayo team’s new system, which locates possible trouble points on individual MRA imaging datasets by combining two complementary techniques. The first technique examines intracranial arteries automatically and finds the trouble points from the segmented vessels; the second tracks down such points directly from the raw, unsegmented image dataset.
Then, after a series of calculations, a small fraction of possible trouble points are retained as candidate aneurysms. After extensive testing, the inventors claimed, their CAD method showed good accuracy – 91 percent for aneurysms of five millimeters or smaller with nine false positives among 287 datasets of images used. 
The new method may, they concluded, have significant applications in improving the sensitivity of aneurysm detection on MR images.
Patent No.: 9,345,448
Title: System and method for non-invasive determination of tissue wall viscoelasticity using ultrasound vibrometry
Inventors: Mostafa Fatemi, Ivan Nenadich

Two Mayo Medical School professors and members of its Ultrasound Imaging Laboratory have been awarded a patent for a new way of measuring the elasticity of the bladder wall using ultrasound, which they claim could have an impact on the care of patients suffering from bladder problems.
The inventors of the new method for ultrasound vibrometry are Mostafa Fatemi, a professor of biomedical engineering, and Ivan Nenadich, an assistant professor of biomedical engineering.
The stiffening of the bladder wall can occur with age, injuries or because of congenital defects. An elastic bladder is important for storing increasing volumes of urine at low pressures, and if it’s not functioning properly, the result can be incontinence or urinary tract infections.
Some patients diagnosed with reduced bladder compliance now must undergo frequent invasive “urodynamic” tests in which a catheter is placed into the bladder, vagina or rectum, and is left for as long as 45 minutes to measure how the bladder expands as it fills. The procedure can be painful and sometimes can result in infections.
With the new system, the Mayo researchers say those measurements can be made non-invasively through the use of a handheld device that uses ultrasound force to “tap” the elastic tissue of the bladder walls. It creates pulse waves that can be measured to track the vibrations of the walls, using space analysis to observe how the waves’ velocity is dispersed.
Doctors have been using ultrasound vibrometry to measure the elasticity of soft tissues for at least a decade, but mainly those efforts have been aimed at the bulky tissues of such organs as the heart, liver, kidney and prostate. The new invention adapts the idea to the thin tissue of the bladder wall, which is only a few millimeters thick.
The Mayo team asserts the device could be “an important step towards understanding various bladder disease processes and improving patient care.”