ARTICLES

ARTICLES IN JOURNALS

EARLY ARTICLE ON ULTRASONIC ARTERIAL STANDING WAVES

Echogenic blood during slow flow

Canadian Association of Radiologists Journal, 1994, Vol. 45: 487

This short publication is very significant because it shows a direct link between transverse resonating megaHertz diagnostic ultrasound standing waves, that are entrapped and are propagated longitudinally in an artery and the exactly similar flow-induced arteriographic standing waves.

 

The high reflectivity of ultrasound in a megaHz diagnostic ultrasound beam causes disc-shaped erythrocytes to flip to become perpendicular to the sound beam, thus making slow blood flow visible on real-time ultrasound. The reflectivity creates standing waves often and causes transverse entrapment of ultrasound in arteries, with transverse standing waves with wavelengths of twice the diameter. Longitudinal focussing of the entrapped standing waves creates simple harmonic sonographic arterial standing waves, identical in appearance and in physics to arteriographic standing waves. This evidence and reasoning fortifies the theory that resonating transverse sound energy is the cause of the phenomenon of transition to turbulence in cylinders, as discussed in “Revolution in Candy Cane Spin – Turbulent Transverse Flows in Tubes.”

A simple method of producing diagnostic copies from over-exposed radiographs

Canadian Association of Radiologists Journal, Volume 42, number 3, June 1991; 216-218. 

Diagnostic film images are created from very over-exposed radiographic images by sandwiching the over-exposed radiograph between a totally black film and an unexposed film and placing them in a cassette. With a low radiation dose, the blackened film masks one fluorescent screen while the other screen transfers the over-exposed radiograph's image onto the unexposed film.
Zero-Added-Dose Gastrointestinal Film Studies

Canadian Association of Radiologists Journal, 1989, Vol. 40: 203-205

This is an important article because it reveals  how the use of a medium format camera (Rolleiflex initially, then, later, Mamiya) to create diagnostic-quality hard copy negative transparencies (standard black-and-white 120 film) of the fluoroscopic image on a high-resolution video monitor, avoided the use of radiographs (the universal custom, with far higher x-ray doses). I used this analog technique for a decade. Currently, fluoroscopic imaging and radiographic imaging go one step further along this line by using computerized digital imaging for fluoroscopy and radiography. The medium format camera technique recorded my diagnostic ultrasound images as transparencies.

 

ABSTRACT: A technique is described to produce diagnostic quality 70 mm x 60 mm films of upper GI fluoroscopy of the video-displayed image on a “slave” monitor, obtained at a dose of 0.01 milligray (1 millirad) for a 20 cm water equivalent phantom. Because the photograph is the same image already being observed, the films require no added dose over that needed for an adequate fluoroscopic examination. Diagnostic films may be made from the replay of a video-cassette recorder. With exposure times of 1/30th of a second, movement blur is easily prevented.

Hypotension During Urography in Patients Taking Beta Blockers

Canadian Medical Association Journal Vol. 133, November 1985

In a three month period, two patients who were taking beta-adrenergic blocking agents suffered severe anaphylactic reactions following intravenous X-ray contrast agent injections. Research revealed that beta blockers should predispose to anaphylaxis, so I reported this in the CMAJ. Two letters criticized my reasoning, allowing me to respond in the CMAJ with even stronger arguments for physiological causes for this effect.  This second publication is cited in William’s Textbook of Endocrinology under a discussion on anaphylaxis. Beta blockers continue to be in common use worldwide. 
Book review: Pattern in Fluid Flow Paradoxes. Variations on a Theme.

By H. Richard Hooper, Ph.D.
Journal of The Canadian Association of Radiologists, Volume 33, March 1982; 56-57

Dr. Hamilton’s explanations of the arteriographic standing waves phenomenon, as well as a number of "everyday and not-so-everyday phenomena” such as, natural water (shear) wave formation, epidermal standing waves along the bodies of dolphins swimming at high speed, and the flaring (transition to turbulence) of laboratory burner gas jets, are reviewed by Dr. (PhD) Hooper, who noted that the terminology and reasoning are easily understood, also emphasizing that, unlike discussions of these topics in fluid dynamics, there is no use of mathematics.
The vascular nephrogram phase of intravenous urography and its implications

Radiology, Vol. 102, No. 1, 37-40, January 1972.

After a rapid injection of an iodinated radiopaque contrast agent, a film taken 6-10 seconds after the patient experiences a hot oropharyngeal sensation reveals a dense vascular nephrogram phase of intravenous aortography. A horseshoe kidney, a small renal tumour (hypernephroma) exemplify the technique’s significance.
Unilateral decrease in renal vascularity on the excretory urogram

CMAJ; Vol. 105: 1151-1154, December 4, 1971.

A new technique describes how a rapidly injected standard IVP examination can produce a timed dense vascular nephrogram phase that can identify causes of unilateral decrease in renal vascularity – curable causes of renin-based hypertension. Unilateral renovascular disease (smaller kidney with reduced vascularity) and ureteral obstruction (swollen kidney with reduced renal vascularity) are examples of the significance of the fleeting vascular nephrogram phase. The decreased vascularity, occurring with ureteral obstruction, reveals a renin-mediated cause for the sudden onset of hypertension in patients with acute ureteral obstruction.

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