BIOC32H3 Lecture Notes - Scoliosis, Spermiogenesis, Osteoporosis

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mauvecat225

24 Oct 2012

School

UTSC

Department

Biological Sciences

Course

BIOC32H3

Professor

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Document Summary

Noninvasive techniques using radioisotopes, radiation, magnetic fields to produce images of internal structures. Gives detailed info about internal systems and structures. High energy radiation that can penetrate living tissues. Not all projected x-rays arrive at the film. Some are absorbed or deflected as they pass through the body. Resistance to x-ray penetration is called radiodensity (least radiodensity) air, fat, liver, blood, muscle, bone (most radiodensity) Bone becomes white, less dense things are black. Used to be called cat (computerized axial tomography) Uses a single x-ray source rotating around the body. X-ray strikes a sensor monitored by a computer. Digital subtraction angiography (dsa) for blood flow in organs like brain, heart, lungs, kidneys. Xrays taken before and after radiopaque dye used and computers subtracts details from both. Xrays rotate around person, less radiation, faster. Surrounds body with magnetic field, 3000x stronger then earth. Affects protons, line up along magnetic lines. Protons absorb energy with proper frequencypulse ends=energy released.

Related Questions

Plese type the answers

1. In mammographic examinations, the breast is compressed between two plates. Answer the following with a brief explanation.

a. Is the geometric unsharpness (blurring) increased or decreased by compression?

b. Why is the image contrast improved by this procedure?

c. Is the required x-ray dose for a given image signal-to-noise ratio (SNR) higher or lower with compression?

2. Two X-ray images of the hand are shown in Figure 2.39. One corresponds to an x-ray beam with an effective energy of 140 keV and the other to an effective energy of 50 keV. Explain which is which, and the reasons for the difference in image contrast and signal intensity.

3. Planar x-ray images of a horseâs leg are shown in Figure 2.40. In (a), the kVp and tube current (mA) are chosen to give high contrast between the bone and surrounding tissue. Explain how the kVp and mA settings would have to be changed (increased, decreased, remain constant) to give the images shown in (b) and (c).

4. An acceptable abdominal radiograph can be obtained with technique factors of (1) 74 kvP, 120 mAs or (2) 82 kvP, 80 mAs. Discuss the reasons for selecting one technique over the other.

5. A dedicated chest imaging system is designed to use radiographic film of size 14 x 17 in (35 x 43 cm). If the source-to-imager distance (SID) is 180 cm and the source-to-diaphragm distance (SDD) is 10 cm, what diaphragm opening will allow an unexposed border of 1 cm around the film?

mauvesquirrel99

Multiple imaging techniques are available to "look inside" the body in a non-invasive way and diagnose a variety of conditions and disorders. Choose one medical imaging technique and include the following in your report:

-Name of the technique.

-Describe the technique in your own words.

-List and describe several applications of the technique (in other words, tell why this particular technique might be used) If you choose ultrasound for this report, include MORE than just obstetrical uses.

- Describe several advantages and disadvantages of technique.

- Find an image prepared using this technique on the web (Try www.google.com and search the images) and provide a link to this image.

-Include any other interesting information.

-Properly reference ALL resouces you used.

Some examples of medical imaging techniques suggestion: X Rays ï¼CT scans (computerized tomography) ï¼Ultrasound scans Magnetic Resonance Imaging (MRI) and Positron Emission Tomography - PET scans.

please answer the following five questions by typing, thanks.

1. Why is it necessary to subtract the background from all of your measurements before you use them in your analysis?

2. Name two other household radioactive products except( sodium- free substitute, ceramic glaze, bananas, Vaseline glass).

3. Letâs say you are a nurse working in the nuclear medicine division. One treatment for thyroid cancer is to have the patient consume a dose of iodine-131. Since I-131 has a half- life of 8 days, the patient must be housed in a lead- lined room and all bodily fluids collected until they are ready for release. How dangerous is I- 131? What precautions do you need to protect yourself while caring for the patient?

4. Standard Curves used to determine concentrations of materials (also called quantitative analysis. What are the two most common biological substances (DNA, fats, proteins, or sugars) that are measured using standard curves?

5. What happens to the radiation intensity of a radioactive source when the distance between the detector and the source is three times as great as the initial distance?

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BIOC32H3 Lecture Notes - Scoliosis, Spermiogenesis, Osteoporosis

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