What is the most common cause of tube failure?

What is the most common cause of tube failure?

The most frequent mode of failure of an x-ray tube is the failure to adequately dissipate the heat generated during normal operation. It is well known that 99%+ of the kinetic energy imparted on the electron beam is lost in the form of heat at the anode target.

When using fluoroscopy Which of the following is directly proportional to the exposure delivered to the patient?

Review for Fluoroscopy final

Question	Answer
When using fluoroscopy, which of the following is directly proportional to the exposure delivered to the patient…. kVp, mA, filter thickness, target to panel/tabletop distance?	mA (Milliampere)

What is last image hold?

Last image hold is a dose saving feature, since it allows physicians to contemplate the last image and plan the next move without additional radiation exposure in an interventional procedure.

What is the minimum source to table top distance for a fluoroscopic system?

Stationary fluoroscopic equipment shall have a means to limit the source-to-skin distance (SSD) to 38 centimeters using a component of the fluoroscopy equipment such as a spacer cone or tabletop.

Which of the following groups of exposure factors will deliver the least amount of exposure to the patient?

Radiation Protection

Question	Answer
Which of the following groups of exposure factors will deliver the LEAST amount of exposure to the patient?	400 ma, 0.25sec, 100 kvp
. When water molecules are irradiated, the principal molecular by-products are:	free radicals

Which is an effective technique to minimizing patient exposure?

Beam Limiting Limiting the FOV to the smallest area that fulfills the clinical requirements is an effective method for reducing unnecessary patient exposure. Under no circumstances should an x-ray beam cover an area that is larger than the receptor.

Which of the following is the most accurate personnel monitoring device?

Radiation Exposure & Monitoring

Question	Answer
Which personnel monitoring device is considered most sensitive and accurate?	OSL
Which type of monitoring device do photons release electrons by their interaction with air?	Pocket Dosimetry
What are the two types of dosimeters?	Personnel & Survey

Which of the following is are possible long term somatic effects of radiation exposure?

Formation of cataracts or cancer (such as leukemia) and embryologic damage are all possible long-term somatic effects of radiation exposure. Bone malignancies, thyroid cancers, leukemia, and skin cancers are examples of carcinogenic somatic effects of radiation.

What is the stochastic effect?

Effects that occur by chance, generally occurring without a threshold level of dose, whose probability is proportional to the dose and whose severity is independent of the dose. In the context of radiation protection, the main stochastic effects are cancer and genetic effects.

Which of the following are possible effects of exposure to high levels of radiation?

Exposure to very high levels of radiation, such as being close to an atomic blast, can cause acute health effects such as skin burns and acute radiation syndrome (“radiation sickness”). It can also result in long-term health effects such as cancer and cardiovascular disease.

What is a RBE?

The relative biological effectiveness (RBE) is defined as the ratio of the doses required by two radiations to cause the same level of effect. Thus, the RBE depends on the dose and the bio- logical endpoint. The magnitude of RBE values and their variations is significantly larger for Car- bon ion therapy.

What is the recommended safe level of rads exposure per year?

The current federal occupational limit of exposure per year for an adult (the limit for a worker using radiation) is “as low as reasonably achievable; however, not to exceed 5,000 millirems” above the 300+ millirems of natural sources of radiation and any medical radiation.

What is the importance of linear energy transfer?

Purpose: Linear energy transfer (LET) plays an important role in radiation response. Recently, the radiation-induced nucleo-shuttling of ATM from cytoplasm to the nucleus was shown to be a major event of the radiation response that permits a normal DNA double-strand break (DSB) recognition and repair.

Which is the result of damage to relative biological effectiveness a high temperature B pollution C radiation D low temperature?

Low temperature does not affect the relative biological effectiveness as the low temperature does not change the power of radiation. High temperature has not much effect on the relative biological effectiveness as it is related to the ionization radiation from the sun.

What is the difference between stopping power and linear energy transfer?

3.1.2 Stopping power and linear energy transfer It is defined as the average energy loss of a particle per unit path length, measured for example in keV/µm [51]. The stopping power is the sum of two processes: electronic stopping and nuclear stopping. Depending on the energy of the ions, one of the two will dominate.

What is low linear energy transfer?

Low linear energy transfer (LET) ionizing radiation (IR) is an important form of therapy for acute leukemias administered externally or as radioimmunotherapy. IR is also a potential source of DNA damage.

What type of radiation has the highest let?

alpha particles