Laser Treatment Parameters & Dosage Flashcards
7 cards from real CLT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Laser Treatment Parameters & Dosage flashcards as text
Which statement about the relationship between wavelength and scattering in tissue is MOST accurate?
Answer: Shorter wavelengths scatter more and penetrate less deeply
Rayleigh and Mie scattering in tissue are inversely related to wavelength, so shorter wavelengths scatter more and have less penetration depth compared to longer wavelengths.
A patient returns two weeks after a laser treatment with hyperpigmentation at the treated site. The MOST likely contributing factor is:
Answer: Post-inflammatory hyperpigmentation from excess thermal injury or UV exposure after treatment
Post-inflammatory hyperpigmentation (PIH) is a common adverse effect caused by excess thermal injury during treatment or UV exposure during the healing phase stimulating melanocytes.
When using a scanning handpiece to deliver CO2 laser treatment, what is the PRIMARY benefit compared to a stationary spot?
Answer: Distributes heat more evenly and reduces the risk of thermal accumulation at any single point
Scanning distributes dwell time across the treatment area, preventing heat buildup at any single point and allowing more uniform, controlled ablation.
A diode laser at 810 nm is used for hair removal. Compared to a 755 nm alexandrite laser, the 810 nm diode will typically:
Answer: Penetrate more deeply and have slightly less melanin absorption
810 nm has lower melanin absorption than 755 nm but greater penetration depth, making it effective for deeper follicles and slightly safer for darker skin types.
In the context of laser safety and dosimetry, the Maximum Permissible Exposure (MPE) is defined as:
Answer: The level of laser radiation to which the eye or skin may be exposed without causing injury
MPE is a safety standard defining the maximum laser exposure (eye or skin) that is considered safe, established by ANSI Z136 standards based on wavelength, pulse duration, and beam size.
A therapist wants to increase the depth of laser energy delivery without changing the wavelength. The BEST strategy is to:
Answer: Increase spot size, as a larger beam experiences less lateral scatter divergence at depth
A larger spot size reduces the relative contribution of lateral scattering at depth, allowing more photons to travel straight down and effectively increasing penetration depth.
Which of the following treatment adjustments is MOST appropriate when treating over bony prominences (e.g., the spine, shin) with photobiomodulation?
Answer: Reduce fluence slightly since underlying bone reflects energy back, effectively increasing local dose
Bone reflects a portion of laser energy back into the overlying soft tissue, potentially doubling local dose; reducing fluence prevents overdosing and thermal buildup.