radiology lesson #6 3D imaging

What is Digital Radiography?

The latest advancement in dental imaging, using electronic sensors instead of film.

What method does digital imaging use to capture an image?

It uses a sensor to break the image into electronic pieces for storage and display.

What are the benefits of digital images in dentistry?

Convenient electronic archiving, access, transfer, and enhanced treatment plan acceptance.

What type of X-ray unit is needed for digital radiography?

An X-ray unit capable of producing very short exposure times, with accurate timers and rectangular collimation.

What is the exposure time reduction when using digital sensors compared to conventional radiography?

Exposure times are reduced by 50-90%.

What are PhotoStimlable Phosphors?

Storage phosphors that require a separate plate for each view and a laser scanner to digitize images.

What does the Central Processing Unit (CPU) do in digital imaging?

It performs operations and electronic processing of the captured data.

What is a Charge Coupled Device (CCD)?

A pure silicon chip that converts x-rays or light energy into electrical energy, creating a latent image.

What is the difference between CCD and CMOS sensors?

CMOS sensors are more durable, cheaper to manufacture, and have lower power requirements.

What is the active area of a sensor?

The portion of the sensor that actually produces the image.

What is the significance of the pixel in digital imaging?

Each pixel in the array equals an electron well that captures the energy from incoming x-ray photons.

What is the role of the scintillator screen in digital sensors?

It converts the x-ray beam to visible light for the sensor.

What are the advantages of rigid receptors in digital radiography?

Instant image capture, reduced radiation exposure, superior gray-scale resolution, and improved efficiency.

What are some disadvantages of rigid receptors?

High initial cost, discomfort due to thickness, more retakes than film, and infection control issues.

What is teleradiography?

The capability of sending images to another site, such as for referrals.

What is the purpose of image enhancement tools in digital imaging?

To allow for manipulation and improvement of captured images.

What is the typical resolution of digital images in terms of line pairs per millimeter (lp/mm)?

Digital images can achieve 6 to 22 lp/mm.

What is the significance of the dead space around sensors?

It can affect image quality and placement comfort.

What is the function of the fiber optic face plate in digital sensors?

It transmits light to the sensor surface from the scintillator screen.

What is the purpose of FDA-cleared barriers in digital radiography?

To ensure infection control for either type of receptor.

What is the importance of having a small focal spot size in X-ray units?

It improves image clarity and detail.

What is the role of the CMOS imaging chip in digital sensors?

It creates a charge in each pixel well based on incoming radiation.

What are the characteristics of intraoral sensors?

They are area arrays where each pixel creates an electrical charge proportional to the energy striking the detector.

What is the purpose of a laser scanner in digital imaging?

To digitize the latent image from phosphor plates for display.

What is the typical kVp range for X-ray units used in digital radiography?

60-70 kVp.

What should be done to minimize cross-contamination of sensors?

Clean and disinfect using an EPA-registered hospital disinfectant with intermediate-level activity after removing the barrier.

What is the protocol for sensor holders?

Most sensor holders are autoclavable and can be sterilized prior to use.

What is critical to refer to for proper use of digital sensors?

Manufacturer-provided recommendations for proper use, equipment, and exposure settings.

How should exposure time for digital sensors compare to conventional film?

Exposure time should be half that of conventional film.

What should be done after capturing all images during a survey?

Evaluate for retakes and save and mount images.

What should be visible in a BWX image?

Alveolar bone should be visible without superimposition of crowns.

What is the recommended placement for maxillary anterior sensors?

Place sensor vertically into XCP, well into the palatal region near the second premolar.

How should the sensor be positioned for mandibular anterior placements?

Center anteriors or lateral/canine on the sensor, and place it approximately even with the 2nd premolar/1st molar.

What is the correct placement for horizontal BWX sensors?

Place the sensor between the tongue and teeth, ensuring the patient closes on their back teeth.

What is the sensor placement for maxillary posteriors?

Place the sensor horizontally in XCP, centering the 1st and 2nd PM on the bite block.

What is the procedure for mandibular posterior sensor placement?

Retract the cheek, place the sensor between the tongue and teeth, and position it above the teeth to be imaged.

What should be done to avoid patient discomfort during sensor placement?

Place the sensor more in the middle of the mouth or on top of softer structures.

What enhancement tool can magnify an image for better detail?

ZOOM can magnify the entire image or an area of the image.

How is measurement used in endodontic therapy?

Measurement is as accurate as the projection geometry and important in the vertical dimension.

What does image inversion do?

It reverses image densities, making radiopaque areas radiolucent and vice versa.

What is pseudocolor in imaging?

Pseudocolor is a random distribution of colors along a gray scale, helpful in patient education.

What is the #1 cause of retakes in imaging?

Improper placement resulting in roots or crowns being cut off, or incorrect teeth not covered.

What should be done to avoid the sensor cord being bitten?

Always 'corral' the cord to avoid a patient biting on it.

What distraction techniques can help reduce gagging?

Breathing through the nose, using Listerine on the sensor, or placing a few salt crystals on the tongue.

What should be ensured for quality images?

Placement is critical, with the correct anatomic area represented and no overlapping interproximal contacts.

What is the importance of the X-ray beam angle?

The X-ray beam should pass perpendicular to the sensor plane for accurate imaging.