Term
| How many bits are in a byte? |
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Definition
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Term
| N bits can represent what range of numbers? |
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Definition
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Term
| One byte can store integer values from |
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Definition
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Term
| What is the major disadvantage of the transmission of information in analog form. |
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Definition
| The signals can become distorted, causing a loss of fidelity of the information and the errors can accumulate. |
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Term
| Most transducers, sensors, or detectors produce ______ data. |
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Definition
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Term
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Definition
| Analog-to-digital converter - used to convert analog signals to digital signals |
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Term
| Converting an analog signal to a digital signal is called ________. This process requires two steps, _____ and ______. |
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Definition
| digitization, sampling and quantization |
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Term
| The conversion of an analog signal to a digital signal does not result in a loss of data, T/F. |
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Definition
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Term
| The pixel size should be ________ the size of the smallest object to be seen. |
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Definition
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Term
| The number of bits per pixel determines the |
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Definition
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Term
| Total number of bytes required to store an image is |
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Definition
| the number of pixels (rows * columns) multiplied by the number of bytes per pixel. |
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Term
| Types of information storage devices |
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Definition
| magnetic disks, flash memory, magnetic tape, optical disks |
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Term
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Definition
| Redundant Array of Independent disks - used for large amounts of on-line storage. Basically, a RAID is several hard disk drives that are linked together. |
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Term
| What types of images benefit from being displayed in color. |
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Definition
| Co-registered dual modality images, false color images, volume rendered images. |
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Term
| In grayscale, each pixel is represented by _____ value. In color, each pixel is represented by _____ values. |
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Definition
| Grayscale - one value, color - 3 values (red, green, and blue intensities) |
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Term
| What type of monitor is most commonly used today? |
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Definition
| Flat panel, liquid crystal displays (LCD) |
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Term
| Briefly, how does an LCD monitor work. |
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Definition
| A backlight source is passed through a horizontal polarizing filter. A voltage is applied to the LC layer that causes the molecules to twist which changes the polarity of the light passing through it. This allows the light to then pass through a vertical polarizing filter. If no voltage is applied, the molecule doesn't twist and the polarity of the light doesn't change, so the light for that pixel gets blocked by the vertical polarizing filter. |
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Term
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Definition
| Rate of light energy emitted or reflected from a surface per unit area, per unit solid angle. Units are cd/m2. |
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Term
| Required maximal luminance for an interpretation workstation? |
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Definition
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Term
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Definition
| Minimal luminance, measured with the entire screen black. |
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Term
| Contrast ratio for a monitor |
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Definition
| Maximal luminance divided by the black level. |
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Term
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Definition
| Stray light from the face of the monitor that occurs when an image is displayed. |
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Term
| Problems with LCD monitors include |
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Definition
| bad pixels and limited viewing angle. |
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Term
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Definition
| Distance from the center of a pixel to the center of an adjacent pixel. |
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Term
| In terms of luminance for a monitor, contrast may be defined as |
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Definition
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Term
| The smallest luminance difference (Lmax-Lmin) that is detectable by half a group of human observers? |
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Definition
| JND - just noticeable difference |
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Term
| Common pixel format for monitors used to display radiographs. |
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Definition
2560 pixels x 2048 pixels
Called a 5 megapixel monitor |
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Term
| Typical pitch of a 5 megapixel monitor? |
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Definition
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Term
| Lookup tables are used to affect the display of image ______. |
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Definition
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Term
| What does the "level" control? |
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Definition
| The midpoint of the pixel values to be displayed. |
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Term
| What does the "window" control? |
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Definition
| The range of pixel values about the level to be displayed. |
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Term
| The signal sent to a display system that produces a luminance is called the |
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Definition
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Term
| What is the display function? |
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Definition
| It describes the luminance produced by the monitor as a function of the magnitude of the digital signal sent to the monitor. |
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Term
| Users adjust medical imaging monitors using the "brightness" and "contrast" controls. T/F |
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Definition
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Term
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Definition
| Digital Imaging and Communication in Medicine |
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Term
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Definition
| Grayscale Standard Display Function |
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Term
| The LUT in a display system converts _____ to ____ so the net display function will conform to the __________. |
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Definition
Presentation Values or P-values to Digital Driving Levels
conform to the DICOM GSDF |
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Term
| Output values from the LUT that are provided to the display system are called |
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Definition
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Term
| What does the DICOM GSDF do? |
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Definition
| It provides a predictable relationship between "presentation values" and the luminance displayed by a monitor. |
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Term
| Advantages of Diagnostic Monitors vs Consumer Grade Monitors? |
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Definition
| 1) higher maximal luminance, 2) more uniform luminance, 3) smaller pixels - better spatial resolution, 4) wider viewing angles |
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Term
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Definition
| Picture Archiving and Communications System |
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Term
| PACS is a system for the ______, _______, and _______ of radiological images. |
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Definition
| storage, transfer, and display |
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Term
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Definition
| The transmission of radiological images for reviewing at remote sites. |
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Term
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Definition
| Hospital Information System |
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Term
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Definition
| Radiology Information System |
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Term
EMR stands for
What does it do? |
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Definition
Electronic Medical Record System
Used to register patients, send a request for a radiology study, store the radiologist's report. |
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Term
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Definition
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Term
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Definition
Digital Imaging and Communications in Medicine
A set of standards to facilitate the transfer of medical images and related information. |
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Term
| What are some of the standards for that DICOM includes. |
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Definition
| Standards for the transfer of images, standards for image formats being transfered, and standards for exchange of information regarding workflow |
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Term
| What are examples of DICOM information objects? |
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Definition
| "patients", "images", and "studies" |
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Term
| What are examples of DICOM composite information objects? |
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Definition
| CT image object, CR image object, DX image object, etc. |
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Term
| What is a DICOM conformance statement? |
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Definition
| A formal statement, provided by a vendor, describing a specific implementation of the DICOM standard. |
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Term
| What are the functions of the RIS? |
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Definition
Ordering and scheduling procedures, protocol descriptions, maintaining patient database, transcription, reporting, and bill preparation.
It supports the entry, use, and storage of text based data. |
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Term
| What is the standard for communicating between the RIS, HIS, EMR, and PACS? |
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Definition
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Term
| In a PACS, each study is typically identified by a unique number. What is it called? |
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Definition
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Term
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Definition
| Integrating the Healthcare Enterprise |
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Term
| The IHE develops documents called _______ and the collection of them is called the _______. |
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Definition
Integration Profiles,
Technical Framework |
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Term
| What do IHE integration profiles do? |
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Definition
| Integration profiles describe solutions to clinical problems using existing standards such as DICOM and HL7. |
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Term
| Two categories of image compression? |
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Definition
| reversible (lossless) and irreversible (lossy) |
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Term
| Reversible compression of medical images results in compression ratios of about ____? |
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Definition
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Term
| Irreversible compression results in compression ratios of _____? |
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Definition
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Term
| A typical interpretation workstation consists of |
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Definition
| Two high-luminance 54 cm diagonal 3 or 5 megapixel grayscale monitors in portrait orientation and a navigation monitor. |
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Term
| What is a hanging protocol? |
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Definition
| It's the way in which a program arranges images for presentation and display. |
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Term
| What controls should the viewer have for manipulating images? |
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Definition
| window, level, pan and zoom |
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Term
| What is illuminance? What are the units? |
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Definition
| It is the light energy impinging on a surface (as opposed to luminance - light coming from the surface). Units are lux. |
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Term
| What is the range of illuminance for viewing clinical images? |
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Definition
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Term
| What is a common test pattern used for evaluating monitors? |
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Definition
| SMPTE - Society of Motion Picture and Television Engineers |
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Term
| What is image co-registration? |
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Definition
| Super-imposing an image from one modality onto an image from another modality. |
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Term
| What is CAD? Where might it be found? |
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Definition
| Computer Aided detection or diagnosis. It is sometimes used in mammography. |
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Term
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Definition
| Maximum Intensity Projection - formed by passing a set of rays through a volume dataset and selecting the maximum pixel value along each ray. |
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Term
| What are two approaches to viewing a 2D image as a 3D object? |
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Definition
| Shaded surface display (SSD), also called surface rendering, and volume rendering |
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Term
| Five main goals of information security. |
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Definition
| 1) privacy, 2) integrity, 3) authentication, 4) nonrepudiation, and 5) availability |
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Term
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Definition
| Health Insurance Portability and Accountability Act |
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Term
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Definition
| A giant massive wall of fire that burns everything that tries to cross it. I'm done. |
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Term
| Give an overview of the workflow when imaging a patient. |
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Definition
| Patient is registered with the EMR. EMR sends a request for a study to the RIS. The RIS schedules the study. Patient and exam info go onto a modality worklist. The study is performed. Images are transfered to PACS for storage and review. The PACS/RIS developes an interpretation worklist. Radiologist reviews images and dictates a report. The report goes to the EMR. |
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Term
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Definition
| It is the information contained in the header of a DICOM file. The information includes patient identity, technical info about the image size, content, and how it was created. |
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Term
| What is each data value in a DICOM header identified with. Describe it. |
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Definition
| A tag. Each tag has two numbers. The first is a group number that groups similar types of information together. The second is unique to the group and identifies a data value. |
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Term
| What is a DICOM object that doesn't contain an image. Give an example. |
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Definition
Structured reports
ex. X-ray radiation dose structured report |
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Term
| What is CPT. Describe it. |
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Definition
| Current Procedural Terminology - it is coding for the description of radiologic procedures performed. |
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Term
| What is RadLex? How is it being used in CT? |
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Definition
| RadLex is a unified language created by RSNA for use in Radiology. By giving CT studies a uniform set of names, dose metrics can be compared through the ACR Dose Index Registry. |
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Term
| What are 4 different types of worklists used in Radiology? |
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Definition
1) Protocol - list of requested studies that need an assigned protocol
2) Interpretation - list of acquired exams that need reviewed
3) Modality - list of exams to be performed on a given modality
4) Billing - list of exams that need to be coded and released for charging |
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