CH 24 Informatics in Medical Imaging

Informatics in Medical Imaging

• Informatics has transformed healthcare by changing how providers determine patient care and manage information.

Informatics

• Informatics is interdisciplinary and aims to enhance the quality and safety of patient care.
• Platforms are configurations of computer devices and processes that utilize informatics applications.
• Integration of informatics platforms is embraced in medical imaging departments in the United States.
• This integration is a significant part of the movement toward value-based patient care.

Biomedical Informatics (BMI)

• Biomedical informatics is an interdisciplinary field of platforms for medical purposes like patient care and research.
• Subspecialties of BMI include translational bioinformatics, clinical research informatics, clinical informatics, consumer health informatics, and public health informatics.
• Clinical informatics is a popular and useful term in medical imaging.

Clinical informatics

• Clinical informatics uses data and information technology to deliver healthcare services.
• It facilitates the generation, manipulation, management, and integration of anatomical images.
• Clinical informatics encompasses clinical documentation, computerized provider order entry (CPOE) systems, and clinical decision support systems (CDSS).

Picture Archiving and Communication System (PACS)

• A PACS manages digital images through a network of computers, servers, and archives.
• PACS requires non-digital images to be converted to a digital format.

Hospital Information System (HIS) and Radiology Information System (RIS)

• The HIS and RIS are BMI platforms used in healthcare and radiology departments.
• These systems can now perform functions electronically such as:
  • Scheduling appointments
  • Issuing reminders
  • Tracking staffing
  • Submitting invoices
  • Monitoring insurance
  • Filing and locating records
  • Printing letters and reports
  • Ordering prescriptions

Electronic Health Record (EHR)

• The EHR is an electronic version of a patient's medical documents within a healthcare facility.
• Patient portals give portal access to medical imaging reports, bloodwork results, and pathology reports.
• EHRs will eventually include explanatory layers for patient understanding.
• PACS integrated with RIS, HIS, and EHR facilitates patient-centered care and productivity in radiology departments.

PACS Platform

• A PACS platform begins with the gathering and organization of images post-acquisition.
• Post-processing is helpful if images are in differing formats.
• Storing processed images and archiving them are vital.
• PACS must have procedure to retrieve and display images in a meaningful format.

PACS

• Allows digital imaging and communication in medicine (DICOM).
• Is vital to patient care.

Vendor Neutral Archive (VNA)

• It is an enterprise storage system that stores images in a nonproprietary format.
• VNA's use a standard interface, provides access to data from differing PACS.

Informatics Standards

• Healthcare information systems must employ standards for data exchange and portability.
• Standards are utilized for content, coding, messaging, data interchange, EHRs, and networks.

The DICOM Standard

• DICOM stands for Digital Imaging and Communications in Medicine.
• DICOM originated in 1983 as an ACR and NEMA collaborative.
• It was made to to establish a public format and protocol for communicating biomedical imaging files.
• Formally introduced and implemented in 1993 and widely used for messaging in medical imaging.
• DICOM allows for multiple PACS platforms to communicate.
• It permits image access to multiple users while providing images on demand, electronic annotations and specialty image processing.
• Sharing imaging data across healthcare facilities is possible through online transmission and management systems.
• DICOM has a reader utility program that may be downloaded for free.
• DICOM allows images to be shared with anyone with access to a DICOM reader.
• DICOM designates real-world objects and the information objects used to achieve that modeling using object-oriented standards.
• There are two classes of information:
  • Object Class: Contains information about the study and patient.
  • Service Class: Describes what to do with objects and includes storage, query, retrieval, print, storage resource, and examination.
• Classes combine to form service object pairs (SOPs).
• The utilization of a service and object constitutes an SOP
• Equipment can either use or provide a service (service class user SCU / provider SCP).
• Workstations function as a user or a provider.

Other standards

• Several official acronyms for standards or regulations affect how BMI or its components operate.

Health Insurance Portability and Accountability Act of 1996 (HIPAA)

• It is a federal law requiring healthcare communications to safeguard individual identity and data confidentiality.
• As a standard, medical information handled electronically must be encrypted, have patient identifiers removed, or be scrubbed of all except the relevant data fields.

Health Level Seven International (HL-7)

• HL-7 provides standards concerning computer-related communications.
• It involves healthcare information such as patient demographics.
• HL-7 is widely adopted throughout the BMI community and utilized with HIS.

Integrating Healthcare Enterprise (IHE)

• IHE promotes the use of DICOM and HL7 standards.
• Systems communicating using the IHE readily share images with new partners seamlessly.

Computers and Networks

• Computers capture, display, and move images in CT, MRI, ultrasound, and nuclear medicine.
• The physical computer is necessary to understand informatics platforms and applications.
• Hardware and software are the main components of informatics platforms/applications and bridge data, information, and knowledge.
• Networks, servers, and cloud computing are significant Informatics components.
• Comprehension of the Informatics platforms links data, information and knowledge together enabling growth across US healthcare.

Hardware

• Includes the central processing unit (CPU), memory, input devices, output devices, and bus.
• The CPU or microprocessor executes commands dictated by a computer program.
• Memory is used to store data and applications and can reside as physical memory or as physical media.
• Input and output devices are extensions of the hardware that allow interaction with the computer.
• The bus connects the motherboard components and the CPU allowing for data transferal and is defined by its width.

Software

• Refers to programs, apps, or operating systems stored the hardware and executed by computers.
• The operating system refers to system software.
• Application software refers to programs that users interact with so as to perform specific tasks.

Network

• It allows computers to exchange data and share resources.
• Computing devices exchange data using a data link.
• Connections are established using cable or wireless media.
• Network router directs packets of data between computer networks and acts as a traffic light between data destinations.

Local area networks (LAN) and wide area networks (WAN)

• LAN is the most common network serving computers in a small area.
• WAN is two or more LANs serving a large area.
• Computer networking results in concurrent delivery of images/reports by integrating of systems.

Intranet and Extranet

• Intranet refers to networks controlled by a single authority.
• Extranet is an internal network to a single entity and public not available due to security measures.

Computer networks

• They are served by switches, which vary in function depending on the data traffic that travels through them.
• Switches or network devices include hubs, bridges, or routers.
• A hub transmits and receives data.
• A network bridge manages connections between attached computers.
• A network router determines data based on the internet protocol address or IP address.

Network infrastructure and file management

• Once images are obtained, they need to be transmitted over a network to a radiologist to be read and stored.
• A PACS allows digital images to be sent from their acquisition point to a radiologist.
• Digital information's transfer requires a network to allow the computers to communicate.
• Large data files transfer requires a network with bandwidth to move image data from a PACS.
• Bandwidth is measured in bits per second (bps).
• Information leaving the system to go to tele-radiology is done over a WAN, and often operates at faster speeds.
• Wireless networks may operate more slowly with large files.
• Network protocols set the rules for communication between devices.
• Data packets are chunks of data which allows different packets, or chunks, of a message to be transmitted via different routes, but end up at the same destination.
• A server provides data or application services.
• Cloud computing provides the virtual access of shared resources, software, and information whilst providing location and device independence.
• Internet connection is vital for the implementation of cloud systems as the speed for accessing and downloading images.

Display and Archives

• Post processing happens inside of the computer with the use of algorithms before the image is displayed and a PACS is utilized for primary image storage.
• PACS's primary function is archiving images and data so as to provide security whilst ensuring said images have personnel accessibility.
• This involves acquisition, display, storage, compression, workflow, and security.

Image Acquisition

• Each digital acquisition system has a computer workstation, which holds the images in files for the technologist to check before sending them for interpretation.
• File size depends on matrix size and bit depth.
• Grayscale bit depth ranges from 8 bits to 32 bits.
• A byte is equal to 8 bits, so the file size of a pixel is multiplied by the bit depth divided by 8.
• A grayscale bit depth of 12 produces 2¹² gray levels.
• The formula for image file size is XY(B/8).
• Diagnostic radiography has a large matrix size for each image to increase resolution, whereas a CT image has a lower matrix for each image, but many more images are obtained for each exam.

Image Display

• The display images depend on user purpose.
• Digital images are viewed on a flat screen monitor (soft copy).
• A light emitting diode use small, efficient lights and are most commonly used.
• Light crystal displays use cold cathode fluorescent lamps.
• Digital images need to be displayed for review and reading.
• Digital image display permits multiple viewing of the same image, variation of image display parameters, and reduced numbers of lost films.
• Advantages of digital imaging involve manipulating image in monitors without patient exposure, viewing in multiple locations simultaneously, quick distribution when in digital format.
• Technologists need to evaluate images prior for diagnostic quality, whereas radiologists need images for interpretation and diagnosis.
• Radiologist requires monitors with the greatest contrast resolution.
• Radiographers must use monitors for determination of diagnostic quality.
• Monitor resolution is based on number of pixels displayed in horizontal and vertical dimensions.
• LCD monitors have resolutions of 3–5 megapixels.
• Radiographer/physicians tend to use lower resolution monitors, whilst radiologists require higher resolution.
• Image quality is affected by resolution, luminance, contrast, bit depth, uniformity, and glare.
• Quality control (QC) programs must be performed regularly.
• Monitor contrast should be set the same on all monitors.
• Contrast must comply with the DICOM Grayscale Standard Display Function (GSDF).
• Ambient light reflections on a monitor have a negative impact on contrast.
• Monitors should not be used in rooms with ambient/bright lighting.
• Contrast is a function of luminance. -Viewers should use direct axis viewing for image contrast.

LED and LCD Monitors

• They are thinner than CRT monitors.
• They regulate the image by using a light source shining on individual pixels and are made of liquid crystal and hydrogenated amorphous silicon (a-Si:H) thin film transistors (TFTs).
• LCD limitations comprise restrict field of views and require regular quality testing.

Storage

• Maintaining images as required by local legal precedents is a problem for all radiology departments.
• Many hospitals store all images for 5-7 years.
• A PACS eliminates space for storage along with lessens time requirements, lowers misfiling issues, facilitates quicker acquisition, and enables remote access.
• Digital storage of images requires vast amounts of memory
• Digital storage of images for a typical large radiology department of digital images of 150,000 exams requires around 3.2 terabytes per year.
• In all an instution with 150,00 annual exams would need 10-16 terabytes.

Short-term, long-term, and off-site storage

• Short-term storage is often on a hard drive.
• The image is sent to the PACS server and can be stored in a redundant array of independent discs (RAID) for ease of short-term access.
• For long-term storage Images are placed in a jukebox.
• Off-site storage is used to ensure data integrity if a catastrophic event were to occur.
• Storing and sharing of medical images with cloud computing provides a reduction in costs to radiology departments.

Compression

• It reduces the size or volume of data to lessen the storage required, bandwidth to transmit the images, and processing times.
• As image resolution rises, the size of the data increases.
• With lossless compression, all of the original information in the image is retained.
• With lossy compression, data is lost and degrades resolution, potentially detrimental to image reading.
• The volume of data acquired in imaging exams is rapidly increasing and and they store and provide convenient access to medical images by rendering images to a data center.

Workflow

• It is vital for understanding clinical informatics workflow and the medical imaging team professional responsibilities.
• The workflow often involves the clinician entering key data in the EHR that may require testing/screening.
• The clinician enters any orders within the EHR platform, utilizing computerized provider entry CPOE in the EHR, allows electronic orders utilizing physician allergy/contraindication alerts.
• CPOE is utilized to reduced unnecessary unnecessary diagnostic orders. Error reduction and conformity with evidence-based practice are major reasons the CPOE system is utilized.
• Decision support systems allow for application designed specifically for healthcare decisions, and include components such as data & modules that provide tool remidners/alerts.

Increase Use of Clinical Decision Support System CDSS

• CDSS can advance imaging by adherence to correct ordering to MRI nuc med and appropriateness by integration within CDSS.
• CDSS can transition volume, seamless via CPOE of exams performed with CPOE and clinical information.
• Information from RIS (reporting) is sent after the technologist checks image quality.

Security

• Security of device and networks must follow applications.
• Personal Practices - many clinical and research institutions have policies and follow personal best practices.
• Implement employer mandates personal computer or network with precaution log-in and log-out.
• Health personnel must not carry or keep information on computers or flashdrives.