HMI 2102 Medical Imaging Computer Science PDF

Medical Imaging Science Medical Imaging Technology II HMI 2102 CLO1 (Part I): Medical Imaging Computer Science Thursday, September 26, 2024 CLO 1: Examine and discuss the science and technology of modern digital image recording and post pro...

Medical Imaging Science Medical Imaging Technology II HMI 2102 CLO1 (Part I): Medical Imaging Computer Science Thursday, September 26, 2024 CLO 1: Examine and discuss the science and technology of modern digital image recording and post processing – Weeks 1-4 (30%) CLO 1.1: Advantages and disadvantages of digital images over analog film images, image storage, cost, image quality and manipulation. Matrix size, pixels, voxels, bit depth. Look-up tables, image contrast and spatial resolution, regions of interest (ROI) and field of view (FOV) CLO 1.2: Digital imaging quality to include: Image quality, Line Spread Function (LSF), Detective quantum efficiency (DQE), Modulation Transfer Function (MTF), image histograms and exposure indices CLO 1.3: CR cassettes and readers function, image processing including viewing parameters, image manipulation and dose considerations. Direct digital radiography (DR) detectors image processing including viewing parameters, image manipulation and dose considerations. 2 Outline Introduction The Power of 2 Notation Bit, Byte, kB, MB, GB, and TB Computer Architecture Computer Principal Parts Computer Program Computer Components Computer Applications to Medical Imaging 3 Introduction The computer has become evident in everyday life. Example: video games, automatic teller machines, highway toll systems, supermarket checkouts, ticket reservation centers, industrial processes, smart phones, traffic lights, and automobile ignition and guidance systems. 4 Cont’d Computer applications in radiology also continue to grow. Examples: Computed tomography, magnetic resonance imaging, diagnostic ultrasonography, and nuclear medicine imaging. Computers control high-voltage x-ray generators and radiographic control panels, making digital fluoroscopy and digital radiography routine. 5 But what are computers? The word computer is used as an abbreviation for any general- purpose, stored-program electronic digital device. - General purpose means the computer can solve problems. - Stored program means the computer has instructions and data stored in its memory. - Electronic means the computer is powered by electrical and electronic devices. - Digital means that the data are in discrete values. 6 The Power of 2 Notation Used in radiologic imaging to describe image size, image dynamic range (shades of gray), and image storage capacity. Examples on image size: - Digital images are made of discrete picture elements, pixels, arranged in a matrix. MRI and CT: 256 × 256 (28) to 1024 × 1024 (210). Digital fluoroscopy: 1024 × 1024 (210). Digital radiography: 2048 × 2048 (211). Digital mammography: 4096 × 4096 (212). 7 Bit, Byte, kB, MB, GB, and TB A bit describes a binary digit (0 or 1). The 26 characters of the alphabet, numerals and other special characters are usually encoded by 8 bits. 8  Cont’d 1 byte (B) = 8 bits 1 kilobyte (kB) = 210 = 1,024 bytes 1 megabyte (MB) = 1 kB × 1 kB = 210 × 210 = 220 = 1,048,576 bytes 1 gigabytes (GB) = 1 kB × 1 kB × 1 kB = 210 × 210 × 210 = 230 = 1,073,741,824 bytes = 1,024 MB 1 terabytes (TB) = 1 kB × 1 kB × 1 kB × 1kB = 210 × 210 × 210 × 210 = 240 = 1,099,511,627,776 bytes = 1,024 GB 9 Cont’d Each pixel contains a series of 1s and 0s (bit) defining the grayscale or shade of that particular point on a digital x-ray image. - Example: Digital mammogram has 16 bit dynamic range. Computer storage capacity is also expressed by the number of bytes that can be accommodated. - The computers typically used in radiology departments have capacities measured in GB or TB. 10 Quiz Q: How many shades of gray can digital mammography display? A: 216 = 65,536 shades of gray. 11 Quiz Q: How much storage space (MB) do you think a 16 bit 2000 × 2500 pixel x-ray image would take? A: 16 bits × 2000 × 2500 pixels = 80,000,000 bits = 10,000,000 bytes 10,000,000 bytes / 1024 = 9,765.625 kB 9,765.625 kB / 1024 ≈ 9.5 MB 12 Computer Principal Parts A computer has two principal parts: A. The hardware:  Everything about the computer that is visible.  Input, processing, memory, storage, output, and communications. B. The software: The computer programs that tell the hardware what to do and how to store and manipulate data. 13 Computer Program A sequence of instructions developed by a software programmer. Two classifications: A. Systems software  Consists of programs that make it easy for the user to operate a computer to its best advantage.  Operating systems (e.g., MAC-OS, Windows, and UNIX) B. Application programs  Computer programs that are written by a computer manufacturer, by a software manufacturer, or by the users themselves to guide the computer to perform a specific task.  Constitute most computer programs as we know them (e.g., Microsoft Office, Zoom, and Chrome).  They are written in one of many high-level computer languages (e.g., Java, C++, and Python) 14 Cont’d 15 Computer Components 1. Central processing unit (CPU) 2. Random access memory (RAM) 3. Read-only memory (ROM) 4. Motherboard 5. Secondary memory (Storage) 6. Output hardware 7. Input hardware 16 Central Processing Unit (CPU) The primary element that allows the computer to manipulate data and carry out software instructions. Often referred to as the microprocessor. Examples: Intel Core i9 and AMD Vermeer Ryzen 5000. Microprocessor speeds usually are defined in megahertz (MHz) (1 million cycles per sec). - Today’s computers commonly run at up to several gigahertz (GHz; 1 GHz = 1000 MHz). 17 Random Access Memory (RAM) Aka. Main memory, primary storage, or internal memory. Its contents are temporary. All data processed by a computer pass through the RAM. The most efficient computers, therefore, have enough main memory to store all data and programs needed for processing. RAM capacity usually is expressed as megabytes (MB), gigabytes (GB), or terabytes (TB). 18 Read-only Memory (ROM) Contains information supplied by the manufacturer, called firmware that cannot be written on or erased. One ROM chip contains instructions that tell the CPU what to do when the system is first turned on. Another ROM chip helps the CPU transfer information among the screen, the printer, and other peripheral devices to ensure that all units are working correctly. 19 Motherboard The main circuit board in a system unit. Contains the microprocessor, any coprocessor chips, RAM chips, ROM chips, other types of memory, and expansion slots. 20 Secondary Memory (Storage) An archival form of memory. Examples: - Optical storage devices:  Compact Discs (CDs) ~800 MB  Digital Video Discs (DVDs) ~4.7 GB  Blu-ray ~25 GB - Hard Disc Drives (HDD) ~500 GB to several TBs - Solid-state storage Devices (SSD)  Flash drives ~8 GB to several TBs  Internal SSD ~500 GB to several TBs - Cloud-based storage services (Dropbox and Google Drive): As much as you pay! CDs, DVDs, and flash drives are today’s common transferable storage devices. 21 Output and Input Hardware Output hardware - Examples: Printers, audio output devices, display screen or monitor. - Soft copy is the term that refers to the output seen on a display screen. Input hardware - Examples: keyboards, mice, trackballs, touchpads, and source data entry devices (include scanners, fax machines, imaging systems, audio and video devices, electronic cameras, voice-recognition systems, sensors, and biologic input devices). - A keyboard includes:  Standard typewriter keys that are used to enter words and numbers  Function keys that enter specific commands. Digital fluoroscopy uses function keys for masking, reregistration, and time-interval difference imaging. 22 Cont’d 23 Computer Applications to Medical Imaging It would be difficult to find a radiology department in the UAE that does not contain at least one computer. Computers in radiology departments are typically used to store, transmit, and read imaging examinations. In addition to the pixel information contained in the image, a typical x-ray image contains information about the patient, type of examination, and place of examination. - This information is stored in the image in what is called the header. 24 Cont’d Computers are becoming so advanced that now many mobile smart phones and tablets available today are more powerful than large computers available less than a decade ago. - This may further change the practice of medical imaging and medicine as well. “The FDA approved the first application that allows for the viewing of medical images on a mobile phone in 2011” “The Ambra Health mobile app provides medical image access across Connecticut Orthopaedic Specialists’ 21 locations.” https://www.itnonline.com/article/mobile-device-app-viewing-radiology 25 Summary A computer has two principal parts: the hardware and the software. Hardware consists of several types of components, including a CPU, memory units, input and output devices, and secondary memory devices. The basic parts of the software are the bits and bytes. Computer capacity is typically expressed in gigabytes or terabytes. Computers use a specific language to communicate commands in software systems and programs. Computers have greatly enhanced the practice of medical imaging. Computers have advanced to virtually eliminate the need for hard copy medical images. 26  Thank You 800 MyHCT (800 www.hct.ac.ae 69428)