Tag John W. Chen MD PhD

Imaging Physics

X-Ray Physics Production of X-Rays X-Ray Tube ( Fig. 14.1 ) An x-ray tube is an energy converter receiving electrical energy and producing heat and X-rays. For a diagnostic x-ray tube operating at 100 peak kilovoltage (kVp), the production of…

Contrast Agents

X-Ray Contrast Agents Iodinated Contrast Agents Classification Iodinated contrast agents can be classified based on osmolarity (high, low, or iso) and ionitiy (ionic or nonionic). A variety of iodinated contrast agents have been developed and are distributed by different manufacturers.…

Nuclear Imaging

Pulmonary Imaging Radiopharmaceuticals Pulmonary scintigraphy uses ventilation agents and/or perfusion agents, depending on the specific imaging task. Overview Agent Half-life Main Energy Collimator Comments Ventilation 133 Xe 5.2 days 81 Low Inexpensive; washout images helpful 99m Tc DTPA aerosol 6 hr…

Pediatric Imaging

Respiratory Tract Upper Airway Approach Inspiratory stridor is the most common indication for radiographic upper airway evaluation. The main role of imaging is to identify conditions that need to be treated emergently and/or surgically (e.g., epiglottitis, foreign bodies). Technique: 1…

Breast Imaging

Mammography Mammography Techniques Mammography is primarily a screening and not a diagnostic tool. The mediolateral oblique (MLO) and craniocaudal (CC) views are standard screening views, whereas additional views described below are used mainly for diagnostic evaluation of lesions. Mammographic Views…

Vascular Imaging

Techniques General Preprocedure Evaluation 1 What is the indication for the procedure? Diagnosis Preoperative staging Therapy 2 Define the problem. What is the diagnostic question that is to be answered? Which study can best answer the question (ultrasound [US], computed…

Head and Neck Imaging

Temporal Bone General The temporal bone is divided into five portions: Mastoid (posterolateral part that includes the mastoid process: attachment for sternocleidomastoid and other muscles) Petrous portion (pyramidal-shaped medial part; inner ear structures, internal auditory canal [IAC], petrous apex) Squamous…

Neurologic Imaging

Imaging Anatomy Parenchymal Anatomy Lobar Anatomy ( Fig. 6.1 ) Frontal lobe: anterior to central sulcus (CS) (Rolando) Parietal lobe: posterior to CS Temporal lobe: inferior to lateral sulcus (Sylvius) Occipital lobe: posterior Limbic lobe Central (insular lobe) Basal Ganglia…

Musculoskeletal Imaging

Trauma General Fracture FRACTURE SYNOPSIS Fracture Finding Spine Jefferson Ring fracture of C1 Hangman's Bilateral pedicle or pars fractures of C2 Teardrop (flexion) Unstable flexion fracture Clay-shoveler's Avulsion fracture of spinous process lower cervical, high thoracic spine Chance Horizontal fracture…