Articles
Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.
530 results found
Article
Radiological image artifact
Most artifacts in radiology refer to something seen on an image that are not present in reality but appear due to a quirk of the modality itself. Artifact is also used to describe findings that are due to things outside the patient that may obscure or distort the image, e.g. clothing, external c...
Article
Geographic appearance
Geographic appearance is a term used in imaging, and other clinical fields (e.g. histopathology) to describe lesions with a well-circumscribed margins with adjacent tissues. The term derives from the somewhat similar appearance of the outline of countries on a map or the clear demarcation forme...
Article
Isikoff's View
The Isikoff's view is a sonographic view which demonstrates the origins of the right and left renal arteries. It is taken in the longitudinal plane with the patient in the left lateral decubitus position 1.
Article
Describing a bone lesion
Describing a bone lesion is an essential skill for the radiologist, used to form an accurate differential diagnosis for neoplastic entities, and occasionally non-neoplastic. In addition to patient demographics, the radiographic features of a bone lesion are often the primary determinant of non-h...
Article
Diagnostic HRCT criteria for usual interstitial pneumonia (UIP) pattern - Fleischner society guideline (2018)
In 2018, the Fleischner Society provided updated diagnostic HRCT criteria for usual interstitial pneumonia (UIP) pattern based on literature review and the expert opinion of members. As a part of this white paper, diagnostic HRCT criteria for usual interstitial pneumonia (UIP) pattern were updat...
Article
Head and neck cancer therapy response interpretation (Hopkins criteria)
The head and neck cancer therapy response interpretation (Hopkins criteria) is a qualitative system of interpretation for therapy response assessment using PET-CT.
Background
Widely used options for therapy response assessment are clinical examination, histopathology, CT and MR imaging, howeve...
Article
Cognitive bias in diagnostic radiology
Cognitive biases have a complex and significant impact on the perception of examinations within diagnostic radiology, with the clear and present danger of diagnostic errors. The following are some of the more common cognitive biases that can affect day-to-day decision making 1.
Alliterative bia...
Article
Tumors of the base of skull (differential diagnosis)
Tumors of the base of skull are histologically varied and are often challenging to preoperatively diagnose and treat.
Exactly which tumors are considered to be tumors of the base of skull is debatable. The broadest definition would include any tumor that involves or abuts the base of skull, thu...
Article
Densitometric vertebral fracture assessment
Densitometric vertebral fracture assessment (VFA) is an image of the lumbar and thoracic spine acquired on dual energy x-ray absorptiometry (DXA) scanners, for the purpose of diagnosing osteoporotic vertebral fractures.
Terminology
The technique is available on DXA scanners under a variety of...
Article
Optic nerve sheath diameter
Optic nerve sheath diameter has significance in the assessment of papilledema in cases of elevated intracranial pressure.
Pathology
The optic nerve sheath demonstrates changes in diameter with CSF pressure changes as there is a layer of subarachnoid space between the nerve and its sheath, whic...
Article
CT angiography of the cerebral arteries (protocol)
CT angiography of the cerebral arteries (also known as a CTA carotids or an arch to vertex angiogram) is a non-invasive technique that allows visualization of the internal and external carotid arteries and vertebral arteries and can include just the intracranial compartment or also extend down t...
Article
Haller index
The Haller index (HI), also known as the pectus index, is a simple mathematical way to assess and describe the chest cage on CT of the thorax and is used in the detection and pre/postoperative assessment of pectus excavatum 1,5.
Measurement
The Haller index is calculated by dividing the transv...
Article
Pyrexia of unknown origin
A pyrexia of unknown origin, commonly shortened to PUO, and also known as a fever of unknown origin (FUO), was originally defined in 1961 as the condition in which the core body temperature is >38.3oC for a period of three weeks or more, with no diagnosis reached after one week of inpatient inve...
Article
Vermian maturity assessment (approach)
Radiological evaluation of the posterior fossa is an essential part of the routine fetal assessment, including vermian maturity assessment.
Radiographic features
Ultrasonography is a readily available diagnostic tool in the assessment of the fetal posterior fossa but is sometimes limited due t...
Article
Abdominal x-ray review: artifacts/external
Abdominal x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using ABDO X is a helpful and systematic method for abdominal x-ray review, where X refers to the assessment of external objects and artifacts.
Summary
introduction
numerous ...
Article
Abdominal x-ray review: organs
Abdominal x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using ABDO X is a helpful and systematic method for abdominal x-ray review, where O refers to the assessment of the intra-abdominal organs and soft tissues.
Summary
intro...
Article
Abdominal x-ray densities
Abdominal x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using ABDO X is a helpful and systematic method for abdominal x-ray review, where D refers to the assessment of dense structures such as the bones and areas of calcification.
S...
Article
Abdominal x-ray review: bowel
Abdominal x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using ABDO X is a helpful and systematic method for abdominal x-ray review, where B refers to the assessment of the bowel loops.
Summary
introduction
stomach, small bowel and...
Article
Abdominal x-ray review: air
Abdominal x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using ABDO X is a helpful and systematic method for abdominal x-ray review, where A refers to the assessment of the presence and location of air.
Summary
introduction
air sho...
Article
Coronary Artery Disease - Reporting and Data System
The Coronary Artery Disease - Reporting and Data System (CAD-RADS) is a standardized method for reporting and communicating coronary CT angiography findings and serves as a clinical decision support tool to guide subsequent patient management.
History and etymology
The system was created by a ...
Article
Abdominal x-ray review: ABDO X
Abdominal x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using ABDO X is a helpful and systematic method for abdominal x-ray review:
A: air - where it should and should not be
B: bowel - position, size and wall thickness
D: dense s...
Article
Computed tomography texture analysis
Computed tomography texture analysis (or CTTA) is a method to obtain new useful biomarkers that provide objective and quantitative assessment of tumor heterogeneity by analyzing the differences and patterns within the pixel values of an image. CTs can be worked with as a matrix of numbers, corre...
Article
Magnetic resonance neurography
Magnetic resonance neurography (MRN) is a relatively new non-invasive imaging technique for dedicated assessment of peripheral nerves.
It is used to assess peripheral nerve entrapments and impingements as well as localization and grading of nerve injuries and lesions.
Dedicated high-resolution...
Article
CT polytrauma (approach)
Below is an approach used for the "primary survey" of a CT polytrauma/multitrauma (also called trauma CT or whole body CT), often performed at the CT console with the patient still on the CT table. It allows rapid communication of significant findings to the trauma team as well as the decision ...
Article
Interseptal distance
The interseptal distance (ISD) is a measurement used to assess septal area atrophy as a marker for neurodegenerative conditions in patients with memory problems 1.
It is proposed that atrophy of the septal nuclei can commonly be seen in conditions associated with hippocampal atrophy, particular...
Article
Physiological pelvic intraperitoneal fluid
Physiological pelvic intraperitoneal fluid refers to the presence of a small volume of free fluid in the pelvis, particularly the pouch of Douglas. It occurs in young females of reproductive age and can be a mimic of traumatic free fluid in abdominal trauma.
Unfortunately, pelvic free fluid may...
Article
Management of Incidental Adrenal Masses: American College of Radiology white paper
The Management of Incidental Adrenal Masses revised in 2017 by the Adrenal Subcommittee of the Incidental Findings Committee of the American College of Radiology is an algorithm for the management of patients who are:
adults (≥18 years old)
asymptomatic for adrenal pathology
referred for imag...
Article
Concurrent suprasellar and pineal region lesions (differential)
Concurrent suprasellar and pineal region lesions have a relatively short differential to be considered, including:
germinoma
other germ cell tumors
choriocarcinoma
embryonal cell carcinoma
yolk sac tumor (endodermal sinus tumor)
primary CNS lymphoma
cerebral metastasis
quadrilateral ret...
Article
11-13 week antenatal scan
11-13 week antenatal (nuchal translucency) scan is considered a routine investigation advised for fetal well-being as well as for early screening in pregnancy (see antenatal screening).
It includes multiple components and is highly dependent on the operator. Traditionally three factors are used...
Article
Giant breast mass
Giant breast masses are defined as breast masses >5 cm and may represent a late presentation of breast pathology, particularly in developing countries. They may be single or multiple and either benign or malignant. Many of the underlying etiologies for giant breast masses are indistinguishable o...
Article
Cerebral edema (summary)
This is a basic article for medical students and other non-radiologists
Cerebral edema describes the collection of additional fluid within the white matter of the brain. It is the brain's response to an insult and may take one of two broad forms: vasogenic (white matter) and cytotoxic (grey and...
Article
Catheter-directed thrombolysis
Catheter-directed thrombolysis (CDT) is an endovascular approach to the treatment of acute iliofemoral deep vein thrombosis. It involves the administration of a lytic agent directly into a thrombus.
Indications
precise diagnosis of iliofemoral deep vein thrombosis
first episode of acute ili...
Article
CHALICE rule
The Children’s Head injury ALgorithm for prediction of Clinically Important Events (CHALICE) clinical decision rule was developed to predict clinically important brain injuries in children with head trauma. This rule identifies high-risk criteria and divides them into history, examination and me...
Article
Canadian CT head rule
The Canadian CT head rule (CCTHR) is a validated clinical decision rule to determine the need for CT head in adult emergency department patients with minor head injuries.
Inclusion criteria
Patient has suffered minor head trauma with resultant:
loss of consciousness
GCS 13-15
confusion
amn...
Article
PECARN traumatic brain injury algorithm
The PECARN (Pediatric Emergency Care Applied Research Network) traumatic brain injury algorithm is a clinical decision rule that aims to identify children at very low risk of clinically important traumatic brain injury (ci-TBI) 1. This validated pediatric algorithm predicts likelihood of the abo...
Article
Canadian C-spine rules
Canadian C-spine rules are a set of guidelines that help a clinician decide if cervical spine imaging is not appropriate for a trauma patient in the emergency department. The patient must be alert and stable.
There are three rules:
is there any high-risk factor present that requires cervical s...
Article
NEXUS criteria
NEXUS (National Emergency X-Radiography Utilization Study) is a set of validated criteria used to decide which trauma patients do not require cervical spine imaging.
Trauma patients who do not require cervical spine imaging require all of the following:
alert and stable
no focal neurologic de...
Article
Transrectal ultrasound
Transrectal ultrasound (TRUS) is a technique that is used most commonly to evaluate
the prostate gland, including ultrasound-guided prostate biopsies
depth of invasion of colon/rectal cancer (for staging purposes)
It can also be used for guidance in placing a transrectal drain, or in r...
Article
Dolan's lines
Dolan's lines are the collective name given to three lines described by Dolan and Jacoby 1 that aid in evaluating for maxillofacial fractures on an occipitomental skull radiograph. They are usually used as an adjunct to McGrigor-Campbell lines.
orbital line traces the inner margins of the later...
Article
McGrigor-Campbell lines
McGrigor-Campbell lines are imaginary lines traced across the face on an occipitomental (Waters) view skull radiograph to assess for fractures of the middle third (especially) of the face 3:
first line is traced from one zygomaticofrontal suture to another, across the superior edge of the orbit...
Article
ACR Thyroid Imaging Reporting and Data System (ACR TI-RADS)
ACR TI-RADS is a reporting system for thyroid nodules on ultrasound proposed by the American College of Radiology (ACR) 1.
This uses a standardized scoring system for reports providing users with recommendations for when to use fine needle aspiration (FNA) or ultrasound follow-up of suspicious ...
Article
Functional endoscopic sinus surgery
Functional endoscopic sinus surgery (FESS) is a type of paranasal sinus surgery performed intranasally using a rigid endoscope. Its primary objective is to restore physiological ventilation and mucociliary transport 1.
Paranasal sinus imaging is crucial in preoperative planning and is also incr...
Article
CVC position on chest x-ray (summary)
This is a basic article for medical students and other non-radiologists
Chest x-ray CVC (central venous catheter) position should be assessed following initial placement and on subsequent radiographs.
Reference article
This is a summary article; for a more in-depth reference article see centr...
Article
Traumatic abdominal wall hernia
Traumatic abdominal wall hernia describes the traumatic disruption of musculature and fascia of anterior abdominal wall without skin penetration.
Clinical presentation
Abdominal skin ecchymosis or abrasions may be seen.
Pathology
Traumatic abdominal wall hernia is caused by blunt trauma to t...
Article
Brock model for pulmonary nodules
The Brock model, also known as the PanCan model, is a multivariable model that estimates the risk that a pulmonary nodule on CT scan is lung cancer.
The model was developed from participants enrolled in the Pan-Canadian Early Detection of Lung Cancer Study 1, has been validated in lung cancer s...
Article
Hemorrhage exclusion sign (prostate)
The hemorrhage exclusion sign can be a useful MRI finding following prostate biopsy.
Pathology
The normal prostate produces high concentrations of citrate, which among other properties, acts as an anticoagulant 1. As tumor cells are dysfunctional, they will produce lower levels of citrate than...
Article
Lung cancer (staging - IASLC 8th edition)
The IASLC (International Association for the Study of Lung Cancer) 8th edition lung cancer staging system was introduced in 2016 and supersedes the IASLC 7th edition. It is a TNM staging system.
Standard-of-care lung cancer staging ideally should be performed in a multidisciplinary meeting usin...
Article
ABC/2
ABC/2, also confusingly written as 1/2ABC in some literature, is a fast and simple method for estimating the volume of intracerebral hemorrhage (or any other ellipsoid lesion for that matter) which does not require volumetric 3D analysis or software.
Intracerebral hemorrhage volume is an import...
Article
Multiphase CT angiography in acute ischemic stroke
Multiphase CT angiography is an evolving imaging technique in acute ischemic stroke. The technique aims to quickly and reliably identify brain which is potentially salvageable with intervention. Brain tissue viability depends on many factors, with this technique assessing collateral leptomeninge...
Article
Coronal balance
Coronal balance is one of the features that needs to be assessed on long spine radiographs obtained for spinal deformity, particularly scoliosis. It measures whether or not the upper spine is located over the midline (normal) or off to one side.
Measurement
To assess coronal balance, a vertic...
Article
Sagittal balance
Sagittal balance forms part of the plain radiographic assessment of spinal deformity including kyphotic or lordotic deformities and scoliosis.
Usage
There are numerous ways of assessing this, using various bony landmarks and angles to evaluate whether or not a normal distribution of weight and...
Article
Breast echotexture
Breast echotexture refers to the background tissue appearance on breast sonography, analogous to breast density/amount of fibroglandular tissue on mammography and MRI. There are three categories of tissue composition according to the BI-RADS lexicon 1:
homogeneous background echotexture – fa...
Article
Central sacral vertical line
The central sacral vertical line (CSVL) is used in the assessment of spinal scoliosis.
It is a line constructed on frontal films of the spine and pelvis to measure coronal balance, drawn as follows:
a line connecting the top of the iliac crests is drawn
a second line is drawn perpendicular t...
Article
CT head (subdural window)
The subdural (blood) window can be used when reviewing a CT brain as it makes intracranial hemorrhage more conspicuous, and may help in the detection of thin acute subdural hematomas that are against the calvaria that are similar density to adjacent bone. It is a wider setting than the standard ...
Article
Pediatric urinary tract infection (NICE guideline)
The British National Institute for Health and Care Excellence (NICE) published the “Urinary tract infection in under 16s: diagnosis and management” in 2007 as a guideline for pediatric urinary tract infection (UTI) management, including imaging, prophylaxis and follow-up 1.
This article intend...
Article
Renal transplant ultrasound
The central approach of renal transplant ultrasound is to evaluate for possibly treatable surgical or medical complications arising in the transplanted kidney.
Institutions vary in the exact schedule of renal transplant ultrasound assessment, but it is common to obtain an initial ultrasound 24-...
Article
Shoulder radiograph (summary approach)
This is a basic article for medical students and other non-radiologists
Shoulder radiographs are commonly performed for shoulder injury assessment and followup. Using a standard system to approach the x-ray means it is much more likely you will find the abnormality.
Summary approach
alignment...
Article
Wrist radiograph (summary approach)
This is a basic article for medical students and other non-radiologists
Wrist radiographs are commonly used for the assessment of the wrist following trauma.
Summary approach
alignment
AP
distal radius and ulna have smooth joint surface
carpal arcs are smooth
carpal bones do not overlap
...
Article
Scrotal scintigraphy
Scrotal scintigraphy is a radioisotope examination of the scrotal contents, primarily in patients presenting with scrotal pain.
Indications
Although, ultrasound remains the mainstay of scrotal imaging, scintigraphy can be used where the diagnosis is unclear, since ultrasound appearances for sc...
Article
Intercristal line
The intercristal line (also known as Jacoby’s Line or Tuffier’s Line) is a horizontal line drawn across the highest points of both the iliac crests in an anteroposterior (AP) lumbar radiograph 1,2.
The intercristal line most often intersects the body of L4 or its inferior endplate in men and th...
Article
Amsterdam wrist rules
The Amsterdam wrist rules are validated clinical decision rules for determining which patients require radiographic imaging (wrist radiography) for acute wrist pain following trauma. The initial study evaluated 882 patients and were published in 2015 1. The decision rules assessed different clin...
Article
Hematospermia
Hematospermia (less commonly hemospermia) refers to the presence of blood in semen or ejaculatory fluid. It is a symptom that can cause great anxiety in patients despite usually being of benign etiology.
Pathology
Etiology
Benign
urogenital infections including sexually transmitted disease, ...
Article
British Thoracic Society guidelines for pulmonary nodules
British Thoracic Society guidelines for pulmonary nodules were published in August 2015 for the management of pulmonary nodules seen on CT. In the United Kingdom, they supersede the Fleischner Society guidelines.
They are based initially on identifying whether the nodule is solid or subsolid an...
Article
Subacromial bursal injection
Subacromial bursal corticosteroid injections, also known as subacromial-subdeltoid bursal injections, are used in patients with limited or no response to initial treatment with impingement syndrome, subacromial bursitis and/or rotator cuff disorders. Non-steroidal anti-inflammatory drugs (NSAIDs...
Article
Cerebroplacental ratio
Cerebroplacental ratio (CPR) is an obstetric ultrasound tool used as a predictor of adverse pregnancy outcome in both small for gestational age (SGA) and appropriate for gestational age (AGA) fetuses. An abnormal CPR reflects redistribution of cardiac output to the cerebral circulation, and has ...
Article
Sonographic approach to dyspnea (mnemonic)
This mnemonic will help with the sonographic approach to the critically ill patient with dyspnea:
CHEST
Mnemonic
C: collapsed lung (pneumothorax)
absence of anterior lung sliding, lung pulse, B-lines, or z-lines
these artifacts arise from the pleural interface; their presence would rule ou...
Article
Small pulmonary nodules (HRCT chest approach)
Small pulmonary lung nodules refer to an HRCT chest imaging descriptor for 5-10 mm lung nodules and are divided into three main categories based on their distribution pattern:
centrilobular
perilymphatic
random
Terminology
Radiologists often informally refer to indeterminate small pulmonary...
Article
Triangle of safety
The triangle of safety is an anatomical region in the axilla that forms a guide as to the safe position for intercostal catheter (ICC) placement. With the arm abducted, the apex is the axilla, and the triangle is formed by the:
lateral border of the pectoralis major anteriorly
lateral border o...
Article
ATA guidelines for assessment of thyroid nodules
The American Thyroid Association (ATA) guidelines for assessment of thyroid nodules are meant to improve inter- and intra-reader consistency during assessment of thyroid nodules on ultrasound, and to facilitate communication with referring endocrinologists.
The 2015 guidelines stress the import...
Article
Carpal height
Carpal height is used to diagnose and assess the severity of carpal collapse. It is defined as the distance between the base of third metacarpal and the subchondral bony cortex of the distal radius. Due to the wide range of normal variations between individuals, several measurement techniques ha...
Article
Rapid ultrasound in shock
The rapid ultrasound in shock (RUSH) protocol is a structured point-of-care ultrasound (POCUS) examination performed at the time of presentation of a shocked patient. It is a more detailed and longer exam than the FAST scan, with the aim to differentiate between hypovolemic, cardiogenic, obstruc...
Article
Abnormal ultrasound findings in rheumatological diseases (definitions)
The OMERACT ultrasound group published a consensus in 2005 of widely accepted definitions of abnormal ultrasound findings in rheumatological diseases:
erosion: an intra-articular discontinuity of the bone surface that is visible in two orthogonal planes 4
joint effusion: abnormal hypoechoic or...
Article
Iliofemoral line
The iliofemoral line is traced on an AP pelvis projection. It is a curvilinear line, along the outer surface of the ilium, through the superior acetabular rim and the femoral neck.
It should be bilaterally symmetrical. Asymmetry may be the result of congenital dysplasia, slipped femoral capital...
Article
Idiopathic interstitial pneumonias: HRCT chest approach
The approach to HRCT chest in patients with suspected idiopathic interstitial pneumonia (IIP) is with the aim to:
make sure an appropriate study requested i.e. HRCT chest with optimal individually adjusted protocol and ensure adequacy of the HRCT chest quality (see imaging protocol below)
meti...
Article
Ottawa ankle rules
The Ottawa ankle rules are a clinical decision-making strategy for determining which patients require radiographic imaging for ankle and midfoot injuries. Proper application has high (97.5%) sensitivity and reduces the need for radiographs by ~35% 1,2,4.
There are two components, assessing for...
Article
Fluoroscopic evaluation of esophagectomy
Fluoroscopic evaluation of esophagectomy is an important study, given the high rate of complication following esophagectomy (~10-20% rate of leak). Although the approach will differ slightly depending on the type of esophagectomy performed, the principles are similar.
Procedure
Preprocedural e...
Article
Investigation of polyarthritis (summary)
This is a basic article for medical students and other non-radiologists
Polyarthritis (arthritis affecting several joints) is common, especially in older patients. Symptoms may range from mild pain and restriction to severe, debilitating disease with mutilated joints.
Assessment
Arthritis may...
Article
Glioblastoma vs cerebral metastasis
Differentiating a glioblastoma (GBM) from a cerebral metastasis is a frequent challenge, with profound surgical, workup and treatment implications. Unfortunately distinguishing between the two entities is not always straightforward and even experienced neuroradiologists will sometimes struggle. ...
Article
Wrist radiograph (approach)
Wrist x-rays are commonly used for the assessment of the wrist following trauma. This is usually a fall onto an outstretched hand.
Systematic review
It is useful to have a systematic approach; I tend to start proximally and work distally looking at structures on both views together:
distal ra...
Article
Supratentorial intracranial mass in an adult (an approach)
The identification of a supratentorial intracranial mass in an adult is a fairly common clinical scenario, the appropriate management of which relies heavily on preoperative imaging. Often important clues will be present in the clinical history (e.g. immunosuppression, systemic malignancy, durat...
Article
Iodinated contrast media adverse reactions
Iodinated contrast media adverse reactions, popularly but erroneously referred to as contrast allergies (see Terminology below), are an uncommon group of symptoms and signs, with different degrees of severity, that may occur after the administration of these drugs.
Anaphylactic-type reactions ...
Article
Chest x-ray: lines and tubes (summary)
This is a basic article for medical students and other non-radiologists
Chest x-ray lines and tubes can be easily assessed and should be the first thing that you look at when reviewing a chest x-ray. Assessment of their position is important, but they also give you an idea about how sick the pa...
Article
Fluid-fluid levels in bone tumors
Fluid-fluid levels in bone tumors is a commonly encountered finding, both in benign as well as malignant bone tumors, and can be used to differentiate between the two.
Measurement
On the sagittal T2W image:
measure the length of the largest fluid-fluid level (A)
measure the maximum length of...
Article
Localization of parotid lesions
The parotid gland consists of a superficial and deep lobe. Determining the location and extent of the lesions affecting the gland is an essential aspect of imaging and vital information which needs to be conveyed to the surgeon.
Method of evaluation
The following lines are proposed for differe...
Article
Hemorrhagic infarct vs intracerebral hemorrhage
Hemorrhagic infarct or hemorrhagic transformation of an infarct is seen following breakdown of the lamina of the microvessels.
Intracerebral hemorrhage (ICH) may overlap with a hemorrhagic infarct and hence needs to be differentiated as the line of treatment will vary.
Differentiating points
...
Article
Intracranial non-neoplastic cysts
Intracranial non-neoplastic cysts are common findings on MRI and CT brain scans.
Location-based diagnostic approach
A location-based approach is useful in establishing an appropriate diagnosis; some locations are virtually pathognomonic for certain lesions e.g. colloid cyst.
Many cysts may oc...
Article
Denver criteria for blunt cerebrovascular injury
The Denver criteria are a set of screening criteria used to determine when CT angiography of the neck is indicated to detect blunt cerebrovascular injury (BCVI) in trauma patients.
Screening criteria
The Denver criteria were initially developed in 1996 1, modified in 2005 to limit the types o...
Article
Cardiac MRI
Cardiac MRI consists of using MRI to study heart anatomy, physiology, and pathology.
Advantages
In comparison to other techniques, cardiac MRI offers:
improved soft tissue definition
protocol can be tailored to likely differential diagnoses
a large number of sequences are available
dynamic...
Article
Chest x-ray review: ABCDE
Chest x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using A, B, C, D, E is a helpful and systematic method for chest x-ray review:
A: airways
B: breathing (the lungs and pleural spaces)
C: circulation (cardiomediastinal contour)
...
Article
Patterns of sinonasal obstruction
Recognizing patterns of sinonasal obstruction is useful to help localize the area of pathology and narrow the differential diagnosis.
Radiographic features
Babbel et al described five pattern of sinonasal obstruction 1, which are readily apparent on CT:
Infundibular pattern
opacification of...
Article
CT cystography
CT cystography is a variation of the traditional fluoroscopic cystogram. Instead of anterograde opacification of the urinary collecting system (as with CT urography), contrast is instilled retrograde into the patient's bladder, and then the pelvis is imaged with CT.
Indications
suspected bladd...
Article
Cystography
Cystography is a fluoroscopic study that images the bladder. It is similar to a voiding cystourethrogram (VCUG), and the difference between the studies is primarily one of emphasis; a cystogram focuses on the bladder and a VCUG focuses on the posterior urethra. The study has been adapted to CT a...
Article
IOTA ultrasound rules for ovarian masses
The International Ovarian Tumor Analysis (IOTA) group ultrasound rules for ovarian masses are a simple set of ultrasound findings that classify ovarian masses into benign, malignant or inconclusive masses. These rules apply to masses that are not a classical ovarian mass (e.g. corpus luteum, end...
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