Assessment of nasogastric (NG) tube positioning is a key competency of all doctors as unidentified malpositioning may have dire consequences, including death.
The ideal position should be in the sub-diaphragmatic position in the stomach - identified on a plain chest radiograph as overlying the ...
Elbow radiographs are common plain films that are obtained frequently in the emergency department.
anterior humeral line
drawn down the anterior surface of the humerus
should intersect the middle 1/3 of the capitellum
if it does not, think distal humeral fracture...
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...
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 patient is and narrow down the differential diagnosis.
Abnormal bowel wall attenuation patterns on CT scan can be grouped under five categories:
water halo sign
fat halo sign
The first three patterns are seen on contrast studies.
It is defined as uniform enhancement of th...
Wrist radiographs are ubiquitous on any night of the week in emergency departments, especially when pavements are icy!
Distal radial contour
Check the contour of the distal radius:
the distal radial articular surface should cup the carpals
the articular surface should ...
Renal artery stenosis (RAS) refers to a narrowing of a renal artery. When the process occurs slowly, it leads to secondary hypertension. Acute renal artery stenosis does not lead to hypersecretion of renin.
When the stenosis occurs slowly, collateral vessels form and supply the kidne...
Intradural spinal mass lesions are relatively uncommon, compared to intracranial or extradural masses, and can be challenging to diagnose. Additionally, the need for a pre-operative/non-operative diagnosis is in many ways greater as biopsy of lesions within the cord has the potential of devastat...
Lymph node imaging has become an important task for the radiologist in present days, aiding the clinician in determining whether they are benign or malignant. Multiple modalities are being used for the assessment and characterization of lymph nodes, each with its advantages and drawbacks.
In breast imaging, forbidden, check or review areas are zones that, according to Tabár, require special attention in mammographic interpretation.
on a mediolateral oblique (MLO) view
the "milky way" (retromammary fat): a 3-4 cm wide band parallel to the edge of the pectoral muscle...
Getting a film with traumatic aortic injury in the exam is one of the many exam set-pieces that can be prepared for.
This is one of the cases you should look and not speak for 10 seconds as there tends to be a lot of findings on the film of patients with traumatic aortic injury.
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...
Isolated free fluid in trauma may or may not represent a significant injury, and this creates a diagnostic dilemma in determining appropriate treatment for these patients.
The presence of isolated free fluid in trauma occurs in 3-5% of blunt trauma patients 1-4.
Small bowel follow through (SBFT) is a fluoroscopic technique designed to obtain high resolution images of the small bowel. The function of the small bowel can also be evaluated.
The small bowel follow through can be used for evaluation of small bowel abnormalities, including:
Myelination of the brain during infancy progresses in an orderly and predictable fashion which can be assessed with MRI.
At birth only certain structures are myelinated:
central corticospinal tracts
posterior limb of the internal ca...
Computed tomographic (CT) colonography, also called CTC, virtual colonoscopy (VC) or CT pneumocolon, is a powerful minimally invasive technique for colorectal cancer screening.
screening test for colorectal carcinoma
colon evaluation after incomplete or unsuccessful conventional c...
Unilateral hypertranslucent hemithorax has many potential causes. It may be the result of rotation away from an optimal position or because of pathology.
A unilateral hypertranslucent hemithorax may be caused by the positioning of the patient. Rotation away from the radiation beam alt...
This mnemonic will help with the sonographic approach to the critically ill patient with dyspnoea:
C: collapsed lung (pneumothorax)
absent anterior lung sliding / anterior B lines
lung point present 1
H: heart failure (acute pulmonary oedema)
diffuse bilateral anterior B ...
In 2017, the Adrenal Subcommittee of the Incidental Findings Committee of the American College of Radiology published a revised algorithm for the management of incidental adrenal masses in patients who are:
adults (i.e. 18-year-old or over)
asymptomatic for adrenal pathology
referred for imag...
Concurrent suprasellar and pineal region lesions have a relatively short differential to be considered, including:
other germ cell tumours
embryonal cell carcinoma
yolk sac tumour (endodermal sinus tumour)
primary CNS lymphoma
The imaging characteristics of blood on MRI can be variable and change with the age of the blood.
In general, five stages of haematoma evolution are recognised:
isointense on T1
isointense to hyperintense on T2
acute (1 to 2 days)
It is important to have a systematic way of approaching a case with subfertility in the exam.
Ultrasound is the initial examination of choice. Always say that you would further assess the uterus with 3D ultrasound. You may also say that in my department we would perform a sonohysterogram or HS...
Due to the overlap in clinical presentation of Crohn disease (CD) and ulcerative colitis (UC), imaging often has a role to play in distinguishing the two. Distinguishing features include:
CD: small bowel 70-80%, only 15-20% have only colonic involvement
UC: rectal involvement 9...
Focal areas of signal intensity (FASI), alternatively called focal abnormal signal intensity or unidentified bright objects, are bright areas on T2-weighted images commonly identified in the basal ganglia (often the globus pallidus), thalamus, brainstem (pons), cerebellum, and subcortical white ...
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 where A refers to assessment of the airways.
This is a summary article; we do not h...
Sleeve gastrectomy is a bariatric surgical procedure involving resection of the greater curvature of the fundus and body of the stomach to leave approximately 15% of the original gastric volume (60 to 100 cc), thus creating a restrictive physiology. The post-surgical gastric pouch resembles a ba...
11-13 week antenatal scan is considered a routine investigation advised for the fetal well being as well as for early screening in pregnancy (see antenatal screening).
It includes multiple components and is highly dependant on the operator. Traditionally three factors are used to calculate the ...
Antenatal screening and diagnosis are currently available for a few selected genetic conditions, including trisomy 21 (Down syndrome), trisomy 18 (Edward syndrome), trisomy 13 (Patau syndrome) and neural tube defects.
For an overview of the conditions and their manifestations, please refer to t...
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 as follows:
T: primary tumour
Tx: primary tumour cannot be assessed or tumour proven by presence of maligna...
Many patients, particularly in developing countries, present late with giant breast masses. They may be single or multiple and either benign or malignant. Many of these conditions are indistinguishable on physical examination alone. Some of these lesions require mastectomy while others can be tr...
CT head review will likely be performed differently by the majority of radiologists. So, this is just a proposition of one way to read a CT head.
What it does do is make use of windowing to maximise pickup rate. With PACS, windowing appropriately is simple, and there is no excuse for not windo...
Mammography is a dedicated radiographic technique for imaging the breast.
Types of mammography
In general terms, there are two types of mammography: screening and diagnostic.
Mammography differs significantly in many respects from the rest of diagnostic imaging.
Ground glass opacification/opacity (GGO) is a descriptive term referring to an area of increased attenuation in the lung on computed tomography (CT) with preserved bronchial and vascular markings. It is a non-specific sign with a wide aetiology including infection, chronic interstitial disease a...
Thoracoplasty is a surgical procedure that was originally designed to permanently collapse the cavities of pulmonary tuberculosis by removing the ribs from the chest wall 1-3 . The resection of multiple ribs, allows the apposition of parietal to the visceral or mediastinal pleura. Until supplant...
Abnormal ductus venosus waveforms can arise in a number of conditions ranging from aneuploidy to vascular malformations and fetal tumours.
Abnormal waveforms in fetal ductus venosus flow assessment can occur in a number of situations:
Down syndrome: around 80...
Ultrasound of the elbow allows high-resolution imaging of elbow anatomy while simultaneously allowing dynamic evaluation of the joint, tendons, and ligaments.
There are multiple possible approaches to imaging the elbow with ultrasound. A typical protocol is as follows 1:
Lines and tubes are important components in chest radiographic evaluation.
Nasogastric (NG) tube
See: nasogastric tube positioning.
NG tube tip ≥10 cm distal to the gastro-oesophageal junction
i.e. below the left hemidiaphragm
insertion into trachea or bron...
CT head is a non-contrast CT and is performed for a variety of reasons. There are a number of ways to read and look at these scans, and these pages should give some help for what to look for.
There is a lot to take in, with scans including thousands of slices. In all cases, there are a few impo...
The fluoroscopic sniff test, also known as diaphragm fluoroscopy, is a quick and easy real time fluoroscopic assessment of diaphragmatic motor function (excursion). It is used most often to confirm absence of muscular contraction of the diaphragm during inspiration in patients with phrenic nerve...
The first metatarsal axis is represented by a line drawn down the longitudinal axis of the shaft of the first metatarsal. It can be drawn on lateral and DP radiographs and is used to measure the:
first metatarsal inclination angle
talo-first metatarsal angle
Ultrasound guided percutaneous breast biopsy is a widely used technique for an accurate histopathological assessment of suspected breast pathology. It is a fast, safe and economical procedure.
Ultrasound guidance is limited to lesions visible on ultrasound study, such as:
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 ...
Left upper lobe collapse has distinctive features but can be challenging to identify on chest radiographs by the uninitiated.
For a general discussion refer to the article on lobar collapse.
The left upper lobe collapses anteriorly becoming a thin sheet...
Computed tomography (CT) of the chest is a cross-sectional evaluation of the heart, airways, lungs, mediastinum, and associated bones and soft tissues.
Two key methods of image acquisition include:
standard CT with 5 mm slice thickness for mediastinum and gross evaluation of lungs
Situs inversus, short form of the Latin “situs inversus viscerum”, is a term used to describe the inverted position of chest and abdominal organs. It is called situs inversus totalis when there is a total transposition of abdominal and thoracic viscera (mirror image of internal organs normal pos...
The anatomic position, also referred to as the standard anatomic position, is the consistent position of the human body in which positional reference is made for anatomical nomenclature. It is not reliant on whether the patient is standing, supine, prone, sitting, etc.
The position is defined a...
Functional endoscopic sinus surgery (FESS) is performed intranasally using a rigid endoscope. Its primary objective is to restore physiological ventilation and mucociliary transport 1.
Sinus imaging is crucial in preoperative planning and is increasingly being used intraoperatively.
Imaging of the brain in patients with suspected neurodegenerative conditions is common and challenging, as in patients with subtle and equivocal signs and symptoms, the imaging findings are also subtle and equivocal. In many instances, by the time imaging findings are clear cut, then the patient...
Deep brain ultrasound (DBUS) therapy is a form of precision medicine using a technique based on the principle of high-intensity focused ultrasound (HIFU), also referred to as focused ultrasound surgery (FUS).
The method combines two main components 1:
MRI of the ...
Nasogastric (NG) tube position on chest x-ray should be assessed following initial placement and on subsequent radiographs.
This is a summary article; we do not have a more in-depth reference article.
x-rays are only performed when the position ...
ABC/2 is a fast and simple method for estimating the volume of intracerebral haemorrhage (or any other ellipsoid lesion for that matter) which does not require volumetric 3D analysis or software. Intracerebral haemorrhage volume is an important predictor of morbidity and mortality (and thus tria...
ABCDEFGHI can be used to guide a systematic interpretation of chest x-rays.
Assessment of quality / Airway
The quality of the image can be assessed using the mnemonic PIER:
position: is this a supine AP file? PA? Lateral?
inspiration: count the posterior ribs. You should see 10 to 11 ribs wi...
Catheter-directed thrombolysis 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.
precise diagnosis of iliofemoral deep vein thrombosis
first episode of acute iliofemor...
Imaging in liver transplantation is aimed to evaluate donor and recipient for successful transplantation and its outcome.
volume of liver
parenchymal disease (diffuse or focal)
Musculoskeletal tuberculosis is always secondary to a primary lesion in the lung.
The prevalence of the disease is around 30 million globally and 1-3% of the 30 million have involvement of their bones and/or joints. Mycobacterium tuberculosis is responsible for almost all of the c...
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...
Cricket is a popular game in Commonwealth countries, injuries in this game can be associated with three aspects of the game: bowling, batting or fielding. Radiologists should know the different kind of injuries related to this game for a better clinical association. Injuries can range from a mus...
Describing a fracture is a basic requirement when making an assessment of a plain radiograph. There are many ways to approach the assessment of the radiograph; this is just one approach.
I: Describe the film
What film (or films) are you looking at? Check the who, what, why, when, and where.
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...
Cardiac MRI consists of using MRI to study heart anatomy and pathology.
Main advantages of cardiac MRI in comparison with other techniques are:
a better definition of soft tissues
use of different types of sequences improves diagnostic accuracy
avoid ionising radiation
Wrist x-rays are commonly used for the assessment of the wrist following trauma. This is usually a fall onto an outstretched hand.
It is useful to have a systematic approach; I tend to start proximally and work distally looking at structures on both views together:
Recurrent bone tumours are a common complication post curettage or resection.
Radiographs taken pre- and postoperatively are sufficient for evaluation of recurrence based on the following features:
matrix mineralisation (characterist...
Standardised reports may be a helpful starting point for reporting examinations. However, with practice and confidence, breaking away from the standard report is possible and, in most cases, desirable.
The standard report may help to remember review areas and in times of increasing litigation m...
Fundoplications are forms of antireflux surgery used as a second line of treatment of gastroesophageal reflux disease after failure of medical treatment and first line of treatment of paraesophageal hernia.
A gastric fold is wrapped around the distal esophagus which enforces the lowe...
The right paratracheal stripe is a normal finding on the frontal chest x-ray and represents the right tracheal wall, adjacent pleural surfaces and any mediastinal fat between them. It is visible because of the silhouette sign created by air within the trachea medially and air within the lung lat...
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 where E refers to "everything else".
This is a summary article; we do not have a mo...
Chest x-ray CVC (central venous catheter) position should be assessed following initial placement and on subsequent radiographs.
This is a summary article; we do not have a more in-depth reference article.
may be inserted via
internal jugular vein (left ...
Testicular and scrotal ultrasound is the primary modality for imaging most of the male reproductive system. It is relatively quick, relatively inexpensive, can be correlated quickly with the patient's signs and symptoms, and, most importantly, is non-ionising.
MRI is occasionally used for probl...
A systematic approach to the pituitary region is crucial as small lesions can have a profound impact on the patient, and can be subtle even on high quality dedicated MRI imaging. Successful assessment of the pituitary region relies not only on a clear understanding of the local anatomy but also ...
An aortic nipple is seen in about 10% of PA chest x-rays on the lateral surface of the aortic arch/aortic knob. It represents the left superior intercostal vein.
When prominent, superior vena cava obstruction should be considered as the left superior intercostal vein serves as a collateral path...
Ultrasound assessment of carotid arterial atherosclerotic disease has become the first choice for carotid artery stenosis screening, permitting the evaluation of both the macroscopic appearance of plaques as well as flow characteristics in the carotid artery.
This article focus on internal caro...
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 rare pro...
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.
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.
Patient has suffered minor head trauma with resultant:
loss of consciousness
The PECARN (Paediatric 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 paediatric algorithm predicts likelihood of the a...
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 paediatric urinary tract infection (UTI) management, including imaging, prophylaxis and follow-up 1.
This article inten...
Haematuria in a child is evaluated differently than in an adult in two main respects:
there is a lower likelihood of a malignancy (renal or bladder) causing the haematuria
preference is given to nonionizing radiation
Haematuria can be considered in three main forms:
Uteroplacental blood flow assessment is an important part of fetal well-being assessment and evaluates Doppler flow in the uterine arteries and rarely the ovarian arteries.
In a non-gravid state and at the very start of pregnancy the flow in the uterine artery is of high pulsatility ...
Umbilical arterial (UA) Doppler assessment is used in surveillance of fetal well-being in the third trimester of pregnancy. Abnormal umbilical artery Doppler is a marker of uteroplacental insufficiency and consequent intrauterine growth restriction (IUGR) or suspected pre-eclampsia.
The second trimester scan is a routine ultrasound examination in many countries that is primarily used to assess fetal anatomy and detect the presence of any fetal anomalies.
The second trimester extends from 13 weeks and 0 days to 27 weeks and 6 days of gestation although the majority of thes...
The two diameter pocket (TDP) method is an alternative method of assessing amniotic fluid volumes on ultrasound. However, it is not thought to be good predictor of adverse neonatal outcome 2.
According to this method 1-2:
TDP <15 cm2: indicative of oligohydramnios
Reversal of umbilical artery end-diastolic flow (REDF) or velocity is often an ominous finding if detected after 16 weeks. It is classified as Class III in severity in abnormal umbilical arterial Dopplers 6.
The estimated incidence is at ~0.5% of all pregnancies with a much higher...
Getting a film with placental abruption (premature separation of placenta from uterus) in the exam is one of the many exam set-pieces that can be prepared for.
Transabdominal and transvaginal pelvic ultrasound show a single live fetus with gestational age of 27 weeks. The cervix i...
Getting a film with perigestational haemorrhage in the exam is one of the many exam set-pieces that can be prepared for.
Transabdominal and transvaginal pelvic ultrasound show an anteverted uterus with an intrauterine gestational sac. MSD is 20 mm in TV study with a single, live e...
The four chamber cardiac view is an important and routinely performed view in both fetal echocardiography as well as on a standard second trimester anatomy scan.
The four chamber view can only detect some of the congenital cardiac anomalies (~64% according to one study 2) ...
The fetal middle cerebral arterial (MCA) peak systolic velocity (PSV) is an important parameter in fetal MCA Doppler assessment.
The fetal MCA should be sampled~2 mm from the origin of the fetal internal carotid artery and the angle of the ultrasound beam and the directi...
Fetal middle cerebral arterial (MCA) Doppler assessment is an important part of assessing fetal cardiovascular distress, fetal anaemia or fetal hypoxia. In the appropriate situation it is a very useful adjunct to umbilical artery Doppler assessment. It is also used in the additional work up of:
Getting a film with anembryonic pregnancy in the radiology fellowship examination is one of the many exam set-pieces that the candidate must be prepared for.
Transabdominal and transvaginal pelvic ultrasound shows a uterus with an intrauterine gestational sac. MSD is at least 25 m...
Amniotic fluid volume (AFV) is a function both of the amount of water transferred to the gestation across the placental membrane, and the flux of water across the amnion.
Change in volume through gestation
The AFV undergoes characteristic changes with gestation. It progressively ri...
The amniotic fluid index (AFI) is an estimate of the amniotic fluid volume in a fetus. It is part of the fetal biophysical profile.
uterus is divided into four imaginary quadrants with linea nigra and umbilicus acting as the vertical and the horizontal axis respectively
Fetal femur length (FL) is one of the basic biometric parameters used to assess fetal size. Femur length together with biparietal diameter, head circumference, and abdominal circumference are computed to produce an estimate of fetal weight. In the second trimester this may be extrapolated to an ...
Paediatric elbow radiographs are commonly encountered in the emergency department and, when approached in a systematic fashion, are not as difficult to interpret as most people think!
Check that the ossification centres are present and in the correct position. T...
Reporting a weightbearing foot series can be a daunting process if you are inexperienced and often results in the films being left for somebody else to report. This article attempts to demystify the whole process by providing a structured approach to their reporting.