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.

348 results found
Article

Intradural spinal mass lesions (an approach)

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...
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Intraventricular masses (an approach)

The ventricular system of the brain plays host to a variety of unique tumours, as well as tumours that are more frequently seen elsewhere (e.g. meningiomas). Besides, some intra-axial (parenchymal) masses can be mostly exophytic and thus appear mostly intraventricular. A systematic approach taki...
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IOTA ultrasound rules for ovarian masses

The International Ovarian Tumour 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, en...
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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.
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Isolated free fluid in trauma

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.  Epidemiology The presence of isolated free fluid in trauma occurs in 3-5% of blunt trauma patients 1-4. Pathology The c...
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Isomerism

Isomerism is a term which in general means 'mirror-image'. It is used in the context of heterotaxy and is of two types: left isomerism right isomerism Left isomerism Mirror image of the structures on the left side of the chest along the left-right axis of the body, i.e. patients with isomeri...
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Joint effusion

A joint effusion is defined as an increased amount of fluid within the synovial compartment of a joint. There is normally only a small amount of physiological intra-articular fluid. Abnormal fluid accumulation can result from inflammation, infection (i.e. pus) or trauma and may be an exudate, t...
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Knee radiograph (an approach)

Systematic review Effusion? Check for an effusion on the lateral: peripatellar fat pads should sit next to each other anterior suprapatellar fat pad prefemoral fat pad soft tissue density between them indicates an effusion if simple effusion (haemarthrosis), think severe ligamentous, meni...
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Left atrial enlargement

Left atrial enlargement may result from many conditions, either congenital or acquired. It has some characteristic findings on a frontal chest radiograph. CT or MRI may also be used for diagnosis. Clinical presentation An enlarged left atrium can have many clinical implications, such as: Ortn...
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Left upper lobe collapse

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. Radiographic features Plain radiograph The left upper lobe collapses anteriorly becoming a thin sheet...
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Left upper lobe collapse in the exam

Getting a film with left upper lobe collapse in the exam is one of the many exam set-pieces that can be prepared for. Description This frontal chest radiograph shows a hazy (or veil-like*) opacification of the left hemithorax that is associated with superior displacement left hilum and horizon...
Article

Left ventricular ejection fraction (echocardiography)

Left ventricular ejection fraction is a surrogate for left ventricular global systolic function, defined as the left ventricular stroke volume divided by the end-diastolic volume. Terminology Point-of-care echocardiography protocols typically use a semi-quantitative approach in defining the ej...
Article

Lines and tubes (chest radiograph)

Lines and tubes are important components in chest radiographic evaluation. Nasogastric (NG) tube See: nasogastric tube positioning.  Correct position NG tube tip ≥10 cm distal to the gastro-oesophageal junction i.e. below the left hemidiaphragm Complications insertion into trachea or bron...
Article

Lobar collapse (summary)

This is a basic article for medical students and other non-radiologists Lobar collapse is relatively common and occurs following obstruction of a bronchus. Gas is resorbed from the lung parenchyma distal to the obstruction resulting in the collapse of the lung, with volume reduction and negativ...
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Localisation 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...
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Lower zone

The lower zone is one of the four chest radiograph zones.  Radiographic features Plain radiograph on frontal chest radiographs, extends inferiorly from the inferior aspect of the hilum to the hemidiaphragm
Article

Low grade osteosarcoma

Low grade osteosarcoma is an uncommon subtype of osteosarcoma accounting less than 1% of all osteosarcomas. Epidemiology Low grade osteosarcoma affects individuals of higher age group as compare to the other subtypes of osteosarcoma. The usual age of presentation is 19 to 54 years with the mea...
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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.  Standard-of-care lung cancer staging ideally should be performed in a multidisciplinary meeting using the information provided ...
Article

Lymph node imaging

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. Modal...
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

Malignant ovarian lesions (sonographic features)

Malignant ovarian lesions can have typical sonographic features, and thus ultrasound is the imaging of choice for initial evaluation of suspected ovarian neoplasm. Radiographic features The features of malignant ovarian neoplasm on ultrasonography include: solid tumour mass >10 cm with locul...
Article

Mammography

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. Screening mammography  In ge...
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 (i.e. 18-year-old or over) asymptomatic for adrenal pathology referr...
Article

Mass of the inguinal region (differential)

The differential diagnosis of a mass in the inguinal region includes: inguinal hernia femoral hernia hydrocele of the canal of Nuck lymphadenopathy or necrotic lymph node aneurysm or pseudoaneurysm of the femoral artery iliopectineal bursa abscess haematoma lymphangioma epidermal inclu...
Article

McGill Thyroid Nodule Score (MTNS)

The McGill Thyroid Nodule Score (MTNS) is a scoring system developed to estimate the risk of malignancy of thyroid nodules.1 Scoring system The MTNS is based on 22 parameters: eight clinical or laboratory parameters gender (male): 1 point age (>45 years old): 1 point palpable nodule (prese...
Article

McGregor line

The McGregor line is a modification of the Chamberlain line and is used in the evaluation of basilar invagination when the opisthion is not identified on plain radiographs. It refers to a line connecting posterior edge of the hard palate to the most caudal point of the occipital curve. If the t...
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: first line is traced from one zygomaticofrontal suture to another, across the superior edge of the orbits second line traces the zygomatic arch, cross...
Article

Medial temporal lobe atrophy score

The medial temporal lobe atrophy (MTA) score is useful in distinguishing patients with mild cognitive impairment and Alzheimer disease from those without impairment 2 is helpful in the assessment of patients with possible dementia (see neurodegenerative MRI brain - an approach). Classification ...
Article

Mediastinal widening (differential)

The differential diagnoses for mediastinal widening include: traumatic aortic injury vascular anomalies unfolded aorta double SVC aberrant right subclavian artery azygous continuation of the IVC pneumomediastinum lung atelectasis pulmonary masses abutting the mediastinum mediastinal l...
Article

Midfoot equinus

Midfoot equinus is an abnormality in foot alignment where there is abnormal plantarflexion of the foot in the midfoot. Related pathology Midfoot equinus occurs as a component of congenital talipes equinovarus.
Article

Mid zone

The mid (or middle) zone is one of the four chest radiograph zones.  Radiographic appearance Plain radiograph on frontal chest radiographs, extends between the superior and inferior aspects of the hilum
Article

M-line of Cremin

M-line of Cremin is an imaginary line that can be used to determine the level at which the blind pouch ends in anal atresia, determining whether the anal atresia is a high or a low type. The line is drawn perpendicular to the long axis of the ischium on the lateral view and passes through the j...
Article

Modified PIOPED criteria for diagnosis of pulmonary embolus

The modified PIOPED criteria for the diagnosis of pulmonary embolus (PE) determine the probability of pulmonary emboli following a VQ scan. Classification High probability two or more large mismatched segmental defects or equivalent moderate/large defects with a normal x-ray any perfusion de...
Article

Monoarticular arthropathy

Monoarticular arthropathy can result from a number of causes: infectious arthritis gout HADD (hydroxyapatite deposition disease) traumatic arthritis secondary osteoarthritis avascular necrosis PVNS synovial osteochondromatosis osteochondritis dissecans
Article

MR enterography

MR enterography is a non-invasive technique for diagnosis of small bowel disorders. Indications MR enterography is most commonly used to evaluate patients with Crohn disease where it is used for assessment of the primary disease and any complications. Other indications include coeliac disease,...
Article

MRI of the brachial plexus

MRI of the brachial plexus is used to provide a causal diagnosis for brachial plexopathies. It provides clear structural analysis of the brachial plexus, its intraneural integrity, as well as surrounding structures 1,3. Related pathology brachial plexus injuries grading of brachial plexus inj...
Article

Multiphase CT angiography in acute ischaemic stroke

Multiphase CT angiography is an evolving imaging technique in acute ischaemic 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 leptomening...
Article

Nasogastric tube positioning

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 ...
Article

Nasogastric tube position on chest x-ray (summary)

This is a basic article for medical students and other non-radiologists   Nasogastric (NG) tube position on chest x-ray should be assessed following initial placement and on subsequent radiographs. Reference article This is a summary article; we have a more in-depth reference article NGT. S...
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Neonatal chest radiograph in the exam setting

The neonatal chest radiograph in the exam setting may strike fear into the heart of many radiology registrars, but it need not! There are only a limited number of diagnoses that will be presented on such films and they are often highlighted by the history. Gestation First of all, have a look ...
Article

Neonatal pneumothorax

Neonatal pneumothorax describes pneumothoraces occurring in neonates. It is a life-threatening condition, associated with high morbidity and mortality. The diagnosis is a challenge especially when the amount of air is small and may accumulate along the anterior or medial pleural space. Epidemio...
Article

Neurodegenerative MRI brain (an approach)

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...
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: alert and stable no focal neurologic deficit no altered level of co...
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Nipple markers

Nipple markers can be a useful technique in the evaluation of densities overlying the expected position of the nipple on a chest radiograph. Not uncommonly a small round opacity projects over the lower thorax on a chest radiograph (see: solitary pulmonary nodule). Often, especially in women, th...
Article

Normal mesenteric lymph nodes

In the pre-multidetector CT era, mesenteric lymph nodes were only really appreciated when enlarged. Following the advent of routine volume acquisition CT (and especially coronal reformats) they are commonly seen in normal individuals, which has raised the obvious question of what counts as mesen...
Article

Normal radiographic measurements of the shoulder

Normal radiographic measurements of the shoulder are important in evaluation of the osseous relationships in plain film radiography. Normal measurements do not rule out pathology, and must be considered in the context of other findings and the clinical presentation. AC joint space: 2-4 mm  inc...
Article

Oesophageal intubation

Oesophageal intubation refers to the incorrect placement of an endotracheal tube in the oesophagus. Within minutes its consequences can be catastrophic with the seriousness of its outcome depending largely on the timeliness of its diagnosis. Epidemiology Accidental oesophageal intubation can h...
Article

Optic nerve sheath diameter

Optic nerve sheath diameter has significance in the assessment of papilloedema 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, whi...
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Osteolytic lesions with septations and trabeculations (differential)

Differential diagnosis of lytic bone lesions with septations and trabeculations include 1: benign lesions unicameral bone cyst aneurysmal bone cyst giant cell tumour non-ossifying fibroma intraosseous lipoma fibrous dysplasia Brown tumour ameloblastoma adamantinoma haemophilic pseudot...
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

Ottawa knee rules

The Ottawa knee rules are a clinical decision-making strategy for determining which patients require radiographic imaging for knee pain. A patient with knee pain qualifies for knee radiographs if any of the following apply: 55 years or older point tenderness at the fibular head isolated poin...
Article

Paediatric elbow radiograph (an approach)

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! Systematic review Ossification Check that the ossification centres are present and in the correct position. T...
Article

Paediatric 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 paediatric urinary tract infection (UTI) management, including imaging, prophylaxis and follow-up 1.  This article inten...
Article

Pancreatic ultrasound

Pancreatic ultrasound can be used to assess for pancreatic malignancy, pancreatitis and its complications, as well as for other pancreatic pathology. Preparation Fast the patient to reduce interference from overlying bowel gas, which may otherwise make visualisation difficult. Scanning techni...
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Pathognomonic

The term pathognomonic in radiology, as well as clinical medicine in general, refers to a finding or a sign that is only found in a single specific condition or specific group of conditions, i.e. the finding has 100% specificity. Thus by implication, a pathognomonic finding cannot and does not h...
Article

Pathology checklists

Pathology checklists are really helpful when reporting a radiograph, ultrasound or cross-sectional examination. It is a key way to ensure that you fully review a film and don't fall foul of satisfaction of search. Plain film radiographs craniofacial skull radiograph checklist facial bones ra...
Article

Patterns of sinonasal obstruction

Recognising patterns of sinonasal obstruction is useful to help localise 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

PECARN traumatic brain injury algorithm

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...
Article

Pelvic pain in the exam

It is important to have a systematic way of approaching a case with pelvic pain in the exam.  Most examinations are performed using ultrasound. 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. Only...
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Pelvic radiograph (an approach)

Systematic review Three rings trace the main pelvic ring and two obturator foramina if a ring is disrupted, think fracture... then look for a second one Joint spaces the sacroiliac joints should be symmetrical, joint space range 2-4 mm the symphysis pubis joint space should be ≤5 mm if ei...
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Pelvic ultrasound

Pelvic ultrasound is usually the initial modality for imaging gynaecologic pathology, including acute pelvic pain and chronic pelvic pain. The exam normally involves two components: a transabdominal (TA) evaluation and a transvaginal (TV) / endovaginal (EV) evaluation. Normal ultrasound anatomy...
Article

Penile Doppler in erectile dysfunction

Penile Doppler in erectile dysfunction or papaverine-induced colour duplex Doppler, is a highly accurate means of assessing patients with erectile dysfunction (ED). Pathology Penile erection is a result of a complex interaction between the nervous, arterial, venous and sinusoidal systems. Any ...
Article

Perigestational haemorrhage in the exam

Getting a film with perigestational haemorrhage in the exam is one of the many exam set-pieces that can be prepared for.  Description Transabdominal and transvaginal (TV) pelvic ultrasound shows an anteverted uterus with an intrauterine gestational sac. MSD is 20 mm in TV study with a single, ...
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Per vaginal bleeding in the exam

It is important to have a systematic way of approaching a case with per vaginal bleeding in the exam.  Premenopausal embedded IUD lost IUD submucosal fibroid Pregnancy related perigestational haemorrhage intrauterine fetal demise ectopic pregnancy ruptured ectopic cervical ectopic  in...
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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

Pineal region (an approach)

A systematic approach to the pineal region is crucial as it is at the confluence of many intracranial structures/regions and is the site of origin of a number of unique pathologies as well as playing host to many entities which are more frequently encountered elsewhere. As such an understanding ...
Article

Pituitary MRI (an approach)

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 ...
Article

Placental abruption in the exam

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.  Description Transabdominal and transvaginal pelvic ultrasound show a single live fetus with gestational age of 27 weeks. The cervix i...
Article

Pleural effusion volume (ultrasound)

Measurement of a pleural effusion volume with point-of-care ultrasonography may be a useful tool for intensivists, and is an active area of research in critical care 7. In controlled settings ultrasound may detect constitutive pleural fluid, can reliably detect effusions >20mL in clinical setti...
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Pneumothorax

Pneumothorax refers to the presence of gas (air) in the pleural space. When this collection of gas is constantly enlarging with resulting compression of mediastinal structures, it can be life-threatening and is known as a tension pneumothorax. For those pneumothoraces occurring in neonates see t...
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Pneumothorax in the exam

Getting a film with a pneumothorax in the exam is one of the many exam set-pieces that can be prepared for.   It is unlikely that they will give you a simple pneumothorax - so, it is worth while considering the likely causes and whether it is under tension. Miss it at your peril (both in real l...
Article

Point-of-care ultrasound (curriculum)

The point-of-care ultrasound (PoCUS) curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core applications of ultrasonography in a point-of-care setting. Point-of-care ultrasound refers to ultrasonography which may be simultaneously performed,...
Article

Polycystic ovarian syndrome in the exam

Getting a film with polycystic ovarian syndrome in a subfertile patient is one of the many exam set-pieces that can be prepared for.  Description Transabdominal and transvaginal pelvic ultrasound show an anteverted uterus with a normal size. There is diffuse thickening of the endometrium to 17...
Article

Polydactyly

Polydactyly (less commonly called hyperdactyly) refers to the situation where there are more than the usual number of digits (five) in a hand or foot. It can be broadly classified as: pre-axial polydactyly: extra digit(s) towards the thumb/hallux (radially) post-axial polydactyly: extra digit(...
Article

Prosthetic cardiac valves on chest x-ray (an approach)

Prosthetic cardiac valves are a routine finding on chest X-ray. The frequency and degree of exposure is greatest in larger hospitals with cardiothoracic centres, however, prosthetic valves are commonplace universally. Recognition of which valve has been replaced, any other related cardiothoraci...
Article

Pulmonary nodule

Pulmonary nodules are small, rounded opacities within the pulmonary interstitium. Pulmonary nodules are common and, as the spatial resolution of CT scanners has increased, detection of smaller and smaller nodules has occurred, which are more often an incidental finding. Classification Pulmonar...
Article

Radiographic assessment of basilar invagination

Five lines have been described and used by most of the radiologists to evaluate basilar invagination on frontal and lateral skull plain radiographs as well as coronal and midsaggital reconstructed CT images. This is based on the relative projection of odontoid process to these lines, which is a...
Article

Radiographic evaluation of anterior cruciate ligament reconstruction

Radiographic evaluation of anterior cruciate ligament (ACL) reconstruction involves: femoral component a line is drawn along the posterior cortex of the femur a second line is drawn along the roof of the intercondylar notch of the femur (Blumensaat line) the point of intersection of these tw...
Article

Radiographic positioning terminology

Radiographic positioning terminology is used routinely to describe the position of the patient for taking various radiographs. Standard nomenclature is employed with respect to the anatomic position. Terminology Basic terms of relations anterior is towards the front of the body (Latin: before...
Article

Radiomics

Radiomics is a new emerging field in which medical images are converted into multidimensional data by data-characterisation algorithms. The data is assessed for improved decision support. Radiomics has the potential to uncover disease characteristics that fail to be recognised by the naked human...
Article

RANO criteria for glioblastoma

Response assessment in neuro-oncology criteria (RANO), published in 2010 1, are used to assess response to first-line treatment of glioblastoma (as well as lower grade astrocytoma 3) and have largely superseded the older Macdonald criteria (which only dealt with glioblastoma multiforme) 2. For ...
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

Renal artery stenosis

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. Pathology When the stenosis occurs slowly, collateral vessels form and supply the kidne...
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

Reporting tips for aortic aneurysms

When issuing an MRI or CT report on a patient with an aortic aneurysm, whether it be thoracic or abdominal, a number of features should be mentioned to aid the referring clinician in managing the patient. Reporting tips for aortic aneurysms include 1-2: size and shape sac dimensions (outer sur...
Article

Retained barium in appendix

Retained barium in appendix refers to the presence of barium in appendix beyond 72 hours from the start of procedure. Proposed significance Previously used as a sign of appendicitis. Actual significance Retained barium outlining the appendiceal lumen allows evaluation of its width and contou...
Article

Reticular and linear pulmonary opacification

In chest radiology, reticular and linear opacification refers to a broad subgroup of pulmonary opacification caused by a decrease in the gas to soft tissue ratio due to a pathological process centred in or around the pulmonary interstitium. This includes thickening of any of the interstitial com...
Article

Retrosternal airspace

The retrosternal airspace is seen as a normal lucency between the posterior aspect of the sternum and anterior aspect of the ascending aorta on lateral chest radiographs. This space normally measures less than 2.5 cm in width. Increased retrosternal airspace is a sign of pulmonary emphysema, whi...
Article

Retrotracheal space

The retrotracheal space (or Raider triangle) is a radiolucent mediastinal space best seen on lateral chest x-rays. It is normally triangular in shape but can vary greatly in size and shape depending on the patient's body habitus and lung volume 1. Boundaries anterior: posterior tracheal stripe...
Article

Reversal of umbilical arterial end diastolic flow

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. Epidemiology The estimated incidence is at ~0.5% of all pregnancies with a much higher...
Article

Reverse total shoulder arthroplasty

Reverse total shoulder arthroplasty (RTSA) is a type of total shoulder replacement. It is often the preferred method when there has been advanced damage to the rotator cuff as seen in rotator cuff arthropathy. Procedure The reverse total shoulder flips the normal mechanical arrangement of the ...
Article

Review areas on chest x-ray

Review areas on a chest x-ray are common areas for missed findings, and special attention should be paid to them: lung apices: masses (e.g. Pancoast tumour), pneumothorax behind the heart: consolidation, masses, hiatus hernia below the diaphragm: free gas, lines and tubes (e.g. nasogastric tu...
Article

Right paratracheal stripe

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...

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