Items tagged “measurement”

41 results found
Article

Skull base angle

The skull base angle (of Boogard) allows the diagnosis of platybasia and basilar kyphosis. Several different techniques may be used on sagittal images from MRI or CT. Traditionally, basal angle measurements were based on plain skull images. With the advent and generalization of MR imaging, it h...
Article

Tentorial angle

The tentorial angle is measured between a line connecting the nasion with the tuberculum sellae and the angle of the straight sinus. Normally it should measure between 27° and 52°. Abnormalities of the posterior fossa or base of skull can alter this. For example, this angle is elevated in achon...
Article

Caudate–right lobe ratio

The caudate-right lobe ratio (C/RL) is used in the assessment of the liver, usually in the setting of cirrhosis, where there is atrophy of the right lobe with hypertrophy of the caudate lobe.  Method image level: axial slice immediately below the bifurcation of the main portal vein line 1: pa...
Case

Caudate-right lobe ratio (diagram)

  Diagnosis not applicable
Frank Gaillard
Published 06 Jan 2010
32% complete
Diagram
Article

Line of Klein

The line of Klein describes an arbitrary line drawn along the superior edge of the femoral neck on the frontal projection, which is useful in detecting early slipped upper femoral epiphysis in adolescents. The line should normally intersect the lateral aspect of the superior femoral epiphysis. ...
Article

Rectosigmoid ratio

The rectosigmoid ratio is a measurement of the diameter of the rectum divided by that of the sigmoid colon during contrast enema. It is of particular use in the diagnosis of Hirschsprung disease. Normal children have a rectum that is larger than the sigmoid (i.e. rectosigmoid ratio >1). In fact...
Article

Flattening of the diaphragm

Flattening of the diaphragm is the most sensitive sign on chest radiographs for the presence of hyperinflation of the lungs, usually due to emphysema 1,2. On a lateral chest radiograph, the normal dome of each hemidiaphragm should rise at least 1.5 cm above a line connecting the costophrenic an...
Case

Bohler's angle (annotated x-ray)

  Diagnosis not applicable
Frank Gaillard
Published 03 Jun 2010
32% complete
X-ray
Case

Normal Chauveaux–Liet angle

  Diagnosis not applicable
Guilherme H. Lopes Nunes
Published 08 Nov 2010
32% complete
Annotated image
Article

Cardiothoracic ratio

The cardiothoracic ratio (CTR) aids in the detection of enlargement of the cardiac silhouette, which is most commonly from cardiomegaly but can be due to other processes such as a pericardial effusion.  Terminology Some report cardiothoracic ratio as a percentage, however this is incorrect, as...
Article

Widening of the presacral space (differential)

Widening of the presacral space is one of the diagnostic indicators of diseases involving pelvic pathology and rectal involvement. It is ideally measured on barium studies at the level of S3/4 disc level on lateral radiographs and the normal value of the presacral space is <15 mm in adults.​ Th...
Article

Midbrain to pons ratio (PSP)

Midbrain to pons ratios as measured on midline sagittal images have been found useful in confirming midbrain atrophy in the setting of progressive supranuclear palsy (PSP). Area ratio A measurement method was described by Oba et al. on the midsagittal MR image using free-hand regions of intere...
Article

Frontal horn width to intercaudate distance ratio

Frontal horn width to intercaudate distance ratio (FH/CC) is used in assessing patients with suspected Huntington disease. An alternative measurement is intercaudate distance to inner table width ratio (CC/IT). Measurement On the same axial plane obtained on the ACPC (anterior commissure and p...
Article

Intercaudate distance to inner table width ratio

Intercaudate distance to inner table width ratio (CC/IT) is used in assessing patients with neurodegenerative diseases that affect the caudate nuclei. It is best known for assessing individuals with suspected Huntington disease but is in no way specific for the diagnosis, also seen in other less...
Article

Acromiohumeral interval

Acromiohumeral interval is a useful and reliable measurement on AP shoulder radiographs and when narrowed is indicative of subacromial impingement, rotator cuff tear and/or tendinopathy. In patients with rotator cuff repair, a narrow acromiohumeral interval is a risk factor for re-tear 7. Meas...
Article

Intermetatarsal angle

The intermetatarsal angle is a measurement used to assess hallux valgus and metatarsus primus varus deformities. Terminology The term intermetatarsal angle alone typically refers to assessment of the first and second metatarsals. Occasionally the term first intermetatarsal angle is used to spe...
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

Coracohumeral interval

The coracohumeral interval is usually measured on axial or oblique sagittal CT or MRI and normally measures between 7-11 mm. A measurement <6 mm is always considered abnormal 1. 
Article

Condyle-C1 interval (CCI)

The condyle-C1 interval (CCI) is the measurement of the interval between condyle and C1 at four equidistant points on the joint surface in sagittal and coronal reconstructions of computed tomography. The CCI is reported to have a high lateral symmetry in children 1. Used with a cut-off of 4 mm,...
Article

Tibiofibular clear space

The tibiofibular clear space is a radiographic measure and defined as the space between the groove of the distal tibial prominence and the medial margin of the distal fibula 1-3. Usage Together with the tibiofibular overlap and the medial clear space, the tibiofibular clear space has been used...

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