Intracranial aneurysm - description of size and neck + calculator

Apart from giving the dimensions of an intracranial aneurysm, its size should be cathegorized according to this table.

Description Size
Small ≤5mm
Medium <15mm
Large <25mm
Giant ≥25mm

The diameter of the neck of the aneurysm is cathegorized as well.

Description Size

Germinal matrix hemorrhage - grading of intracranial bleeding in neonates

Grading of intracranial hemorrhage in neonates is based on ultrasound imaging. It has four grades with increasing mortality and decreasing outcome.

Grade Description
Grade I hemorrhage is confined to the germinal matrix
Grade II intraventricular hemorrhage without ventricular dilation
Grade III intraventricular hemorrhage with ventricular dilation
Grade IV

Shoulder impingement syndrome - Neer classification

Neer classification divides lesions of the rotator cuff into three stages that typically succeed in this order during one's life.

Stage Description Age group
Stage I actue inflammation, edema, hemorrhage in the rotator cuff younger patients <25 years
Stage II progression to fibrosis and tendinitis of the rotator cuff usually between 25 and 40 years
Stage III

Fracture types of axis, C2 by Effendi, modified by Levine & Edwards

The classification of fractures of axis was introduced by Effendi et al. and later modified by Lewine and Edwards. With further two types added (IA and IIA), the modified classification has five types.

Type Description
Type I fracture of the pedicles, intervertebral disc C2/3 is intact, dislocation ≤3mm without angulation
Type IA fracture lines on each side are not parallel, fracture line may involve foramen transversarium on one side

Grading of meniscal injury

Lesions of the menisci on MRI are divided into four grades. Normal meniscus has uniformly low signal intensity on T2-weighted images (T2W). Grade I and II lesions can be a normal appearance of ageing in older patients.

Grade Description
Grade I small focus of increased signal intensity on T2W, that does not extend to the articular surface
Grade II linear area of increased signal intensity without extension to the articular surface

Grading of injury of the collateral ligament of the knee on MRI and ultrasound

Injuries to the medial collateral injury are divided into three grades similarly to other ligamentous lesions elsewhere.

Grade Description Description - MRI Description - US
Grade I microscopic tear or strain injury edema superficial to the ligament hypoechoic fluid parallel to the ligament
Grade II partial tear

Doubling time - calculation of growth rate of a lesion or a mass

Calculating doubling time of focal lesions or massess can give a hint, whether it has a malignant or rather benign growth dynamics. Doubling time of malignant lesions is between 30 and 500 days with a median of 100 days.

Intervertebral disc degeneration in lumbar spine - MRI classification by Pfirrmann et al.

The Pfirrmann classification was developed in 2001 and was based on previous systems. It was validated on 60 MRI examinations of the lumbar spine assessed by three independent observers. The imaging protocol included sagittal T1 weighted spin-echo, T2 weighted fast spin echo (FSE) in sagittal and axial plane.

Grade Structure Distinction of nucleus pulposus and anulus fibrosus Signal intensity on T2 weighted images Height of intervertebral disc
Grade I

Intervertebral disk degeneration - MRI classification by Watanabe et al.

In 2007, Watanabe et al. published grading of degenerative changes of the intervertebral disc by MRI. It is based on T2 weighted axial sections.

Grade T2 signal intensity (SI) of nucleus pulposus T2 signal intensity (SI) of anulus fibrosus Distinction of nucleus pulposus and anulus fibrosus
Grade I
  • high SI
  • homogeneous
  • low SI
  • homogeneous

Adams classification of diffuse axonal injury, DAI

Grading of Diffuse Axonal Injury as proposed by Adams et al.

Grade I:

  • axonal injury limited to white matter (grey-white matter interfaces)

Grade II:

  • Grade I + involvement of corpus callosum

Grade III:

  • Grade II + involvement of brainstem


1. Adams JH, Doyle D, Ford I, Gennarelli TA, Graham DI, Mclellan DR. Diffuse axonal injury in head injury: Definition, diagnosis and grading. Histopathology. 1989;15(1):49–59.

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