CT
Hinchey classification of acute diverticulitis
The original Hinchey classification was based on perioperative surgical finding. It has been later modified by Sher et al.:
Modified Hinchey classification (Sher et al., 1997):
| Stage | Description |
|---|---|
| I | Pericolic abscess |
| IIa | Distant abscess amendable to percutaneous drainage |
| IIb | Complex abscess associated with fistula |
| III | Generalized purulent peritonitis |
Adrenal lesion characterization by washout on a three-phase CT
Characterization of adrenal masses that are less than 3cm in diameter can be achieved by calculating its washout on a three-phase CT acquisition (unenhanced, venous, and delayed phase). It does not apply to masses that have a specific appearance such as myelolipoma (fat attenuation). Lesions with attenuation ≤10HU on unenhanced scan are lipid-rich adenomas.
Staging of colorectal cancer
TNM classification of colorectal cancer
| T | Primary tumor |
|---|---|
| Tx | Primary tumor cannot be assessed |
| T0 | No evidence of primary tumor |
| Tis | Carcinoma in situ: invasion up to lamina propria mucosae |
| T1 | Tumor invades submucosa |
| T2 |
Malrotation of the gut
During development, the bowel rotates 270° anticlockwise in two locations: the foregut and midgut junction (duodenum) and midgut-hindgut location (cecum), so that the ligament of Treitz is located left to the midline and cecum reaches the right iliac fossa. Completeness of rotation can be classified into four cathegories:
| Cathegory | Description |
|---|---|
| Normal rotation | Normal appearance of the gut, cecum in the right iliac fossa and the ligament of Treitz left to the midline |
Subependymal hemorrhage (SEH) into germinal matrix
Subependymal hemorrhage or germinal matrix hemorrhage occurs in premature infants with very low birth weight (<1500g). The germinal matrix in the immature brain is located around the lateral ventricles and it contains a fine network of fragile blood vessels, which are sensitive to ischemia and changes in perfusion pressure. Subependymal hemorrhage in premature neonates can be easily assessed by ultrasound and be divided into four grades.
| Grade | Description |
|---|---|
| Grade I | hemorrhage confined to the germinal matrix |
| Grade II | intraventricular hemorrhage (hemocephalus) without ventricular dilation |
| Grade III | intraventricular hemorrhage (hemocephalus) with ventricular dilation |
| Grade IV | intraventricular rupture with hemorrhage into the surrounding white matter |
References:
1. Bowerman R, Donn S, Silver T, Jaffe M. Natural history of neonatal periventricular/intraventricular hemorrhage and its complications: sonographic observations. American Journal of Roentgenology. 1984 Nov 1;143(5):1041–52.
2. Radack DM, Baumgart S, Gross GW. Subependymal (grade 1) intracranial hemorrhage in neonates on extracorporeal membrane oxygenation. Frequency and patterns of evolution. Clin Pediatr (Phila). 1994 Oct;33(10):583–7.
3. Smith WL, McGuinness G, Cavanaugh D, Courtney S. Ultrasound screening of premature infants: longitudinal follow-up of intracranial hemorrhage. Radiology. 1983 May 1;147(2):445–8.
Estimate of spleen volume on CT or MRI, splenic index - calculator
This formula can be used to estimate volume of the spleen on crossectional imaging methods by measuring three dimensions - caudocranial (L), maximum size in axial plane (D), and maximum thickness in axial plane (T).
Splenic index = L x D x T
A normal value is considered ≤480.
Volume [mL] = 30 + 0.58 x L x D x T
A normal value is considered between 110 and 340mL
Sternoclavicular joint injury - Allman classification
Posttraumatic instability of the sternoclavicular joint is a result of injury to the joint capsule, the sternoclavicular or costoclavicular ligament.
| Grade | Description |
|---|---|
| Grade I | sprain of the sternoclaviular joint without laxity and minimum pain |
| Grade II | rupture of the sternoclavicular ligaments without rupture of the costoclavicular ligament |
| Grade III |
Perilunate instability - Mayfield classification of carpal instability
Mayfield et al. described in 1980 the following four stages of progressive carpal instability.
| Stage | Description |
|---|---|
| Stage I | scapholunate dissociation: dorsal dislocation of the proximal scaphoid pole in the radiocarpal joint (rotatory subluxation of the scaphoid) with disruption of the dorsal scapholunate ligament leads to widened scapholunate distance (Terry Tomas sign) on radiograph |
| Stage II |
Posterior dislocation of the hip - Thompson-Epstein classification
Thompson-Epstein classification describes five types of posterior hip dislocation defined by associated acetabular fracture or fracture of the femoral head as depicted on plain radiographs. In general, there are three types of dislocations in the hip joint:
- posterior: the femoral head is dislocated posteriorly, most commont type
- anterior: the femoral head is dislocated anteriorly
- central: impact of the femoral through the acetabular floor into the pelvis
Dislocation in acromioclavicular joint - Rockwood classification of AC dislocation
Rockwood classification divides dislocations in AC joint into six grades. It is an extension of the previous classification by Tossy et al. Normal width of AC joint is considered 1-3mm, widened AC joint has >7mm in men or >6mm in women.
| Grade | Description |
|---|---|
| Grade I | sprain of the acromioclavicular (AC) ligaments |
| Grade II | complete rupture of the AC ligaments |
| Grade III |
