3/25/07

MRI feature of white matter disease

Brain atrophy
Involved symmetericity
Myelin abnormality
Brainstem & cerebellar involvement
Contrast enhancement
Malformation
Dynamic imaging pattern

Pseudomyxoma peritonei

Ruptured mucocele with foreign body peritonitis
Male: cystadenocarcinoma of appendix
Female: cystadenocarcinoma of ovary

*Thickening of peritoneal + omental sufaces
*Omental cake
*Posterior fixation of bowel loops and mesentery
*Voluminous septated/loculated pseudoascites
*Several thin-walled cystic masses of different size throughout abdominal cavity
*Scalloped contour of liver and splenic margins
Annular / semicircular calcifications

3/23/07

GIST

Esophageal GIST

Gastric GIST



3/20/07

Hiatal hernia



Sliding hernia (axial type): 95%
- GEJ is aboe the diaphragm
- Reflux is more likely with larger hernias
- May be reducible in erect position
Paraesophageal hernia
- GEJ is in its normal position
- Part of the fundus is herniated above the diaphragm through esophageal hiatus and lies to the side of the esophagus
- Not reflux
- More prone to mechanical complications
- Usually nonreducible

*Gastric folds aboe diaphragm
*B line above diaphragm
*Schatzki's ring above diaphragm

%Esophagitis
%Duodenal ulcers

3/16/07

Sign of Intraperitoneal Free Air

Rigler's sign
Triangle sign
Falciform ligament sign
Inverted V sign
Urachus sign
Hyperlucent liver sign
Hepatic age som
Doge cape sign
Anterior superior oal sign
Foot ball sign
Dolphin sign

3/15/07

The pathway of ascites flow over lower abdomen

a. The pelvic cavity, especially the pouch of Douglas
Pouch of Douglas - The most caudal and posterior part of the peritoneal cavity
Upper 4th sarcal segment
Fixation of the peritoneum to Denonvillier's fascia
b. The right lower quadrant at the termination of the small bowel mesentery
c. The superior aspect of the sigmoid mesocolon
d. The right paracolic gutter

Gastric Volvulus

Gastric volvulus
- Mesenteroaxial type: from lesser to greater curve
- Organoaxial type: from cardia to pylorus
Cause
- Diaphragmatic defect
- Intestinal malrotation
- Wandering spleen
-Absence of gastrophrenic ligament and gastrosplenic ligament
Resolve spontaneously sometimes.
*Organoaxial vovulus*

Juxtapapillary diverticula

3/12/07

Rotator Cuff

Muscle Origin on scapula Attachment on humerus Function
Supraspinatus muscle supraspinous fossa greater tubercle abducts the arm
Infraspinatus muscle infraspinous fossa greater tubercle laterally rotates the arm
Teres minor muscle lateral border greater tubercle laterally rotates the arm
Subscapularis muscle subscapular fossa lesser tubercle medially rotates the humerus

3/9/07

Major Upper Abdominal Peritoneal Reflection

Falciform ligament - Right coronary ligament - Left triangular ligament
Lesser omentum
Gastrohepatic ligament
- Glisson's capsule
- Left gastric artery
- Coronary vein
- Left gastric nodal chain
Hepatoduodenal ligament
- Free edge of gastrohepatic ligament
- Portal triad
- Portacaval region

Gastrocolic ligament
- Gastroepiploic vessels
- superior mesenteric vein ate the level of uncinate process of pancreas
- Transverse mesocolon
- Taenia mesocolica
Duodenocolic ligament
- descending duodenum
- posterior hepatic flexure
Gastrosplenic ligament
- Gastrocolic ligament and extended from the greater curvature of the stomach to the spleen.
Phrenicocolic ligament
- From the anatomic splenic flexure of the colon to the diaphragm at the level of 11th rib and serves to support the spleen in the left upper quadrant
Small bowel mesentery
- Extended from the left side of the second lumbar vertebra downward to the right. across the aorta and inferior vena cava, to the right sarcoiliac joint, about 15cm.

3/7/07

Complication of subtotal gastrectomy

Esophageal Symptoms

Delayed Gastric Emptying

Recurrent Ulcers

Carcinoma

Afferent Loop Syndrome

Diarrhea

Weight Loss and Malabsorption

Anemia

Cholelithiasis

Dumping syndrome : early and late

Typical aging change of pancreas

3/5/07

ICH in MRI appearance

T1WI
Hyperacute (intracellular oxy-Hgb): Isointense
Acute (intracelluar deoxy-Hgb): Isointense
Subacute-early (intracellular met-Hgb): Hyperintense
Subacute-late (extracelluar met-Hgb): Hyperintense
Chronic-early (extraelluar met-Hgb & ferritin/hemosiderin wall): Hyperintense
Chronic-late (hemosiderin): Isointense
T2WI

Hyperacute (intracellular oxy-Hgb): Hyperintense with/without hypointense rim
Acute (intracelluar deoxy-Hgb): Hypointense
Subacute-early (intracellular met-Hgb): Hypointense
Subacute-late (extracelluar met-Hgb): Hyper
Hyperintense
Chronic-early (extraelluar met-Hgb & ferritin/hemosiderin wall): Hyperintense with pronounced low signal rim
Chronic-late (hemosiderin): Hypointense
T2*GRE
All hypointense, senseitive to some lesions
DWI
Findings parallel that of convential T2WI
Significant correlation between lesion volume and degree of ADC elevation in perihematoma edema
T1WI with contrast

Ring enhancement appearance in subacute phase

3/4/07

Bone Island

A bone island, also known as an enostosis, is a focus of compact bone located in cancellous bone. This is a benign entity that is usually found incidentally on imaging studies; however, the bone island may mimic a more sinister process, such as an osteoblastic metastasis.
In CT: a round nodule without extension outside the cancellous bone and does not cause bony destruction