HEPATIC HEMANGIOMA

Q.All are true regarding MRI of hepatic hemangioma except

a.MRI ---the most sensitive modality for detection

b.T1 and T2 relaxation times considerably shorter  than that of solid hepatc tumour or normal heapatic parenchyma

c.hypointense on T1 image and significantly hyperintense on T2 image

d.light bulb sign on T2

e.show greater hypointensity on T1 and proton-weighted image compared to cyst

ANS.---b

T1 and T2 relaxation times of hemangioma are considerably longer  than that of solid hepatc tumour or normal heapatic parenchyma.So,hemangioma appear hypointense on T1 images and significantly hyperintense on T2images.Unlike most primary or metastatic liver lesions ,which generally have shorter T2relaxation times ,hemangioma typically retain their marked signal intensity on heavily T2-Weighted multiecho (echo delay times in excess of 100msec) accounting for the so called “light bulb” sign .The signal intensity of hemangioma resembles that of CSF ,which may be used as an internal reference standard on such images.Although simple hepatic cyst may demonstrate a similar hyperintensity on T2 images ,they can usually be distinguished by their relative greater hypointensity on both T1 and proton density

Hemangioma typically exhibit a homogenous hyperintense pattern ,whereas metastases commonly display a heterogenous amorphous appearance .Ringed morphology,indistinct margination ,or surrounding peritumoral edema. The light-bulb sign is not 100% specific for hemangioma ,as anywhere from 9% to 27% of hepatic metastases also demonstrate a homogeneous hyperintense pattern on T2 images.

CYSTOCELES---GREEN

 The traditional radiological classification of cystoceles, originally proposed by Green, is based on
----1. descent of the bladder neck,
---- 2.retrovesical angle—the angle between the proximal urethra and
---- 3.the trigonal surface of the bladder —and the degree of urethral rotation. 
-----Green type I is described as cystocele with open retrovesical angle (≥ 140°) and urethral rotation < 45°.
------ Green type II describes a cystocele with open retrovesical angle (≥ 140°) and urethral rotation between 45 and 120°, also called cystourethrocele. 
------A cystocele with intact retrovesical angle (< 140°) is defined as Green type III.

Both cystourethrography and ultrasound can distinguish between two main types of cystocele, i.e. cystourethrocele (Green type II) and cystocele with intact retrovesical angle (Green type III)
----. For this purpose, translabial ultrasound seems particularly useful since it is non-invasive and can easily identify not just the bladder, but also surrounding soft tissues, allowing assessment of bladder neck descent, retrovesical angle and degree of cystocele descent.

------. These two types of cystocele may have different etiologies and functional implications. Cystocele type III is more likely to be associated with levator trauma, i.e. avulsion injury, which is due to childbirth, associated with prolapse and prolapse recurrence
----. A Green type II cystocele is more commonly found in patients with stress incontinence and an intact levator
-----. Women with a Green type III cystocele tend to suffer more from voiding dysfunction than stress incontinence. The etiology of cystourethrocele is less likely to be caused by paravaginal defects than is the type III cystocele

Tc 99m

Q.All are true regarding Tc 99m sulphur colloid  except

a.minimal activity in blood after 20 minutes after IV bolus

b.60 to 70% taken by liver

c.particle size  approx. 0.3 to 0.5 microns in diameter

d. 3 to 8 millicuries injected for routine liver scan

e.indium 113m colloid used as alternative

ANS.---b

Tc 99m sulphur colloid is taken by the reticuloendothelial system –80 to 90 % by the liver ,5 to 10 % by the spleen,and a minimal amount by the bone marrow of normal individuals.

The indium 113m colloid is not an ideal radionuclide because of its high energy ,393 ke V. The In 113 generator needs replacement twice yearly as opposed to weekly with the Tc 99m generator.

PORTAL HYPERTENSION

q.A case of cirrhosis of liver undergoes Doppler study to detect the  portosystemic shunt .A rounded lucency is seen within the fissure for the ligamentum teres in transverse section .Doppler study shows tubular structure in saggital section running caudal from the left portal vein  along the ligamentum teres .What is the vein involved in the shunt formation

a.left gastric vein            

b.the paraumbilical vein

c.splenorenal shunt

d.esophageal varices

e.paraesophageal varices

ANS.---b