PEDUNCULATED SUBSEROSAL FIBROID

T2FS SAGITTAL IMAGE SHOWING MULTIPLE UTERINE FIBROIDS. ARROW SHOWS STALK OF PEDUNCULATED FIBROID

STIR CORONAL IMAGE

T1 CORONAL IMAGE

A middle aged female with menorrhagia showed multiple uterine fibroids on ultrasound. Ultrasound also showed a pelvic mass just above the uterus the origin of which could not be clearly ascertained. MRI was done which clearly showed its connection to the uterine wall by a narrow stalk thus confirming its origin.

SUBMUCOSAL UTERINE FIBROID

MRI of the pelvis in a 22 year young lady with infertility showed a large submucosal fibroid of uterus.

• Sagittal and coronal T2FS and STIR images show a large submucosal leiomyoma that arises from the posterior uterine wall and causes significant distortion of the endometrial cavity.
• These can be differentiated from polyps on the basis of signal characteristics and location. Leiomyomas are hypointense on T2. Also, the origin of the leiomyoma is from the uterine wall rather than endometrium.

Mayer-Rokitansky-Kuster-Hauser syndrome

Sagittal T2FS image showing vaginal and uterine agenesis

Axial image showing normal left ovary

Axial image showing absence of vagina

17 year old patient presenting with primary amenorrhoea. MR reveals uterovaginal agenesis. Ovaries and kidneys were normally present.

Combined uterovaginal agenesis is the most common type of class I mullerian duct anomalies.
In Mayer-Rokitansky-Kuster-Hauser syndrome, patients usually have  agenesis or hypoplasia of upper two-thirds of vagina with intact ovaries. There may be variable anomalies of uterus, urinary tract and vertebrae.

CERVICO-ISTHMIC PREGNANCY

MRI sagittal images of the uterus( T1, T2FS) show a low lying gestational sac containing a fetus with empty uterine cavity above it and a large placenta  surrounding the gestational sac.  The cervix is shortened but shows a closed cervical canal suggesting a cervico-isthmic pregnancy. 

A patient presented in her mid thirties with a first trimester intra-uterine pregnancy having conceived after IVF.  USG showed a fetus with cardiac activity and crown-rump length corresponding to 11 weeks' gestation.  The gestation sac was abnormally low lying with an empty endometrial cavity above it. The cervix was poorly visualized. An MRI was indicated to rule out true cervical pregnancy.

MRI showed a low lying gestation sac with empty endometrial cavity above it. The cervix was shortened with a closed cervical canal and internal os. There was a large low lying placenta surrounding the sac with loss of interface between the placenta and myometrium. The myometrium was thinned out. A diagnosis of cervico-isthmic pregnancy was made with the likelihood of adherent placenta.

CERVICO-ISTHMIC PREGNANCY


INTRODUCTION: A cervico-isthmic pregnancy is an ectopic pregnancy which implants in the isthmus. The isthmus is the region between the cervix and fundus.

It is a rare complication of pregnancy and is often confused with a cervical pregnancy. Distinguishing between these is crucial as a cervical pregnancy is virtually not viable while there are a few reports of cervico-isthmic pregnancies being carried successfully to term. Also, cervical pregnancies are more dangerous and associated with serious risks like haemorrhage, rupture, blood transfusions, hysterectomy etc.

INCIDENCE:
Incidence of cervical pregnancy: 1:1000 to 1:16000.
Cervico-isthmic pregnancies are more common than true cervical pregnancies.

IMAGING FINDINGS:
USG: Typically, ultrasound shows an empty uterine cavity with a low lying pregnancy. It may be confused with true cervical pregnancy. In a true cervical pregnancy, the sac is completely within the cervix.

MRI: shows a  low lying gestation sac with a well preserved and closed cervical canal. It is hence helpful in distinguishing cervical from cervico-isthmic pregnancy.

IMPLICATIONS: Although there are reports of successful cervico-isthmic pregnancies, these pregnacies are also exposed to risks like:

• Spontaneous abortion/ premature delivery
• premature rupture of membranes
• placenta accreta
• postpartum hemorrhage
• hysterectomy
• Uterine rupture if associated with thinned out myometrium

REFERENCES:

1. Oyelese Y, Elliott T B, Asomani N, Hamm R, Napoli L, Lewis KM: Sonography and Magnetic Resonance Imaging in the Diagnosis of Cervico-Isthmic pregnancy. J Ultrasound Med 2003; 22: 981-983
2. Strobelt N, Locatelli A, Ratti M, Ghidini A: Cervico-isthmic pregnancy: a case report, critical appraisal of the diagnostic criteria, and reassessment of the outcome. Acta Obstet Gynecol Scand 2001; 80: 586-588.
3. Jelsema RD, Zuidema L: First trimester diagnosed cervico-isthmic pregnancy resulting in term delivery. Obstet Gynecol 1992; 80: 517-519
4. Wikipedia