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.

MILWAUKEE SHOULDER

T2 GRE-AXIAL

T2FS-AXIAL PLANE

PDFS-CORONAL PLANE

STIR-SAG PLANE

H

T1-SAG PLANE

 60 year old female with shoulder pain and decreases range of motion: Above images show large globular foci of hypointense signal on all sequences in the infraspinatous tendon/ associated bursa  s/o calcification due to Hydroxyapatite deposition disease. There is fluid in adjacent bursa / oedema in adjacent soft tissues.

TALOCALCANEAL COALITION

STIR coronal image

STIR coronal image

PDFS-sagittal image

T1-sagittal image

T1-sagittal image

Coronal and sagittal T1, STIR and PDFS sequences in a 30 year old female showing talocalcaneal coaltion.
There is continuity of marrow fat from the talus through the sustentaculum tali.
Secondary signs of talocalcaneal coalition are seen with talar beaking ( on last image).

This 30 year old female presented with rearfoot pain localized to the medial part of the foot along with flat foot.


Talocalcaneal coalition respresents 37 % cases of tarsal coalition with calcaneo-navicular coalition being the most comon type( 53 %).
Talocalcaneal coalition can occur through any of the 3 facets but is most common in the middle facet through the sustentacumum tali. These are best evaluated  on coronal images.
In fibrous coalition, there may be subchondral marrow oedema.

Secondary signs of a talocalcaneal coalition include:
Talar beaking adjacent to talonavicular articulation- also seen on lateral x-rays
Degenerative dorsal changes in calcaneocuboid joint

REFERENCES:

• Stoller DW, Ferkel RD: The Ankle and Foot. Magnetic Resonance Imaging in Orthopaedics and Sports Medicine: Volume I: Third Edition. Lippincott Williams & Wilkins:1009-1013, 2007.
• Radiopaedia.org

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

RHOMBENCEPHALOSYNAPSIS

Figure 1: Coronal T2 image showing fused dentate nucleus

Figure 2: Coronal T2 weighted image showing typical transverse folia and sulci with fused cerebellar hemispheres

Figure 3: Axial T2WI showing fusion of the interfoliate sulci across midline along with fusion of cerebellar folia.

Figure 4: Axial T2WI showing "keyhole appearanca" of 4th ventricle and midline fusion of cerebellar white matter. Vermis is not seen.

Figure 5: Sagittal T2WI showIng absent primary fissure. There is also slight rounding of the fastgial recess. Note the corpus callosum in a patient of isolated rhombencephalosynapsis.

The above MR was done in an adult patient presenting with mild gait ataxia. Rhombencephalosynapsis was detected in him as an isolated finding.

• Rhombencephalosynapsis is a rare  posterior fossa malformation characterized by aplastic/ hypoplastic cerbellar vermis and fusion of cerebellar hemispheres in the midline.
• It was forst described by Obersteiner in 1914.
• Pathogenesis is related to disturbed cerebellar development between 28 to 41 days of gestation.
• Clinical profile varies and is related to the posterior fossa malformation and associated supratentorial anomalies. It might vary from mild truncal ataxia and normal intelligence to cerebral palsy.
• Isolated rhombencephalosynapsis is less common than rhombencephalosynapsis associated with supratentorial anomalies
• Most cases are reported in infancy or pediatric age group with only few cases reported in adults.

Diagnosis is usually by MRI which is clearly superior to CT in evaluating these patients.

Distinctive radiological features are:
Posterior fossa:

• Agenesis / hypoplastic vermis 
• Absent posterior cerebellar incisura, vallecula
• agenesis or hypogenesis of anterior vermis ( rostral ) with hypoplastic posterior vermis( caudal  nodulus may form
• Midline fusion of cerebellar hemispheres to form a single lobed cerebellum
• Fissures and cerebellar folia are transversely oriented best seen on coronal MRI
• Superior and middle cerebellar peduncles may be fused along with dentate nuclei giving a characeteristic diamond shaped, posteriorly pointing 4th ventricle

Supratentorial anomalies:

• Most common supratentorial anomaly is hydrocephalus with aqueductal stenosis
• Sometimes, there may be fused thalami, fornIces, cerebral peduncles, inferior collicluli with absent septum pellucidum
• Dysgenetic limbic system
• cortical malformatins
• sutural synostosis
• hypoplastic commissures, hypoplastic anterior visual pathway and agenesis of posterior lobe of pituitary gland
• Association with septo-optic dysplasia and holoprosencephaly

 References:

• Mendonca JLF, Natal MRCR, Viana SL et al. Rhombencephalosynapsis: CT and MRI findings. Neurology India;152:118-120, 2004.
• Weerakkody Y, Gaillard F et al. Rhombencephalosynapsis. Radiopaedia.org.
• Blaser SI: Rhombencephalosynapsis. Diagnostic Imaging Brain: First Edition. Amirsys: I-1-30, 2005.

IDIOPATHIC INTRACRANIAL HYPERTENSION

IDIOPATHIC INTRACRANIAL HYPERTENSION:

 Figure 1: showing increased fluid in sheaths surrounding optic nerves along with tortuosity of the sheaths

 Figure 2: showing flattening of posterior sclera

Figure 3: Sagittal T2 WI showing a partially empty sella

The above pictures are of a 35 year old female who presented with headache and progressive visual loss.

MRI of the brain and orbits showed a partially empty sella, dilated/ tortuous optic nerve sheaths along with posterior scleral flattening. 
There was no evidence of an intracranial mass/ space occupying lesion or dural sinus thrombosis.

IDIOPATHIC INTRACRANIAL HYPERTENSION( IIH):
Also called pseudotumor cerebri.
As the name implies,the intracranial pressure is raised with no obvious underlying pathology in the brain.
Most common clinical presentation is an obese female aged 20-40 years with headache( aggravated by Valsalva), papilledema, progressive visual loss, diplopia etc.
MRI reveals a partially empty sella, optic nerve sheath dilatation with vertical tortuosity, optic nerve head protrusion and scleral flattening.
The diagnosis is made after other potential causes of raised intracranial hypertension like dural sinus thrombosis, space occupying lesion are excluded.
Aim of treatment is to prevent visual loss which is a potential danger from chronic papilledema.

REFERENCES:

1.  Suzuki H, Takanashi J, Kobayashi K et al: MR Imaging of Idiopathic Intracranial Hypertension. AJNR 22:196-199, 2011
2. Hingwala DR, Kesavadas C, Thomas B et al: Imaging signs in idiopathic intracranial hypertension: Are these signs seen in secondary intracranial hypertension too? Ann Indian Acad Neurol 16(2):229-233, 2013
3. Castillo M: Idiopathic Intracranial Hypertension. Diagnostic Imaging Brain: First Edition. Amirsys: I-10-36, 2005.

MRI in Spigelian Hernia

T1 weighted images in axial and sagittal plane, T2 FS images in axial plane of an 80 year old male presenting with palpable swelling in the right ventral abdominal wall shows focal herniation of mesenteric / omental fat and vessels through a defect in the right spigelian aponeurosis ( that of the internal oblique and transversus abdominis muscles) inferior to the umbilicus. The hernial sac is covered externally by an intact aponeurosis of the extrenal oblique muscle. There is no herniation of bowel loops through this defect.

• Spigelian Hernia is a hernia through a defect in the aponeurosis of internal oblique and transversus abdominis muscles.
• It is seen seen as a defect in the spigelian aponeurosis  lateral to the rectus muscles, inferior to umbilicus where the sheath is deficient posteriorly.
• The external oblique aponeurosis is intact with the hernial sac lying in interparietal/ intermuscular plane 
• It is named after a Belgian surgeon-anatomist by the name of Adriaan van den Spiegel although it was first described by KLINKOSCH
• Raveenthiran has described the existence of spigelian hernias with cryptorchidism called the Raveenthiran Syndrome

• It is a rare hernia, approx. 1%( range of 0.2 -2%) of ventral hernias.
• It is commoner on the right side in 4th-7th decade of life.
• It is commoner in females with a male to female ratio of approx. 1:1.18.

• It may be congenital or acquired
• It may be entirely asymptomatic. Its clinical significance lies in the fact that the hernial opening is small predisposing the bowel loops to strangulation/ obstruction. Hence, it is importatnt to repair it. The repair is usually straightforward and rarely requires a mesh prosthesis.
• It is difficult to diagnose clinically, especially in obese patients
• Imaging: USG is often used in conjunction with Valsalva's manouvre in real time to demonstrate the hernia. CT is considered optimal especially with oral contrast. The role of MRI is less described in literature being a more expensive modality. However, with the wider availability of MRI and its better anatomical visualization, it may prove useful in preoperative evaluation as in this patient.
• Differentials are ventral hernias, umbilical hernia, hernia thorugh laparoscopy port etc.

REFERENCES:

• Harrison LA, Keeshing CA, Martin NL et al. Abdominal wall hernias: Overview of herniography and correlation with cross-sectional imaging. Radiographics 1995; 15(2):315-22.
• Mittal T, Kumar V, Khullar R et al: Diagnosis and management of Spigelian Hernia: A review of literature and our experience. J. Minimum Access Surgery 2008; 4(4): 95-98
• Raveenthiran V. Congenital spigelian hernia with Cryptorchidism: Probably a new syndrome. Hernia 2005; 9(4):378-80
• Federle MP, Jeffrey, RB, Woodward PJ, Borhani AA. Spigelian Hernia. Diagnostic Imaging Abdomen: Second Edition. Amirsys: II-1, 37,2010