Renal Duplex Systems

  

Case of Bilateral Renal Duplex System

Patient is a 36year old female, with h/o right ureterocele excision. 

USG was done initially, in which there was a tubular anechoic structure in right adnexa, mimicking a Hydrosalpinx. TVS confirmed the structure to be a dilated lower ureter, which was showing peristalsis and was seen in continuity with the right VUJ. This type of Ureteric Dilatation (Possibly secondary to reflux) can be easily mistaken for a hydrosalpinx. See the link below.

 CASE REPORTS: 'Duplex Megaureter Misdiagnosed as a Hydrosalpinx on Ultrasound '

Since there was right upper calyceal dilatation, Right Duplex System was suspected. LK was normal at time of USG.

LK shows two ureters	LK shows two ureters

CT images showed bilateral entirely duplicated ureters, bilateral upper moeity hydronephrosis. Right superior moeity ureter was seen inserted at a lower than normal position, with abnormal segmental dilatation of the distal 8-9cm.

Fetal PCA

FETAL POSTERIOR CEREBRAL ARTERY (PCA)

• In this anomaly, the Posterior Communicating artery(PCom) is prominent, with hypoplastic / Absent P1. Original Fetal PCA has absent P1, which is very rare.   

• Unilateral right OR Unilateral left PCA has an incidence of ~10% each. Bilateral Fetal PCA has an incidence of ~8%.

• The calibre of the PCom can be same as or greater than the PCA, and thereby the blood supply to the occipital lobes will be derived from the ICA through the PCom. The importance of this comes when ICA gets occluded, and will involve the ACA, MCA and PCA territories altogether (which will be difficult to explain by embolization). 

• Fetal origin of the posterior cerebral artery occurs when the embryonic posterior cerebral artery fails to regress.

Following are Axial Sections of NECT Brain of a middle aged female, which shows possible bilateral fetal PCAs. Here the Basilar artery bifurcation is not visualized and bilateral PComs are seen prominent (fig.3).

Small Basilar Artery anterior to Pons	Prominent bilateral PComs
Prominent bilateral PComs
P2 starts here!	Further continuation of PCAs(P2)

Lumbosacral transitional vertebrae

SYNONYMS : Lumbosacral transitional segment, lumbarization, sacralization, lumbosacral transanomaly, borderline vertebra.

A lumbar segment with enlarged transverse elements and an upper sacral segment with  lumbar-type posterior elements are the two most common presentations.
The relationship of LSTV to back and leg pain has long been a subject of debate.
The association of back pain with antalgic scoliosis was first described by Bertolotti in 1917 
(sacralization douleureuse, Bertolotti’s syndrome).

Radiological Findings: 

LSTV is characterized by enlargement of the transverse process(es). Frontal and lateral views should be performed and preferably supplemented with an angulated view of the lumbosacral junction (Ferguson-Hibb view).

Note: L3 has the longest transverse process and L4 has a pointed TP. 

Castellvi et al described a radiographic classification system identifying 4 types of LSTVs on the basis of morphologic characteristics.

Type I includes unilateral (Ia) or bilateral (Ib) dysplastic transverse processes, measuring at least 19 mm in width (craniocaudad dimension).Here the transverse process is expanded toward its tip as a spatulated bony process that is < 19 mm with no obvious connection to the sacral ala. This anomaly has a dubious role in back pain syndromes.

Type II exhibits incomplete unilateral (IIa) or bilateral (IIb) lumbarization/sacralization with an enlarged transverse process that has a diarthrodial joint between itself and the sacrum. The joint is usually referred to as a pseudo-articulation and is marked radiologically by corticated opposing bony surfaces with a 1- to 2-mm joint space. The vertebral body is often small and wedged laterally with narrowing on the side of attempted union, often precipitating a scoliosis. On the lateral view, a transitional vertebral body will be wedged posteriorly and the inferior endplate length will typically be less than the superior endplate length by a ratio of 1.37 or less (squaring sign). The intervening disc and facet joints are usually hypoplastic.

Type III LSTV describes unilateral (IIIa) or bilateral (IIIb) lumbarization/sacralization with complete osseous fusion of the transverse process(es) to the sacrum, with no visible joint.

A : Ordinary AP View B: Cranially Angulated (tilt-up) X Ray with central beam parallel to L5-S1 Disc shows a right sided type III LSTV.

Type IV involves a unilateral type II (pseudo-joint type) transition with a type III (osseous fusion) on the contralateral side.


Ref : Lumbosacral Transitional Vertebrae @ AJNR
        ESR 3rd Edition.

Urinary Bladder Herniation

URINARY BLADDER HERNIATION

Herniation of the Urinary Bladder into the inguinal canal or femoral hernia was first describe by Plater in 1550.
Incidence of UB hernia in Inguinal hernia is ~ 1-3% (rare).

Has been divided into 3 types :

1. Paraperitoneal : Most frequent.UB remains extraperitoneal and remains medial to the peritoneal herniation.
2. Intraperitoneal : UB hernia is completely covered by the peritnoeal sac.
3. Extraperitoneal: UB alone herniates, with no peritoneal herniation.

Herniation of Bladder diverticulum is also described.

But the difference between Bladder Hernia and Diverticulum is that, bladder hernia contains all the components of Bladder wall.
Diverticulum is only an outpouching of the mucosa through the defect in muscular layer (Detrusor).

Cystocele is a midline projection of bladder, whereas Bladder Hernia is more lateral.

Bladder ears are a normal variant, most commonly seen in infants <6months.
However it's been seen in young children and adults.
It's also called as the 'Transitory Extraperitoneal Hernia of Bladder in Infants'.


These following CT Axial sections of an elderly male shows the herniation of UB into the right inguinal canal.

Hiatus Hernia

This elderly male patient had Hiatus Hernia, Duodenal Diverticulum and Urinary Bladder herniation !!! 

Duodenal Diverticulum - CT sections

Duodenal Diverticulum

Fenestrations and Duplications

A duplication is defined as two distinct arteries with separate origins and no distal arterial
convergence .

Fenestration, by contrast, is defined as a division of the arterial lumen into distinctly separate
channels, each with its own endothelial and muscularis layers, while the adventitia may be shared.

Multiple Cavernomas in Brain

Young male patient with recurrent brain hemorrhages, due to multiple Cavernomas.

Cavum Septum Pellucidum

Cavum Vergae

The main lesion - which is heterogenously hyperdense. Lesion also showed CSF density areas - possibly sequelae to old hemorrhages. Characteristic MRI appearance is described in T2WI as 'Popcorn Appearance'.

Tiny lesion in right high frontal lobe.

This patient had previously undergone MRI Brain, which showed multiple cavernomas (SWI blooming) - much more than that in present CT.

'Popcorn Appearance' of Cavernoma in T2 WI MRI.

Bilateral thalamic and cerebellar hypodensity

These are the CT Brain images of a young male patient, who had h/o fever & Status Epilepticus 

(? for 1 hour),became unresponsive and was intubated.

Left Centrum Semi Ovale showed two calcific foci.

Left frontal lobe showed a round, relatively well defined hypodensity - ? Focal Infarct. Smaller scattered hypodensities were also present bilaterally.

Bilateral symmetrical parieto-occipital, basal ganglia and thalamic hypodensities were noted. See following images.

Thalami are sort of expanded ? Edematous.

Temporal horns and sulci show effeacement -( brain edema)

The patient unfortunately expired after 2 days of the CT.

Hypodensities due to severe Ischemia or Hypoxia usually spares the Cerebellum and the Central structures - which is called as the White Cerebellum Sign or the Dense Cerebellum Sign or Reversal Sign.

See Radiopaedia Article  http://radiopaedia.org/articles/white-cerebellum-sign

But in this case there is Symmetrical involvement of bilateral thalami and cerebellar white matter ! - point against Hypoxic etiology.

Symmetrical cerebellar involvement also !

So this case would be Atypical for Hypoxia/Ischemia alone. One thing here to be noted is, majority of the cerebral parenchyma is not showing much decreased attenuation and the grey-white differentiation is preserved.

These findings 1. Diffuse brain edema +/- Thalamic +/- Cerebellar hypodensities , infarcts has been described in Cerebral Malaria !!

For further data on Imaging in Cerebral Malaria : 

1. Adult Cerebral Malaria: Prognostic Importance of Imaging Findings and Correlation with Postmortem Findings - Radiology 2002, September by Patankar et al.
Cerebral Malaria Imaging @ Radiology RSNA, Patankar et al.

2. http://radiopaedia.org/articles/cerebral-malarial-infection

Patankar et al describes 4 patterns in cases of Cerebral Malaria
1. Normal Imaging 2. Diffuse brain edema 3. Diffuse brain edema with bilateral thalamic hypoattenuation and 4. Diffuse cerebral edema with thalamic and cerebellar hypoattenuation.

"These areas of hypoattenuation represent infarction in the territories supplied by the thalamoperforating and cerebellar vessels as a result of microvascular occlusion.  "

4th pattern is the most severe and survival is rare, as in our case. 

Normal imaging is the most common pattern. (2nd pattern was the MC in Patankar et al Study). 


"Focal hemorrhagic or nonhemorrhagic infarcts in the cortex, basal ganglia, thalamus, pons, and cerebellum in patients with cerebral malaria occasionally have been described in isolated case reports." The left frontal lesion may represent a focal infarct.


"Bilateral, symmetric infarction of the thalami has been seen in internal cerebral vein thrombosis, Japanese encephalitis, and occlusion of both paramedian thalamic and mesencephalic arteries caused by atherosclerosis or tuberculous meningitis."

"Hypoglycemia, which occurs in 8%–32% of patients with cerebral malaria , may also cause serious cerebral damage. The cortex, hippocampus, basal ganglia, and the substantia nigra (but not the thalamus or cerebellum) are particularly vulnerable to this."


So our possible diagnosis for this case would be CEREBRAL MALARIA.


Whats your opinion on this case?