Wednesday, May 30, 2012

Osteopoikilosis

There are multiple areas of sclerotic foci in the femoral heads and acetabulum which likely indicate osteopoikilosis, benign condition characterized by numerous bone islands. Osteopoikilosis is an benign, autosomal dominant sclerosing dysplasia of bone. The radiographic appearance of osteopoikilosis on an x-ray is characterized by a pattern of numerous white densities of similar size spread throughout all the bones.


Friday, May 25, 2012

Variant course of the vertebral artery


We present a 69 year old female with dizziness. During the evaluation of the carotid we did not found the vertebral artery in the transverse foramina in the middle of the neck. However an  artery was traveling  side by side with carotid, in the level of the mandible this artery  turns and enters the intraspinal foramen.


Image Vas:
The right  vertebral artery  follows a parallel course  side by side with the  common carotid artery .


Image Va turn: 
At the level of the mandible the VA  turns and enters the transverse  foramen.

Image U l ob:
RIGHT oblique view: The lower segment, thefirst part, of the  vertebral artery
LEFT transverse view: The upper  segment of the  extraspinal vertebral artery before to  enter the transverse foramen.

TRA  RCC RVA
RIGHT transverse view:    The extraspinal  vertebral artery before to  enter  the transverse foramen and the common carotid artery .
LEFT transverse view:   the bifurcation of the common carotid artery .

Discussion by Dr Nikos Vougiouklis

The vertebral arteries may present in a number of variant positions. The presence of a vertebral variant must be considered in patients in whom the normal position of the vertebral artery cannot be detected. The vertebral arteries enter the 6th cervical foramen in most cases.

 In cases in which the vertebral artery enters  of the higher vertebral foramina, the artery may lie directly behind the common carotid artery. In a study by Bergman et al based on 693 laboratory specimens, dual or accessory vertebral arteries were encountered in 5 of 693 specimens, and all were left-sided.

References:
  1. Koenigsberg RA, Peereira L, Nair B, et al. Unusual vertebral artery origins: examples and related pathology. Catheter CardiovascInterv 2003;59:244–5
  2. Bergman RA, et al. Opus II: cardiovascular system vertebral artery variations. In: Bergman RA, Afifi AF, Miyauchi R, eds. Illustrated Encyclopedia of Human Anatomic Variation. 

Wednesday, May 23, 2012

Corpus Callosum Infarction-MRI


An elderly hypertensive male presents with gait apraxia  and MRI with MRA show
·         An ill-defined restricted diffusion focus  with no bleed or  significant mass effect or herniation or shift of midline in the anterior corpus callosum  suggesting recent onset non-hemorrhagic infarction.
·         MRA suggests  atherogenic focus   in the pericallosal branch of ACA suggesting the etiology is local and  unlikely to be cardiogenic embolism





Teaching points by Dr MGK Murthy, Dr Preeti Saxena
·         Callosal infarctions are uncommon because  of rich vascular supply form the 3 vessels namely ACA, ACom and Posterior cerebrals (PCA)
·         Pericallosal branch  of ACA is the main supply for body
·         Subcallosal and medial callosal  vessels from A.Com  (hence ACA supplies  a total of 4/5ths of callosum) are  mainly responsible for anterior portion
·         Posteror pericallosal  from  PCA  supplies splenium
·         Individual   Variations are common from the above  typical  distribution
·         Symptoms can vary  and can be silent/ transient weakness/ speech disturbance / alien hand syndrome/ gait apraxia  etc
·         Splenium is more commonly involved as PCA infarctions are more frequent than ACA

Tuesday, May 22, 2012

Spinoglenoid Ganglion Cyst with isolated Infraspinatus Atrophy


Evidence of 3.5 x 1.5cm cystic lesion with minimal sepate in the spinoglenoid notch likely ganglion cyst with probable impingement of the suprascapular nerve. There is altered signal intensity and minimal atrophy of the infraspinatus muscle, likely implying isolated denervation of the infraspinatus muscle. 



Monday, May 21, 2012

Double Bubble Sign


[On antenatal ultrasound  a case with Double Bubble sign  turned out to be  midgut malrotation postnatally]

Appearance-  Two well defined echofree cystic areas seen  in fetal upper abdomen due to fluid distended stomach and proximal duodenum.  Abdominal radiograph of these cases also usually reveals two gaseous/ lucent areas [double bubble] representing air in stomach & duodenum , with gasless rest of the abdomen.



By-
Dr.Subhash Tailor M.D.[ Radiology]
Dr.Gaurav Bahety M Ch [Ped.Surgery ]
Bhilwara [Rajasthan] , INDIA

Possible D/Ds
Intrinsic duodenal obstructions like- duodenal atresia,stenosis and web
Extrinsic causes like – Annular pancreas & Ladd’s band with midgut malrotation

Case details
A 19 yr primi gravida was asked  for antenatal ultrasound in last trimester for fetal well being. She also complained of pain abdomen & slight leaking PV.
At US- Fetal abdomen revealed a Double Bubble Sign [fig. 1 ] . Mild oligohydramnios was also present [due to recent leaking pv]. Fetal gestation was about 35 weeks. No any other abnormality was seen. In keeping  with antenatal sonography findings, a probable diagnosis of Duodenal atresia was made. The patient then delivered  a female child same day.
 Neonatal abdominal radiograph showed  a large single gaseous shadow due to distended stomach , with relatively gasless abdomen [fig. 2 ] . The second bubble was absent , likely the duodenal air was deflated with NG tube or passed distally,which  raised the suspecian of some other pathology or cause .
Again postnatal abdominal ultrasound was asked which  revealed upper abdominal  epigastric whirlpool sign on B-mode  & color Doppler due to mesenteric twist .  There was transposition of superior mesenteric artery & vein with clockwise 360degree rotation of SMV over SMA [fig.3 ] . Rest of abdomen was normal except mildly promiment & fluid filled small bowel loops .So ,on the basis of mesenteric whirlpool sign a possibility of midgut malrotation with volvulus was  suggested.
The neonate was operated in emergency to avoid impending mesenteric ischemia due to suspected volvulus , & the diagnosis of midgut malrotation with volvulus was confirmed  [ fig.4 & 5].


Fig.1 – Fetal upper abdomen shows Double Bubble sign due to fluid distended stomach & prox.duodenum


Fig. 2- Neonatal abdominal radiograph reveals single lucent shadow of stomach with NG tube in situ , & gasless rest of the abdomen


Fig. 3 – Upper abdominal B-mode & color Doppler TS images shows classical Whirlpool sign due to mesenteric twist

Fig.4 – Peroperative photograph of mesenteric twist & midgut malrotation

Fig.5 – Peroperative photograph of mesenteric twist & midgut malrotation after complete exploration

Friday, May 18, 2012

Photo acoustics for Breast Cancer- Update

"Researchers are in the initial stages of testing photoacoustics that may allow radiologists to detect  breast tumors with improved accuracy without exposing patients to radiation. This research, published in the open-access journal Optics Express, isn’t yet ready for clinical implementation. Photoacoustics is a hybrid optical and acoustical imaging technique that uses red and infrared light technology, known as optical mammography, to image tissue and detect tumors."

Reference and Further Reading:

Posterior Fossa Arachnoid Cyst & Tonsillar Descent


17 year old girl with headache. Evidence of CSF iso-intense lesion measuring 2.1 x 1cm, non-enhancing in nature in the right cerebellopontine region extending inferiorly to perimedullary region possible arachnoid cyst. There is evidence of tonsillar descent bilaterally, which may be   congenital chiari malformation or secondary to arachnoid cyst.  There is resultant dilatation of the lateral, IIIrd and IVth ventricle with periventrricular ooze, which indicates hydrocephalus.





Thursday, May 17, 2012

Inflammatory pseudotumour of the carotid sheath-Doppler

We present a 28 year old female with palpable mass in the neck and ultrasound shows a mass encasing the carotid. We have given the possibility as inflammatory pseudotumour of carotid sheath. Further evaluation with cross sectional imaging with contrast is suggested. We will update with follow up. The treatment of pseudotumor includes use of steroids, but a definitive diagnosis often requires surgery.  This is a benign process but it occasionally recurs.Nonspecific, nonneoplastic benign inflammatory process without identifiable local or systemic causes characterized by polymorphous lymphoid infiltrate with varying degrees of fibrosis.  Case Submitted by Dr Ravi Kadasne, senior radiologist  at Emirates International Hospital Al aAin, UAE. Comments are welcome.






PSEUDOANEURYSM OF ULNAR ARTERY - Color Doppler


 INTRODUCTION  
A pseudoaneurysm, or false aneurysm is a confined collection of thrombus and blood adjacent to an artery with disruption of one or more layers of it . Pseudoaneurysm differ from true aneurysm in that the latter contain all three histologic layers of the arterial wall, whereas pseudoaneurysm contain less than three and often none of these layers and contained by only compressed fibrous tissue. The pseudoaneuyrsm lumen is connected to the underlying native  artery by a cylindrical neck-variable in length and diameter , & shows typical blood flow in it . Pseudoaneurysm can be a complication of arterial  trauma  ,including arterial puncture  during a diagnostic angiography or interventional procedures. Both  True & pseudo aneurysms forms pulsatile masses, as  former is truly pulsatile ,& later can only  feebly shares  the pulsations of native artery .
Ultrasound  with color Doppler is the imaging modality of choice for  this diagnosis , & here we present a case of pseudoaneurysm of ulnar artery following trauma with classical findings on color Doppler sonography . 

Contributed by: Dr. Subhash Tailor, Dr. Gopal Dhakar, Radiologists, Bhilwara [Rajasthan ],  India.


Case History: A 30 years old was referred for evaluation of swelling in right
                       forearm following a trauma.

Findings: The  study was done on GE VOLUSON 730PRO color Doppler with 
                 10 MHz high frequency linear probe. Gray scale sonogram showed a large  thick walled complex pulsatile cystic mass with  mobile internal echoes adjacent to right ulnar artery ( Fig 1). Color Doppler image of the same lesion showed color flow signals within it with swirling pattern, suggestive of a vascular mass, probably pseudoaneurysm. An eccentric area of focal aliasing noted near ulnar artery through which blood is seen gushing in and out, s/o  neck of  pseudoaneurysm which is arising from the right ulnar artery proximal to wrist  (Fig 2). Turbulent flow was well demonstrated in pseudoaneurysm with the classic "ying-yang" appearance on color flow imaging (Fig 2, 3). Spectral Doppler sampling  from the pseudoaneurysm neck showed the characteristic to-and-fro blood flow pattern( Fig 4).   On the basis H/O trauma , USG B-mode , color & spectral Doppler findings the diagnosis of  Post traumatic pseudoaneurysm of right ulnar artery suggested  , which was later confirmed by angiography .


Discussion & review of literature

The definitive diagnosis of pseudoaneurysm requires detection of the neck
connecting the pseudoaneurysm with the injured artery, and identification
within this neck of the pathognomonic``to and fro'' spectral waveform pattern (Fig-4). To-and-fro flow occurs in the neck of a pseudoaneurysm due to changing pressures: at the high intraluminal pressure during systole, blood flows through the narrow neck into the aneurysm at a rather high velocity. Under the reversed pressure conditions during diastole, the blood flows back into the artery at a slightly lower flow rate. Reflux is typically turbulent ( Fig 2). The characteristic appearance of pseudoaneurysm in triplex ultrasound (B-mode combined with color and pulsed Doppler spectral analysis) include the presence of a hematoma of variable echogenicity, which may represent separate episodes of bleeding and rebleeding, expansile pulsatility and detection of turbulent flow (``yin-yang'' appearance) within the mass(Fig-3).
A false aneurysm must be differentiated from a perivascular hematoma with transmitted pulsation, but this is difficult on clinical grounds  Using duplex ultrasound,an aneurysm can be differentiated from hypoechoic,
perivascular structures such as lymphnode, hematoma, seroma, or lymphocele by the depiction of to-and-fro flow, which is diagnostic of a pseudoaneurysm and requires no angiographic confirmation.

The objective of doppler imaging is to differentiate between hematomas associated with pseudoaneurysm and those that are not. Whereas hematomas resolve spontaneously, a pseudoaneurysm can potentially rupture and therefore must be identified, closely monitored and in most instances treated.
Before ultrasound enabled the precise localization of the aneurysmal neck relative to the skin surface, the treatment of choice was surgical closure. With advances in ultrasound equipment, it is now possible to occlude over 90% aneurysms by compression of the neck using color duplex imaging  guidance.  

 Thrombosis occurs after 10–30 min of compression with success rates of 70–90% have been reported for ultrasound guided compression of pseudoaneurysm in literature , compared with 95–100% for induction of thrombosis by sonographically guided thrombin injection into the aneurysmal sac .
So to conclude color Doppler US is  cost effective and reliable imaging modality to diagnose pseudoaneurysms, and can also be utilized for guided compression and thrombin therapy.





Fig 1- Gray scale imaging showing complex cystic  pulsatile mass in forearm along ulnar artery with mobile internal echos in realtime
.

Fig-2 Color doppler imaging showing color signals within cyst  & aliasing at the neck of  pseudoaneurysm due to turbulent blood flow.

Fig 3- Color flow imaging showing characteristic “yin-yang” sign due to swirling
          pattern of blood flow. The  red and blue color flow signals due to inflow and  
          outflow turn of blood respectively via neck of pseudoaneurysm.


Fig 4- Duplex spectral waveform sampling in the ulnar artery pseudoaneurysm
          neck demonstrating characteristic to-and-fro blood flow.

Wednesday, May 16, 2012

MRI Friendly Pacemaker-Now in India


Magnetic resonance imaging (MRI) is generally contraindicated in patients with pacemakers. However, in February 2011, the US Food and Drug Administration (FDA) approved the Revo MRI SureScan Pacing System, which is the first cardiac pacemaker designed to be used safely during MRI examinations.

Meditronic manufactures the same. This is available in India and  is being used by Cardiologists 

So  next time , we refuse  a case, ask "is it  MR Safe"? By Dr MGK Murthy.

Sunday, May 13, 2012

CONGENITAL HIGH AIRWAY OBSTRUCTION SYNDROME [CHAOS ] - An antenatal ultrasound diagnosis



CHAOS  -  Refers to a rare & fatal congenital anomaly seen due to obstruction of upper airway  in fetal life either due to oropharyngeal or neck masses , & or most common being laryngeal / tracheal atresia.  The risk of associated  chromosomal anomaly is very rare , and overall the prognosis is considered to be poor.  However some cases can be treated with neonatal intervention such as ,  ex -  utero – intrapartum treatment By- Dr.Subhash Tailor
M.D.[ Radiology]
Bhilwara [Rajasthan]

Antenatal ultraound diagnostic criterias are  -
1.       Dilated fluid filled trachea / bronchi distal to obstruction
2.      Bulky echogenic lungs
3.      Diaphragmatic flattening and or inversion
4.      Midline positioned & compressed fetal heart
5.      Fetal ascites  and Anasarca
6.      Fetal neck mass , if any
7.      Polyhydramnios


A case of CHAOS diagnosed antenatally with  ultrasound at about 17 weeks of gestation is being presented here featuring classical findings . 

Case details -  A 28 yrs old  2nd gravida was asked for anomaly scan .  Her previous  pregnancy was stated to be  normal . 

AT  USG - fetal chest showed bulky echogenic lungs with dilated and fluid filled trachea and proximal bronchi.  The domes were also inverted .  Fetal heart was seen narrowed , midline positioned and appeared compressed between bulky echogenic lungs .  Fetal hydropic changes were also seen as skin / soft tissue edema and ascites [ likely due to fetal heart failure ].  See figures 1 to 4  
The liquer amnio was average in this case .  These antenatal ultrasound  findings were  diagnostic of  CHAOS . The parents decided to terminate the pregnancy .
                                                                 

Figure 1-  Fetal coronal  thoracic  & axial head scans shows bulky echogenic both lungs , dilated fluid filled trachea & bronchi with inverted diaphragms ,& scalp edema .



Figure 2- Coronal US scan of fetal chest including part ofupper  abdomen - shows enlarged echogenic lung masses & mild ascites



Figure 3- Fetal thorax  coronal color Doppler scan shows fluid filled dilated trachea –bronchi [color void]


Figure 4 – TS fetal thorax shows midline narrow compressed heart[arrows]

Thursday, May 10, 2012

Migrated Urethral Stent-Rare Case Report




This patient 70 years-old, could not provide any information except that he was operated in the bladder 7 years ago. He was referred for CT from the urologist because he felt some hardness in the perineum. A percutaneous catheter was used for urination. We found diastasis of the pubic symphysis with sclerotic edges. A metallic apparatus is seen into the symphysis. We speculate that urethral stent migrated into the symphysis. Any comments or suggestions are welcome. 
Case submitted by - NIKOLAOS VOUGIOUKLIS






Friday, May 04, 2012

Intradural spinal lipoma-MRI

This is a 30 year old patient with evidence of focal area of T1/T2 hyperintensity in relation to intradural compartment at L1-L2 level inseparable to conus terminalis possibly indicating intradural lipoma. No obvious posterior element dysraphism. No obvious communication to subcutaneous adipose tissue.


Intradural spinal lipoma is the least common form of spinal lipoma representing less than 1% of primary spinal tumours. They are believed to be embryogenetic in origin and are related to lipomyelo(meningo)cele with which they share a common origin in the separation of the neural from the cutaneous ectoderm during neurolation that allows some mesoderm to gain the dorsal surface of the neural tissue. This mesoderm constitutes the lipoma by transforming into fat tissue; it remains incarcerated in the folding neural tissue in which it prevents complete dorsal fusion but, in distinction to myelo(meningo)cele, does not prevent the dorsal fusion of the dura and of the osseous posterior elements of the spine.

Wednesday, May 02, 2012

Penang Work shop announcement-MSK Imaging

Yet another episode of immensely popular and reputed MSK imaging course in Penang Malaysia conducted by Professor John George. Registrations are open and limited. Here is the flyer. Hurry up seats here fill up very fast.  Those who would like the flyer , programme and registration  fee to please contact on msk.rad@gmail.com



Term of the day-Meniscal Flounce

The meniscal flounce is thought to be a transient physiologic distortion and may be related to meniscal locations on the tibial plateau. It may be changed by varying the knee position.


Image courtesy   Brian Sabb
Team Physician, The Orthopaedic Radiology Specialist for Athletic Medicine Division at Eastern Michigan University
Co-Chairman, Musculoskeletal Anatomy Course at University of Michigan Medical School



Tuesday, May 01, 2012

Possible Intracortical Lipoma

This is a  rare case of intracortical lipoma of the  femur. Magnetic resonance imaging of the femur demonstrated an intracortical lesion in the lateral diaphysis which is isointense to fat on all sequences. No medullary involvement by the lesion was noted. Possibility of Intracortical lipoma was suggested.



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