Friday, April 29, 2011

Facebook for Diagnostic Centres

Now off and on, we see diagnostic centres and imaging centres on facebook. Another one of my Radiology 2.0 application. What are the pros and cons of this in future?
Pros

1. Presence on premier social media helps in brand building

2. More connection with the referring physicians as well as patients.

3. Venue to get service feedback

4. Portal to share your work, academic cases, milestones and event invitations to patient and referring physicians clientele.

5. You can even announce jobs on these pages.
Cons
1. Needs constant updating unlike static websites

2. Negative feedback needs to be acted upon fast and responded.

3. Remember patients confidentiality issues and compliance issues.


Tuesday, April 26, 2011

Acromioclavicular junction injury-MRI

27 years old male presence with sports injury to the right shoulder. The MR shows disruption of superior and inferior acromioclavicular ligaments with horizontal instability of the joint with marrow edema including the articular margins along with trapezoid component of the coracoclavicular ligament edema suggesting type II / III variety. Case submitted by Dr MGK Murthy and Mr Hari Om.





 
Teaching Points :
• AC joint functions primarily to transmit the weight bearing from axial skeleton to appendicular skeleton with small rotatory movement possible (5 to 20 degrees in various studies).
• Usually occur in contact sports with shoulder and the body falling over the joint in falls on out stretched hand.
• Rockwood classification has 6 types depending of the severity, with type I and II responsible for horizontal instability (anteroposterior) due to superior and inferior acromioclavicular ligament injuries.
• Type III to VI also include vertical in stability due to additional coracoclavicular ligament injury.
• CC ligament has triangular medial component (conoid) and quadrilateral trapezoid component (lateral) with conoid being responsible for anterosuperior stability and the later for posterior stability.
• Usually type I, II and occasionally type III can be managed conservatively, with other types offen requiring surgical procedures.
• Removal of the coracoclavicular screw after some time is needed to permit rotatory movement.

Monday, April 25, 2011

Tuberous Sclerosis with SGCA


14 yr old male child has seizures and mental retardation. MRI shows non enhancing cortical  hyperintensities on T2 and FLAIR.  In addition, a large intensely and heterogenously enhancing intraventricular, foramen of Monroe Space occupying lesion with obstructive hydrocephalus  with calcification. Features possibly  represent  cortical tubers with subependymal giant cell astrocytoma. Case submitted by-Dr MGK Murthy.






Tuberous sclerosis for the Radiologist

Synonym:  Bournveilles disease. Genetic disease – mutation of TSC1and TSC2, which encode for proteins hamartin and Tuberin (act as tumour growth suppressive factors )

Dignostic  criteria=   11 Major criteria and 9 minor criteria

Brain lesions
Tubers- triangular in shape with apex towards ventricles  and look hyperintense on T2. It may subside with age , but histopathology will still reveal it. Represents neuronal migration disorder. Other MR findings –Radial white matter tracts hyperintense on  T2. Heterotopic grey matter-Subependymal  nodules—abnormal  swollen glial cells and bizarre multinucleated cells . These could turn in to subependymal giant cell astrocytoma (SGCA). Ventricular enlargement


Thursday, April 21, 2011

Sumer's Radiology Site Rated as Top Radiology Blog

According to recent analysis  by radiologytechnician.com , our radiology blog has been rated as top radiology blog resource.  Further the story says following about yours truly blog.
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Sumer's Radiology SiteBlogger Sumer knows how to tease a healthy strand of succulence from the apparently bland subject of radiology. Currently working with an organization in India, he wields a lengthy resume of top-tier radiology experience and parlays all of that knowledge into simple yet insightful posts on his chosen scientific profession. His is a radiology blog we would recommend even to laymen, for its warm writing style and big-picture analysis.
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Bulk versus detail- New age radiology Dilemma

This new age of radiology in India is exciting, with many new modalities hitting the Indian radiology scene in a big way. More and more centres are now acquiring the 3Tesla MRI machine, cardiac CT is also catching up, PET- CT is now available in more places. There is also an upgradation in the quality and details provided in the MRI reports by radiologists and there is hint towards subspecialization need in almost every conference in India.

However, with all these developments academically the commercial angle involved cannot be ignored. Most of these machines have been installed by investors, venture funding agencies etc and their continous quest and desire for numbers. Academic radiologists on the other hand are looking for details, for example, we would love to have axial and sagittal CISS in knee for details on ligaments while my centre agencies want to do with routine sequences and see me as someone who is stopping them from getting the numbers. To give detailed reports require sometime and bosses love people who can just write off in one or two lines. Surely, bulk is going to be the dominant model in radiology imaging industry in India right now, are we sure that is the right way?


Have you faced this pressure of delivering bulk and compromising on details ever? All comments and inputs are welcome.

Gadolinium For Radiologist




 This is a supplement to our previous post on  MRI contrast media, submitted by Dr MGK Murthy.
  • Chemical element with Atomic No 64 in periodic table in lanthanide series  
  • Atomic weight of 157.25g.mol_1 
  • malleable 
  • world produces pure gadolinium of appx 400 tonnes  
  • because of nature of high absorption of neutrons used in nuclear medicine 
  • because of paramagentic properties used in MRI for contrast after chelating, as free gadolinum is toxic
Recommendation with no bias for any specific chemical or marketing production houses :

 

  • If the patient has normal renal function, use of any gadolinium compound makes no difference as renal excretion gets it out of the body 
  • If the patient has moderate renal dysfunction, use of less dose, interval of at least 7days between repeat doses and preferable use of macromolecule varities would help 
  • If the patient has severe renal dysfunction, use of macromolecules would be advised
  • In extremes of age and lactating mothers , macromolecules is recommended
  • If the patient has Calculated GFR of < 30ml/mt/1.73m2, Gadolinuim use is prohibited
  • In pregnancy , Gadolinium is contraindicated

Wednesday, April 20, 2011

MPPG-2011 Radiology questions


Questions submitted by students of DAMS by memory recall 
Q1 Non ionic iv iodinated contrast agents are better than ionic contrast due to:


[a]reduced rate of adverse reaction 
[b]improve imaging due to increase concentration of contrast in collecting system
[c] both
[d] none

Answer is a)  Non-ionic compounds have a lower rate of adverse reactions, but in IVP their concentration is lower than ionic.

Q2 Minimal ascitis best detected by-


a] USG [b] x ray [c]MRI [d] CT

Answer- A ) USG

Q 3. when x ray or gamma rays enter a material/tissue in its path ,all possible except:
[a] intensity of radiation fall by at least 80%
 [b]radiation may travel without any interaction
 [c] radiation may be completely absorbed by interaction 
[d] the radiation is partially attenuated and result in scattered radiation

Answer- a)
Reference- http://www.sprawls.org/ppmi2/INTERACT/#Photon%20Interactions

As an x-ray beam or gamma radiation passes through an object, three possible fates await each photon, as shown in the figure below:
1. It can penetrate the section of matter without interacting.
2. It can interact with the matter and be completely absorbed by depositing its energy.
3. It can interact and be scattered or deflected from its original direction and deposit part of its energy.


Q4 The highly accurate imaging modality in investigation of ureteric colic
a X ray 
b Spiral ct 
c USG 
d IVU

Answer- Spiral CT

Q5 Cancer cells are LEAST SENSITIVE to Radiotherapy -


a) G1
b) G2

c) M phase
d) Later phase of S phase.

answer-d)
The cell cycle phase also determines a cell's relative radiosensitivity, with cells being most radiosensitive in the G(2)-M phase, less sensitive in the G(1) phase, and least sensitive during the latter part of the S phase.



MRI contrast agents - Review Points

Teaching points


Submitted by Dr MGK Murthy
• Definition: Basically Gadolinium containing chelates

• Two types-“macrocyclic” chelates where Gd3+ is caged in the pre-organized cavity of the ligand, and “open- chain” (or “linear”) chelates.

• Taking in to account thermodynamic and kinetic stability factors ,macrocyclic chelatesare more stable particularly if they are ionic

• Exact cause of Nephrogenic Systemic Fibrosis is not known, but is postulated free Gd released in to circulation is responsible

• No patient with normal renal function has developed NSF

• So far about approximately 200 million patients have received MRI contrast

• Till 1997 no major contrast reaction was reported

• Between 1997 and 2009, 850 cases are reported all over the world (none from India)

• Toxic free Gd +3 from chelates is attached to fibrocytes leading to fibrosis

• Other factors possibly playing role are proinflammatory complexes, vascular injuries, high serum calcium etc


Various varieties of Gd Contrast agents in the market are :

A) Macrocyclic compounds with Trade names in brackets

1.Gd -DOTA (DOTAREM) (Guerbet company)

2.Gd-HP-DO3A (PROHANCE)(Bracco)

3.GD-BT-DO3A(GADOVIST)(Bayer Schering)


B) Open Chain Chelates

1.Gd-DTPA (MAGNEVIST)(Bayer Schering)(1stGdcontrast )

2.Gd-BOPTA(MULTIHANCE)(Bracco)

3.Gd-EOBDTPA(PRIMOVIST)(Bayer Schering)

4.MS325(ABLAVAR)(LantheusMedical imaging company)

5.Gd DTPA BMA(OMNISCAN)(GE)

6.GdDTPABMEA(OPTIMARK)(Mallinckrodt)



Recommendation for use in general

1. Use when necessary with cost benefit/Risk ratio calculation

2. Preferably screen for Renal dysfunction and calculated Glomerular filtration rate of >30ml/mt/1.73 m2 is needed before injecting the Gd

3. In Pregnancy all contrast agents are contraindicated as teratogenicity is not known

4. In Neonates less than 4 weeks open chain chelates contraindicated and macrocyclic variety could be given with minimum dosage

5. Always keep at least 7 days between administrations

6. Patients more than 65 yrs age need to be particularly screened for Renal dysfunction

7. Liver Transplant patients and Breast feeding mothers could receive minimum dose of macrocyclic varieties

8. Generally classified by European medical agency (EMA)as

(a) High Risk group-- Omniscan®

- Optimark® - Magnevist

(b)Moderate risk group-Primovist and Multihance

[c] Low Risk Group-Dotarem, prohance and Gadovist

9. High Strength magnets particularly 3.0 T could reduce the quantity of contrast injected

10. Hemodialysis is not recommended if renal dysfunction patients have received gadolinium, though patients on hemodialysis have benefitted by continuing it

Monday, April 18, 2011

Calcification of Articular Cartilage

Hypertrophic chondrocyte differentiation is a key step in endochondral ossification that produces basic calcium phosphates. Although chondrocyte hypertrophy has been associated with osteoarthritis, chondrocalcinosis has been mainly linked to calcium pyrophosphate dihydrate deposition. 


Wednesday, April 13, 2011

Bone Island

Definition: mature compact bone(cortical) within the cancellous(spongy) bone


Etiology: some call it hamartoma, but usually congenital or developmental with failure to resorb during endochondral ossification
Prevalence: prefers pelvis and all long bones with occasional one in spine and others
Asymptomatic and incidentaloma on X-ray
Xray- Homogenously dense sclerotic opacity within medullary region with distinct radiating streaks merging with normal host trabecular pattern giving Thorny Radiation appearance
CT and MRI- Relatively Lower attenuation compared to cortical density (usually) with MRI homogenously low signal on all pulse sequences
Radionuclide scan –classically COLD and is used as gold standard. However occasionally active in which case morphology on other modalities an clinical relevance would help


This is 80 yr old with non specific pain likely to represent enostosis and needs no further workup. Case and discussion by Dr MGK Murthy.





Tuesday, April 12, 2011

Malpositioned Ryles Tube into Left Bronchus


Clinical signs of nasogastric tube malpositioning in intensive care patients may be absent or misleading, chest radiography can accurately detect nasogastric tube malpositions in the tracheobronchial tree, may prevent complications, and avoid the use of further costly or invasive diagnostic techniques. This is a post operative patient in whom ryles tube was placed in OT setting and passage was considered difficult. CXR shows RT with distal end on left bronchus. 



Monday, April 11, 2011

Mucocele and Pyocele of concha bullosa


It is due to migration of ethmoidal air cells. Pneumatization of middle turbinate called concha bullosa is the commonest anomaly of paranasal sinuses (24 to 54% in various series). Usually drains through the frontal recess, has its own mucociliary transport mechanism, and occasionally in to middle meatus

When the ostium is blocked due to inflammation (usual), polyp/ surgery/RT/ and other causes, leads to accumulation  of secretions called mucocele and when  this gets infected --called pyocele. Usually in pyocele , Nasal septum is deviated to the other side.  Case submitted by Dr MGK Murthy.



Articular cartilage Defect- MRI


The International Cartilage Repair Society has set up an arthroscopic grading system by which cartilage defects can be ranked:
  • grade 0: Healthy cartilage
  • grade 1: the cartilage has a soft spot 
  • grade 2: minor tears visible in the cartilage
  • grade 3: lesions have deep crevices (more than 50% of cartilage layer)
  • grade 4: the cartilage tear exposes the underlying (subchondral) bone

On MRI,  FS 3D gradient-echo MRI is helpful for differentiating between grade 3 and grade 4 cartilage defects.



Left Ventricle Thrombus-CT

Selected images from the CT in 52 year old lady with history of CAD demonstrates a filling defect in the left ventricle consistent with a left ventricular thrombus. 






Friday, April 08, 2011

Entrepreneurship-Future of Radiology Practise in India


Question-Who owns the Radiology in India & who earns more from Radiology?

Brief overview of the structure of the radiology practise in India will reveal  that no more are the diagnostic centres predominately owned by Radiologists.   Did we notice more and more larger practise are owned by investors and some by clinicians themselves. Some of the practises have assessed their collections in past and showed that a significant percentage of their collection (please note it is Gross collection-NOT PROFIT) is spent in incentive for referring physicians. Surprisingly it is not the radiologist who earns maximum from radiology, it is the referring physician, followed by the investor. 

Until and unless younger radiologists understand this issue and look for more and more models of  service delivery which will get us back into the major stake holders position in this imaging business, there seem to be a problem. Teleradiology is probably one of them. Other possible methods include- managed radiology services, taking up outsourcing offers from hospitals etc. My personal recommendation to radiologists of future to do away with fixed pay model totally in India and don't be fooled by good pay packages which kind of divert us from entrepreurship. Any comments and opinions are welcome. 


Thursday, April 07, 2011

Brachial Plexitis -MRI


20 year old girl presented with severe pain right shoulder and neck regions with no history of trauma and pain is followed by weakness of the muscles. MRI of the brachial plexus origin is unremarkable. However there is extensive edema along dorsoscapular (supplying rhomboideus major and minor ) and suprascapular ( supraspinatus and infraspinatus  ) supplying branches of the brachial plexus of C5 and C6 nerve roots. Case submitted by- Dr MGK Murthy and  Mr Abdul Hamid.


-          Uncommon with 1.64 cases per 100,000 population in the US
-          Simulates disc disease
-          Male preponderance with 20 to 60 years age
-          Severe pain followed by weakness is hall mark
-          15% follow immunization
-          Viral etiology is postulated
-          Other causes are drugs, idiopathic, radiation etc.
-          MRI shows extensive edema along the nerve branches along with corresponding muscle edemata, leading to atrophy on the followup scans
-          Electromyography suggest fibrillation potentials and positive waves
-          Nerve conduction suggest denervation 




Wednesday, April 06, 2011

Living donor workup for Liver Transplant -Multislice CT


Living donor workup for Liver Transplant  is ideally done by multislice CT presently with 2 phase  acquisition

Technique: 120 ml non ionic contrast with 5cc/sec with volume  acquisition using bolus tracking for arterial phase and 55 to 80 sec for portal and hepatic  venous study

Submitted by Dr Sudheer , Dr Krishna Mohan & Dr MGK Murthy

How to evaluate--

1. Is the study optimal- i.e. quality, timing and area covered?

2.Evaluation of hepatic parenchyma
    -look for any focal lesions 
   - presence of Fatty infiltration/hepatitis and haemochromatosis

Precontrast Liver Attenuation Index is calculated (LAI) = mean attenuation of liver -spleen by planning multiple ROIs 

LAI>5HU=0-5%steatosis          -10HU&5HU=6to 30%steatosis            <-10HU =>30%steatosis 
Upper limit of steatosis for donor liver is 30%

3.Reconstruction of hepatic vasculature 
Using three techniques MIP/SSD/Volume Rendering (VR)
1st phase is arterial using bolus track for any anomalies or abnormalities
2nd phase  for portal and hepatic venous evaluation

4.Calculation of hepatic volume --usually in portal venous phase (as hepatic veins are well visualised)

Can be done by Auto or Manual  technique  and exclude Portal vein, IVC and Gallbladder 
Whole Liver volume should include caudate in axial sections
Right lobe volume calculated by------ inserting imaginary line 1cm lateral to MHV 
                                              ------can also be done by excluding IVC and GB

5. Study Hepatic veins 
Middle hepatic vein-is it joining with common trunk with left to ivc or independently
if patency of segment IV lobe graft is not preserved , hepatic congestion will occur leading to heaptofugal flow and consequent atrophy





Tuesday, April 05, 2011

Medial Malleolus Ossicle


41 yr old male presented with pain and no swelling. Xrays show apparent bony injury  of medial malleolus with no soft tissue swelling. Medial malleolus ossicle is likely It is bilateral in 25% population. General incidence though not known may be around 15% adults and more common on lateral malleolus.  Case Submitted by Dr MGK Murthy.
 
An accessory, distal focus of epiphyseal ossification may develop in either malleolus. These foci are not anatomically separate entities, even though they appear to be radiographically. They usually are asymptomatic. However, they may be injured, either acutely or chronically. The diagnosis of such injury by conventional radiography is limited. Bone scintigraphy may be positive if there is a stress fracture.

  
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Monday, April 04, 2011

Incidental Findings -Dilemma

According to an article published March  in the Archives of Internal Medicine - "More often than not, incidental findings do more harm than good, leading to unnecessary imaging and excessive angst". According to me this is debatable. Lot of times we radiologists are referred scans for example ureteric calculus and we point out lytic lesion in the vertebrae or bulky adrenal or some nodules in the lung base which point towards the diagnosis which was previously unsuspected. Further, i disagree with the comment made by the authors- "non-indicated physiology in imaging may be better off behind a dark screen rather than seen as a free screen". Think of us radiologists as analogous to crime scene investigator, you cannot just ask me to look at one aspect and ignore all other incidental findings. On the other hand it is one of the advantages of an expert radiologist reading a study that he can report incidental unsuspected findings as well.  

Another persepctive of the article is available here-AIM: Should radiology ignore incidental findings?

Sunday, April 03, 2011

Fibrous Cortical Defect Metacarpal



10yr old boy history of fall, shows cortical lucency of 3rd metacarpal
Teaching point by Dr MGK Murthy.
  • Both non-ossifying fibroma (fibroxanthomas) and fibrous cortical defects are composed of spindle shaped fibroblasts in a cartwheel pattern with scattered giant cells, foam cells and collegan along with abundend hemosiderin, cholestrol christals in the cytoplasm of fibroblasts.
  • Very common incidental radiographic lesion (caffey reported 36 % in population) in asymptomatic children with slight male predominance.
  • Usually present 4 to 8 years age, with peak incidence 10 to 15 years.
  • 90 % occur in tubular long bones with commonest sites being, distal femoral, proximal and distal tibial and around the knee with upper extremity being an uncommon site. however cases are reported in the innominate bone, clavical, skull, scapula, mandible and small bones of hands and feet.
  • Typically metaphyseal and close to physeal plate.
  • The FCD arises within the cortex where as NOF arises eccentrically within the medullary cavity, with multiplicity being moe common with FCD.
  • Both arise from the posterior wall of the tubular bone and involvement of medial rather than lateral osseous surface is characteristic.
  • May involute and disappear or persist into adult life with epiphyseal location rare.


D/D :- Include chondromyxoid fibroma, fibrous dysplasia, osteoid osteoma, bone abscess, periosteal chondroma, avulsive cortical irregularity, periosteal desmoid fibromatosis, desmoplastic fibroma, cortical avulsive injury.
The presence of extraskeletal congenital anomalies like cafe-as-lait spots, mental retardation, hypogonadism or cryptorchidism, cardiovascular malformations in association with multiple nonossifying fibroxanthomas constitute the  Jaffe-Campanacci syndrome.

Pseudoepiphysis Index Finger Metacarpal Base

" Phylogenetically, there are potential epiphyses at both the proximal and distal ends of the tubular hand bones.... A persistent expression of the distal epiphysis of the thumb metacarpal is called a pseudoepiphysis. The pseudoepiphysis appears earlier than its standard counterparts, then fuses rapidly. BY the sixth or seventh year it has been incorporated and is inconspicuous. Pseudoepiphysis have also been noted at the proximal ends of the finger metacarpals, usually of the index finger. Its only clinical significance is that it must be differentiated from an acute fracture." -- Rockwood and Green, Fractures in Children. 4th Ed.1996, p326.

Teaching Point submitted by - Dr MGK Murthy.



Saturday, April 02, 2011

Teleradiology Providers- IRIA 2011

This is one of stills from IRIA 2011, the largest Indian Radiology congress, where Sumer Sethi was invited as faculty to present Asian -African perspective-Teleradiology. According to him teleradiology represented a paradigm shift in the way radiology is practised.

Teleradiology Providers- DD News

Our company has been recently covered by DD News as it was female oriented programme, they focussed on positive for ladies as they can work from home with teleradiology. Featured in this video are our main Radiologists Dr Sumer Sethi and Dr Priya Chudgar.  Being one of the pioneers of this business in India, this coverage by leading official news channel in the country is another feather in the cap of Prime Telerad Providers (P) Ltd-Teleradiology Providers.

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