Thursday, December 30, 2010

Arteriovenous Malformation-Urinary Bladder

Localized arteriovenous malformation of the bladder is extremely rare.  When arteriovenous malformation is suspected, an angiogram and pelvic computed tomography or magnetic resonance imaging is essential to delineate the extent of the disease and to plan appropriate therapy. Common symptoms include pain, gross hematuria and acute urinary retention. This is a 60 year old male with previous history of unknown pelvic surgery and flow voids in the bladder base involving the seminal vesicles and prostate as well.




PET Isotopes produced without cyclotron



Advantage of PET is the use of the positron emitting biologic radiotracers, e.g., 11C, 13N, 15O ,  and most important 18F (Half life = 110 min) that mimic natural substrate. However, due to relatively short half-lives, they are unable to be transported to sites at great distances from the production facility.

(Generator nuclides)

44Sc --- Bone disease
 68Ga  --- Blood–brain barrier; tumor localization
72As-- Toxicological study
82Rb Myocardial perfusion
118Sb First pass angiography
128Cs Myocardial perfusion

Post Cricoid Carcinoma-CT

This is a 45 year old female with post cricoid carcinoma. The postcricoid region, pyriform sinus, and posterior hypopharyngeal wall comprise the hypopharynx. Tumors rarely appear in the posterior pharyngeal wall or postcricoid region without also involving the pyriform sinus. Well known etiological association is with Plummer-Vinson syndrome (Paterson-Brown-Kelly syndrome). The syndrome includes hypopharyngeal webs, usually centered in the postcricoid area.

Possible Pancreatic Cystosis

  1. Pancreatic involvement in cystic fibrosis can result in exocrine or endocrine insufficiency. 
  2. The spectrum of pancreatic appearances has been described as follows: complete replacement of the pancreas by fibrofatty tissue, with enlargement of the pancreas corresponding to lipomatous pseudohypertrophy; partial replacement of the pancreas by fibrofatty tissue; complete atrophy of the pancreas without fatty replacement; diffuse pancreatic fibrosis; and cystic transformation of the pancreas. Calcifications may also be found.  
  3. Macroscopic cysts measuring more than 1 cm are a rare condition. Macrocysts of different sizes distributed throughout the gland represent an extremely unusual form of pancreatic involvement in CF that has been described in only a few patients and is known as pancreatic cystosis.




Saturday, December 25, 2010

Intramuscular Cyst-Rotator cuff

The cause of intramuscular cysts is not entirely clear but may be similar to that of paralabral cysts in the shoulder and hip and parameniscal cysts in the knee. As in those other types of cysts, a defect in the surface of a rotator cuff tendon may allow fluid from the glenohumeral joint (or associated bursae) to enter the substance of the rotator cuff tendon and then dissect along the tendon fibers and intramuscular planes to form a cyst either within the sheath or within the substance of a muscle.

Friday, December 24, 2010

Now Google for Learning Anatomy

Google body browser
"Google has released a new Body Browser experiment that shows a detailed 3D model of the human body in Google Chrome web browser beta. Users can view through the anatomical layers of human body, zoom in and navigate to explore the human body parts. The new Google Body Browser is pretty commendable for use in a medical education environment and especially for radiologists who need to look up anatomy every now and then."

Have a look here-



Thursday, December 23, 2010

Omental Fat Necrosis

This is case of chronic pancreatitis with calcification and atrophy in pancreas. Along with fat attenuation lesion in the omentum with surrounding capsule seen on STIR images and adhesion to parietal peritoneum and surrounding stranding.


Saturday, December 18, 2010

Branchial cleft cyst-CT

First branchial cleft cysts are divided into type I and type II. Type I cysts are located near the external auditory canal. Type II cysts are associated with the submandibular gland or found in the anterior triangle of the neck.

The second branchial cleft are most frequently identified along the anterior border of the upper third of the sternocleidomastoid muscle and adjacent to the muscle. However, these cysts may present anywhere along the course of a second branchial fistula, which proceeds from the skin of the lateral neck, between the internal and external carotid arteries, and into the palatine tonsil .

Third branchial cleft cysts are rare. Third branchial cleft cyst are characteristically located deep to the sternocleidomastoid muscle as in our case which was diagnosed as third branchial cleft cyst.



Thrombosed Aortic Aneurysm

Old man with a history of coronary artery disease  & pain and numbness in the lower extremities. Computed tomography showed a thrombosed  infrarenal abdominal aortic aneurysm and diffuse aortic atherosclerosis.  


Friday, December 17, 2010

Os Navicularis Syndrome-MRI

Os naviculare is a large ossicle adjacent to the medial side of the navicular bone. The tibialis posterior tendon often inserts with a broad attachment onto the ossicle. Most cases are asymptomatic but in a small proportion it may cause a painful tendinosis due traction between the ossicle and the navicular. Such changes are best seen on MRI as in our case with marrow and soft tissue edema on STIR images in relation to the bony ossicle.



Sciatic Schwannoma-MRI

MRI scan through the pelvic area  in a 15 year old boy shows large soft tissue mass arising in the retroperitoneal portion of the left  hemipelvis, extruding out into the subgluteal area through the sciatic notch. This picture suggests the diagnosis of sciatic schwannoma spanning the sciatic notch.



Shoulder Dislocation-MRI

Area of high signal intensity involving the posterosuperior humeral head. This site is charactersitic of hatchet/hill sach lesion usually sequale to previous dislocation. Altered signal intensity is also noted in relation to the anteroinferior glenoid labrum, possibly associated bankart's lesion.  This is 20 year old boy with history of shoulder trauma 2 years back, no other details were available.

There is minimal atrophy/fatty changes in the infraspinatus muscle, ?significance. Atrophy localized to the infraspinatus muscle can occur secondary to suprascapular neuropathy and can be caused by either a compressive mass in the suprascapular or spinoglenoid notch or a traction injury to the nerve. No obvious mass/cyst was demonstrable in the spinoglenoid notch, indicating traction injury in this case.



Wednesday, December 15, 2010

Carpal Fusion-MRI

The anthropological significance of this anomaly has been the subject of interesting speculation. It may represent an advance towards specialisation of the hand, or it may signify an attempt to stabilise the post-axial border of the hand, in which case it is probably a primitive adaptation which has persisted. This latter is the favoured view. Lunate-triquetral fusion never causes symptoms.

Monday, December 13, 2010

Fibular osteoid osteoma

Significant eccentric cortical thickening in the mid shaft of fibula along with marrow and periosteal edema. There is relatively hyperintense area within the cortical thickening. These findings indicate possible osteoid osteoma.  CT sections confirm osteoid osteoma showing nidus in thin sections. This is a 13 year old boy with pain in the leg.


Friday, December 10, 2010

PET-MR Commercial Scanner Possible In Near Future

According to a recent press release by Siemens, about launch of Biograph mMR, "Combining MRI and PET was a great technological feat, as the two processes using different physical effects could normally not work close to each other. The magnetic fields generated in MRI interfere with usual PET detectors, what until now prevented simultaneously taken high-resolution human images. Patients had to be scanned in two separate systems, with a certain time interval between the exams. With the Biograph mMR, Siemens has developed the first system that provide highly innovative PET detectors, which work very well inside an MR system."

Ventriculitis- Diffusion weighted MRI

Usually the most frequent sign of ventriculitis is intraventricular debris and pus. Abnormal periventricular intensities or enhancements are also seen. Both FLAIR and DWI sequences contribute to the diagnosis of ventriculitis. This is a case of an old gentleman with fever, and CSF revealed high WBC count. Diffusion-weighted imaging provides better lesion contrast than FLAIR imaging for the detection of intraventricular debris and pus as in this case.

Thursday, December 09, 2010

Infraspinatus muscle cyst-MRI

A middle aged man complains of sudden give after weight lifting and constant pain since than for the last 2 years. Clinically partial thickness rotator cuff tear. MR shows a fusiform, relatively well defined, regular, fluid signal intensity , intrasubstance cyst within the infraspinatus muscle. There is associated partial thickness supraspinatus tendon tear. Glenoidal labrum is normal.

Diagnosis-Infraspinatus muscle cyst





Case submitted by Dr MGK Murthy
Teaching points -
A well enclosed oval, elliptical or fusiform fluid collection, aligned along the along axis the fibers of the involved rotator cuff muscles, completely within the sheath or the substance is referred to as intramuscular cysts. It does not extend to the paralabral location thus differentiating it from the latter.

The etiology is not known. However a plausible explanation is a defect in the surface of a rotator cuff tendon may allow fluid from the glenohumeral joint (or associated bursae) to enter the substance of the rotator cuff tendon and then dissect along the tendon fibers and intramuscular planes to form a cyst either within the sheath or within the substance of a muscle.

Synonymous with intramuscular ganglion. Clinically and arthroscopically these lesions are silent. Weight lifting is known to predispose to these. Partial rotator cuff tendon tear particularly of the supraspinatus is a known common association, that needs to be always excluded.

There are 3 cysts in the shoulder region -
a) Commonest is paralabral in location as a sequlae of glenoidal labral tear
b) Acromioclavicular joint cysts as a progression of degenerative changes
c) Intramuscular varieties

Cardiac Pacemaker for a General Radiologist

The attached xray shows multiple leads biventricular cardiac pacer in post sternotomy patient with Azygos lobe and possible perihilar oedema.


Cardiac pacemaker for a general radiologist-by Dr MGK Murthy.

 

 
Types of permanent pacing :
  • Single chamber cardiac pacers: lead terminates in right ventricle.
  • Dual chamber cardiac pacers: leads terminate in right atrial appendage and right ventricular apex.
  • Biventricular pacers: Left ventricular epicardial leads are used. The leads go directly to the surface of the left ventricle, and they are usually associated with typical pacing electrodes in the right atrial appendage and right ventricular apex. In other cases, the left ventricular pacing electrodes are introduced through the coronary sinus and wedged into a left ventricular cardiac vein.
Two components
(a) control unit: has lithium battery usually with sense amplifiers to sense the natural heart beats and computer logic to correct

 
(b)leads-number depending on the case, external casing of the control unit is made of inert titanium to avoid any immunological rejections

  
Note --MRI is contraindicated- but on demand pacemakers in future may permit MRI in future

Radiology Journal Update

New issue of Journal of Surgical Radiology is now available.



The January 1, 2011 issue (Vol 2, No 1) of the Journal of Surgical Radiology is now available online.
View FULL TEXT | FLASH PDF

Monday, December 06, 2010

Os Subfibularis


17 yr old girl has pain ankle ater trivial trauma. Radiograph shows radiopacity with normal soft tissues and no donor site  and normal articulation-possibly ossicle - suggest followup and other side comparison though it is not  necessary to find the ossicle on both sides. In general, accessory ossicles commonly observed in order of frequency of the lower extremity include: tibiale externum, os trigonum and os peroneum. Accessory bones that are rare in the foot include accessory interphalangeus,  anamolous os calcaneum and talus. 

Case submitted by Dr MGK Murthy, MD, DNB



An accessory, distal focus of epiphyseal ossification may develop in either malleolus. These foci are not anatomically separate entities, even though they can appear to be radiographically. They usually are asymptomatic. However, they may be injured, either acutely or chronically. If fractured, the injury can extend through a segment of the malleolus. An ossicle may also be avulsed as a ligament failure analogue, similar to a sleeve fracture of the patella. This is more common in the lateral than in the medial malleolus.

These avulsions, if not adequately diagnosed and treated, may progress to delayed union, nonunion, or a chronically painful ankle. Normally, the secondary center of ossification of the lateral malleolus appears during the first year of life, and fuses with the shaft at 15 years. 22% of normal children under the age of 16 have one or more accessory ossicles in the foot and ankle.

Majority  are asymptomatic and  few that cause pain and swelling can be managed conservatively. Surgery is the option if symptoms are recalcitrant ,  with excision and resuturing of ligament  being necessary . Cause of symptoms is not  known.    The most likely explanation is that anomalous ossification centers, not yet fused to the body of the epiphysis, have been subjected to trauma, causing disruption to the fibrous or cartilaginous attachment and results in a fibrous union or pseudo-arthrosis. Mechanical irritation or joint instability may produce local pain and tenderness and contribute to recurrent ankle sprains.

Sunday, December 05, 2010

Passion for Radiology

This thought struck me when few days back was discussing radiology versus other specialities to some interns following their entrance examination results. Was kind of surprised at the fact that girl who had topped was considering radiology as an option (usual practise in India, radiology is one of the top choices), however, was afraid that would it be boring? Another hardcore medicine aspirant intern actually believed radiology was not worth it.  

For a person like me who is really passionate about Radiology and am totally in love with the subject, this was surprising for sure. Possibly we radiologists are so busy in our (black and white) world, and we never really bother to influence and educate medical students about our speciality. Boring is probably the last world i would describe my life as a radiologist. And to add to it please note “I am not an interventional radiologist” Some how, these days whenever, i am discussing career with medical students from DAMS most of them say –“ok i may take radiology and then take intervention to keep my clinical side going”.  What i want them to understand is Radiology per se (yes diagnostic radiology) is thrilling, if you  have ever felt the thrill while playing chess or solving a puzzle or finding our way out or you just love computers and their capabilities, diagnostic radiology has it all. We get the same thrill in diagnosing a lesion, yes  same as the surgeon who removes it. We feel  the same as surgeon when dissect things layer by layer on our 3D work stations. We seamlessly in a day of work, think of pancreatic tumours, hirayama disease, perinephric abscesses and hip dysplasia. We know of developmental changes in the human anatomically similar to paediatricians and with ultrasounds we know similar to gynaecologists about their domains. Thrilling is what would best describe an active radiology practise.

Add to these, time for your own life, no night calls (if you choose so), possibility of teleradiology practise (sit at home and carry work with you), technology advancing at lightning pace and yes interventional radiology if want surgical thrills as well, Radiology is career with more merits that just possibility of better income/salary that most medical students believe. 

My own recommendation to MCI would be possible compulsory  radiology rotation and exams about radiology in Final MBBS in India, while at best in most colleges radiology is an optional subject. Think of it what would help a general physician more in 5years time knowledge of ophthalmology, cataract operations!! Or merits of various imaging modalities. 

Think of it. 

Comments and suggestions are welcome.

Saturday, December 04, 2010

Symphysis Pubis Fusion

Fusion or bridging of the symphysis pubis 


 Differential diagnosis
Post traumatic
Post infective
Osteitis pubis
Osteoarthritis
Ankylosing spondylitis
Alkaptonuria
Fluorosis


Friday, December 03, 2010

Aberrant Right Subclavian Artery and Dysphagia Lusoria-CT

The most common congenital anomaly of the aortic arch is a left aortic arch with an aberrant right subclavian artery. This abnormal origin of the right subclavian artery can be explained by the involution of the 4th vascular arch with the right dorsal aorta.3 The 7th intersegmental artery remains attached to the descending aorta, and this persistent intersegmental artery becomes the right subclavian artery. This leads to the aberrant artery, which often follows a retro-esophageal course. Note the aberrant right subclavian arising from the left sided aortic arch and showing retro-esophageal course, and will show posterior indentation on barium swallow.



Thursday, December 02, 2010

Sunshine Vitamin Deficiency for Radiologists?

This was brought to my notice by a very senior orthopedician in Delhi on his daily rounds. He had just seen a senior radiologist with vague body pain and microfractures due to possible vitamin D deficiency. His lifestyle was walking into MRI department at 8am and going back at 8pm. No sunlight in the entire day. Well it kind of scared me as my lifestyle and possibly most of the radiologists i know of is similar. Tried to search the internet for this, but got nothing for radiologist population.  We radiologists most of the time don't even get filtered sunshine.

Vitamin D levels amongst Doctors and comparison between clinicians and radiologists might yield interesting results.

What are your opinions?  Feel free to share in the comments section.

Wednesday, December 01, 2010

Bronchogenic Cyst-MRI

Middle aged lady with non specific respiratory symptoms for evaluation on Xray showing opacity. CT suggested cyst. MR shows a well defined, regular, approximately 6 cm sized predominantly fluid signal intensity, thin walled space occupying lesion seen in the left anterior mediastinum with mass effect on the ipsilateral lung parenchyma, and great vessels particularly the arch of the aorta and pulmonary trunk. There is no fluid / fluid level. Features are suggestive of Bronchogenic cyst.

 Case by Dr MGK Murthy


Teaching points :

- Congenital in nature derived predominantly from foregut diverticulum.

- Constitutes 40-50% of all mediastinal cyst.

- Seen as asymptomatic or nonspecific mass effect symptoms in the form of vascular or lung compression, with increase incidence in males predominantly.

- Usually fluid signal on all studies with possible T1 hyperintensity suggesting proteinaceous contents with no water lilly sign or nodules or septae or fluid blood levels or calcification.

- Differential diagnosis includes parasitic ( water lily sign would help for hydatid), teratoma ( fat or calcification ), thymic, ( nonhomogenous, presence of thymomegaly ), ectopic thyroid, ( intense uptake of iodine based contrast agents with heterogenity), great vessels aneurysms, ( presence of flow signal abnormality, calcification ), and nonspecific etiology.

- CEMR would usually help exclude enhancing nodule within, which could suggest malignant transformation, as squamous metaplasia is a known sequale.

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