Radiation Dose units

Units of Radiation

1. 'Curie' and 'Becquerel' :- are radiation units for quantity of radionucleotide disintegration per second.

2. 'Rad', 'Gray', 'cGy' are units of Absorbed dose of Radiation.

3. 'Sievert' :- is the S.I. Unit of Equivalent dose of Radiation

What is Equivalent dose of Radiation ?

A: Equivalent dose of radiation = Absorbed Dose of Radiation x Weighing Ratio (WR). 

Radiation units

• Activity is the transformation (disintegration) rate of a radioactive substance
  • Curie (Ci)
  • Becquerel (Bq) - S.I. Unit

  1 Bq = 1 disintegration per second (dps)
  1 Ci = 3.7 x 10¹⁰ dps
  1 Ci = 3.7 x 10¹⁰ Bq

• Absorbed dose is a physical quantity which represents the energy imparted by radiation onto an absorbing material.
  • Rad
  • Gray (Gy) - SI Unit

    1 Gy = 1 joule per kilogram
    1 Gy = 100 rads
    

• Dose Equivalent (DE) may be regarded as an expression of dose in terms of its biological effect. DE takes account of the fact that, for a given absorbed dose, such as 1 Gray, a radiation of one type and/or energy may give rise to a greater biological effect than a radiation of another type and/or energy.
  
  

  DE = Absorbed Dose x Quality Factor (Q)

  • Q depends on the type of radiation.
    Q = 1 for gamma, x-ray and beta
    Q = 10 for alpha
    
    Q is used to compare the biological damage producing potential of various types of radiation, given equal absorbed doses. The effectiveness of radiation in producing damage is related to the energy loss of the radiation per unit path length. The term used to express this is linear energy transfer (LET). Generally, the greater the LET in tissue, the more effective the radiation is in producing damage.
  • REMS
    
  • SIEVERT (Sv) - S.I. Unit
    
    1 Sv = 100 rems
    
    
• Exposure is a quantity that expresses the ability of radiation to ionize air and thereby create electric charges which can be collected and measured
  • Roentgen (R)
    1 R = 2.58 x 10^-4 c/kg of air
  
  

Most Commons Medicine

Most common finding in histopathological examination of kidney in Denys-Drash Syndrome - Diffuse Mesangial Sclerosis

MC ECG manifestation of PTE / Pulm.ThromboEmbolism : Sinus Tachcardia >> Irregular ST-T changes

MCC for Drug induced SLE : Procainamide > Hydrallazine

Exposure to Secondhand Smoke May Raise Dementia Risk

February 25, 2009 — Smoking is an established risk factor for cognitive impairment and dementia, and now a new large study suggests secondhand smoke is also detrimental.

"The odds of cognitive impairment were 44% higher in those exposed to the highest levels of secondhand smoke compared with those exposed to negligible levels," lead author David Llewellyn, PhD, from the Department of Public Health and Primary Care at the University of Cambridge, in the United Kingdom, told Medscape Neurology & Neurosurgery.

Results from the national population-based study are published online February 12 in BMJ.

Investigators examined saliva samples from almost 5000 nonsmoking adults older than 50 years. Participants were part of the Health Survey for England and had also taken part in the English Longitudinal Study of Aging. Saliva samples were tested for cotinine — a product of nicotine that can be found for about 25 hours after exposure to secondhand smoke. Participants in the study also provided a detailed smoking history. Investigators assessed never smokers and previous smokers separately.

High Levels of Cotinine Linked to Cognitive Impairment

READ :  http://www.medscape.com/viewarticle/588691?src=nldne

New Guidelines Recommend 5-Alpha Reductase Inhibitors for Preventing Prostate Cancer

February 25, 2009 — A new joint guideline produced by the American Society of Clinical Oncology (ASCO) and the American Urological Association (AUA) has recommended chemoprevention for prostate cancer in healthy men.

Specifically, it recommends that asymptomatic men with a prostate-specific antigen (PSA) of 3.0 ng/mL or lower and who receive regular screening consider using a 5-alpha reductase inhibitor (5-ARI), such as finasteride or dutasteride, to help prevent prostate cancer.

According to the new guideline, published online February 24 in the Journal of Clinical Oncologyand scheduled to appear in the April issue of The Journal of Urology, men in this category might benefit from a discussion with their physicians about the benefits and risks of 5-ARIs for the prevention of prostate cancer.

In addition, patients currently using these agents to treat benign conditions, such as lower urinary tract symptoms, should discuss continuing this treatment to reduce their likelihood of developing cancer.

http://www.medscape.com/viewarticle/588711?src=nldne

Mutations in NR5A1 Associated with Ovarian Insufficiency

 The genetic causes of nonsyndromic ovarian insufficiency are largely unknown. A nuclear receptor, NR5A1 (also called steroidogenic factor 1), is a key transcriptional regulator of genes involved in the hypothalamic–pituitary–steroidogenic axis. Mutation of NR5A1 causes 46,XY disorders of sex development, with or without adrenal failure, but growing experimental evidence from studies in mice suggests a key role for this factor in ovarian development and function as well.

Conclusions NR5A1 mutations are associated with 46,XX primary ovarian insufficiency and 46,XY disorders of sex development.

Read Full Article at N.E.J.M : http://content.nejm.org/cgi/content/full/NEJMoa0806228?query=TOC

Comparison of Weight-Loss Diets with Different Compositions of Fat, Protein, and Carbohydrates

Results At 6 months, participants assigned to each diet had lost an average of 6 kg, which represented 7% of their initial weight; they began to regain weight after 12 months. By 2 years, weight loss remained similar in those who were assigned to a diet with 15% protein and those assigned to a diet with 25% protein (3.0 and 3.6 kg, respectively); in those assigned to a diet with 20% fat and those assigned to a diet with 40% fat (3.3 kg for both groups); and in those assigned to a diet with 65% carbohydrates and those assigned to a diet with 35% carbohydrates (2.9 and 3.4 kg, respectively) (P>0.20 for all comparisons). Among the 80% of participants who completed the trial, the average weight loss was 4 kg; 14 to 15% of the participants had a reduction of at least 10% of their initial body weight. Satiety, hunger, satisfaction with the diet, and attendance at group sessions were similar for all diets; attendance was strongly associated with weight loss (0.2 kg per session attended). The diets improved lipid-related risk factors and fasting insulin levels.

Read Full Article at NEJM : http://content.nejm.org/cgi/content/full/360/9/859?query=TOC

Most Commons : Surgery Blood Vessels Thrombosis

Most Common Cause of Lower limb gangrene : Atherosclerosis

Best Conduit for Iliac Artery Graft : KNITTED DACRON > WOVEN DACRON

Most Common site of Arterial Emboli : Saddle Thrombus - (Junction of Common Femoral, Deep Femoral and Superficial Femorals)

Most Common Cause of Raynaud's Phenomenon in a 60 yr old male : Atherosclerosis

Most Common site of False Aneurysm : Femoral Artery.

Most Common site of true aneurysm : Popliteal Artery.




Most Common Cause of Retrograde Ejaculation : Diabetic Autonomic Neuropathy > Prostatectomy

Intracranial Neuropathies of Aneurysmal Etiology

1. Anterior Cerebral Artery Aneurysm / Supraclinoid Carotid artery aneurysm ---> Optic Nerve Compression ----> Visual Field defects.

2. Middle Cerebral Artery expanding aneurysm - Pain in eye / behind eye / in temple region.

3. Posterior Cerebral Artery (P.C.A) Aneurysm - Occulomotor Nerve.

4. AICA / PICA aneurysm - occipital or posterior cervical pain.

5. Ophthalmic Artery Aneurysm - Optic Nerve Compression --> Visual Loss.

pgmeenotes by dv........

Most Commons : Renal lesion in HIV infection

** The most common renal lesion in HIV infected individuals is  : 

                              OR 

** The most common HIV Associated Nephropathy is                :

ANSWER : FSGS- Collapsing Variant.

Reference : Robbins 7/e, p.n. 984 : pgmeenotes by dv.

Classic TRIAD of REITER's Disease

Described by Hans Reiter.

1. Urethritis - Non-gonococcal.

2. Arthritis.

3. Conjunctivitis.

This classic triad is seen only in 33% or 1/3rd of the patients with Reiter's Disease / ReA.

The Most Common cause of ReA is Chlamydia Trachomatis.

Other organisms include Shigella, Salmonella, Campylobacter, Yersinia.

pgmeenotes by dv

VIRCHOW'S TRIAD

Virchow's Triad of Thrombosis

1. Altered Blood Flow ---> STASIS

2. Hypercoagulabillity.

3. Endothelial Injury.

USMLE Step 2 : Clinical Vignettes Pretest Series

PreTest Self-assessment and Review - Clinical Vignettes for the USMLE Step 2 

USMLE STEP 2 : Pretest Series : Clinical Vignettes

for pgmeenotes by dv

Most Commons Surgery contd..

Most Common source for Thromboembolism - which vessels - Calf veins

Most Common source for massive ThromboEmbolism - Ilio-Femoral veins
(Note: Gold standard treatment in the prevention of DVT : LMWH)

Most Common cause of SVC Obstruction : Lung Cancer
(Note: Treatment option for SVC syndrome in Lung Ca is Radiation)

Most Common cause of IVC Obstruction : Extension of a Thrombus

Most Common cause of Acute Lymphangitis : Streptococcus pyogenes.

Most Common cause of upper limb lymphedema : Ca Breast.

Most Common performed operation for lymphedema : Limb Reduction Surgeries

PGMEE Notes : Mnemonic : Radioresistant-Chemoresistant Tumors

A Must Learn.

This is a well known Mnemonic for remembering Radio-resistant / Radio-sensitive and Chemo-resistant / Chemo-sensitive Tumors / Cancers.

It's not an easy one to learn, but it has shown it's worth many times in exams.

Radioresistant Tumors (M.O.P)

   1. Melanoma.

   2. Osteosarcoma.

   3. Pancreatic Carcinoma.

Radiosensitive Tumors (W.E.L.Se.M)

   1. Wilm's Tumor.

   2. Ewing's Sarcoma.

   3. Lymphoma.

   4. Seminoma.

   5. Multiple Myeloma.

   6. Medulloblastoma.

(Remember Both as MOP-WELSeM, if you could)

Chemoresistant Tumors - (G.B.S.S)

  1. Gastric carcinoma.

  2. Bladder Carcinoma.

  3. Soft Tissue Sarcoma.

  4. Squamous Cell carcinoma of Head and Neck.

Chemosensitive Tumors - 

  1. Wilm's Tumor.

  2. Lymphoma.

  3. Teratoma.

  4. ALL in Children.

  5. Choriocarcinoma.

  6. Ewing's Sarcoma.

  7. Rhabdomyosarcoma.

Slightly Complicated or I made it  a little. It can be remembered as either " Wimbledon Lawn Tennis ACER" or " Lead The World RACE ", "World of Tender Loving CARE"  and many, adopt or derive a good one and learn.

for pgmeenotes by dv

dhanesh.

Most Commons : PUO (Medicine)

********MC - Most Common ::: MCC- Most Common Cause ::: MCS - Most Common Site***********


PUO - Pyrexia of Unknown Origin MC

MCC of PUO - Extrapulmonary Tuberculosis

MCC of PUO in Elderly - Giant Cell Arteritis

MC Infectious cause responsible for PUO in elderly : Tuberculosis

MC fungus to cause PUO - Histoplasmosis

(These 4 are from Harrison 17th, the next one is from a guide)

MC Cancer to present as PUO - Leukemia & Lymphoma.

Nagging Synonyms

Sometimes it may happen that you might face a question regarding a disease / syndrome / test / pathway you never heard of, and you guess the answer and goes wrong, only to find later that the entity was just a synonym of another which you knew very well. Here in this section, I have tried to include many of such, 'Nagging Synonyms' as I would put.

NAGGING SYNONYMS

1. Carrion's Disease - Oroya Fever ... (Bartonella Bacilliformis, Vector: Sandfly)

2. Le-juene Syndrome - Cri-du-chat syndrome or 5p-deletion syndrome.

3. Dickeris-Horecker Pathway : HMP Shunt (Phosphoglunoate oxidative pathway)

4. Crow-Fukase Syndrome : POEMS Syndrome.

5. Bassen - Kornzweig Syndrome : Abetalipoproteinemia.

6. Steele-Richardson-Olzewski Syndrome - Progressive Supranuclear Palsy.

7. Lou Gherigh's disease - Motor Neuron Disease.

8. Lafora's Disease - Progressive Myoclonic Epilepsy.

9. Korsakoff Mayer Syndrome - Poly Arteritis Nodosa.

10. Gunther's Disease - Congenital Erythropoietic Protoporphyria.

11. Gull Disease - Myxedema.

12. Bechterew's Disease - Ankylosing Spondylosis.

13. Albers-Schonberg Disease - Marble Bone Disease / Osteopetrosis.

14. Dejerine - Roussy Syndrome - Facio-Scapulo humeral dystrophy.

15. Little Disease - Congenital Spastic Diplegia.

16. Louis Bar Synddrome - Ataxia-Telengectasia

17. Runt Disease - Graft Versus Host Disease.

18. Grawitz Tumor - Renal cell Carcinoma.

19. Pena-Shokeir Syndrome - Arthrogryposis Multiplex Congenita with Pulmonary Hypoplasia.

20. Ogilive Syndrome - Acute Colonic Pseudo-obstruction.

To be Continued...

DV..

FDA Approves New Deep Brain Stimulation Device for OCD

February 20, 2009 – Doctors could soon treat patients with resistant obsessive-compulsive disorder (OCD) with an implantable device that stimulates the brain to block nerve signals that may cause OCD symptoms.

The US Food and Drug Administration (FDA) has announced approval of a humanitarian device exemption (HDE) for the deep brain stimulator. Such exemptions facilitate the development and marketing of medical devices that treat or diagnose a disease or condition that affects fewer than 4000 people a year in the United States.

The small battery-powered deep brain stimulator — called Reclaim DBS Therapy (Medtronic, Minneapolis, Minnesota) — is implanted near the abdomen or the collarbone and connected through a lead to electrodes in the brain. The device delivers intermittent electrical stimulation that blocks nerve signals. One device may be implanted with 2 leads, or 2 systems can be implanted to stimulate both sides of the brain.

Psoriasis Drug Linked to Deaths From Progressive Multifocal Leukoencephalopathy

February 19, 2009 — Three deaths from progressive multifocal leukoencephalopathy (PML) and a possible fourth case have been reported in patients taking the immunosuppressant drug efalizumab (Raptiva, Genentech, Inc), according to a public health advisory issued today by the US Food and Drug Administration (FDA).

(Our point of interest : Efalizumab is an anti-CD11a antibody immunosuppressant drug indicated for the treatment of adults with chronic moderate to severe plaque psoriasis.)

According to the FDA, all 4 patients had been taking efalizumab for at least 3 years and had taken no other immunosuppressant drugs.

The FDA is advising clinicians to follow patients who are receiving efalizumab closely, as well as those who have discontinued the drug, and to periodically reevaluate whether patients should continue to receive treatment.

Coffee Intake Associated With Decreased Stroke Risk in Women

February 19, 2009 — A new analysis of data from the Nurses' Health Study shows that long-term intake of up to 4 or more cups of coffee per day was not associated with an increased risk for stroke and actually appeared to be protective against stroke in women who did not also smoke.

Among women who currently smoked, there appeared to be no effect of coffee intake, neither raising nor lowering stroke risk. No association was seen with other caffeinated drinks, including tea or soft drinks, and decaffeinated coffee still showed a trend toward a protective effect.

The report was published online February 16 and will appear in the March 3 print issue of Circulation.

Full article at--

site:http://www.medscape.com/viewarticle/588445?src=mpnews&spon=34&uac=126137EG

'MOST COMMONS' : Surgery contd..

Most performed operation in GERD : Laparoscopic Fundoplication

Most Important D/D of Esophagial Varices in Barium Swallow - Candidiasis

Most Common Diaphragmatic Hernia : Hiatus Hernia

Most Common Congenital Diaphragmatic Hernia : Bochdalek's Hernia

Most common conduit used after Esophagectomy : Jejunum
(NOTE : Best Conduit after esophagectomy is STOMACH, not jejunum)

Most Common cause of Death in Esophagial Cancer : Cachexia

Most Common cause of death after Esophagectomy : Anostomotic Leak

Most Common cause of death in Cervical Cancer : Uremia

New Link Opened for "PGMEE 2009 Counseling"

New page has been created in the http://mohfw.nic.in, for pgmee 2009 counseling with these 

links. 

Important notice for PH candidate

32 point reservation roster

Seat earmarked for OBC candidate

Seat of central institutes under 50 all India quota

Mode of implementation of OBC and PH reservation

Corrigendum AIPGEE courses 2009

Revised schedule PG counselling

AIIH&PH   KOKKATTA

Vaccancy Position (Degree)

Vaccancy Position (Diploma)

 

USMLE Step 1 : Pretest Series : Pathology Download

USMLE Step 1 : Pretest Series : Pathology Download

MOSt COMMONS Surgery Contd..

** MC Site of Lung abscess in supine position : 

Posterior Segment of right upper lobe > Left upper lobe > Apical Segment of Right lower lobe.

** MC Site of aspiration Pneumonia - Right Lower Lobe.

-- Most Common congenital neck cysts / The most common midline neck swellings in the neck - THYROGLOSSAL CYST. (AIIMS NOV' 07)

DNB : CET Centralized Entrance Test - June 2009

Click Here

The National Board of Examinations is an autonomous

organization of the Ministry of Health & Family Welfare,

Government of India.

NBE conducts DNB programme at various accredited medical

colleges/hospitals/institutions leading to the award of DNB.

DNB is a recognized qualification as per provisions of Indian

Medical Council Act, and the Government of India vide its

various notifications issued from time to time has equated the

DNB qualifications to the corresponding MD/MS qualification

awarded by various Indian Universities.

Centralized Entrance Test is the entrance examination for

admission to the 3 years post graduate (post MBBS) DNB

Programme.

The Board shall be conducting the next session of DNB CET

on 14th June, 2009.

For list of accredited hospitals, course/specialties available,

eligibility criteria, pattern of examination, examination centers,

validity of results, etc. candidates may kindly refer to the

Information Bulletin-cum-Application Form for the DNB CET

June 2009 session which can be obtained from (w.e.f. 10th

February, 2009):-

(A) Selected branches of Indian Bank on cash payment of

Rs.500/- only (For list of branches, kindly refer to detailed notice

on website or contact helpline No. 46054605).

(B) Can be downloaded from website of the Board

www.natboard.edu.in (The cost of Rs.500/- towards the

Information Bulletin and Application Form shall be payable

with the Examination Fees).

Duly complete application form along with Examination

Fees of Rs. 3,000/- only can be submitted to the office of

NBE latest by 9th March, 2009.

POINTS ONLY : ENT (Oto-Rhino-Laryngology) PART 2

To see PART 1 click here

17. Cholesteatoma of the nose : RHINITIS CASEOSA

18. The pathognomonic radiological sign of Nasopharyngeal Angiofibroma : Antral Sign / Holman - Miller sign - due to involvement of Pterygopalatine fossa.

19. Gateway of tears in esophagoscopy is KILLIAN'S DEHISCENSE - between Cricopharyngeus and Thyropharyngeus parts of Inferior Constrictor muscle.

20. Nasopharyngeal Bursa -----> Pharyngeal Bursitis is called THORNWALDT's Disease

21. Pharyngeal Recess = Fossa of Rosenmuller

22. Pharyngeal Pouch = Zenker's Diverticulum

23. Herpangina is caused by Group A Cox-sackie virus.

24. Pharyngitis + Conjunctivitis + Abdominal Pain mimicking appendicitis + Fever : Diagnosis is PHARYNGO-CONJUNCTIVAL fever caused by Adenovirus.

25. Acute Lymphondoular Pharyngitis - mainly caused by Coxsackie virus.

26. Horny excrescences on tonsils, pharyngeal wall or lingual tonsils are seen in - KERATOSIS PHARYNGITIS. 

(Note : they cannot be wiped off, no inflammation or constitutional symptoms, treatment is Reassurance)

27. Irwin-Moure sign - Pressure on anterior faucial pillar extruding pus in tonsillitis.

28. Bad taste in mouth is called as - CAGUS.

29. 'Hot Potato Voice' - seen in QUINSY / Peritonsillar Abscess.

30. Potato tumor is Rhinophyma.

31. Spaces of GILLETTE : are the 2 divisions of retropharyngeal space.

32. Styloid process is related to parapharyngeal space and it divides the space into anterior and posterior compartments.

33. Apple Jelly Nodules are seen in LUPUS VULGARIS.

To be continued.

Structures passing between skull and superior constrictor

Structures passing between skull and superior constrictor muscle

1. Levator Palati.

2. Tensor Palati.

3. Ascending Pharyngeal Artery (br. of ECA)

4. Ascending Palatine Artery (Branch of Facial Artery)

5. Eustachian tube

Structures passing between Superior and Middle Pharyngeal Constrictors

1. Stylopharyngeus

2. Glossopharyngeal Nerve.

Structures Passing between Middle and inferior constrictors

1. Superior thyroid artery

2. Internal Laryngeal nerve

3. Laryngeal Artery and Vein.

Structures passing below Inferior Constrictor Muscle

1. Recurrent Laryngeal Nerve.

2. Branch of Inferior Thyroid artery.