14 - AIIMS november 2008 radiology mcqs

1q: a pt comes with proptosis and abducent n palsy. A dark homogenous mass on t2w MRI is seen which shows intense enhancement with contrast.diagnosis is?

A. Cavernous hemangioma
b. Meningioma
c. Astrocytoma
d. Glioma

Answer:

2q: central dot sign is seen in?

A. Carolis disease
b. Primary sclerosing cholangitis
c. Polycystic liver disease
d. liver hamartoma

Answer:

3q: On USG diffuse thickening of gall bladder with hyperechoic shadow at neck and comet tailing is seen in?

A. Xanthogranulomatous cholecystitis
b. Adenomyomatosis
c. Adenomyomatous polyps
d. Cholesterol crystals

Answer:

4q: CT index. True is?

A. By reducing KVP by 50% radiation dose is reduced to half
B.
C.
D.

Answer:

13 - radiodiagnosis mcqs - 61 to 73

61q: a child with acute respiratory distress shows hyperinflation of unilateral lung in chest x ray . most likely cause for above presentation is ?

Answer : foreign body aspiration .

62q: which one of the following statement is false about loculated pleural effusion ?

1. they form obtuse angles against the mediastinum/chest wall when viewed in profile
2. they have unsharp margins when viewed enface
3. they do not conform to segmental distribution
4. the opacity may show air bronchogram

answer : d .

63q: radiographic appearance of pindborg’s tumor ?

Answer: driven snow appearance

64q: left cardiac border bulge can be seen in all except ?

1. enlarged azygous vein
2. left appendicular overgrowth
3. coronary artery aneurysm
4. pericardial defect

answer : a .

65q: all are seen in CCF except

1. kerley B lines
2. prominent lower lobe vessels
3. pleural effusion
4. cardiomegaly

answer : b .

66q: calcification of intervertebral disc is seen in

1. alkaptonuria
2. gout
3. RA
4. Psoriasis

Answer : a .

67q: impaired renal function is assessed by?

1. DTPA
2. DMSA scan
3. MAGS
4. Iodohippurate

Answer : a .

68q: a patient presented with ARF with complete anuria, but a normal USG . Next investigation is ?

1. IVP
2. Antegrade pyeolgraphy
3. Retrograde pyeolgraphy
4. Radio renogram

Answer : d .

69q: in cerebral angiography the dye is injected through

Answer : femoral artery

70q: disseminated small nodules with calcification in chest suggest ?

1. histoplasmosis
2. aspergillosis
3. cryptococcosis
4. coccidiomycosis

answer : a .

71q: pulmonary embolism is best diagnosed by ?

1. spiral CT scan
2. ventilation perfusion scan
3. x ray chest
4. pulmonary function

answer : a .

72q: pneumothorax is best demonstrated by taking of radiograph , with the patient in ?

1. inspiration
2. expiration
3. full inspiration
4. full expiration

answer : d .

73q: most direct and reliable roentgen sign of lobar collapse ?

1. air bronchogram
2. displacement of interlobar septum
3. mediastinal shift
4. radio density

answer : b .

12 - radiology mcqs - 51 to 60

51q: 45 year old female presents with fracture of femur following trivial fall. Investigations show multiple sclerotic skeletal metastasis with pathological frx of the right femur.the most common carcinoma in this clinical picture is ?

1. ca ovary
2. ca breast
3. ca endometrium
4. ca pancreas

answer : b .

52q: which of the following is the most specific and sensitive screening test for renovascular hypertension ?

Answer : duplex Doppler flow study .

53q: a dense persistent nephrogram may be seen in all except ?

1. acute ureteral obstruction
2. systemic hypertension
3. severe hydronephrosis
4. dehydration

answer : b .

54q: a young man with TB presents with massive recurrent hemoptysis . for angiographic treatment which of the following vessels should first be evaluated ?

1. pulmonary artery
2. bronchial artery
3. pulmonary vein
4. superior vena cava

answer : b .

55q: a nodular lesion on chest x ray with all of the following features suggest malignancy except ?

1. umbilicated margins
2. central cavitation
3. diffuse calcification
4. peripheral calcification

answer : d .

56q: unilateral small smooth kidney is seen in ?

1. reflux nephropathy
2. lobar infarction
3. renal artery stenosis
4. chronic glomerulonephritis

answer : renal artery stenosis .

57q: on a chest radiograph , a double shadow behind the heart , signs of aspiration pneumonia and absence of air in stomach is suggestive of ?

1. aneurysm of thoracic aorta
2. achalasia
3. carcinoma esophagus
4. peptic ulcer (stomach)

answer : b .

58q: what minimal amount of pleural space fluid is seen on x ray chest ?

Answer : 150 ml

59q: fraying and cupping of metaphyses of long bones in a child does not occur in ?

1. rickets
2. lead poisoning
3. metaphyseal dysplasia
4. hypophosphatasia

answer: lead poisoning .

60q: extensive pleural thickening and calcification especially involving the diaphragmatic pleura are classical features of ?

Answer : asbestosis .

11 - radiology mcqs - 40 to 50

40q: which of the following is used in the treatment of differentiated thyroid cancer?

1. I 131
2. Tc 99
3. P 32
4. I 131 – MIBG

Answer : a .

41q: phosphorous 32 emits ?

1. beta particles
2. alpha particles
3. gamma particles
4. positrons

answer : a . beta particles .

42q: cataracts are induced by single exposure X rays of equivalent dose of ?

Answer : 2 Sv .

15q: part of the GIT involved first in radiation injury is ?

Answer: small bowel mucosa .

43q: A one year old infant is brought with complaints of difficulty in breathing with irritability. CXR shows a suspicious white opacity extending from hila to right mid hemithorax with undulating border. Diagnosis is ?

1. no significant abnormality
2. collapse
3. consolidation
4. TGV

Answer : a . I wonder y !

44q: most sensitive imaging technique for detection of myocardial infarct is ?

Answer : cardiac MR .

45q: two techniques of cardiac MR are ?

Answer: dark blood and bright blood .

46q: 3 day old premature infant presents with blood-streaked stools , explosive diarrhea ,bile emesis and mild respiratory distress. X ray abdomen shows “bubbly” appearance of bowel. Diagnosis is ?

Answer : neonatal scleroderma .

47q: USG marker of greatest increased risk of trisomy 21 is ?

1. echogenic heart foci
2. hyperechogenic bowel
3. cystic hygroma
4. nuchal edema

answer : a .

48q: a patient has calcification on the right side of the abdomen in AP view . in lateral view it is seen to overlie spine . the most likely diagnosis ?

1. gall stone
2. calcified mesenteric stones
3. renal stones
4. vertebral osteophytes

answer : renal stones .

49q: most radiosensitive tumor ?

1. ca cervix
2. ca ovary
3. RCC
4. Pancreatic ca

Answer : ca cervix .

50q: maximum penetration is seen with ?

1. alpha rays
2. beta rays
3. gamma rays
4. electron beam

answer : c . gamma rays .

11 - radiology mcqs - 29 to 39

29q: the commonest site of CSF rhinorrhea ?

1. ethmoid
2. frontal
3. petrous temporal
4. sphenoid

answer : ethmoid .

30q: which of the following is not a branch of the cavernous segment of the internal carotid artery ?

1. dorsal meningeal branch
2. inferior hypophyseal artery
3. anterior meningeal artery
4. ophthalmic artery

answer : d .

31q: which of the following isotopes is used for radioimmuno assay ?

a. I 131 b. I 125 c. I 132 d. I 123

answer : d . iodine 123

32q: what is the gold standard investigation for diverticulosis ?

Answer : CT .

33Q: what is the gold standard investigation for increased intracranial pressure ?

Answer : subarachnoid probe .

34q: rigler’s measurement and eyeler’s ratio are used to ?

Answer : to differentiate LV enlargement from RV enlargement .

35q: calcifying metastasis are seen in ?

1. mucinous adenocarcinoma
2. bronchogenic carcinoma
3. PNET
4. CNS lymphoma

Answer : a . mucinous adenocarcinoma .

36q: solitary and localized periosteal reactions are seen in ?

1. trauma
2. inflammation
3. neoplastic change
4. all the above

answer : d .

37q: 50 year old male patient with positive family history of prostate cancer has come to u for a screening test . the most sensitive screening test to pick up prostate cancer in this case would be?

1. DRE
2. DRE + PSA
3. PSA
4. Endorectal coil MRI with T1W and T2W images

Answer : b .

38q: BARE orbit appearance is seen in all except ?

1. neurofibromatosis
2. metastasis
3. meningioma
4. bupthalmos

answer : c . meningioma .

39q: the MRI imaging in multiple sclerosis will show lesion in ?

1. white matter
2. grey matter
3. thalamus
4. basal ganglia

answer : white matter . a .

10 - MRI - mcqs and faqs

Magnetic Resonance Imaging (MRI):

1. ideal test to detect bone metastasis to only spine .( all other bones - metastasis : bone scan )
2. imaging of pancoast’s tumor ( superior sulcus tumor )
3. imaging of posterior mediastinal masses
4. for all brain tumors ( contrast enhanced MRI )
5. chronic subarachnoid hemorrhage
6. investigation of choice in traumatic paraplegia
7. the most sensitive and specific investigation in renal artery hypertension
8. investigation of choice in aortic dissection
9. in perinatal asphyxia , neurological damage can be predicted by MRI
10. the best investigation for parameningeal rhabdomyosarcoma
11. best choice to radiologically evaluate a posterior fossa tumor
12. a patient is suspected to have vestibular schwannoma , the investigation of choice for its diagnosis is GADOLINIUM enhanced MRI .
13. best diagnosis for dissecting aorta ( aortic dissection )
14. the most accurate investigation for assessing ventricular function
15. investigation of choice for evaluation of suspected perthes disease
16. 40 year old female patient on long term steroid therapy presents with recent onset of severe pain in the right hip. Imaging modality of choice for this patient is MRI .
17. investigation of choice for a pregnant lady with upper abdominal mass
18. first investigation of choice for spinal cord tumor
19. investigation of choice for multiple sclerosis
20. in MRI strength of magnetic field is 1.1 Tesla.

9 - radiology mcqs - 22 to 28

22q. what is the imaging modality of choice to detect bone metastasis ?

1. bone scan
2. CT
3. MRI
4. X ray

Answer : a . bone scan is the most commonly used imaging modality to detect bone metastasis except for spine metastasis .

23q: what is the imaging modality of choice to detect metastasis to spine ?

1. CT
2. MRI
3. X ray
4. Bone scan

Answer : b . MRI .

24q: what is the usually preferred imaging modality for lung imaging ?

1. CT
2. MRI
3. X ray
4. PET SCAN

Answer : a . CT .

25q: what is the best imaging modality for pancoast tumor ?

1. CT
2. MRI
3. X RAY
4. PET SCAN

Answer : b. MRI . because it involves the branchial plexus and sympathetic chain.

26q: what is the best imaging modality for superior sulcus tumor ?

1. CT
2. MRI
3. X ray
4. PET scan

Answer : b . MRI . superior sulcus tumor is the other name of pancoast’s tumor .

27q: what is the investigation of choice for posterior mediastinal tumors ?

Answer : MRI .

28q: what is the best investigation for all the brain tumors ?

Answer : contrast enhanced MRI .

8 - Thumb print sign

Q.3."thumb print " sign seen in ?
a.acute epiglottitis
b.acute sinusitis
c.acute laryngitis

ans is a.acute epiglottitis . ( it is also seen in ischemic colitis )

Epiglottitis
The term acute epiglottitis is used to describe a condition in which there is inflammation of the epiglottis and commonly the soft tissues surrounding the epiglottis. The condition is rare, but can be life threatening as inflammation of the epiglottis and surrounding tissues may lead to the complete obstruction of the upper respiratory tract.

Causes
Haemophilus influenzae type B (most common)
Pneumococci
Group A beta-haemolytic Streptococcus
Pseudomonas
Mycobacterium tuberculosis
Viruses
Local trauma e.g. following inhalation of foreign bodies or post intubation
Epidemiology
Acute epiglottitis is most common in children between the age of 2 and 8, although it can occur at any age
Males are more commonly affected than females with a ratio of 2.5:11
In adults, smoking and reduced levels of immunity appears to be risk factors, and there is some evidence to suggest an increased risk in diabetics2
Since the advent of vaccination against Haemophilus influenzae type b in children, the incidence of acute epiglottitis in children has reduced
Over the last few years the presence of epiglottitis in adults is being increasingly seen3,1
Presentation
Many of the signs and symptoms associated with acute epiglottitis are common, and may occur in many less serious disorders. Patients with epiglottitis may present with any of the following, and the symptoms may evolve very quickly over a period of a few hours.4

Commonest symptoms
Sore throat
Odynophagia
Muffled voice
Drooling
Fever
Anterior neck tenderness
Other features
Irritability
Cough
Ear pain
Cervical lymphadenopathy
The " rxpg sign" - patient leans forward on outstretched arms to move inflamed structures forward thereby easing the upper airway obstruction2
With more severe epiglottitis
Dyspnoea
Dysphagia
Dysphonia
Stridor (late finding-indicates airway obstruction)
Respiratory distress

Investigations
Patients who are suspected of having acute epiglottitis should not have their throat examined with the aid of a tongue depressor, due to the risk of laryngeal obstruction, but should be urgently referred for laryngoscopy.


Fibreoptic laryngoscopy remains the "gold standard" for diagnosing epiglottitis as the epiglottis can be seen directly. Laryngoscopy in these patients should only be performed in areas such as operating theatres which are prepared for intubation or tracheostomy in the event of upper airway obstruction.
Lateral neck X ray may be useful if laryngoscopy is not possible. Soft-tissue radiograph of the neck may show the "thumbprint sign".5
Throat swabs may be taken when the airway is secure, or when intubation/tracheostomy facilities are at hand. Streptococci are becoming the major pathogens in acute epiglottitis now.6
Blood cultures may be taken if the patient is systemically unwell.
CT or MRI scans may be performed if abscess formation is suspected.

7 - The Collar sign

*Diagnostic CT signs of diaphragm injury include a defect in the continuity of the diaphragm or crus and a waist-like constriction of abdominal viscera or omentum at the site of herniation as seen on axial or reformatted CT images, the CT “collar sign”


*On CT scans, herniation of an organ or omental fat may be visible through an abrupt discontinuity in the diaphragm. A waistlike constriction (collar sign) produced by diaphragmatic compression of herniated organs may be seen. Sagittal, coronal, and 3-dimensional (3D) reformation of CT scans may improve sensitivity.

*CT collar sign.
- Fig-a: Coronal volume-rendered image shows distinct collar sign (arrow).  
- Fig-b: Sagittal volume-rendered image shows collar sign and contact of the stomach directly with the posterior chest wall (dependent viscera sign)

6 - Emergency Radiotherapy indications

Q: Emergency Radiotherapy is given in ?
a. superior vena cava syndrome
b. pericardial tamponade
c. increased ICP
d. spinal cord compression

answer a,b,c,d. all of them.

- The indications of emergency radiotherapy are : ( mnemonic: emergency radiotherapy SANS Tumor )
S- Superior vena cava syndrome
A- Acute epidural spinal cord compression
N- Neoplastic cardiac tamponade
S- Severe hypercalcemia
Tumor – Tumor lysis syndrome

5 - Twin peak sign

*The twin peak sign refers to a triangular projection of placental tissue extending from the placental surface, insinuating itself between the layers of the intertwin membrane, and seen on ultrasonographic (US) studies of multiple gestations. This placental tissue is widest at the placental surface and tapers gradually at a variable distance into the intertwin membrane .

*Transverse image of the placenta of a twin pregnancy at 17 weeks gestational age reveals a triangular peak of villi (short arrow) extending from the placenta into the intertwin membrane (long arrow): the twin peak sign. Amniocentesis confirmed the pregnancy to be dizygotic, with male and female fetuses.

*In a dichorionic pregnancy, both the amnions and the chorions reflect away from the placental surface, creating a potential space into which villi can grow. Large arrow shows the resulting twin peak sign.

*Monochorionic diamniotic pregnancies have a single layer of continuous chorion (large arrow) limiting villous growth; the apposed amnions form a thin membrane separating the two amniotic cavities. A = amnion, C = chorion.

*The twin peak sign indicates the presence of a dichorionic-diamniotic twin gestation .
*The twin peak represents the extension of placental villi into the potential space that is formed from the reflection of apposed amniotic and chorionic layers from each fetus .
*It forms where two separate placentas grow contiguously and appear fused.
*The twin peak can be of variable size, and only its presence is required to suggest that the pregnancy is dichorionic-diamniotic .
*This sign is most useful in assessing the chorionicity of pregnancies after 10 weeks . Prior to this time, gestational sacs are readily recognizable and allow a rapid and accurate determination of chorionicity.

*DISCUSSION :
- Seventy percent of twins are dizygotic, resulting from the fertilization of two ova, whereas 30% are monozygotic, arising from a single fertilized ovum .
- Three placentation types can occur depending on the timing of the development of twins from fertilization. From earlier division to later, the three types of placentation are dichorionic-diamniotic, monochorionic-diamniotic, and monochorionic-monoamniotic.
- Dizygotic twins are always dichorionic. Monozygotic twins are dichorionic in one-third of cases, monochorionic-diamniotic in two-thirds of cases, and monochorionic-monoamniotic pregnancies are seen in less than 1% of cases .
- The only absolute sign of dizygosity on USG studies is documentation of different sex fetuses.
- The twin peak sign is a strong suggestion of a dichorionic pregnancy; it can also serve to determine the chorionicity of any number of multiple pregnancies. However, the geometry of fused placentas, when multiple, can be complex and difficult to assess sonographically .
- A twin peak between two fetuses can infer only the chorionicity of this pair. 
- Other USG criteria of dichorionicity include the demonstration of anatomically separate placentas and identification of a thick intertwin membrane . The two amniotic and two chorionic layers separating the two gestational sacs in a dichorionic gestation compose a thick membrane, which is often hyperechoic and reflective.
- Monochorionic pregnancies have a thin wispy membrane between the sacs made up of two layers of amnion and generally less than 1 mm in thickness .
- Wood et al conducted a prospective study to evaluate the diagnostic ability of the twin peak sign in assessing dichorionicity. Forty-five twin pairs were examined, of which 36 were dichorionic. They found that optimal evaluation was performed in the second trimester of gestation. In this subgroup, sensitivity and specificity were 100% and 86%, respectively, with positive predictive values for dichorionicity and monochorionicity of 97% and 100%, respectively.
- When third-trimester scans were included in the calculations these numbers decreased slightly with positive predictive values of 97% for dichorionicity and 78% for monochorionicity. Overall, the identification of a twin peak at any stage of pregnancy can be considered strong evidence of dichorionicity.
- However, as gestational age advances, crowding and shadowing from fetal body parts can limit the recognition of a twin peak. Furthermore, some researchers have reported natural regression of chorion laeve throughout gestation so that the twin peak may actually regress in size with time.
- Prenatal diagnosis of chorionicity is important because monochorionic pregnancies have increased rates and severity of all types of obstetric complications when compared with dichorionic pregnancies.
- The vascular communications between the fetuses through the unique placenta put these pregnancies at risk for twin-twin transfusion syndrome, twin embolization syndrome, and acardiac parabiotic twin syndrome .
- Determining that a pregnancy is dichorionic will allow selective intervention for a malformed or otherwise abnormal fetus without harming the healthy fetus.

4 - Radiological appearance of heart in various diseases

*Fallots Tetralogy : Boot shaped heart
(Remember this as : Fallot shoe Company.)

*Tricuspid Atresia: Box shaped heart
(Draw a box , that is a cube , u can only view 3 sides of a cube , right? so 3 is for tricuspid , thats why tricuspid atresia.)

*TAPVC (total anomalus pulmonary venous connection.) : Snow man appearance , 8 shaped heart , cottage loaf appearance.
(imagine and view a giant Yati (snow man) is bringing a large loaf of bread which is 8 shaped . i mean not vertical '8' but horizontal '8' )
- The below picture shows a cottage loaf :

*Constrictive pericarditis : Egg in cup
(you are putting a large egg in a cup, it’s not getting in , so u r constricitng it.. and pressing it .. )

*Pericardial effusion : water bottle , pear shaped .
(imagine a patient has got pericardial effusion and a water bottle or bisleri is coming out from his left chest wall... the bottle is filled with many pears!)

*Pulmonary hypertension : Jug handle
(Imagine - a jug is tightly packed , the lid is so much tight , but the Jug has got Hypertension , so ultimately the lid just pops up!)

*Transposition of vessels : egg shell cracking
(imagine a huge Ostrich Egg , containing many veins and arteries, all transposed and getting bigger and bigger , causing cracking of the egg )

3 - Radiodiagnosis and Radiotherapy mcqs - 11 to 21

11q) Double Shadow is seen in
a. Mitral Stenosis
b. IBD
c. Pinealoma
d. None of the above

answer a. Mitral stenosis.

12) Hilar dance on fluoroscopy is seen in cases of
a. ASD
b. Bronchiectasis
c. Both
d. None

answer c. Both.

13) Consistent feature of Pulmonary Tuberculosis
a. Upper lobe infiltrates
b. Cavities
c. Miliary mottlings
d. Nothing

answer d. Nothing.

Reference: Harrison 15th Edition Chapter 169. The initial suspicion of pulmonary tuberculosis is often based on abnormal chest radiographic findings in a patient with respiratory symptoms. Although the "classic" picture is that of upper lobe disease with infiltrates and cavities, virtually any radiographic pattern from a normal film or a solitary pulmonary nodule to diffuse alveolar infiltrates in a patient with ARDS may be seen. In the era of AIDS, no radiographic pattern can be considered pathognomonic.


14) Water’s view is
a. Anteroposterior view
b. Occipitomental view
c. Occipitofrontal view
d. Lateral View

answer b. Occipitomental view.

Reference: Logan Turner


15) Gray is a Unit for
a. Activity
b. Absorbed dose
c. Exposure
d. Dose equivalent

answer b. Absorbed dose.

16) Cranio spinal irradiation is given for
a. Medulloblastomas
b. Pineoblastomas
c. Pineal germinoma
d. All of the above

answer d. All of the above

Reference: Harrison 15th Edition


17) Rhabdomyosarcoma is treated by
a. Chemotherapy
b. Radiation
c. Surgery
d. All of the above

answer d. All of the above.

Reference: OP Ghai 6th Edition Page 576.


18) Which one of the following is a recognized X-Ray feature of rheumatoid arthritis?
a. Juxta-articular osteosclerosis.
b. Sacroilitis.
c. Bone erosions.
d. Peri-articular calcification.

answer c. Bone erosions

Reference : Given in Harrison 15th Edition Chapter 312 Page 1933.


19) High resolution computed tomography of the chest is the ideal modality for evaluating:
a. Pleural effusion.
b. Interstitial lung disease.
c. Lung mass.
d. Mediastinal adenopathy.

answer b. Interstitial lung diseases

Reference Textbook of Radiology and Imaging - 7th Edition - David Sutton Page 187 Harrison 15th Edition.


20) CT scan of a patient with history of head injury shows a biconvex hyperdense lesion displacing the grey-white matter interface. The most likely diagnosis is:
a. Subdural hematoma.
b. Diffuse axonal injury.
c. Extradural hematoma.
d. Hemorrhagic contusion.

answer c. Extradural hematoma.

Reference Schwartz Surgery : 7th Edition Page 1882 : Fig 40-1 Bailey & Love,23rd, Pg-550.


21) Intestinal infarction all are signs on CT except?
a) Bowel wall thickening
b) Thumb printing
c) Free Peritoneal air
d) Intramural gas

answer b. Thumb printing.

*The most common CT finding in bowel ischemia is bowel wall thickening, although it is nonspecific. The thickened bowel wall is sometimes associated with the target sign, alternating layers of high and low attenuation within the thickened bowel wall, which results from submucosal edema or hemorrhage. However, the bowel wall is thinned or occasionally invisible when the involved bowel segment becomes gangrenous.
*Other CT findings of bowel ischemia reported in the literature include arterial occlusion, mesenteric or portal vein thrombosis, bowel dilatation, engorgement of mesenteric veins and mesenteric edema, intramural gas (intestinal pneumatosis), mesenteric or portal venous gas, lack of bowel wall enhancement, increased enhancement of the thickened bowel wall, and infarction of other abdominal organs
*The intramural gas is caused by dissection of luminal gas into the bowel wall across the compromised mucosa.
*Mesenteric or portal venous gas is an even less common CT manifestation of ischemic bowel disease and represents the propagation of intramural gas into the mesenteric venous system. Free intraperitoneal gas is an ominous CT sign in ischemic bowel disease because it indicates perforation of an infarcted bowel segment . Absent or poor enhancement of the bowel wall appears to be the most specific finding for bowel ischemia.

Ref: radiographics.rsnajnls.org/cgi/content/full/20/1/29

Thumbprinting is seen in plain Xray Abdomen and Barium studies only.

3 - Radiodiagnosis and Radiotherapy mcqs - 1 to 10

1q: Left Atrial enlargement is seen in :
a. AP View
b. PA View
c. Left Oblique View
d. Right Anterior Oblique View

answer d. RAO view

Reference: Braunwald, Chapter 7 - Radiology of the Heart

RIGHT ANTERIOR OBLIQUE (RAO) PROJECTION:
Chest radiography in this projection is performed with the patient in a 45-degree right anterior oblique relationship to the film cassette (right shoulder toward the cassette). In this view there is elongation of the ventricles; the long axes of the ventricles are in view and the atrioventricular groove is in profile. This position permits optimal visualization of a calcified mitral or tricuspid valve. The right anterior oblique view is used by angiographers to determine the presence of left atrial enlargement, a common feature in mitral stenosis. It is also helpful to the fluoroscopist when studying the function of a mechanical mitral valve prosthesis. The aortic arch is foreshortened in this view, so that the arch and proximal descending aorta are often superimposed and obscured. The anterior border of the heart consists of the sinus portion of the right ventricle inferiorly and the right ventricular outflow tract and the main pulmonary artery superiorly. The right-sided or posterior heart border consists of the right atrium superiorly and the left atrium inferiorly.

LEFT ANTERIOR OBLIQUE (LAO) PROJECTION:
The left anterior oblique projection is performed with the patient in a 60-degree oblique relationhip to the cassette. This is a useful angiographic view to diagnose the presence of left ventricular enlargement. Since the ventricular septum is in profile in the LAO projection, septal defects, dyskinesia, and displacement, due to right heart enlargement, can be identified. In this projection the aortic and pulmonary valves are in profile, so that aortic valve calcifications can be clearly visualized and aortic or pulmonary stenosis and regurgitation can be assessed. The aortic arch is also in profile in the LAO projection so that abnormalities of the arch including dissection, contained rupture, aortitis, aneurysm, and coarctation can be detected with aortography or cross-sectional imaging. The anterior (right) heart border consists of the right atrium above and right ventricle below. Along the left posterior heart border, the left atrium is border-forming superiorly and the left ventricle inferiorly. The LAO projection is superior to other projections for detecting right ventricular enlargement, characterized by an increase in the convexity of the anterior border of the cardiac silhouette. An enlarged right atrium may cause bulging of the upper anterior border of the cardiac shadow, producing a shelf-like configuration.

2q: NMR is based on the properties of
a. Protons
b. Spin
c. Both
d. None

answer c. both

Reference: Nelson 15th Edition Chapter 381.7

*Nuclear magnetic resonance (NMR) is a physical phenomenon based upon the magnetic properties of an atom's nucleus. All nuclei that contain odd numbers of nucleons and some that contain even numbers of nucleons have an intrinsic magnetic moment. The most commonly used nuclei are hydrogen-1 and carbon-13, although certain isotopes of many other elements nuclei can also be observed. NMR studies a magnetic nucleus, like that of a hydrogen atom (protium being the most receptive isotope at natural abundance) by aligning it with a very powerful external magnetic field and perturbing this alignment using an electromagnetic field. The response to the field by perturbing is what is exploited in nuclear magnetic resonance spectroscopy and magnetic resonance imaging.
NMR spectroscopy is one of the principal techniques used to obtain physical, chemical, electronic and structural information about a molecule. It is the only technique that can provide detailed information on the exact three-dimensional structure of biological molecules in solution. Also, nuclear magnetic resonance is one of the techniques that has been used to build elementary quantum computers.

3q: Lentiform appearance
a. Extradural Haemorrage
b. Subdural
c. Sub Arachnoid Hemorrhage
d. Intra Cerebral hemorrhage

answer a. extradural hemorrhage

Reference:
Concise Textbook of Surgery - 3rd Edition - Das Page 546 Fig 31.2
Schwartz Surgery : 7th Edition Page 1882 : Fig 40-1
Bailey 22nd Edition Page 395

Facts:
1. Lentiform-shaped hyperdense lesion is Acute Extradural Hemorrahge.
2. Crescent-shaped hypodense lesion is Chronic Subdural Hematoma.
3. Crescent-shaped hyperdense lesion is Acute Subdural Hematoma.
4. Lentiform-shaped hypodense lesion is Chronic Extradural Hematoma. 

* This is easy to understand. When the blood is between Skull and Dura, as in the case of Extra dural haemorrhage, it is limited by the inner aspect of skull and the dura and gives the classical biconvex or lentiform shaped. Remember that the common lens (including the lens in our eye) is biconvex.

*When the blood is between Dura and Arachnoid, as in the case of SubDural, it assumes a concavo- convex shape, limited by Dura on the outer aspect and Arachnoid on the inner aspect to produce a crescent shaped lesion.

4q: A patient presents with mass in lung with hyperosmolality of urine. The probable cause of this is
a. SIADH
b. Lab Error
c. Renal Secondaries
d. None of the above

answer a. SIADH

Reference: Robbins 7th Edition Page 334

5q) Most common cause of lymphedema of developed countries-
a. Malignancy
b. Filaria
c. Trauma
d. None of the above

answer a. Malignancy

Reference: Bailey and Love 24th Edition Page 981

6q) Which of the following Techniques and Instruments allow more accurate placement of radiation beams than is possible using conventional X-rays, where soft-tissue structures are often difficult to assess and normal tissues difficult to protect; and to measure cancer volume for Rx for Teletherapy in Radiotherapy ?
a. Virtual simulation
b. 3-dimensional conformal radiotherapy,
c. Intensity-modulated radiotherapy
d. All of the above

answer d. all of the above.

Reference: Bucci M, Bevan A, Roach M (2005). "Advances in radiation therapy: conventional to 3D, to IMRT, to 4D, and beyond.". CA Cancer J Clin 55 (2): 117-34. PMID 15761080.

*The planning of radiotherapy treatment has been revolutionized by the ability to delineate tumors and adjacent normal structures in three dimensions using specialized CT scanners and planning software.
*Virtual simulation, the most basic form of planning, allows more accurate placement of radiation beams than is possible using conventional X-rays, where soft-tissue structures are often difficult to assess and normal tissues difficult to protect.
*An enhancement of virtual simulation is 3-Dimensional Conformal Radiotherapy (3DCRT), in which the profile of each radiation beam is shaped to fit the profile of the target from a beam's eye view (BEV) using a multileaf collimator (MLC) and a variable number of beams. When the treatment volume conforms to the shape of the tumour, the relative toxicity of radiation to the surrounding normal tissues is reduced, allowing a higher dose of radiation to be delivered to the tumor than conventional techniques would allow.
*An enhancement of 3DCRT is intensity-modulated radiotherapy (IMRT), employing dynamic multileaf collimation not only to shape the profile of the beam, but also to vary the intensity of the beam over its area. The goal is to achieve greater conformality than 3DCRT provides. IMRT also improves the ability to conform the treatment volume to concave tumour shapes, for example when the tumour is wrapped around a vulnerable structure such as the spinal cord or a major organ or blood vessel.
*3DCRT is used extensively. Use of IMRT is growing but is limited by its need for additional time from medical personnel. Proof of improved survival benefit from either of these techniques over conventional radiotherapy is limited to a few tumor sites, but the ability to reduce toxicity is generally accepted. Both techniques may enable dose escalation, potentially increasing usefulness. There has been some concern, particularly with IMRT, about increased exposure of normal tissues to radiation and the consequent potential for secondary malignancy. Overconfidence in the accuracy of imaging may increase the chance of missing lesions that are invisible on the planning scans (and therefore not included in the treatment plan) or which may move between treatments or during a treatment (for example, due to respiration or inadequate patient immobilization). New techniques are being developed to better control this uncertainty — for example, real-time imaging combined with real-time adjustment of the therapeutic beams. This new technology is called image-guided radiation therapy (IGRT) or four-dimensional radiotherapy.

7Q) Cell Most Sensitive to Radiotherapy
a. Rapidly Proliferating Cell
b. Slowly dividing cells
c. Central Nervous system
d. None of the above

answer a. Rapidly proliferating cell

Reference: Robbins 7th Edition Page 437

8q) Which one of the following radioisotope is not used as permanent implant?
a. Iodine- 125.
b. Palladium - 103.
c. Gold - 198.
d. Caesium - 137.

answer d. Cesium-137.

Reference:
Radiation in Medicine: A Need for Regulatory Reform (1996) Page 71 TABLE 2.13 published by the institute of Medicine http://www.iom.edu/
Oxford Textbook of Surgery, Chap 35.7
http://books.nap.edu/books/0309053862/html/71.html
http://mrcas.mpe.ntu.edu.sg/groups/urobot/bt/brachytherapy.html

Discussion:
*The original method of brachytherapy is now sometimes called "low dose rate" (LDR) brachytherapy. The radioactivity of sources available at the time of brachytherapy's development was such that, to give a tumor-killing dose, sources had to be left in place for days. Because of the low activity, these sources could be handled manually. LDR therapy typically involves tumor dose rates of from 0.3 to 0.6 Gy per hour.
*For interstitial brachytherapy, sources are either inserted directly into tissues or are afterloaded into hollow needles or plastic catheters that pierce the tumor. In some cases, seeds are implanted directly into tissues and left permanently. For radiation safety and radiobiological considerations, permanent implants are feasible only with nuclides having a fairly short half-life.
*In the early days of brachytherapy, radium-226 (Ra-226) was the only radionuclide available. After World War II, reactor-produced nuclides became available and the use of Ra-226 gradually declined. The radionuclides commonly applied in brachytherapy are listed in in the table below in approximate order of prevalence of use.

Some Properties of Radionuclides Commonly Used for Brachytherapy
Element	Isotope	Half-Life	Source Forms	Implant Type
Gold	Au-198	2.7 days	Seeds	Permanent
Palladium	Pd-103	17 days	Seeds	Permanent
Iodine	I-125	60 days	Seeds	Permanent
Iridium	Ir-192	74 days	Seeds, wire	Temporary
Cesium	Cs-137	30 years	Tubes, needles	Temporary
Strontium	Sr-90	29 years	Plaque	Temporary

*In a permanent implant, the radioactive sources are permanently implanted into the tumor and allowed to decay. Hence, neither the dose nor the dose distribution can be changed after the initial insertion. It is, however, a simple procedure, and some of them can be done on an out-patient basis. *Other advantages of the permanent implant are that, in deep-seated tumors, it is safer because of the lower risk of infection and that a second operation for its removal is not required. Permanent implantations are performed with relatively short half-life radiosotopes like iodine-125, palladium-103, or gold-198
*Iodine 125 PERMANENT IMPLANTS are used in prostate cancer.
*Palladium is used for Prostate cancers and Choroidal melanoma.
*Gold is used in the following cases:
-Palliative treatment of inoperable tumours obstructing the trachea can be achieved using a number of techniques.
-A diathermy loop can be used to core out large volumes of tumour from within the lumen. Laser resection is more elegant but no more effective.
-Local radiotherapy can be achieved by inserting radioactive gold grains; this technique may be supplanted by placing a cannula into the tumour site and inserting iridium-199.
*Although nasopharyngeal carcinoma is radiosensitive, local failure in the form of persistent or recurrent tumour is not uncommon. Administration of further external radiation is limited by the tolerance of structures such as the inner ear and brain-stem. Brachytherapy has been successfully employed in the management of local disease. This requires adequate exposure of the nasopharynx to allow accurate insertion of radioactive implants. Under general anaesthesia, the hard and soft palates can be split in the midline to expose the tumour in the nasopharynx; radioactive gold grains can then be inserted into the tumour under direct vision. The operative procedure is simple and the complication rate is minimal. Small recurrent or persistent tumours in the nasopharynx can be managed successfully in this way.

9q) half life of Cobalt 60
a. 5.2 hours
b. 5.2 years
c. 8 days
d. 8 months

answer b. 5.2 years

Important Radioactive elements
Rays	Mass	Symbol	Atomic Number	Actual Mass	Element	t ½	t ½
b	32	P	15	30	Phosphorus	14.3	Days
b	90	Sr	38	87	Strontium	28	Years
b	90	Y	39	88	Yttrium	2.54	Days
b,g	226	Ra	88	226	Radium	1622	Years
b,g	198	Au	79	197	Gold	2.7	Days
b,g	131	I	53	127	Iodine (Mainly b)	8	Days
g		Ir	77	192	Iridium	74.5	Days
g	60	Co	27	57	Cobalt	5.2	Years
g	137	Cs	55	133	Caesium	30	Years
N,g	252	Cf	98	252	Californium	2.6	Years
	182	Ta	73	180	Tantulum	4	Months
					Tritium	12.4	Years
g	133	Xe	54	131	Xenon	5.2	Days
	123	I	53	127	Iodine	13	Hours
	132	I	53	127	Iodine	2.3	Hours
g	99	Tc	43	99	Technetium	6	Hours
		Ga	31	70	Gallium Citrate	3.2	Days
g	201	Tl	81	204	Thallous Chloride	3.1	Days
	222	Rn	76	222	Radon	3 to 6	Days
	51	Cr	24	52	Chromium	3.8
g	81	K	36		Krypton
g		Se	34		Selenium

10q) Phantom is used in
a. Stereotactic Surgery.
b. Electron Beam CT
c. Both
d. None

answer c. Both

Reference:
Robert Levy, A Short History of Stereotactic Surgery, Cyber Museum of Neurosurgery. This is based on
Patrick J. Kelly, "Introduction and Historical Aspects", Tumor Stereotaxis, Philadelphia: W.B. Saunders Company (1991)
Philip L. Gildenberg, "Stereotactic Surgery: Present and Past", Stereotactic Neurosurgery, (Editor: M. Peter Heilbrun) Baltimore: Williams and Wilkins (1988)

*Stereotactic neurosurgery :

- Stereotactic neurosurgery has become an indispensable portion of the neurosurgeon's repitoire, a method allowing three dimensional localization of specific sites within the complex and compact human nervous system.
- The word stereotactic is derived from the Greek word stereos, meaning three dimensional, and the Latin word tactus, meaning to touch. Originally used to create accurate maps of the human brain, its first clinical application occurred at the end of World War II. At this time physicians attempted to treat patients with movement disorders, such as Parkinson's disease, by creating defects within abnormal portions of the brain.
- Stereotactic guidance was used to increase the accuracy of the lesion produced. Despite the initial attempts, stereotactic neurosurgery did not become popularized until the late 1970's when dramatic improvements in neuroimaging occurred. At this time computed tomography, CT, redefined the ability of a physician to identify diseases within the brain. More recently magnetic resonance imaging, MRI, has also been applied to stereotactic procedures, increasing the neurosurgeon's accuracy and the diversity of disease processes treated.
- Combined with these neuroimaging techniques, stereotactic neurosurgery has found a role in both the therapeutic as well as diagnostic approaches to treating diseases of the nervous system.

*How is stereotactic neurosurgery performed?

- There are a number of different stereotactic systems, each employs the same basic principle to localize a specific site within the brain. The system pictured is known as the Cosman-Roberts-Wells System. At Columbia Presbyterian Medical Center this system, as well as the Brown-Roberts-Wells System, is utilized. Although a number of different procedures can be performed with stereotactic techniques, the following description is for a stereotactic brain biopsy.
- The initial step to stereotactic localization is the application of the base ring. With the help of an anesthesiologist, the patient is mildly sedated and four points on the scalp are infiltrated with local anesthetic. The ring is then fastened to the patient's skull with four pins, inserted through the anesthetized regions. The exact pin sites are determined based on the location of the lesion. The localizing ring is then attached to the base ring and the patient is taken to the neuroradiology department where a CT or MRI is performed. Brain Targeting
- The image obtained in conjunction with the localizing ring allows the neurosurgeon to compute the exact three dimensional position of the region of interest. The patient is then taken to the operating room and placed on the operating table. The base ring is attached to the operating table. This maintains the base ring in a fixed position and avoids the patient having to support the weight of the apparatus. The entry site is selected, and both the entry site and point of interest are mapped onto a "phantom," which relates each point to the patient's head. Coordinates are obtained from the phantom and entered into a computer which determines the final trajectory.
- The localizing ring is removed and an arc ring is attached to the base ring. The arc ring will guide the neurosurgeon in the proper trajectory. A small incision, about 0.5 cm, is made in the scalp at the entry site, and a hole is drilled through the skull which has a diameter smaller than a pencil. The biopsy needle is inserted, guided by the arc ring, to the point of interest. Samples of tissue are obtained and sent for analysis. Once enough specimens have been obtained the biopsy needle is removed and the scalp incision is sutured, often requiring only one stitch. The arc ring is then disassembled and the base ring removed from the patient's skull by unscrewing the four pins. The entry sites for the pins are small and do not require any stitches. The patient is taken to the recovery room, observed overnight, and returns home the next day.


*What are the applications of stereotactic neurosurgery?

- The description above is for a stereotactic brain biopsy, which is one of the more common procedures employing stereotactic techniques. This type of procedure is purely diagnostic, and will only identify a disease process. Stereotactic techniques also aid in the diagnosis of abnormal brain in patients with epilepsy. Such patients often do not have discrete areas which can be identified as the seizure focus. The implantation of electrodes is required to record the activity of brain tissue. Based on these recordings the abnormal tissue is located. Stereotactic insertion of these electrodes insures that the electrodes will be placed in the suspected region of pathology.
- Besides diagnostic applications, there are therapeutic procedures performed with stereotactic techniques. One procedure gaining increasing popularity is stereotactic radiosurgery. There are numerous advantages to combining radiation treatments with stereotactic techniques. As opposed to conventional radiation therapy, stereotactic radiosurgery allows a higher dose of radiation to be focused onto the lesion of interest. In addition there is a decreased spread of radiation into the normal brain. The type of radiation employed is either gamma rays or heavy charged particles, such as protons or helium ions. Stereotactic radiosurgery allows a more effective treatment of brain tumors with a decreased incidence of complications.
- Certain disease processes produce an abnormal collection of fluid within the brain. These collections produce pressure on the surrounding brain and can lead to damage of normal structures. Examples of abnormal fluid collections include neoplastic and non-neoplastic cysts, hydrocephalus, and traumatic fluid collections. Utilizing stereotactic procedures the neurosurgeon is able to precisely insert a catheter into the fluid collection. The fluid can then be drained with a temporary catheter, or a permanent draining device. Stereotactic techniques are also employed to determine the exact location of a skull opening, known as a craniotomy, in order to remove lesions within the brain.
- Finally, stereotactic techniques are also utilized in the treatment of various neurological diseases that produce movement disorders, such as Parkinson's disease, Hemiballismus, Essential Tremor, or Huntington's Chorea. The procedures utilized to treat such conditions are known as Pallidotomy and Thalamotomy. Such procedures are designed to create an ablative lesion within various brain structures, such as the pallidum or the thalamus. Precise localization is required so as not to include adjacent structures within this compact area of the brain. Such precision is only obtained with stereotactic techniques.

Diagnostic Imaging: McQs