Bremsstrahlung refers to:

 # Bremsstrahlung refers to: 

a. the primary source of X-rays from an X-ray tube 

b. Characteristic radiation emitted when an electron is displaced from the outer shell of a tungsten atom in the target 

c. the electromagnetic spectrum 

d. particulate radiation 

The correct answer is: A. a. the primary source of X-rays from an X-ray tube. 

BREMSSTRAHLUNG RADIATION: The sudden stopping or slowing of high-speed electrons by tungsten nuclei in the target produces bremsstrahlung photons, the primary source of radiation from an x-ray tube. (Bremsstrahlung means “braking radiation” in German.)

Multiple punched out radiolucencies is a feature of:

 # Multiple punched-out radiolucencies is a feature of: 

a. Multiple Myeloma 

b. Thalassemia 

c. Fibrous Dysplasia 

d. Ewing's Sarcoma 

The correct answer is A. Multiple myeloma.

The periphery of multiple myeloma lesions is well-defined but not corticated; it lacks any sign of bone reaction. The lesions have been described as appearing “punched out.” However, many appear ragged and even infiltrative. Some lesions have an oval or cystic shape. Untreated or aggressive areas of destruction may become confluent, giving the appearance of multilocularity.

Bleeding time is prolonged in:

 # Bleeding time is prolonged in:

A. Hemophilia

B. Von willebrand disease

C. Telangiectasia

D. Henoch Schonlein purpura 

The correct answer is B. Von Willebrand disease.

Von Willebrand disease (VWD) is the most common hereditary blood-clotting disorder in humans. An acquired form can sometimes result from other medical conditions. It arises from a deficiency in the quality or quantity of von Willebrand factor (VWF), a multimeric protein that is required for platelet adhesion. It is known to affect several breeds of dogs as well as humans. The three forms of VWD are hereditary, acquired, and pseudo or platelet type. The three types of hereditary VWD are VWD type 1, VWD type 2, and VWD type 3. Type 2 contains various subtypes. Platelet type VWD is also an inherited condition.

The various types of VWD present with varying degrees of bleeding tendency, usually in the form of easy bruising, nosebleeds, and bleeding gums. Women may experience heavy menstrual periods and blood loss during childbirth.

Severe internal bleeding and bleeding into joints are uncommon in all but the most severe type, VWD type 3.

Hair-on-end appearance in a skull roentgenogram is seen in:

 # " Hair-on-end" appearance in a skull roentgenogram is seen in:

a. Fibrous dysplasia 

b. Thalassemia 

c. Garre's Osteomyelitis 

d. Paget's Disease 

The correct answer is B. Thalassemia.

Similar to sickle cell anemia, the features of thalassemia generally result from hyperplasia of the ineffective bone marrow and its subsequent failure to produce normal red blood cells. However, these changes are usually more severe than with other anemias. There is a generalized radiolucency of the long bones with cortical thinning. In the skull, the diploic space exhibits marked thickening, especially in the frontal region. The skull also shows a generalized granular appearance, and occasionally a “hair-on-end” effect may develop.

Vesicles rupture at followed by pseudo membrane formation on a 3 year old child

 # A 3 year old patient has extensive vesicles on lip, tongue, oral mucous membrane. After 2-4 days vesicles rupture at followed by pseudo membrane formation and also some dermal lesions are seen. What will be the diagnosis? 

a. Herpetic stomatitis 

b. Erythema multiforme 

c. ANUG 

d. Steven-Johnson Syndrome 

The correct answer is B. Erythema multiforme. 

Erythema multiforme (EM) is acute, self‐limited, inflammatory mucocutaneous disease that manifests on the skin and often oral mucosa, although other mucosal surfaces, such as the genitalia, may also be involved. It represents a hypersensitivity reaction to infectious agents (majority of cases) or medications. In general, EM is classified as EM minor if there is less than 10% of skin involvement and there is minimal to no mucous membrane involvement, whereas EM major has more extensive but still characteristic skin involvement, with the oral mucosa and other mucous membranes affected.

Three inherent characteristics of a radiographic film:

 # Three inherent characteristics of a radiographic film:

a. density, distortion, contrast 

b. sharpness, contrast, density 

c. definition, sharpness, penumbra 

d. distortion, detail, sharpness 

The correct answer is: B. Sharpness, contrast, density.

Image quality describes the subjective judgment by the clinician of the overall appearance of a radiograph. It combines the features of density, contrast, latitude, sharpness, resolution, and perhaps other parameters.

Use of intensifying screen is:

 # Use of intensifying screen is:

a. to decrease scattered radiation 

b. to decrease patient radiation 

c. to increase contrast 

d. to increase number of photons striking the anode filament 

The correct answer is B. To decrease patient radiation.

The presence of intensifying screens creates an image receptor system that is 10 to 60 times more sensitive to x-rays than the film alone. Consequently, the use of intensifying screens substantially reduces the dose of x radiation to the patient. Intensifying screens are used with films for virtually all extraoral radiography, including panoramic, cephalometric, and skull projections.