Pituitary Gland Radiological Exploration
40 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What anatomical reference point may be modified during tumoral expansion of the pituitary gland?

  • Foramen magnum
  • Anterior clinoidal process (correct)
  • Sphenoid sinus
  • Optic chiasm

    • Which imaging technique provides a two-dimensional projection of three-dimensional body parts?

  • Skull X-ray (correct)
  • Computed Tomography
  • Magnetic Resonance Imaging
  • Ultrasound

    • What is the main disadvantage of using X-rays for visualizing the pituitary gland?

  • They are unable to differentiate between soft tissues. (correct)
  • They use minimal radiation.
  • They are less sensitive than CT scans.
  • They provide a three-dimensional view.

    • What year was CT originally introduced, and by whom?

    <p>1971, Hounsfield</p> Signup and view all the answers

    What appearance may the normal pituitary gland have on a CT scan?

    <p>Nonhomogeneous with intermingled lucent and dense areas</p> Signup and view all the answers

    What factor relates the absorption of X-rays to the imaging of body structures?

    <p>Density of the structures</p> Signup and view all the answers

    What is a common allergic reaction associated with CT scans?

    <p>Contrast dye allergy</p> Signup and view all the answers

    What is the diameter of the sella turcica in millimeters for its length?

    <p>15 mm</p> Signup and view all the answers

    What is the normal range for urinary amylase?

    <p>32-64 UW</p> Signup and view all the answers

    Which mode is primarily used for a thyroid scintigram?

    <p>Histogram Mode</p> Signup and view all the answers

    What characterizes the concentric rings formed in the Rosenbach reaction?

    <p>Green for bilirubin presence</p> Signup and view all the answers

    What is the primary function of contrast dye in imaging procedures?

    <p>To enhance image contrast and delineate tumors</p> Signup and view all the answers

    What is NOT a characteristic of MRI as described?

    <p>MRI creates images using X-rays</p> Signup and view all the answers

    Which radioactive isotope is commonly used for thyroid imaging?

    <p>Iodine 123 (I123)</p> Signup and view all the answers

    What is the primary purpose of using short half-life isotopes in nuclear medicine?

    <p>Reduce patient exposure to radiation</p> Signup and view all the answers

    What is a limitation of MRI in detecting pituitary tumors?

    <p>It may miss microadenomas smaller than 3 mm</p> Signup and view all the answers

    During the Thyroid Scintigraphy, how is the information ultimately processed?

    <p>Using a computer for further processing</p> Signup and view all the answers

    How does MRI differ from CT in terms of image acquisition?

    <p>MRI views can be obtained in any plane of space but CT is restricted to transverse images</p> Signup and view all the answers

    Which statement about the interaction of MRI with metallic objects is true?

    <p>Metallic objects can cause image degradation</p> Signup and view all the answers

    In the histogram mode, what effect do more pictures over time have on the pixels?

    <p>They become darker or more red</p> Signup and view all the answers

    What is the initial step in performing the Rosenbach reaction for bile pigment identification?

    <p>Dripping bile solution on filter paper</p> Signup and view all the answers

    What is a prevalent issue faced by a percentage of healthy individuals on an MRI scan of the pituitary gland?

    <p>They exhibit minor abnormalities that are often benign</p> Signup and view all the answers

    Which best explains why no harmful biological effects have been proven for MRI under standard conditions?

    <p>MRI employs magnetism rather than radiation</p> Signup and view all the answers

    Which part of the pituitary gland is typically represented as whiter in MRI imaging?

    <p>Posterior pituitary</p> Signup and view all the answers

    What is the typical scanning time after administration of I123 agents?

    <p>4 hours</p> Signup and view all the answers

    Which statement about thyroid nodules is correct?

    <p>Warm nodules show intermediate risk of malignancy.</p> Signup and view all the answers

    In the context of thyroid scintigraphy, what does the term 'cold nodule' indicate?

    <p>Hypofunctioning thyroid tissue</p> Signup and view all the answers

    Graves' disease is associated with which of the following conditions?

    <p>Thyrotoxicosis and diffuse goiter</p> Signup and view all the answers

    What risk percentage pertains to malignancy in a cold nodule?

    <p>15 to 25%</p> Signup and view all the answers

    Which factor is implicated in the autoimmune nature of Graves' disease?

    <p>IgG class immunoglobulins acting on TSH receptors</p> Signup and view all the answers

    What major role does scintigraphy play in assessing a thyroid nodule?

    <p>To evaluate the metabolic activity of the nodule</p> Signup and view all the answers

    What percentage of solitary, hot nodules are typically benign?

    <p>90%</p> Signup and view all the answers

    What is the primary disadvantage of using urine to determine amylase activity compared to plasma?

    <p>Diuresis causes wider reference ranges for analytes in urine.</p> Signup and view all the answers

    At what temperature should the test tubes be incubated during the amylase determination procedure?

    <p>37ºC</p> Signup and view all the answers

    What does one Wohlgemuth Unit signify in terms of starch hydrolysis?

    <p>It is the amount of amylase that can hydrolyze 1 mg of starch at 37ºC in 30 minutes.</p> Signup and view all the answers

    Which dilution factor corresponds to an undiluted urine that contains 64 Wohlgemuth Units if the test shows colorless at the sixth tube?

    <p>1/32</p> Signup and view all the answers

    In the context of chronic pancreatitis with exocrine pancreatic insufficiency, how is the amylase level expected to be affected?

    <p>It is expected to be significantly decreased.</p> Signup and view all the answers

    How does the hyperamylasemia function in the diagnosis of acute pancreatitis?

    <p>It is characterized by increased pancreatic amylase activity.</p> Signup and view all the answers

    What is the initial step for creating dilutions for amylase determination?

    <p>Add 2 ml of urine to the first tube.</p> Signup and view all the answers

    What color indicates the presence of undigested starch in the test tubes after the procedure?

    <p>Blue</p> Signup and view all the answers

    Study Notes

    Pituitary Gland Radiological Exploration

    • Pituitary pathologies are primarily tumors (adenomas).
    • Growing tumors compress bone, eroding and invading the sphenoid bone.
    • Normal sella turcica is defined by anterior and posterior clinoid processes; these may disappear during tumor expansion.
    • X-rays, discovered by Roentgen (1895), can visualize these injuries.
    • Skull X-rays (lateral view): X-rays penetrate body structures, projecting shadows onto detectors.
    • Bones appear in varying shades of gray; soft tissues appear black.
    • Three-dimensional structures are projected onto two-dimensional film, losing information.
    • X-rays can visualize sella turcica bony walls.
    • Normal sella turcica dimensions: 15/12/19 mm (length/depth/width).
    • Normal image variations form the basis for pituitary adenoma diagnosis and classification.

    Computed Tomography (CT)

    • Hounsfield introduced CT in 1971, earning a Nobel Prize in 1979.
    • CT extends basic X-ray technology.
    • X-ray tube and detectors rotate around patient (head to toe).
    • X-ray absorption is proportional to tissue density.
    • Density profile of a body slice (transverse or axial cut) is obtained.
    • Detection system includes scintillating crystals and photodiodes.
    • Computer reconstructs the image from raw scan data.
    • Bone appears white; gases and liquids are black; tissues are gray.
    • CT provides tomodensitometric analysis of sella turcica (pituitary tissue).
    • Normal pituitary gland may have a non-homogeneous appearance (mixed light and dense areas).
    • This heterogeneity relates to microscopic variations in the anterior and posterior lobes.
    • Contrast dye enhances image contrast, facilitating tumor demarcation.

    Magnetic Resonance Imaging (MRI)

    • MRI uses hydrogen's magnetic properties with a large external magnetic field.
    • Protons in body water align with the magnetic field and pulsed radio waves modify their orientation.
    • Protons return to their alignment and emit characteristic radio waves.
    • These radio waves are detected by antennas.
    • Computer translates the wave patterns into detailed images.
    • Contrast material can improve image quality.
    • MRI images can be obtained in any plane.
    • MRI does not use X-rays; no proven harmful effects.
    • MRI is the best imaging technique to identify pituitary tumors (macro- or microadenomas).
    • MRI may not detect microadenomas smaller than 3 mm.
    • Relatively low cost, no electricity, no radiation.

    Normal Head MRI

    • Sagittal view through pituitary gland; large arrow indicates anterior portion, small arrow posterior.
    • Coronal MRI showing posterior pituitary bright spot (ectopic) at hypothalamus base.
    • Sagittal MRI view of infant pituitary gland exhibiting transected hypothalamic-pituitary stalk.

    Urinary Amylase Determination

    • Amylase is filtered by kidneys and expelled in urine.
    • Acute pancreatitis causes elevated plasma amylase, which can be reflected in urine.
    • Amylase activity in plasma varies widely and depends on inflammation severity and pancreatic function.
    • Urine amylase levels show gradual reduction over 4-10 days, reaching normal levels.
    • Wohlgemuth method establishes urine amylase activity, useful but with wider reference ranges compared to serum.
    • Urine disadvantages include variable diuresis, making ranges broader than for serum.
    • Chronic pancreatitis with exocrine insufficiency shows decreased urinary amylase.

    Rosenbach Reaction (Bile Pigments Identification)

    • Used to identify bile pigments.
    • Filter paper, bile pigments solutions, concentrated nitric acid, sodium nitrite crystals required.
    • Drop bile pigment solution onto filter paper, then nitric acid.
    • Concentric rings form (yellow/red, violet/blue, green).
    • Green rings indicate bilirubin presence.

    Thyroid Scintigram

    • Nuclear medicine investigation (histogram mode, list mode, synchronized recordings, 3D reconstruction).
    • Thyroid imaging can detect activity distribution using gamma cameras.
    • Histogram mode uses pixels that become darker with increasing picture accumulation.
    • Three-dimensional reconstruction (SPECT) processes multiple two-dimensional images to create 3D image.
    • Positron emission tomography (PET) is more precise, using positron-emitting isotopes and recording simultaneous emissions, determining precise location of radiation source.
    • Radiolabeled material is injected; gamma camera detects emission information and sends it to computer for image processing.
    • Iodine 123 (I123), Iodine 131 (I131), Technetium (Tc 9m) pertechnetate, and Thallium 201 (Tl 201) isotopic agents are used for imaging.
    • Scans are performed at specific intervals post-injection depending on the agent.
    • Thyroid scintigrams provide information on thyroid gland size, shape, activity distribution (homogeneous or inhomogeneous), and nodule details.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Radiological Exploration Of The Pituitary Gland PDF

    Description

    Explore the radiological techniques used for examining the pituitary gland, focusing on the role of X-rays and CT scans in diagnosing tumors like adenomas. Understand the anatomy of the sella turcica and how normal variations can aid in identifying pathologies. This quiz provides essential insights into imaging processes and their significance in medical diagnoses.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser