[01.11b] RAD - Requesting for Imaging Modalities (Part 2) V2.pdf

Hydrogen atoms

What element in the body aligns with an external magnetic field during an MRI?

Radio waves

What type of waves are sent into the body to disrupt the alignment of hydrogen atoms during an MRI?

They emit a signal

What happens when hydrogen molecules return to random positions after the radio waves are turned off?

Ancillary procedure

How is MRI generally used in relation to ultrasound or CT findings?

T1-weighted image

Which MRI sequence measures a proton’s ability to exchange energy with its surrounding chemical matrix?

T2-weighted image

Which MRI sequence conveys how quickly a tissue loses magnetization?

T1-weighted image

Which MRI sequence provides the best anatomic detail?

T2-weighted image

Which MRI sequence is best for detecting edema and assessing pathologies?

Bright

How does physiologic fluid appear on a T2-weighted image?

Fat, hemorrhage, and proteinaceous fluid

What are three things a T1-weighted image is specifically good for identifying?

Hyperintense

What is the radiographic term for a structure that appears bright on an MRI?

Gadolinium

What is the name of the magnetic contrast agent used in MRI?

Fat, sub-acute blood, and proteinaceous fluid

What are three examples of structures that appear hyperintense on a T1-weighted image?

Fluid, calcium, and gas

What are three examples of structures that appear hyperintense on a T2-weighted image?

Chronic blood and mature fibrous tissue

Besides calcium and gas, what are two other structures that appear hyperintense on T2?

TR or Time of repetition

What is the term for the repetition time for protons to align with the main magnetic field?

TE or Time of echo

What is the term for the time provided for absorbed radio waves to be released and detected?

Short TR and short TE

What are the specific TR and TE settings for a T1-weighted image?

Long TR and long TE

What are the specific TR and TE settings for a T2-weighted image?

Soft tissue resolution

MRI is known for having outstanding resolution of what type of tissue?

Any anatomic plane

In which anatomic planes can MRI provide images?

Ionizing radiation

What safety-related component does MRI lack compared to CT and X-ray?

Fetal MRI

What type of MRI can detect congenital anomalies that ultrasound might miss?

Long imaging time

What is a disadvantage of MRI regarding the duration of the procedure?

One hour

Approximately how long does a standard MRI imaging session take?

Dense bone detail or calcifications

What anatomical features does MRI have a limited ability to demonstrate?

Electrically, magnetically, and mechanically activated implants

MRI is strictly contraindicated in patients with what types of implants?

Metallic implants

Which surgical history items require caution as they may move or increase in temperature during an MRI?

Titanium

What type of metallic implant is considered safe for MRI?

Creatinine clearance

What must be checked before giving MRI contrast to a patient with poor renal function?

Claustrophobia

What psychological condition might cause a patient to be unable to tolerate an MRI?

Movement

What can produce artifacts and make MRI unsuitable for certain abdominal visualizations?

PI-RADS

What scoring system is used for the evaluation of prostate cancer via MRI?

Diffusion weighted imaging

What specific MRI sequence is used to detect signs of hyperacute infarcts in neurological cases?

Neurological

MRI is the imaging of choice for which specific type of medical case, such as stroke?

Knee and shoulders

In which two joints are muscle and joint disorders frequently assessed by MRI?

MRCP or Magnetic resonance cholangiopancreotography

What is the excellent non-invasive modality used to visualize the biliary tract system?

ERCP or Endoscopic retrograde cholangiopancreotography

Which biliary procedure is therapeutic and allows for the removal of stones?

Fluoroscopy

What imaging technique is used during an ERCP?

Inside the lumen

What is the visualization limit for an ERCP compared to an MRCP?

Ultrasound

What is the initial imaging study used to assess female pelvic organs?

Adenomyosis vs Myoma

Which two female reproductive conditions are often differentiated using MRI instead of CT?

Circle of Willis

Which vascular structure in the brain is commonly visualized via contrast MRI?

Brachiocephalic artery

In an MRI of the neck, what is the first branch of the aortic arch?

Left common carotid artery

In an MRI of the neck, what is the second branch of the aortic arch?

Left subclavian artery

In an MRI of the neck, what is the third branch of the aortic arch?

Sound energy

In an ultrasound, electric energy is converted into what other form of energy?

Piezoelectric crystals

What components inside an ultrasound transducer produce sound waves?

1 to 10 MHz

What is the frequency range of the sound pulses used in ultrasound?

Speckled pattern

What type of tissue texture pattern do solid tissues demonstrate on ultrasound?

Black

How does fluid appear on an ultrasound image?

Anechoic

What is the term for a fluid-filled space that contains no internal echoes?

Artifact

How does gas or air appear on an ultrasound?

High frequency

Which type of ultrasound transducer has a short wavelength and is used for superficial structures?

Thyroid, breast, and testes

What are three superficial structures typically visualized with a high-frequency transducer?

Low frequency

Which type of ultrasound transducer has a longer wavelength and is used for deeper structures?

Abdominal, pelvic, and obstetric

What are three clinical applications for a low-frequency transducer?

Endocavitary probe

What type of probe is specifically used to view the prostate and ovaries?

Bone and gas

Which two anatomical factors limit ultrasound visualization by creating artifacts?

Dirty shadowing

How does air specifically appear on an ultrasound image?

Fasting

What preparation is required before an abdominal ultrasound to minimize intestinal air?

Pancreas

Which organ is often covered by air from the stomach and duodenum if a patient has recently eaten?

Different shades of gray

How do solid tissues present on an ultrasound?

Operator-dependent

What is a primary disadvantage of ultrasound regarding the consistency of images obtained?

Transvaginal ultrasound

What type of ultrasound is best for the first trimester of pregnancy?

The structures are very small

Why must the probe be closer to the organ of interest during a first-trimester ultrasound?

Cardiac activity

Besides the embryo and yolk sac, what small structure is evaluated in the first trimester?

Yolk sac

Which structure provides nutrition to the embryo in early pregnancy?

Pelvic ultrasound

What type of ultrasound is used for the second and third trimesters?

Gestational sac

What does a bracket represent in an ultrasound of intrauterine pregnancy?

Caliper or cross-hairs

What tool measures the crown-rump length of an embryo?

Crown-rump length

What measurement serves as the basis for the LMP thereafter?

Anechoic

How does amniotic fluid appear in a second or third-trimester pregnancy?

Retroverted

What is the term for a uterus where the fundus and cervix point posteriorly in a sagittal view?

Endometrium

In a uterine ultrasound, what is the brighter part outlined in red?

Myometrium

In a uterine ultrasound, what is the darker part outlined in blue?

Intussusception

What is the major exception to the rule that intestines are not visualized by ultrasound?

Currant jelly stools

The history of what specific symptom in babies suggests intussusception?

Pseudo-kidney and target sign

What are the two characteristic ultrasound signs of intussusception?

Ileocecal region

What is the most common site of intussusception in pediatric patients?

Left hepatic vein

Which hepatic vein subdivides the left lobe of the liver into medial and lateral segments?

Middle hepatic vein

Which hepatic vein divides the liver into left and right lobes?

Right hepatic vein

Which hepatic vein subdivides the right lobe into anterior and posterior segments?

Crow’s feet

What specific appearance of the hepatic veins suggests you are viewing superior segments of the liver?

Gallbladder

If an ultrasound shows the inferior segments of the liver, what other organ should be close by?

II

Which liver segment is the superolateral segment?

IVa

Which liver segment is the superomedial segment?

VIII

Which liver segment is the anterosuperior segment?

VII

Which liver segment is the superoposterior segment?

Morrison’s pouch

What is another name for the hepatorenal space?

Ascites

What is the term for fluid collection between the liver and the kidney?

Bile

Why is the gallbladder lumen black on ultrasound?

Acalculous cholecystitis

What condition is characterized by a thickened gallbladder wall without the presence of stones?

Cholelithiasis

What is the medical term for the presence of gallstones?

Posterior shadowing

What do gallstones cause on an ultrasound image due to their curvilinear echoes?

Splenic vein

Which anechoic structure is found above the pancreas in a transverse view?

Aorta

Which anechoic structure is round on a transverse cut and sits posterior to the pancreas?

Celiac artery

Which artery branches from the aorta and is seen en face posterior to the pancreas?

Cortex and medulla

What two components make up the renal parenchyma?

Renal sinus

What is the center or middle part of the kidney called?