Final Flashcards
Know what prostate issue creates the greatest need for imaging.
Prostate cancer
BPH and prostatitis- does not require imaging
Know whether imaging is more important for prostate cancer screening or prostate cancer detection.
All imaging is used for detection, not screening
Know whether imaging is more important for determining Gleason scores or T-N-M scores, and why.
T-N-M scores are for staging and factor in how extensive the tumor is, if there is any spread to nearby lymph nodes, and if there is any metz to distant sites.
Gleason scores are done by pathologist (based on histology).
Know what is the first and most likely imaging test for the average treating doctor to order to evaluate the prostate.
Diagnostic ultrasound All imaging is for detection and not screening. Abnormal PSA or DRE Difficulty urinating BPH? Only if it becomes really annoying Detect neoplasia? (not definitive) Can also be used to guide biopsy
Know what TRUS is and what it is used for.
Transrectal ultrasound (B-mode-gray scale image- and doppler mode-blood flow-) used for the indications listed in the question above. Also used to see if a biopsy is indicated.
Diagnostic U/S to evaluate Prostate
Know what elastography is and whether it might have any use for prostate.
Provides a stiffness value. A push pulse slightly compresses the tissue leading to shear waves. The hardware is the same as normal US but different software is added.
Cancers are stiffer than normal tissues so this help differentiate different masses.
Know what the role is for prostate CT.
Used in looking for metz which is needed in T-N-M scoring
Know what the role is for prostate MRI.
Morphological T1 and T2 are done but also diffusion (DWI-MRI)and perfusion (PWI-MRI) capacities are usually added plus MR spectroscopy can be used. An endorectal receiver coil is used for better detail. MRI providers better soft tissue discrimination.
Could also use a high magnetic for better detail.
DWI-MRI follow water movement. Less water movement in tumors.
PWI-MRI uses GAD and follows blood.
MRI can be used to guide biopsy
Know what the most likely nuclear imaging study would be if the patient had known prostate cancer.
Bone scan (osteoscintigraphy) is used to detect prostate metz which would help stage the patient and help with prognosis
Know what is the first and most likely imaging test for the average treating doctor to order to evaluate the scrotum and testicles.
Diagnostic ultrasound
Know whether testicular ultrasound might be useful for differentiating between simple and complex hydrocele.
Simple- anechogenicity because it only contains water
Complex- would have a higher echogenicity because it contains other things like pus or blood.
Know what the average treating doctor should do if he/she suspects testicular torsion and how imaging is related.
Emergency situation. You only have a few hours to get the patient into surgery. As a referring doctor you would NOT order ultrasound.
In unusual equivocal cases where imaging is done the testicle will be more hypoechoic.
Know what the recommended imaging test is to evaluate breast masses in males.
Most commonly it is gynecomastia -usually bilateral- but could be breast cancer -usually unilateral- (no fibrotic changes in male breast like is seen in female breasts)
Mammography is the image of choice, US is usually not necessary
Know whether prostate calculi can be visualized on plain films, along with their significance.
Can see little gravel like calcifications within the prostate. These are very common esp. With advancing age, but if you see them in younger men it suggests they may have had multiple bouts of prostatitis. No clinical significance at all.
Know what sealed source radiation therapy is and whether there could be any residual evidence of it on plain films if a male had undergone this procedure.
May see metallic seeds left over from internal radiation on plain films.
Sealed source radiation- radioactive isotope is contained in wire or seeds
Unsealed source radiation- ingested or injected radioactive isotope combined with a substance that will help drive it to a certain area of the body.
External radiation- ionizing radiation up to multiple thousand of RADs.
Know the most common imaging presentation on plain films for metastasis to bone from prostate cancer.
Metz in the pelvis and lumbar spine. 90% of prostate metz are of the blastic type (extra dense). much less common to see a lytic or bone destructive pattern.
Know what a therapeutic bone scan is.
Semarium isotope used (Quadramet is the brand name), emits beta to diminish activity of the bone metz and gamma rays for metabolic activity can be visualized. An example of unsealed source of nuclear medicine therapy. Doesn’t cure anything, just provides pain relief.
Know whether there is any imaging for diabetes.
No imaging for diabetes
Know what role plain films might have for pancreas.
Can see calcifications incidentally but plain films are of no use for visualizing the pancreas.
Calcifications can commonly be seen in chronic pancreatitis and possibly around cysts.
Know what the primary imaging method is for pancreas.
CECT is the primary imaging method, but MRI is being increasingly used for further identification of pancreatic disease.
CECT is the primary choice for chronic pancreatitis. Calcifications are common in chronic pancreatitis and they increase as the disease progresses.
Know what ERCP is and what role it might play in pancreas evaluation.
Endoscopic retrograde cholangiopancreatography (ERCP) used for therapeutic procedures need to be done. Used to be used to visualize the pancreatic duct but not anymore.
A duodenoscope used to located the duodenal ampulla, then a catheter is advanced through the scope and contrast injected through the catheter and a fluoroscopic image is produced. A guidewire is advanced through the catheter and then a cytology brush is advanced over the wire. Stents can also be placed with this method.
Know what EUS is and what role it might play in pancreas evaluation.
Endoscopic ultrasound (EUS) approach is the same as ERCP and only available for the pancreas due to its location. Much more detailed than transabdominal US that used prior to this being available. Need to refer to gastroenterologist. Can also add doppler for vascularity. Can also used EUS to do fine needle aspiration (FNA), help with guidance of interventional procedures like neurolysis, or can be used to drain cysts and abscesses. Can be used to diagnose acute pancreatitis. EUS is the most sensitive for finding neuroendocrine tumors (NETs) and then FNA can be performed.
Know what role MRA (MR angiography) might play in pancreas surgical decisions.
Can be used to assess vessels around the pancreas because tumors that contain blood vessels are not resectable.
Know what MRCP is and what role it might play in pancreas evaluation.
Magnetic resonance cholangiopancreatography (MRCP) is a special sequence that can be added to MR image of the gallbladder or pancreas to visualize the pancreatic and bile ducts. The fluid that naturally resides in the ducts serve as their own contrast and can be visualized well on a heavily T2 sequence. GAD can be used but is not necessary. Gives similar information as ERCP without the risks of the more invasive procedure.
Know what contrast-enhanced EUS is, how it is achieved, and what its value is.
Gas filled microbubbles are used for the contrast. Encapsulated with phospholipid or albumin shell to keep them from expanding and bursting right away. Sometimes called bubble studied. Shows blood perfusion in the structure.
Know the role of nuclear imaging in pancreas evaluation.
FDG-PET can show glucose metabolism for identifying tumors and metz.
PET-CT allows to visualize metabolic activity and provide localization.
Know one striking imaging feature of the neuroendocrine tumors of the pancreas.
NET or islet cell tumors are rare. Can be non-functioning or functioning. Functioning tumors secrete insulin and can cause hypoglycemia. EUS is the most sensitive for finding these and then FNA can be performed.
Know the clinical significance of imaging for osteoporosis
Detection
Management
Monitoring response to treatment
Clinical importance 1. Hip fractures 2. Vertebral fractures Once one vertebra fractures the individual is at a 10 fold increased risk for another vertebral fracture 3. Wrist and Pelvis fractures
Know the main generally accepted imaging method for assessing osteoporosis
Dual energy x-ray absorptiometry (DXA or DEXA)- for bone density but not quality of the bone (quantitative)
Know what T scores and Z scores are and which you use for clinical management in the average case
T score- used for management (the ones you want) how your patient compares to a compilation of peak bone mass
*More constant
*Within 1 standard deviation is normal
Z score- compared to an age matched population. Use these with younger males, females and children (normal within 2 STD)
Know the numerical standards for measuring “osteopenia,” “osteoporosis,” and “severe osteoporosis”
-1 - 2.5 STD = osteopenia
> -2.5 STD = osteoporosis
> -2.5 STD + > 1 fragility fractures = severe osteoporosis
Know the main confounders in interpreting DXA results
People with a small skeleton will be interpreted as having lower BMD even tho they just have smaller bones
The x-rays used don’t travel well through obese patients
Various spinal curves can cause a problem due to overlapping vertebra
Calcifications will add to the BMD (arterial, spurs, etc.)
Surgical instrumentation will also confound the results
Those levels will be omitted or the test will not be done on area where instrumentation is (ex: spinal rod in scoliosis or hip replacement)
Know the standard indications for DXA
Asymptomatic screening for females > 65 regardless of risk factors
Asymptomatic screening for males > 70 regardless of risk factors
Screening for perimenopausal females with risk factors
Screening males 50-69 with risk factors
Postmenopausal females and male > 50 with adult low-impact fracture
**Only is local xray didn’t show any pathology that could cause the fracture
Evaluation and re-test of individuals being treated for osteoporosis
**No more than once a year, usually every 2 years
Know what advantages and disadvantages quantitative CT provides in osteoporosis assessment.
Pros
Independent of skeleton size and is better for small skeletal people
Can measure purely trabecular bone
More accurate measurement in patients with fragility fracture
Better suited for patients with superimposed calcifications
Cons
Higher radiation dose
Not completely accurate in obesity (still better than DEXA)
Less research data as how accurately fracture risk can be assessed
Know how bone density differs from bone quality
Quality- More of an architectural thing. It reflects the organization and thickness of the bone trabeculae, any microfractures in it and organization of its minerals. Parameter or biomarker and provides information on susceptibility of fracture.
Density- Standard and state of the art technique for quantifying osteoporosis
Know a couple research imaging methods for assessing bone quality
High-resolution MRI MR spectroscopy PWI-MRI DWI-MRI Quantitative US (has problems though)
Know the difference between a stress fracture and an insufficiency/fragility fracture
Stress Fracture- Results from abnormal stress to a normal bone
Insufficiency/Fragility fracture (also called pathologic fractures)- Results from normal stresses on abnormal bone (osteoporosis, malignancy, infection, etc.)
In addition to decreased density, know three other plain film findings of osteoporosis
Bone hyperlucency: Compare bone to soft tissue. Sometimes there is so much bone loss the bone is the same signal as the soft tissue.
Cortical thinning
Trabecular accentuation
Compression fracture or bi-concave vertebral bodies
(Costochondral calcinosis in a young patient is especially suspicious)
Know the causative mechanism of bi-concave vertebral bodies in osteoporosis
Discs literally impress themselves into the vertebral bodies because the hydrated discs are stronger than osteoporotic bone. DOn’t often see this because by the time someone becomes this osteoporotic their discs are usually not hydrated very well
Vertebroplasty is an outpatient procedure for stabilizing compression fractures in the spine. Bone cement is injected into back bones (vertebrae) that have cracked or broken, often because of osteoporosis. The cement hardens, stabilizing the fractures and supporting your spine.
Know what vertebroplasty is
Injection of polymethylmethacrylate (PMMA) into the vertebral body after a compression fracture. The plastic is added to barium contrast so they can see it with fluoroscopy during the procedure
Know two risks of long-term intake of bisphosphonates that can be seen on skeletal plain films
Atypical fractures in the femur. Finding on plain films:
*They are in the subtrochanteric region
*If the fracture line can be seen it will be transverse or *short oblique
*No comminution
*Cortical thickening
Small periosteal reaction at lateral cortex
Bisphosphonate related osteonecrosis of the jaw (BRONJ)
Know three circumstances where osteoporosis can occur regionally, rather than systemically
II and III stages of complex regional pain syndrome
Sudeck’s atrophy
Transient osteoporosis of the hip (TOH)
**Disappears within 6-12 months
**More often in men, but can occur in women during pregnancy
**Exclusively in the left hip
Post-traumatic osteolysis of the distal clavicle Other regions Medial clavicle Pubic symphysis Ischial rami Distal ulna and radius Carpals Distal phalanges Post-Casting
