Random_8 Flashcards
When to aspirate a breast cyst demonstrated on US
- A cyst should be aspirated if there are internal echoes (ie. when it is unclear whether it is a cyst or solid) or if the patient seeks relief from symptoms.
- Cysts get larger and smaller, come and go. –> Enlargement of a simple cyst is not in and of itself an indication for aspiration.
Good oral boards tip
Special Oral Boards Note: BEWARE of the case with more than one finding!
A good practice is to identify the obvious finding… “I see a 2cm round mass in the central breast”
and diligently search the rest of the breast tissue… “I am looking for any other finding.”
IF you don’t see anything else then… “I don’t see anything else, so we have a round mass with smooth margins in the…”
IF you see a second finding… “I also see a second finding which looks more suspicious. I’ll first describe the more suspicious area: a 1.5cm spiculated mass is present in the…”
There is no concept if intra- vs. extra-capsular rupture with saline implants, so there is no need to perform MRI for evaluation of saline implants. MRI is reserved for evaluation of silicone implant rupture
There is no concept if intra- vs. extra-capsular rupture with saline implants, so there is no need to perform MRI for evaluation of saline implants. MRI is reserved for evaluation of silicone implant rupture
Breast feeding patient noticing rapidly enlarging breast mass
Statistically, the most likely diagnosis of a well-defined hypoechoic mass with thin septations and a thin echogenic rim is a fibroadenoma. However, with the history of a rapidly enlarging palpable mass during pregnancy, this most likely represents (and was found to be) a lactating adenoma.
Lactating adenomas tend to be large well-defined lobulated masses with fibrotic septae which can appear as echogenic bands within the mass. They are benign, but are usually removed surgically because of their large size and rapid growth.
Breast mammogram screening guidelines
- no recommendations for 40-49y/o
- but if they do screening, then q1yr
- screening for everyone 50-74y/o
- q2yr
What additional views to get for
query architectural distortion?
Rolled biplane (CC/ML) spot compression views
DDx of restricted diffusion on brain MR
- ischemia
- abscess
- empyema
- epidermoid cyst
Configuration of cerebral lesiosn that demosntrate restricted diffusio
- rounded, diffuse restriction –> infectious etiology - abscess or septic emboli
- restriction only in the walls and projections of the lesion (not in its core)–> fungal abscesses
- special with fungal (esp with aspergillosis infection/abscess): T2-hypointense zones and magnetic susceptibility within the wall of cerebral Aspergillus lesions can be attributed to a dense population of Aspergillus paramagnetic hyphal elements, especially iron and magnesium, which are essential for hyphal growth. It has also been postulated that this MR finding may correspond to hemorrhage in the capsular wall.
LATERAL lesion moves LOWER on true LATERAL projection on mammo
LATERAL lesion moves LOWER on true LATERAL projection on mammo
Cancers in younger women tend to be more aggressive, therefore need yearly screening in order to catch interval cancers
But stage by stage, the prognosis is the same, if not better
Cancers in younger women tend to be more aggressive, therefore need yearly screening in order to catch interval cancers
But stage by stage, the prognosis is the same, if not better
Screening for high risk patients
- lifetime risk > 20% –> MRI screening
- lifetime risk 15-20% –> may add U/S screening
What type of breast cancer can be barely detectable now but become a 5-cm mass 5 months later?
Lobular carcinoma
What features help confirm male gynecomastia?
- Flame shaped fibrogladular tissues
- Concave borders - lack of mass effect
From an epidemiologic standpoint, the most common fungal infections to cause brain abscesses are aspergillosis, candidiasis, and mucormycosis.
From an epidemiologic standpoint, the most common fungal infections to cause brain abscesses are
aspergillosis,
candidiasis,
and mucormycosis.
Cerebral aspergillosis
- Cerebral aspergillosis is seen in approximately 10-20% cases of invasive aspergillosis.
- The usual primary site of aspergillosis infection is the lungs and paranasal sinuses, since the route of transmission is via spore inhalation.
- CNS involvement occurs via hematogenous spread from the lungs or direct invasion via the paranasal sinuses.
- Invasive aspergillosis involving the CNS is rare but occurs with increased frequency in immunosuppressed individuals.
TB vs
Fungal vs
Pyogenic
cerebral abscesses
- TB
- TB meningitis way more common than TB abscess (tuberculoma)
- tuberculoma
- T2 hyper, with T2 hypo rim
- NO retricted diffusion!
- generally solitary
- Pyogenic abscess
- staph, strep, GNB
- “light bulb bright” restricted diffusion
- Fungal abscess
- T2 hyper
- may have some T2 hypointensity, due to microhemorrhage or Fe/Mg containing hyphae
- mild restricted diffusion involving the rim or projections
What is normal post void residual volume?
<10%
or
< 50cc
Epididymis anatomy
- A - head of epididymis
- B - body of epididymis
- C - tail of epididymis
- D - vas deferens
Normal
- cervical length
- distance b/t placenta and cervix
- normal cervical length > 2.5cm
- normal distance b/t placenta and cervix > 2.0cm
Leiomyoma
- a benign smooth muscle neoplasm
- most common locations
- uterus
- esophagus
- small bowel
- leimyoma vs leiomyosarcoma
- cytologic atypia
- increased or atypical mitoses or necrosis
Layers of scrotum
from superficial tu deep
- skin
- dartos fascia
- external spermatic fascia
- cremaster muscle
- internal spermatic fascia
- parietal layer of tunica vaginalis.
Where does scrotal leiomyoma arise from?
Scrotal leiomyoma arises from the dartos muscle fascia, which is composed of smooth muscle fibers in a scattered arrangement forming a poorly defined muscle layer in the scrotum.
Incidence vs Prevalence of breast cancer
- prevalence screening
- number of women living with breast cancer at any given time
- prevalence screening = 1st mammogram performed in previsouly unscreened women
- rate = 6-10/1000 (higher than incidence screening)
- incidence screening
- number of new cases of breast cancer over a specific period
- incidence rate = number /per100000ppl over 1 year
- rate = 3/1000
Cerebral cavernomas
- most often intra-axial, extra-axial cavernomas are very rare
- exophytic cavernous malformations are most often asymptomatic; when they beome symptomatic, the most common symptom is focal neurological signs (as opposed to seizures)
- cavernous malformations may develop after radiation therapy to the brain
- high-resolution, SWI MRI is a 3-D, gradient echo (GRE) imaging technique based on blood oxygen level dependent (BOLD)-induced phase effects between venous blood and the adjacent brain parenchyma. It allows noninvasive visualization of small veins in the brain at higher spatial resolution and with greater detail than standard MRI, thus allowing enhanced visualization of deoxyhemoglobin within the intralesional tubular structures
- size of a cavernous malformation did NOT affect rates of hemorrhage
SWI
vs
GRE
High-resolution, SWI MRI is a 3-D, gradient echo (GRE) imaging technique based on blood oxygen level dependent (BOLD)-induced phase effects between venous blood and the adjacent brain parenchyma.
It allows noninvasive visualization of small veins in the brain at higher spatial resolution and with greater detail than standard MRI, thus allowing enhanced visualization of deoxyhemoglobin within the intralesional tubular structures.
Cavernous malformation
- 80-90% of cerebral cavernous malformations are supratentorial. Of the remainder, some may arise exophytically from the brain stem where they may be mistaken for aneurysms, AVMs, or vascular metastases.
- Cavernous malformations are catheter angiographically OCCULT. MRI is almost always diagnostic. T2* GRE and SWI sequences are the current gold standard, as they can show smaller foci with blooming artifacts to better advantage than a T2-weighted sequence alone.
- AVMs show “flow voids” secondary to rapid internal shunting and intra-voxel dephasing. Cavernous malformations do not show flow voids or pulsation artifacts
What is cavernous malformation commonly associated with?
DVA
Cavernoma
vs
AVM
Whereas AVMs show flow voids secondary to rapid internal shunting and intravoxel dephasing, cavernous malformations do not show flow voids or pulsation artifacts.
AVM has intervening brain parenchyma, cavernoma does not
FNH
- 2nd most common benign hepatic neoplasm (most common benign hepatic neoplasm - hemangioma)
- incidence 1-3%
- U/S - homogeneous and isoechoic
- CT - hyperdense on arterial phase, iso to hypodense on PV phase, and isodense on delayed phase; central scar enhances on delayed phase
Gastric diverticulum
- 0.02% incidence
- DDx
- pancreatic pseudocyst
- abdominal abscess
- adrenal cyst
- renal cyst
- retroperitoneal lymphangioma
Mesenteric panniculitis
- inflammation of the adipose tissue of the mesentery
- > 50y/o
- usually idiopathic
- other causes
- recent surgery, esp cholecystectomy or appendectomy
- cholelithiasis
- lymphoma
- cirrhosis
- AAA
- peptic ulcer
- gastric carcinoma
- autoimmune dz
- abdo trauma
- can be chronic - 3 stages
- degeneration of fat - mesenteric lipodystrophy - asymptomatic
- inflamation - mesenteric panniculitis - can be associated with abdo pain, nausea, malaise and other symtoms
- fobrisis - retractile mesenteritis - rare, can result in intestinal obstruction
*
DDx for Misty Mesentery
- Mesenteric panniculitis
Hypoalbuminemia
Cirrhosis
Lymphedema of the mesentery
Pancreatitis
Tuberculosis
Hemorrhage
Non-Hodgkin’s Lymphoma
Fixed bowel structure in the abdomen
- The fixed gastrointestinal structures in the abdomen are those that are secondarily retroperitoneal, or attached firmly to the posterior wall of the abdomen
- Includes:
- ligament of Treitz (which is the only fixed point of the small bowel beyond the duodenum)
- ascending and descending colon (including the hepatic and splenic flexures)
- rectum
- The cecum is variable in its fixation (as it is mobile in many patients). The transverse colon and sigmoid colon are on mesenteries and are not fixed.
Prognosis of colloid cyst
- Most are asymptomatic - can be monitored by serial imaging, as 90% remain stable without enlargement
- Rare complications: Acute hydrocephalus >herniation>death secondary to obstruction of Foramen of Monro
- Classically presents as acute severe headache, reproduced by patient tilting head forward (Brun phenomenon)
Action if previously “known” fibroadenoma has grown in size in the interval?
Biopsy
What to do if seeing a lesion favored to represent a fibroadenoma on first mammogram (i.e., no previous for comarison)?
BI-RADS 3
followup in 6/12
Causes of denser breast on following mammo?
- pt has lost weight
- less compression
- hormone replacement Rx
*
What to do if a women presents with a palpable mass?
- if < 30(35) y/o –> starts with U/S
- if > 30(35) y/o –> starts with Mammo
Pattern of breast glandular tissue involution?
medial to lateral
posterior to anterior
3 vessel view
- from right to left
- SVC
- ascending aorta
- PA
- normal configuration
- V shaped
- trachea is right to the aorta
- if U shaped configuration
- trachea is left to th aorta
- right sided aortic arch
Frontal AP pelvis xray
how do you differentiate
anterior from posterior
acetabular walls?
POSTERIOR acetabular walls are more lateral!!!
Crossed Cerebellar Diaschisis
- CCD is defined as a functional matched metabolic depression or decreased blood flow and oxygen extraction in the cerebellar hemisphere contralateral to a focal supratentorial lesion.
- The underlying mechanism of CCD is disruption of the supratentorial portion of the corticopontocerebellar tract secondary to damaged excitatory corticopontine projections, which is most commonly seen with large MCA territory infarctions.
- Although most commonly seen with infarction, CCD is seen with other etiologies such as brain tumors, spinocerebellar degeneration, Alzheimer’s disease, and epilepsy.
- Most CCD studies have not shown anatomic changes such as cerebellar atrophy particularly when caused by ischemia; however, crossed cerebellar atrophy on MRI has been noted in patients with longstanding intractable seizures and large areas of cerebral atrophy.
Persistent sciatic artery
- Abnormally enlarged internal iliac artery on DSA should raise the question of collateralization in the setting of peripheral arterial disease as well as the rare anatomic variant of a PSA.
- PSA results from abnormal embryogenesis with the embryologic axial artery remaining the dominant vessel to the lower extremity rather than the external iliac circulation taking over through the SFA.
- Clinical concerns are for the complication of aneurysm formation with resulting thrombosis and embolization.
- The sciatic artery persists in approximately 0.05% of the population.
Nutcracker syndrome
- Nutcracker syndrome refers to symptomatic renal disease resulting from the compression of the left renal vein between the abdominal aorta and the superior mesenteric artery.
- The most common abnormality on contrast-enhanced CT is compression of the left renal vein by 50% or more, and unilateral enlargement and edema of the left kidney may be present. The presence and extent of collateral vessel formation should be documented.
- Patients with mild symptoms may be treated conservatively. However, surgical and endovascular therapies may be employed in the setting of persistent or massive hematuria.
Talc granulomatosis
- IV drug user
- Talc granulomatosis is confirmed by the presence of birefringent crystals in a histologic specimen on polarized light microscopy
- 4 types of pulmonary disease secondary to talc exposure have been defined:
- talcosilicosis - occupational exposure and inhalation of dust, which contains talc as well as silica or asbestos
- talcoasbestosis - occupational exposure and inhalation of dust, which contains talc as well as silica or asbestos
- talcosis - associated with the inhalation of pure talc
- talc granulomatosis - occurs in intravenous drug abusers who inject tablets intended for oral use
*
Pancreas divisum
- embryologically:
- dorsal - pancreatic body and tail - accessary duct of Santorini draining into minor papilla
- ventral - eventually becomes head and uncinate process - main duct of Wirsung draining major papilla
- usually the accessary duct and main duct fuse, and both drain into the major papilla
- if the accessary duct remains patent, and has no communication with the main duct, and drains separately into the minor papilla - crossing over the CBD into the duodenal - T sign – pancreas divisum
- increased risk of pancreatitis
Chemical shift
- only on T2 weighted sequence (maybe b/c both water and fat would be bright?)
- only happen to macroscopic fat
- only occur in the direction of frequency encoding
- at higher frequency encoding gradient, the water molecules appear to move to this direction, and become bright; fat molecules appear to move down the gradient, and appear dark
Gamna-Gandy bodies
aka
Splenic siderotic nodules
- in the spleen
- most commonly encountered in portal hypertension
- microhaemorhage resulting in haemosiderin and calcium deposition followed by fibroblastic reaction
- resembling “tobacco flecks”
- associated with
- portal hypertension
- sickle cell anemia
- paroxysmal nocturnal haemoglobinuria
- leukemia/lymphoma
- blood transfusions
- U/S - Multiple tiny echogenic foci without acoustic shadowing
- MR - punctate siderotic nodules; T2 hypo, GRE susceptibility artifact
Variant hepatic duct anatomy
Metastatic IPMN
- intraductal papillary mucnous neoplasm
- composed of ductal columnar epithelial cells that have hypertrophied.
- produce substantial amounts of mucin and can cause obstruction and ductal dilatation
- men between the ages of 60 and 80
- main duct IPMN - risk of malignant degeneration –> surgical resection
- side branch IPMN –> imaing followup
- concerning features of malignant degeneration:
- solid mass within panc duct
- main duct dilataion > 10mm
- diffuse multifocal involvement
Management of focal cystic pancreatic lesion
