Most common 2 Flashcards
LS (500 cards)
1
Q
MC site of schwannomas
A
skin and subcutaneous tissues (outside CNS)
2
Q
MCC of unilateral sensorineural hearing loss
A
vestibulochochlear schwannoma
3
Q
MCC of multiple enhancing CNs
A
mets
4
Q
MC cerebellopontine cistern mass
A
vestibular schwannoma
5
Q
MC of all Meckel cave tumors
A
schwannomas
6
Q
MC jugular foramen schwannoma but still rare
A
glossopharyngeal schwannomas (IX)
7
Q
MC site of facial nerve schwannomas
A
geniculate fossa
8
Q
MC of the pure motor nerve shwannomas but rare
A
oculomotor (III)
9
Q
MC location of CN III schwannoma
A
interpeduncular cistern (2nd mc: cavernous sinus)
10
Q
MC reported sites of intraparenchymal schwannomas
A
frontal and temporal lobes
11
Q
Scalp and orbital plexiform neurofibromas most commonly involve what nerve?
A
V1 (ophthalmic)
12
Q
Most commonly affected CNs in malignant peripheral nerve sheath tumors
A
vestibular, facial, and trigeminal
13
Q
MC site of distant extracranial mets in malignant peripheral nerve sheath tumors
A
lung
14
Q
MC type of (CNS) lymphomas / Vast majority of primary CNS lymphomas / Approximately 80% of secondary CNS lymphomas
A
diffuse large B-cell lymphoma
15
Q
Preferred site of primary CNS lymphomas
A
cerebral hemispheres - deep-seated w/ predilection for periventricular WM, esp the corpus callosum (next mc: basal ganglia and thalami)
16
Q
MCC of a solitary ring-enhancing lesion in an HIV/AIDS patient
A
lymphoma
17
Q
MC involved site in lymphomatoid granulomatosis
A
lung > skin
18
Q
MC manifestation of LCH / MC overall manifestationf of LCH
A
bone lesions / skin and bone lesions
19
Q
MC presenting symptom of CNS LCH
A
central diabetes insipidus
20
Q
MC presentation of CNS LCH
A
craniofacial involvement
21
Q
MC manifestations of LCH on NECT
A
one or more sharply marginated lytic skull or facial bone defects
22
Q
Most commonly affected sites in LCH
A
craniofacial bones and skull base (followed by hypothalamic-pituitary region)
23
Q
MC sites of LCH-related neurodegenerative lesions
A
brainstem and/or cerebellum (bilaterally symmetrical confluent T2/FLAIR typically in dentate nuclei)
24
Q
MC site of punctate foci of parenchymal enhancement in LCH
A
pons
25
MC form of childhood cancer / MC malignancy in children
leukemia (ALL (80%) > AML)
26
Solitary bone plasmacytomas/solitary plasmacytomas are most commonly found in the?
vertebrae and skull
27
Solitary bone plasmacytomas occur most frequently in the?
spine > skull - always red marrow
28
MC primary bone malignancy
multiple myeloma
29
Most sensitive imaging modality for detecting diffuse and focal bony lesions
whole-body MR
30
MC etiologies/MC underlying causes of extramedullary hematopoiesis
anemias (thalassemia, SCD, hereditary spherocytosis) > myelofibrosis/myelodysplastic syndromes
31
MC site of extramedullary hematopoiesis
axial skeleton
32
MC head and neck sites of extramedullary hematopoiesis
face and skull
33
MC intracranial location of extramedullary hematopoiesis
subdural space
34
Pathologic hyperplasia most commonly occurs in response to?
end-organ failure
35
MCC of pathologic pituitary hyperplasia
primary hypothyroidism -> TSH cell hyperplasia
36
MC physiologic form of pituitary hyperplasia / MC etiology of pituitary hyperplasia
diffuse PRL cell hyerplasia (during preg and lactation) / PRL cell hyperplasia
37
MC abnormality in children w/ isolated growth hormone deficiency
hypoplastic pituitary gland (pag multiple - stalk abnormalities)
38
MC suprasellar mass in children / MC suprasellar mass in the pediatric population
craniopharyngioma (2nd MC: optic pathway/hypothalamic pilocytic astrocytoma)
39
MC nonglial neoplasm in children
craniopharyngioma
40
MC nonneuroepithelial intracranial neoplasm in children
craniopharyngioma
41
MC site of ectopic pituitary adenomas
sphenoid sinus
42
2 MC pituitary adenomas
prolactinomas and GH-secreting tumors
43
MC extracranial sources of mets to the stalk and/or pituitary gland
lung and breast
44
MC type of hypophysitis
lymphocytic hypophysitis (MC in pregnant and postpartum females - difficult to distinguish from physiologic PRL cell hyperplasia; if (+) stalk enlargement - hypophysitis > hyperplasia)
45
MC site of sarcoidosis
hilar lymph nodes
46
MC type of sphenoid pneumatization
sellar
47
5 MC overall suprasellar masses / big 5
macroadenoma, meningioma, aneurysm, craniopharyngioma, and astrocytoma
48
MC calvarial site of fibrous dysplasia
frontal bone
49
MC sites of FD in the face
orbit, zygoma, maxilla, and mandible
50
2nd MC pediatric primary skull lesion (after dermoid cysts)
fibrous dysplasia
51
Most exaggerated example of abnormal osseous remodeling
Padet disease
52
Most commonly affected CN in Paget disease
CN VIII
53
MC overall aneurysmal bone cyst location
metaphysis of long bones 70-80% (vertebrae, generally posterior elements 15%)
54
2nd mc pathologically proven bone tumor of childhood
aneurysmal bone cyst
55
MC site of chordomas
sacrum > sphenooccipital (clival) region > spine
56
Most helpful feature in the classification of intracranial cysts
location
57
MC scalp mass in children
Langerhans cell histiocytosis
58
3 statistically mc scalp cysts
epidermoid, trichilemmal, and dermoid
59
MC type of extraaxial cyst / MC off-midline extraaxial supratentorial cyst / 2nd MC cystic-appearing extraaxial mass in the CPA cistern (after epidermoid) / MC of all congenital intracranial cysts / MC nonneoplastic intracranial cyst
arachnoid cyst
60
Nearly 2/3 of arachnoid cysts are found in the?
middle cranial fossa, anteromedial to the temporal lobe (next mc: cerebral convexity, pred over frontal lobes 15%)
61
MC supratentorial midline location for arachnoid cysts (although relatively rare)
suprasellar cistern > quadrigeminal cistern and velum interpositum
62
MC location of arachnoid cysts in the posterior fossa
CPA cistern > retrocerebellar
63
Best sequences to distinguish cystic-appearing intracranual masses from one another
FLAIR and DWI
64
MC intracranial developmental cyst / 3rd mc CPA mass (after vestibular schwannoma and meningioma) / MC cystic mass in the CPA
epidermoid cyst
65
Single mc site of epidermoid cysts
CPA cistern - nearly half (other locations: middle cranial fossa (sylvian fissure) and parasellar region - 10-15%)
66
MC site of dermoid cysts
suprasellar cistern > posterior fossa and frontonasal region
67
MC location of intracranial neurenteric cysts
midline posterior fossa (anterior to the pontomedullary junction)
68
MC CNS site of neurenteric cysts
spine > skull - always red marrow
69
MC parenchymal cysts
prominent perivascular spaces > hippocampal sulcus remnants
70
MC nonneoplastic parenchymal brain "cysts"
perivascular spaces
71
Perivascular spaces have striking predilection for?
inferior 3rd of basal ganglia, esp near anterior commissure
72
MC site of neuroglial cysts
frontal lobe (supratentorial) (adj to but no communication w/ ventricles)
73
MC location of choroid plexus cysts
atrium of the lateral ventricle (within the choroid plexus glomus)
74
MC of all intracranial cysts
choroid plexus cysts
75
MC "lesion" that mimics a colloid cyst on MR
pulsatile CSF flow
76
MC location of ependymal cysts
atrium of the lateral ventricles
77
Largest and most prominent of the deep GM nuclei
thalami
78
MC bilateral basal ganglia lesions
normal variants, such as physiologic calcification and prominent perivascular spaces
79
MCC of abnormality in the bilateral basal ganglia
vascular, hypoxic-schemic insults, common metab disorders, such as chronic liver failure
80
MC lesion to affect the putamen
hypertensive hemorrhage
81
Part of basal ganglia most sensitive to hypoxia
globus pallidus
82
Most commonly affected locations in Wernicke encephalopathy
mammillary bodies, hypothalamus, medial thalamic nuclei (adj to 3rd ventricle), tectal plate, and periaqueductal GM
83
MCC of Wernicke encephalopathy
alcohol use disorder
84
Most characteristic imaging feature of methanol poisoning
bilateral basal ganglia
85
Most commonly abused opioid
heroin
86
MC acute complication of injected heroin
stroke (inhaled - leukoencephalopathy)
87
MC secondary complication of heroin abuse
infection - endocarditis
88
Radiation-induced vascular malformations are most commonly seen in?
children who have recevied whole-brain RT for ALL
89
Single most important risk factor for developing a new primary CNS neoplasm
radiotherapy (70% meningiomas, 20% malignant astrocytomas or medulloblastomas)
90
2 mc abnormalities in chemotherapy-assoc acute toxic CNS injury
PRES and treatment-induced leukoencephalopathy
91
MC single protein or enzyme deficiency disease to present in childhood
X-linked adrenoleukodystrophy
92
MC inborn error of amino acid metabolism
phenylketonuria
93
2nd mc inherited disorder of amino acid metabolism
nonketotic hyperglycinemia
94
MC type of neurodegeneration w/ brain iron accumulation (NBIA)
PKAN - panthothenate kinase-associated neurodegeneration
95
MC manifestation of acute hypertensive encephalopathy
PRES
96
MC overall cause of PRES
preeclampsia
97
MC imaging pattern of PRES
dominant parieto-occipital pattern
98
MC overall condition predisposing to malignant hypertension
essential hypertension
99
2nd mc manifestation of chronic hypertensive enceph (after WM lesions)
microhemorrhages
100
MC location of hypertensive microhemorrhages
basal ganglia
101
Childhood hypoglycemic enceph is most commonly associated w/ ?
type 1 DM
102
MCC of transient (neonatal/infantile) hypoglycemia
maternal diabetes
103
MCC of severe, persistent (neonatal/infantile) hypoglycemia
congenital hyperinsulinemia
104
MC imaging abnormality in patients w/ acute DKA
vasogenic cerebral edema
105
MC location for an ectopic thyroid
central tongue base
106
MC findings in the brain in primary hyperparathyroidism
basal ganglia calcifications on NECT
107
MCC of secondary HPTH
chronic renal disease
108
MC progressive compressive CN involvement/neuropathy in secondary hyperparathyroidism due to renal osteodystrophy
optic neuropathy
109
Most commonly associated condition / MCC of cytotoxic lesions of the corpus callosum
use and subsequent withdrawal of antiepileptic drugs
110
Iron accumulation is greatest in the?
pars reticulata of the substantia nigra
111
MC site of obstructing membranes
foramina of Luschka
112
MC mass found at the foramen of Monro
colloid cyst
113
MC tumor that causes intraventricular obstructive hydrocephalus in children
medulloblastoma
114
MC general imaging feature of normal pressure hydroceph
ventriculosulcal disproportion
115
Spontaneous intracranial CSF leaks are most commonly associated with
arachnoid granulations in the lateral sphenoid sinus
116
Largest and deepest of all cranial fossae
posterior fossa
117
MC type of Chiari malformation
Chiari 1
118
MC of all congenital brain malformations / MC CNS malformation / Single mc malformation that accompanies other developmental brain anomalies and syndrome
anomalies of the cerebral commissures (especially the corpos callosum) / corpus callosum dysgenesis
119
MC congenital cerebellar malformation
Dandy-Walker malformation
120
MC presentation of DWM
increased ICP sec to hydrocephalus
121
MC brain morphologic defects in fetal alcohol syndrome
CC agenesis and regional increases in cortical thickness
122
MC inherited cause of mental retardation in boys
fragile X syndrome
123
MC causes of secondary microcephaly
ischemia, infection, maternal diabetes, and trauma
124
MC and mildest form of primary microcephaly
microcephaly with simplified gyral pattern (MSG)
125
MC type of focal cortical dysplasia
Type IIb
126
Single mcc of severe early-onset drug-resistant epilepsy in children and young adults
focal cortical dysplasias
127
MC form of cortical malformation in adults
periventricular nodular heterotopia (PVNH)
128
MC associated abnormality w/ PVNH
ventriculomegaly
129
Mildest form of classic licencephaly
subcortical band heteroptopia / double cortex syndrome
130
MC location of polymicrogyria
bilateral perisylvian
131
MC imaging abnormality in infants with CMV infection / MC malformation of cortical development associated with CMV infection
polymicrogyria (more common than calcification)
132
Most severe end of the holoprosencephaly continuum
aprosencephaly and atelencephaly (AP/AT) - rare
133
Most severe form of holoprosencephaly
alobar
134
MC form of holoprosencephaly
alobar > semilobar > lobar > unclassifiable
135
MC human forebrain malformation / Only malformation in which the posterior corpus callosum forms while the anterior aspects are absent
holoprosencephaly
136
Most developed and least anomalous form of HPE
lobar
137
MC CNS tumor predisposition syndromes
neurofibromatoses
138
MC CNS neoplasm in NF1 / MC glioma in NF1
pilocytic astrocytoma
139
MC site of NF1 pilocytic astrocytomas
optic pathway
140
MC site of plexiform neurofibromas
orbit
141
MC sites of meningiomas in NF2
falx and cerebral convexities
142
2nd MC inherited tumor syndrome (after NF1)
tuberous sclerosis complex
143
MC site of subependymal nodules in tuberous sclerosis complex
along the caudothalamic groove
144
MC site of hemangioblastomas
dorsal half of the cerebellum (2nd: medulla)
145
MC site of supratentorial hemangioblastomas
pituitary stalk
146
MC location of leptomeningial angioma in Sturge-Weber
parietooccipital
147
MC site of extracutaneous hemangiomas
subglottis
148
MC location of atretic cephalocele (contains just dura, fibrous tissue, and degenerated brain tissue)
obelion (sagittal suture at the level of the parietal foramina)
149
MC type of cephalocele in European/North America Caucasians / MC type of cephalocele among Caucasians
occipital
150
MC location of congenital cephalocele
squamous portion of occipital bone
151
MC type of cephalocele in SEA
frontoethmoidal
152
MC type of cephalocele among Australian aborigines, Malaysians, and select Southeast Asian groups
sincipital (sabi ni Osborn synonymous ang frontoethmoidal at sincipital)
153
MC of the 3 subtypes of frontoethmoidal cephaloceles
frontonasal > nasoethmoidal > nasoorbital
154
MC single-suture craniosynostosis / MC nonsyndromic craniosynostosis
sagittal/scaphocephaly > coronal > metopic > lambdoid
155
Rarest type of nonsyndromic craniosynostoses
lambdoid
156
MC syndromic craniosynostosis
bilateral coronal
157
MC of all soft tissue tumors
ordinary lipoma
158
MC overall site of intracranial lipomas
interhemispheric fissure (supratentorial, mostly in or near midline)
159
MC posterior fossa site of intracranial lipomas
CPA cistern
160
Prob the MCC of marrow reconversion seen on MRI
incidental finding in women who are obese (and who are often smokers)
161
MC tendon abnormalities seen on MRI
degeneration, tenosynovitis, and tears
162
Most commonly affected tendon in xanthomas
Achilles tendon and extensor tendons of the hand
163
MC injuries in sports
muscle strains
164
Fascial herniation of muscle is most commonly seen where?
anterior lower leg or thigh
165
Most commonly involved in (diabetic) muscle ischemia
thigh, especially the vastus musculature (80%); next is the calf (20%)
166
Site most commonly involved in fibrolipomatous hamartoma
hand, especially the median nerve
167
Most commonly affected by ganglion cysts
peroneal nerve at the knee
168
MC location of pain and numbness because of Morton's neuromas
2nd and 3rd web spaces
169
MC locations for Morton's neuroma
2nd and 3rd intermetatarsal spaces
170
MC sites of involvement of Brodie's abscess (or subacute osteomyelitis?)
tibia and femur
171
Most specific sign of active chronic osteomyelitis
sequestrum (best shown w/ CT)
172
MC causative agent of pyomyositis
S. aureus
173
MC sites of involvement of neuroathropathy (diabetes)
Lisfranc joints, Chopart joints (talonavicular and calcaneocuboid joints), and subtalar joints
174
MC tumor-like entities that originate in joints and may manifest as a swollen joint
synovial chondromatosis and PVNS
175
MC site of loose bodies
knee
176
MC location of intraosseous lipoma
calcaneus, proximal femur, and humerus
177
MC benign tumor of bone
osteochondroma
178
MC mechanism of injury that results in a complete tear of the ACL
twisting force combined with a valgus stress
179
MC mechanism of ACL injury
forced valgus in external rotation
180
Site that is most vulnerable to injuries from excessive tensile forces
musculotendinous junction
181
MC site of avulsion fractures
pelvis
182
MC avulsion fracture in upper limb
medial epicondyle apophysis (common flexor/pronator tendon) in children
183
MCC of insufficiency fractures
osteoporosis
184
MC site of transient osteoporosis
hips
185
MC site of spontaneous osteonecrosis of the knee
weight-bearing surface of the medial femoral condyle
186
MC site of osteochondritis dissecans
knee, ankle, elbow
187
MC site of osteochondritis dissecans in the knee
lateral aspect of the medial femoral condyle along its non-weight-bearing surface
188
MC location of partial-thickness tears of the supraspinatus tendon
undersurface/articular aspect (rather than superior/bursal surface)
189
MC partial-thickness tear / MC cuff tear of all kinds
rim rent tear - insertional fibers of the cuff on the greater tuberosity are disrupted from the bone / PASSTA or PASTA lesions - partial supraspinatus tendon avulsion; can occur either anteriorly on greater tuberosity involving supraspinatus or posteriorly on greater tuberosity involving infraspinatus
190
Abnormalities in posterosuperior impingement most commonly affects the?
supraspinatus tendon, posterosuperior labrum, and humeral head where the greater tuberosity abuts the posteriosuperior glenoid during abduction and ER
191
After rotator cuff disease, the major abnormality that affects the shoulder
instability
192
Most variable of the 3 glenohumeral ligaments / Most variable in morphology of all the anterior glenohumeral capsular ligaments
middle
193
Most important of the glenohumeral ligaments for anterior and posterior joint stabilization
inferior
194
Glenohumeral ligament most frequently affected with instability
inferior
195
Largest and most important of the glenohumeral ligaments
IGHL or IGL
196
MC of all glenohumeral joint instabilities
anterior instability, particularly that prooduced by lesions of the IGHL-labral complex
197
Primary restraint to anterior translation of the humeral head at 90 deg of abduction
anterior band of the IGHL
198
MC labral shapes
triangular > round > flat > absent
199
Bennett lesion is most commonly seen in?
pitchers
200
MC injury after anterior dislocation of the glenohumeral joint
Bankart lesion
201
MC location of paralabral cysts
seen postero-superiorly in assoc w/ a superior or posterior labral tear
202
MC location of posterior labral tears
posterior superior quadrant of the glenoid labrum
203
MC predisposing factors for adhesive capsulitis
trauma, immobilization, hemiplegia, DM, cervical disk disease
204
MC site of calcium hydroxyapatite deposition
around the shoulder, w/ the supraspinatus tendon being the site most frequently involved
205
MCC of suprascapular nerve compression
ganglion cyst (usually assoc w/ superior or posterior labral tear)
206
2nd MC site of osteonecrosis after the femoral head
humeral head
207
MC site of osteonecrosis in the humeral head
superomedial aspect
208
MC signal in the center of osteonecrosis
fat
209
MC benign tumors that affect the shoulder girdle
lipoma and benign fibrous histiocytoma
210
MC primary bone tumor found incidentally on shoulder MRI
enchondroma
211
MC focal primary malignant tumor in the shoulder
chondrosarcoma
212
MC malignant processes that affect the shoulder
mets and myeloma
213
MC malignant soft tissue tumors in the shoulder
malignant fibrous histiocytoma and liposarcoma
214
Most sensitive for assessing fracture and edema
T1, STIR, and fat-suppressed FSE
215
Least sensitive technique for evaluating marrow
GRE
216
MCC of lateral ulnar collateral ligament rupture
posterior dislocation or varus stress, often FOOSH
217
MC ulnar collateral ligament tear
midsubstance rupture of the anterior bundle
218
Most commonly (completely) torn tendon of the elbow
distal biceps tendon (but uncommon, 3% of all biceps ruptures)
219
Least commonly ruptured tendon in the body
triceps
220
MC location of elbow pain in the general population
lateral aspect of the elbow
221
MC neuropathy / Most frequently injured nerve in the elbow
ulnar neuropathy / cubital tunnel syndrome / ulnar nerve - because superficial
222
MCC of median nerve entrapment
pronator syndrome
223
MCC of pronator syndrome/median nerve compression
2 heads of pronator teres w/ pronation / dynamic compression by the pronator teres muscle
224
MC causes for distention of the olecranon bursa
gout, trauma (hemorrhage), and infection
225
Strongest portion of scapholunate ligament / Most important for carpal instability
dorsal portion
226
Results in the MC type of carpal instability
scapholunate pathology
227
MC instability in wrist / MC carpal instability syndrome
dorsal intercalated segmental instability (DISI) / scapholunate dissociation
228
2nd MCC of carpal instability
tears of the lunotriquetral ligament - VISI
229
Largest ligament of the wrist
radiolunotriquetral ligament
230
Primary stabilizer of the distal radioulnar joint
triangular fibrocartilage complex (TFCC)
231
Main component of TFCC that is most often abnormal
TCF
232
Which surface are partial tears of the TFC noted more frequently
proximal articulating surface (facing the distal RU joint)
233
Location where the carpal tunnel is most constricted
level of the hook of the hamate
234
MC compressive neuropathy that affects the upper extremity
carpal tunnel syndrome
235
MCC of carpal tunnel syndrome
tenosynovitis of flexor tendons from overuse of the hands (sa Stoller, median neuritis is most often idiopathic)
236
MCC of postoperative failure in carpal tunnel syndrome
incomplete release of the flexor retinaculum
237
MC nerve in the body to be affected by fibrolipomatous hamartoma
median nerve
238
MC fractured carpal bone / Largest and most radial bone in the proximal row / MC fractures of the carpus
scaphoid / scaphoid fractures
239
2nd mc fracture of the carpus
fractures of the triquetrum
240
2 MC sites for osteonecrosis in the wrist
proximal pole of the scaphoid and the lunate
241
MC carpal coalition
lunate and triquetrum / lunotriquetral fusion
242
MCC of a mass involving the wrist
ganglion cyst
243
2nd MC soft tissue mass of the hand and wrist
giant cell tumors of the tendon sheath
244
MC soft tissue masses in the hand and wrist
ganglion cysts, GCTs of the tendon sheath, nerve sheath tumors, soft tissue chondromas, glomus tumors, and anomalous muscles
245
MC site of GCTs of the tendon sheath
volar aspects of the fingers
246
(Some clinicians believe this to be the) Leading cause of failed disk surgery
missed sequestrations
247
About 90% of all focal disk abnormalities in the lumbar spine occur at?
L4-L5 / L5-S1
248
About 90% of all focal disk abnormalities in the cervical spine occur at?
C5-C6 and C6-C7
249
Earliest marrow changes encountered
Modic type 1
250
Nerve appears to be most readily identified in which aspect of the foramen?
superior and medial aspect (because of the large dorsal root ganglion)
251
When is fibrosis best displayed?
after injection of gadolinium
252
When is the degree of enhancement of postop fibrosis greatest?
1st yr after surg
253
MC causes of failed back surgery
recurrent or persistent disk extrusions, postop scarrring, nerve root damage/neuritis, and inadequate surgery (missed free fragments, inadequate decompression of spinal stenosis, wrong level treated, or what was treated was not the pain source)
254
MC appearance of avascular necrosis of the femoral head
focal serpiginous low signal line w/ fatty center b/n 10:00 and 2:00 on coronal (anterosuperior quadrant)
255
MC finding in Legg-Calve-Perthes disease
diffuse low signal in the femoral head on T1 and T2
256
Best predictor of growth arrest in Legg-Calve-Perthes disease
physeal bridging
257
MC location of stress fractures in the femoral neck
medial aspect (compressive surface)
258
MC malignant entities that affect hip and pelvis
mets and myeloma (plasmacytoma)
259
Most frequently injured thigh muscles
hamstring muscles
260
Of the 4 adductor muscles, chiefly implicated in groin pain in athlethes (athletic pubalgia)
adductor longus (usually microtear at pubic attachment)
261
Largest bursa in the body
iliopsoas bursa
262
MC malignant ST tumor in the hip
malignant fibrohistiocytoma
263
MC location of labral tears
anterosuperior (US); posterior (Asians) - squatting position
264
MC disease process affecting the sacroiliac joint
osteoarthritis
265
MC type of meniscal tear
oblique/horizontal tear that affects the undersurface of the posterior horn of the medial meniscus - commonly degenerative
266
Most reliable sign for a radial tear
cleft
267
More commonly affected in discoid meniscus
lateral meniscus
268
MC knee bursa
popliteal bursa / Baker's cyst / semimembranosus-gastrocnemius bursa
269
Most commonly involved in meniscal tear with double anterior horn sign
lateral meniscus
270
MC location of Morel-Lavalle lesion
gluteal region
271
MC location of posterior tibial tendon tears
at the level of the medial malleolus (rather than more distally)
272
MC location of tibialis posterior tendon injuries
midportion at the level of and immediately distal to the medial malleolus, corresponding to the relative zone of tendon hypovascularity
273
MC abnormal tendon on the medial side of the ankle
posterior tibial tendon
274
Most likely of all anterior tendons to be abnormal
anterior tibial tendon
275
Most commonly torn of the ankle ligaments
anterior talofibular ligament (ATFL)
276
MCC of sinus tarsi syndrome (70%)
trauma
277
2 MCC of tarsal tunnel syndrome
ganglion cysts and nerve sheath tumors
278
2 MC types of tarsal coalition
calcaneonavicular and talocalcaneal
279
MC syndromes in the foot
os trigonum syndrome/posterior ankle impingement syndrome, accessory navicular bone, hallux sesamoids
280
MC ST abnormality to occur in the region of the hallux sesamoids
turf toe
281
MC malignant ST tumor of the foot
synovial sarcoma
282
MC accessory muscles encountered in the foot and ankle
accessory soleus and peroneus quartus muscles
283
MC location of neuropathic changes / MC site of neuropathic
osteoarthropathy in diabetes
tarsometatarsal joints / Lisfranc joint
284
Most sensitive and specific technique for evaluation of chondrocalcinosis and CPPD deposition disease
T2* gradient-echo contrast
285
Most anterior hip muscle
sartorius
286
Most posteromedial tendon on axial knee images at the joint line
semitendinosus
287
MC initial location of chondral degeneration in the hip joint
anterior superior quadrant
288
Most commonly involved in avascular necrosis
femoral head
289
MC site of muscle strain
midsubstance location
290
(MC location of muscle fiber failure / weakest biomechanical link)
muscle-tendon unit
291
Most frequently injured quadriceps muscle
rectus femoris
292
Structures in the hip region most prone to avulsion injury
iliac crest, ASIS, AIIS, lesser and greater trochanters, ischial tuberosity, acetabular rim, adductor insertion at the symphysis pubis
293
MCC of the piriformis syndrome
trauma to the gluteal region
294
MC type of the snapping hip syndrome or coxa saltans
external
295
MC type of femoroacetubular impingement / MC mechanism of femoroacetabular impingement
mixed cam-pincer / mixed cam-pincer impingement
296
Most substantial part of the labrum
posterior superior extent (anteroinferiorly - thinner)
297
MC location of labral tears
anterosuperior (US); posterior (Asians) - squatting position
298
MC location of labral tears
anteroposterior or posterosuperior
299
MC type of (traumatic) labral tears
radial flap
300
MC location of paralabral cysts
anterosuperior > posterosuperior, inferior
301
MC femoral head migration in OA (?)
superolateral
302
MC location of loose bodies
acetabular fossa
303
MC source of chondral debris
OA
304
Most commonly affected locations in the hip by RA
femoral head, acetabulum, and joint capsule
305
Most commonly affected joint in pigmented villonodular synovitis
knee
306
Most frequently involved in stress fractures of the hip
femoral neck
307
MC acetabular fracture type
posterior wall fracture / posterior lip or posterior rim fracture
308
MC type of associated or complex acetabular fracture
transverse and posterior wall fracture
309
Most complex of acetabular fractures
fracture of both anterior and posterior columns
310
Most weight-bearing surface of the acetabulum
posterior wall
311
MC type of hip dislocation (90%)
posterior (femoral head lateral and superior to the acetabulum)
312
MCC of hip dislocations
traumatic injurues from motor vehicle accidents and sports injuries
313
MC mechanism of hip dislocations in older patients over 65 yo
trauma secondary to a fall
314
MC infecting organism in osteomyelitis among all age groups
Staph aureus
315
View/images that provide the most information in early synovial reactions (defining the free-edge contour of Hoffa's fat pad) and cartilage erosions in patients with degenerative or inflammatory arthritis
sagittal
316
MC location of meniscal grade 2 signal intensity / Receives the greatest femoral tibial forces during biomechanical loading / MC location for the occurrence of a meniscal tear / Grade 3 signal intensity is most frequent in? / Horizontal tears are mc within? / Flap tears most commonly involve the?
posterior horn of medial meniscus
317
MC classic radial meniscal tear
involves the anterior horn-body junction of the free edge of the lateral meniscus
318
MC clinical tear type
flap tears
319
MC findings in flap tears / MC meniscal tear type / Most commonly seen tear pattern
vertical grade 3 signal intensity in the inner 1/3 to 1/2 of the meniscus and relative deficiency of the inferior surface of the meniscus
320
Most specific secondary sign in ACL tear / Most commonly seen osseous injury associated w/ ACL tears
lateral compartment osseous contusions (posterolateral tibial plateau)
321
Most commonly involved component of ACL in incomplete or partial tears
anteromedial bundle
322
MC and successful procedure for ACL reconstruction
bone-patellar tendon-bone graft using central (middle) third of the patellar tendon
323
MC injury present in graft impingement
fractured bundles involving the anterior portion of the graft
324
MCC of failed ACL reconstruction
anteriorly placed femoral tunnel
325
MC site of PCL tears
midportion
326
MCC of damage to the PCL
MVA (dashboard injuries) and injuries sustained in contact sports such as football
327
Most sensitive signs of grade II MCL injury
fascial edema and loss of demarcation from adjacent fat
328
MC patellar facet configuration
type 2 (medial facet is smaller than the lateral)
329
MC form of patellar malalignment and abnormal tracking
lateral subluxation of the patella
330
MC location of patellar chondromalacia
central area (ridge) of the patella w/ sparing of the superior and inferior thirds of the articular surface
331
MC location of bipartite patellar dysplasia
superolateral corner
332
Most commonly affected portion in patellar tendinitis
proximal posterior (deep) fibers
333
Most commonly affected portion (demonstrating focal thickening) in patellar tendinitis
medial to central portion
334
MC site of patellar tendon ruptures
proximal patellar tendon at the inferior patellar pole junction
335
MCC of patella baja
postop complication of ACL surgery or lateral retinacular release
336
MCC of lateral knee pain in long-distance runners
iliotibial band syndrome
337
MC subtype of juvenile chronic arthritis (formerly juvenile RA) in the absence of other rheumatic disorders
pauciarticular arthritis
338
MC affected joint in lyme disease/arthritis
knee
339
MCC of spontaneous osteonecrosis involving the medial femoral condyle
prior insufficiency fratures
340
Most frequently seen fracture about the knee
tibial plateau fracture (predominantly lateral plateau)
341
MCC of tibial plateau fractures
impaction of the anterior portion of the lateral femoral condyle in a valgus mechanism of injury
342
MC osseous tarsal coalitions / MC tarsal coalitions
calcaneonavicular (MC) and talocalcaneal
343
First involved cord in most plantar aponeurosis pathology
medial cord
344
The most likely of the extensor tendons to tear
tibialis anterior
345
MC mechanism in (lateral?) osteochondral talar lesions
strong inversion force w/ dorsiflexion of the foot and internal rotation of the tibia
346
3rd most frequently ruptured tendon / Largest tendon in the body
Achilles tendon
347
Site of Achilles tendon most susceptible to rupture
2-6 cm superior to the os calcis
348
MC etiology of tibialis posterior dysfunction
chronic degeneration
349
MC flexor hallucis longus tendon abnormality
paratendinitis (tenosynovitis)
350
2nd most frequently injured ankle ligament
calcaneofibular ligament
351
2nd MC ankle injury after lateral ligament injury
syndesmotic injuries
352
MC of the ST impingements
anterolateral impingement
353
MCC of anterolateral impingement
posttraumatic change with planterflexion inversion
354
2nd MC accessory bone of the foot
os tibiale externum
355
MC site of plantar plate tears
distal attachment
356
MC epiphyseal injury
lateral malleolus Salter-Harris type I fracture - through the growth plate
357
MC of tarsal bone fractures
fractures of the calcaneus
358
2nd most commonly fractured bone of the foot
talus
359
MC site of talar fractures
neck
360
MC type of talar neck injuries
type II - subluxation and/or dislocation of the talus w/ respect to the subtalar joint (dislocation of the posterior facet)
361
MC location of tarsometatarsal or Lisfranc fractures
bases of the second and third metatarsals
362
MC fractures leading to compartment syndrome
tibial fractures, especially open fractures involving prox and middle thirds
363
MC of the four compartments involved
anterior compartment
364
Most susceptible to injury/muscle strains
gastrocnemius, rectus femoris, hamstring, and adductor longus
365
MCC of peroneal spastic flatfoot
tarsal coalition
366
MC etiology of Morton's neuroma
entrapment neuropathy secondary to compressive forces against the deep transverse intermetatarsal ligament
367
Most commonly affected site in plantar fasciitis
origin of the plantar fascia from the calcaneal tuberosity
368
MC manifestation of plantar fasciitis
pain in the area of the medial tuberosity of the calcaneus
369
Most commonly involved in Freiberg's infraction
second metatarsal head
370
Most frequently affected joint in the hindfoot in rheumatoid arthritis
talonavicular joint
371
Joint in the hindfoot that is affected with the greatest severity in rheumatoid arthritis
subtalar joint
372
MC sites of ganglia of the foot and ankle
dorsolateral aspect of the foot, where ganglia may cause sinus tarsi syndrome, and at DIPJ in assoc w/ arthritis
373
MCC of sciatic neuropathy at the hip
iatrogenic, assoc w/ total hip replacements, usually after revision
374
Most prominent feature of sciatic neuropathy
foot drop (anterior tibial muscle - peroneal division)
375
MC neurovasculalr injury after knee arthroscopy
saphenous nerve injury
376
MC location of the trifurcation/division of the common peroneal nerve
at or distal to the fibular neck
377
MC mononeuropathy in the LE
common peroneal neuropathy
378
MC entrapment syndrome along the deep peroneal nerve
anterior tarsal syndrome (underneath the distal edge of inferior extensor retinaculum or at talonavicular joint)
379
MC of the thin septa separating the tarsal tunnel into multiple compartments
transverse interfascicular septum
380
Truncation artifact occurs at high signal interfaces and is most typically seen in the?
spinal cord at thr spinal fluid-cord interface, creating a pseudo-syrinx
381
Most commonly, tears of the subscapularis tendon begin in the?
superior articular margin
382
MC starting point for tears of the supraspinatus tendon
anterior leading edge (anterior-most portion of the distal supraspinatus tendon)
383
MC acromial spurs
inferior spurs, arising from the anterior margin of the acromion at or near the coracoacromial ligament attachment, and broad-based undersurface spurs that extend along the majority of the acromial undersurface area
384
Most frequently involved in impingement-related rotator cuff tears
supraspinatus and superior aspect of the infraspinatus
385
MC location for impingement
between the anterior 3rd of the acromion and the underlying tendons
386
MC type of os acromiale (based on the location of articulation of the unfused ossification centers)
mesoacromion-meta-acromion type
387
MC form of anterior dislocation
subcoracoid dislocation
388
MC site of origin of superior paralabral cysts
spinoglenoid notch
389
MCC of biceps tendinitis (tendinosis)
impingement tendinitis
390
MC site of biceps tendon tears
rotator interval
391
Most commonly affected tendons in calcific tendinitis
supraspinatus > infraspinatus > teres minor > subscapularis
392
Most biceps brachii tears occur where?
proximally involving the long head
393
MC tendon involved in medial epicondylitis/golfer's elbow/pitcher's elbow/medial tennis elbow
flexor carpi radialis along w/ the pronator teres
394
MC tendon involved in lateral epicondylitis/tennis elbow
extensor carpi radialis brevis
395
MC location for ulnar neuritis
posterior to the medial epicondyle
396
2nd mc joint to be dislocated, after the shoulder
elbow
397
2nd mc major joint dislocation (after the shoulder) in adults (although unusual) / MC dislocation in children under 10 years of age
posterior dislocation of the elbow
398
MCC of lateral collateral ligament complex insufficiency
elbow dislocation
399
MC finding after complete dislocation
complete disruption of the MCL
400
MC elbow fracture in adults / MC injury assoc w/ a coronoid fracture
fractures of the radial head
401
MC fracture in the juvenile or adolescent throwing athlete
medial epicondylar avulsion fracture
402
MC pediatric elbow injury
supracondylar fracture / Gartland fracture
403
MC complication of supracondylar fractures
cubitus varus
404
Most severe complication of supracondylar fractures
Volkmann's contracture
405
MC physeal injury / MC specific type of physeal injury about the elbow
lateral condylar fracture (usually Salter-Harris type IV)
406
2nd MC site of loose bodies, after the knee
elbow
407
MC location of loose bodies in the elbow
anteriorly or lodged in the trochlear notch
408
Most commonly observed biceps tendon injury (?)
complete rupture from its insertion on the radial tuberosity
409
MC compression site of radial nerve entrapment in the elbow (radial tunnel syndrome)
arcade of Frohse
410
MC site of bursitis in the body / MC superficial site of bursitis in the body
olecranon bursitis / olecranon bursa - subcutaneous
411
MCC of olecranon bursitis / miner's elbow / student's elbow
trauma, either acute or repetitive
412
MC site of bone infection in the elbow
olecranon
413
MC site for osteomyelitis (?)
elbow
414
MC site of degenerative arthrosis in the wrist
radioscaphoid arthrosis
415
MC pattern of degenerative arthritis of the wrist
SLAC wrist (develops in response to scaphoid rotation) - SLAC wrist involves the scaphoradial, capitolunate, and scaphocapitate joints,
416
2nd MC site of wrist arthrosis / 2nd MC form of degenerative arthritis of the carpus
triscaphe joint (distal pole of the scaphoid articulating w/ the trapezoid and trapezium) / triscaphe arthritis - triscaphe arthritis involves the
scaphotrapezial, scaphotrapezoidal, and trapeziotrapezoidal
articulations
417
3rd mc form of degenerative arthritis
combination of SLAC and triscaphe arthritis
418
Strongest and most important of the scapholunate ligament components for maintaning carpal instability
dorsal component
419
MC type of carpal instability
tears of the scapholunate ligament
420
Degenerative tears and perforations of TFC most commonly are seen where?
just proximal to the radial attachment of the TFC
421
MC site of carpometacarpal arthrosis
1st carpal-metacarpal joint
422
Most radially located tendon within the carpal tunnel
flexor pollicis longus tendon
423
Most constant and the strongest of the extrinsic ligaments
volar extrinsic ligaments
424
Contains the most elastic tissue of any ligament in the wrist
radioscapholunate ligament
425
MC site of tears in the TFC complex
central portion, or centrum - thin
426
MC location of TFC tears
near or adjacent to the radial attachment
427
MC carpal dislocations or fracture-dislocations
scaphoid either fractures or dislocates from the lunate
428
MC non-Kienbock's related fracture pattern of the lunate
volar-pole fractures
429
MC carpal fracture causing compression of the ulnar nerve in Guyon's canal
fracture of the hook of the hamate
430
Intraosseous ganglions are most common in the?
lunate
431
MC ST mass of the wrist
ganglions
432
MC finding of ganglion cysts on MRI
homogeneous fluid-filled mass in communication w/ the scapholunate interval
433
2nd mc ST mass of the hand / 2nd mc tumors of the STs in the hand
localized type of the giant cell tumor of the tendon sheath / tenosynovial GCTs
434
MC locations of GCTTS
volar aspect of the hand and fingers adjacent to the DIP joint (most commonly index and long finger)
435
MC stenosing tenosynovitis in athletes
de Quervain's tenosynovitis
436
MC finding in de Quervain's
edema and fluid associated w/ the 1st extensor compartment
437
2nd mc site of stenosing tenosynovitis in the upper extremity
extensor carpi ulnaris tendinitis
438
MC location of extensor carpi ulnaris tendinitis
dorsal ulnar aspect of wrist and the 6th extensor comparment
439
Most characteristic finding in intersection syndrome
peritendinous edema around the 1st and 2nd extensor compartment tendons, extending proximally from the crossover point
440
Finger (flexor annular pulley) most often injured in baseball pitchers / Most frequently involved in flexor digitorum profundus avulsions
ring finger
441
Most obvious sign of FDP avulsion
absent or retracted tendon (axial or sag)
442
MC closed tendon injury seen in sports
mallet finger (zone I)
443
MC closed rupture of the flexor tendons
distal avulsion of the FDP tendon (rugby or jersey finger)
444
Most commonly affected with ganglion cysts
ring finger
445
MC pseudotumors involving the fingers
ganglions and Dupuytren's contracture
446
MC benign tumors involving the fingers
tenosynovial GCTs and vascular malformations
447
MCC of chronic infections of the tendon sheaths of the hand
TB
448
MC type of vascular malformation (in the fingers)
venous malformation
449
MC location of lipomas in the fingers (uncommon location)
proximally in the thenar and hypothenar eminences
450
MC bone tumors of the hand
enchondromas
451
MC location of GCTs in the hand / Most frequently affected bones in the hand by aneurysmal bone cysts
metacarpals
452
Malignant bone tumors of the hand are extremely rare and are almost always?
chondrosarcomas
453
Most common location of glomus tumors
subungal area, in the supporting tissue of the nail bed or the matrix
454
Most frequently affected joints in the hand in OA
IP joints of the long fingers and thum (PIP and DIP often involved simultaneously)
455
Most commonly affected joints in RA
MCP and PIP
456
*OA of the fingers may also be secondary to crystal-induced arthropathies, w/ a predilection for the?
2nd and 3rd MP joints
457
Most sensitive in detecting bone sclerosis
T1
458
Most severe degree of nerve injury
neurotmesis (others: neuropraxia/1st-deg nerve injury and axonotmesis/2nd-deg)
459
Most commonly involved nerve in shoulder dislocations
axillary nerve
460
Most frequently compromised nerve in Parsonage-Turner syndrome
(dati, long thoracic nerve) now, isolated suprascapular nerve
461
Most commonly affected muscles in Parsonage-Turner syndrome
those innervated by suprascapular nerve including supra and infraspinatus
462
MC site of ulnar neuropathy
cubital tunnel
463
MC nerve variation of the median and ulnar nerves
Martin Gruber anastomosis
464
2nd mc neuropathy in the UE, exceeded only by carpal tunnel syndrome
ulnar nerve compression
465
Most distal, as well as 2nd mc, site of median nerve compression
fibrous arch of the origin of the flexor digitorum superficialis muscle
466
MC site of compression in anerior interosseous syndrome/Kiloh-Nevin syndrome
when anterior interosseous diverges from the median nerve
467
MC compression site in radial tunnel syndrome/compression of the posterior interosseous nerve w/ motor deficit
arcade of Frohse
468
MC malignant disease in childhood
acute leukemia
469
MC form of leukemia in the US
CLL
470
Most aggressive form of Langerhans cell histiocytosis
Letterer-Siwe disease
471
MC primary neoplasm of bone
multiple myeloma
472
In adults, marrow mets most commonly results from?
ca of the prostate, breast, lung, kidney, GIT, and melanoma
473
In pedia patients, mc primaries that metastasize to the marrow
neuroblastoma, rhabdomyosarcoma, and Ewing sarcoma
474
The halo sign is most commonly seen in?
osteoblastic mets from prostate ca
475
Most sensitive in evaluating the extent of hyperemic marrow in transient osteoporosis and reflex sympathetic dystrophy
STIR
476
Bones most commonly involved in Paget's disease
pelvic bones > femur, skull, tibia, LSS, dorsal spine, clavicles, and ribs
477
Most sensitive in detecting the nidus in osteoid osteomas
CT
478
MC site of involvement of osteoid osteomas
femur - long tubular bones
479
Clinical hallmark of osteoid osteomas
pain that is most prominent at night and can be relieved by salicylated such as aspirin
480
Osteoblastomas most frequently involves the?
flat bones, posterior osseous elements of the vertebrae, and long bones
481
Ossifying fibromas most commonly arise in the?
facial bones of young females
482
Unicameral bone cyst are most likely to occur in the?
proximal humerus or femur, in proximity to the cartilaginous growth plate
483
Aneurysmal bone cysts are most commonly found in the
posterior elements of the vertebrae and shafts of the long bones
484
Most frequently involved bones in hemangiomas
spine and flat bones of the skull and mandible
485
Most commonly affected by GCTs
long tubular bones - around the knee (distal femur, proximal tibia), abut the subchondral bone
486
MC primary malignant bone tumor in childhood / MC primary malignancy of bone except for multiple myeloma
osteosarcoma
487
2nd mc malignant bone tumor in childhood
Ewing sarcoma
488
MC sites of Ewing sarcoma
femur, ilium, humerus, and tibia
489
Chondrosarcomas most commonly arise in the?
central skeleton (pelvis and ribs) and within the metadiaphysis of the femur and humerus
490
MC pathohistologic type of non-Hodgkin lymphoma
large cell (ie reticulum cell) lymphoma
491
MC soft-tissue tumor
lipoma
492
Most commonly, lipomas are found in the?
subcutaneous regions of the back and shoulder
493
MC locations of cystic hygromas - often encompass neurovascular structures
neck and axilla
494
Most commonly observed variant of liposarcomas
myxoid liposarcoma
495
Ganglion cysts are most commonly found where?
around the hands and feet, especially the wrist
496
MC site of intraosseous ganglion cysts
medial malleolus of the tibia
497
The proximal radius and ulna most often dislocate where?
posteriorly
498
Perilunate dislocations may be accompanied by fractures of the carpal bones, most commonly the?
scaphoid and/or capitate
499
MC acetabular injury
both-column fractures
500
A lucent lesion in the anterior calcaneus is most commonly a?
simple bone cyst
