Hill-Sachs lesion – compression defect at the top of the humeral head at the posterolateral aspect. It is a sign of previous anterior shoulder dislocation at which time the humeral head will have impacted against the anteroinferior part of the glenoid creating the compression fracture. It is often associated with a Bankart lesion of the glenoid and with shoulder instability. The MRI image shows a Hill-Sachs lesion with adjacent bright signal marrow oedema indicating recent dislocation.
from our tumblr blog: http://radiologysigns.tumblr.com/post/27856682364
Water bottle sign – refers to the shape of the cardiac silhouette on erect frontal chest x-rays in patients who have a very large pericardial effusion. The fluid, often measuring a litre or more, causes the pericardium to sag mimicking an old-fashioned water bottle sitting on a bench. Typically the effusion has accumulated over many weeks (e.g. in patients with malignancy) and the pericardium has gradually stretched. Coronal CT image is shown for correlation.
from our tumblr blog: http://radiologysigns.tumblr.com/post/27608746064
Drooping lily sign – a urographic sign of duplicated renal collecting system. It refers to the inferolateral displacement of the opacified lower pole moiety due to an obstructed (and relatively unopacified) upper pole moeity. The similarity to a lily is further strengthened by the small number of calyces the lower pole moiety has. In duplicated collecting system it is classically the upper pole ureter that is obstructed due to a ureterocoele and the lower pole ureter that refluxes: as described by the Weigert-Meyer law.
from our tumblr blog: http://radiologysigns.tumblr.com/post/27296288584
Our new MSK pack is now available for download via our app. It has a great collection of upper limb fractures and dislocations. Perfect for the clumsy and health professionals alike.
from our tumblr blog: http://radiologysigns.tumblr.com/post/27164679275
Subdural haemorrhage – collection of blood between the dura and arachnoid mater of the meninges. The crescent shape of subdural haematoma is classically taught as the major method of distinguishing it from the more typically lentiform shaped extradural haematoma, however there are other helpful distinguishing signs. Due to the physical structure of the meninges subdural blood is able to cross skull sutures and extend along dural reflections (falx and tentorium) while extradural blood cannot. The above case shows blood which on shape assessment could be extradural or subdural in location, however the fact that it crosses the lambdoid suture means it must be subdural.
from our tumblr blog: http://radiologysigns.tumblr.com/post/27100256742
Tree in bud sign – describes the CT chest appearance of multiple centrilobular nodules that are connected by branching opacified bronchioles. Although initially described in patients with endobronchial tuberculosis, it is now recognised in a large number of conditions ranging from small airways infections like mycobacterium avium complex, to connective tissue diseases like rheumatoid arthritis, to neoplastic conditions like bronchioloalveolar cell carcinoma.
from our tumblr blog: http://radiologysigns.tumblr.com/post/26951480530
Intussusception – ultrasound is extremely sensitive in detecting intestinal intussusception and several different sonographic ‘signs’ are described.
When bowel telescopes into itself concentric rings are seen creating the target sign (left image) also known as the doughnut sign. The appearance is not only due to three bowel walls paralleling each other, but is also due to each wall itself demonstrating the normal striation of echogenic mucosa, hypoechoic submucosa and echogenic muscularis.
When a large portion of mesenteric fat is incorporated within the intussusception then an additional echogenic crescent may be seen creating the crescent within a doughnut sign.
Finally, the combination of intussusception and adjacent enlarged mesenteric lymph nodes may simulate the appearance of a kidney creating the pseudokidney sign (right image) where hypoechoic lymph nodes appear like renal medullary pyramids.
from our tumblr blog: http://radiologysigns.tumblr.com/post/26825013177
Apple core sign – describes a short segment irregular circumferential stricture of the large bowel that has abrupt “shouldered” margins resembling an apple core. The appearance is classically described on contrast enema studies and is almost always due to a stenosing annular colon carcinoma. The same term has also been used for the circumferential erosion of the femoral neck seen in synovial osteochondromatosis.
from our tumblr blog: http://radiologysigns.tumblr.com/post/26610041309