Articles
Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and continuously improved upon by countless contributing members. Our dedicated editors oversee each edit for accuracy and style. Find out more about articles.
74 results found
Article
Perinephric stranding
Perinephric stranding refers to the appearance of edema within the fat of the perirenal space on CT or MRI. While a degree of symmetric bilateral perinephric stranding is common, particularly in the elderly, asymmetric or unilateral perinephric stranding is an important sign of renal inflammatio...
Article
Doughnut sign (missed testicular torsion)
The doughnut sign, also known as the bull's-eye, halo or ring sign, is the name of a distinctive appearance of a missed testicular torsion on scrotal scintigraphy.
In a missed torsion (i.e. established testicular infarction), there is a reactive hyperperfusion of the ipsilateral dartos muscle ...
Article
Aubergine sign (penis)
The aubergine sign (also known as egg-plant sign or deformity) is a clinical sign of a fractured penis. Hemorrhage beyond the tunica albuginea produces swelling and bruising of the penis simulating the appearance of an aubergine.
Article
Pear-shaped bladder
Pear-shaped (or teardrop-shaped) bladder is one whose normal round or ovoid shape has been extrinsically compressed to resemble a pear. The pear may be inverted or upright, depending on how the excess pelvic tissue compresses the bladder.
Pathology
Etiology
Causes of a pear-shaped bladder inc...
Article
Tulip sign
The tulip sign is a sonographic clue for in utero diagnosis of severe hypospadias.
The configuration of a tulip is given by the severe curvature of the penis in association with the penoscrotal transposition of a bifid scrotum.
History and etymology
The tulip sign was first described in 2002 ...
Article
Flip-flop renal enhancement
Flip-flop renal enhancement describes when an infarcted renal parenchyma alternates between hypoattenuation during the arterial phase, and hyperattenuation on the delayed phase of a contrast enhanced CT 1,2.
Terminology
Flip-flop renal enhancement should not be confused with the flip-flop eff...
Article
Hairy kidney sign (Erdheim-Chester disease)
The hairy kidney sign refers to the soft tissue ring of perirenal infiltration seen on cross-sectional imaging studies in Erdheim-Chester disease and is considered to be pathognomonic of this disease. The ‘‘hairy’’ description refers to the associated thickening of the bridging perirenal septa (...
Article
Salt and pepper sign (disambiguation)
The salt and pepper sign is used to refer to a speckled appearance of tissue on imaging. It is used in many contexts, but most commonly for the appearance of certain lesions on MRI, especially paragangliomas.
salt and pepper noise (MRI artifact) 9
salt and pepper sign (ARPCKD) 8
salt and pepp...
Article
Spaghetti sign (bladder)
The spaghetti sign may be seen in upper urinary tract bleeding.
It refers to the presence of a linear worm- or spaghetti-like filling defect within a contrast-opacified bladder 1,2. This linear filling defect represents blood clot extruded from the ureter and thereby molded into a tubular shape...
Article
Staghorn calculus (kidney)
Staghorn calculi, also sometimes called coral calculi, are renal calculi that obtain their characteristic shape by forming a cast of the renal pelvis and calyces, thus resembling the horns of a stag. They refer to struvite calculi involving the renal pelvis and extending into at least two calyce...
Article
Whirlpool sign (testicular torsion)
The whirlpool sign of the spermatic cord is a direct sign of testicular torsion, both complete and incomplete (i.e. <360°). It is considered to be the most specific and sensitive sign for testicular torsion.
Terminology
The term whirlpool sign is used in other contexts: see whirlpool sign (dis...
Article
Goblet sign (ureter)
The goblet sign, also known as the champagne glass sign, refers to the appearance of the ureter when it is focally dilated by an intraluminal mass. It is best seen when the ureter is opacified by retrograde contrast (retrograde ureterogram). Presence of this sign indicates the pathology to be ch...
Article
Oncocalyx
An oncocalyx is a tumor-filled, distended renal calyx, typically seen in patients with transitional cell carcinomas of the renal pelvis.
Article
Sigmoid kidney
A sigmoid kidney is an uncommon variant of the horseshoe kidney. Whereas the typical horseshoe kidney is fused only at the lower poles, in a sigmoid kidney both the upper and the lower poles are fused 1.
Article
Fishhook ureters
Fishhook ureters, also known as J-shaped ureters or hockey stick ureters describe the appearance of the distal ureter in patients with significant benign prostatic hypertrophy. It has also been used to describe the appearance of a retrocaval ureter in type 1 or low loop variety. As the right ure...
Article
Drooping lily sign (ureter)
The drooping lily sign is a urographic sign in some patients with a duplicated collecting system. It refers to the inferolateral displacement of the opacified lower pole moiety due to an obstructed (and unopacified) upper pole moiety.
The similarity to a lily is further strengthened by the smal...
Article
Curlicue ureter sign (sciatic hernia)
The curlicue ureter sign 1 was described on intravenous pyelogram studies in cases of ureteral herniation into a sciatic hernia, causing a curled appearance of the herniated ureter. Although very rare, this sign is pathognomonic of ureterosciatic hernias. It can also be seen on CT urogram studies.
Article
Soft tissue rim sign (ureteric calculus)
The soft tissue rim sign is used to distinguish a ureteric calculus from a phlebolith. The former appears as a calcific density with a surrounding soft tissue rim, representing the edematous ureteric wall. On the other hand, phleboliths usually have invisible walls (up to 8% may have a soft tiss...
Article
Kerr kink
The Kerr kink is a sign of renal tuberculosis. Scarring in the adjacent tissues due to chronic inflammation leads to a sharp kink at the pelviureteric junction (PUJ).
History and etymology
William "Bill" K Kerr, a Canadian urologist, described his eponymous sign in 1967 3.
Article
Bouquet of flowers appearance (medullary sponge kidney)
A bouquet of flowers appearance is a description given to the appearances of medullary sponge kidney on a traditional intravenous pyelogram (IVP) study. The ectatic distal collecting ducts contain the microcalcifications typical of the disease. This is also known as the bunch of grapes appearanc...
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