Radiologic Signs
The Largest Illustrated Collection of Imaging Signs on the Web



S Index

Sandwich Sign-adenopathy most often from mesenteric lymphoma is the "bun" that encases the mesenteric vessels and fat (filling)
Scalloped Vertebra-anterior: pressure usually from aneurysm; posterior: from spinal tumors, neurofibromatosis or communicating hydrocephalus
Sentinel Loop-one or two dilated loops of small bowel which may indicate the presence of an irritative process in the region, e.g., inflammation
Spine Sign-paradoxically increased density of lower spine seen on lateral chest x-ray indicative of a lower lobe process such as pneumonia
Snowman Sign-dilated vertical vein and SVC form head of snowman in Type 1 supracardiac Total Anomalous Pulmonary Venous Return; RA is "body"
Swan neck deformity-hyperextension of proximal interphalangeal joint and flexion of distal interphalangeal joint, e.g. in rheumatoid arthritis
String of Beads Sign-multiple, linearly-arranged small pockets of air in a fluid-dilated small bowel loop seen with mechanical SBO
Scimitar Sign-anomalous draining pulmonary vein along right heart border that usually empties into IVC; shaped like Turkish sword
Silver Fork Deformity-appearance of acutely dorsally angulated wrist from distal radius fracture seen in Colles fx
Snowstorm Appearance-innumerable small pulmonary nodules frequently associated with metastatic carcinoma from thyroid
Small Bowel Feces Sign-on abdominal CT, heterogeneous solid material containing air bubbles in dilated small bowel from SB obstruction
Silhouette Sign-the process whereby two substances of the same density which touch each other blur the edges between them
Scottie Dog-the appearance of the pedicle, transverse process and facets on an oblique lumbar spine x-ray
Shaggy Esophagus-irregularly ulcerated appearance of the lumen of the esophagus described with Candidiasis
Spinnaker Sail Sign-abnormal elevation of lobes of the thymus seen with pneumomediastinum; thymic sail sign is normal
Snowcapping-dense appearance of humeral head from avascular necrosis thought to resemble snow on mountain top
Snowstorm Pattern-breast-ultrasound sign of breast implant rupture; silicone granulomata produce multiple echoes in extracapsular breast silicone leaks
Shmoo Sign-appearance of prominent, rounded left ventricle and dilated aorta likened to the Shmoo in L'il Abner comic
Sister Mary Joseph Sign-nodule bulging at umbilicus as a result of metastatic disease in the abdomen, most often from GI tract and ovary
Shepherd's Crook Deformity-coxa vara with outward bowing of proximal femur in fibrous dysplasia or osteogenesis imperfecta
Soft Tissue Rim Sign-CT-edema of the ureteral wall surrounding an impacted ureteral stone; aids in DDX from phlebolith
Stack of Coins-dilated small bowel with little or no infiltration of the submucosa, as in scleroderma or sprue
String Sign-very thin luminal contrast usually in terminal ileum from spasm and eventually fibrosis, most often seen in Crohn disease
Sunburst Periosteal Reaction-highly aggressive spiculated reaction indicating a malignancy such as osteosarcoma
Steeple Sign-croup-smoothly tapered air shadow seen at level of larynx on AP chest or neck because of subglottic swelling
Salt and Pepper Skull-multiple, small areas of resorption of skull in hyperparathyroidism results in mottled appearance like salt and pepper
Signet Ring Sign-pulmonary-dilated bronchus is larger than accompanying pulmonary artery, seen on chest CT in bronchiectasis
Stepladder Appearance-multiple loops of small bowel in the left upper quadrant in a mechanical small bowel obstruction
Split Pleura Sign-on CT, contrast-enhanced visceral and parietal pleurae divide around a less-dense empyema
Stepladder Sign-breast-US sign of intracapsular breast implant rupture. Multiple parallel horizontal echogenic lines within collapsed implant shell
String of Beads (IR) Sign-corrugated or pleated appearance of artery affected by fibromuscular hyperplasia
Spilled Teacup Sign-appearance of volar displaced concave surface of lunate in a lunate dislocation
Spoke Wheel Appearance-angiographic appearance of vessels originally thought secondary to oncocytoma but also seen with renal cell carcinoma
Sausage Digit-fusiform swelling of a single digit resembling a cocktail sausage, classically seen in psoriasis
Soap Bubbly Appearance-expansile, septated appearance of solitary plasmacytoma or renal or thyroid cell carcinoma metastases
Sandwich Vertebra-appearance of vertebra in osteopetrosis due to increased density of endplates
Stipple Sign-contrast in the interstices of a papillary GU lesion suggestive of transitional cell tumors
Spotted Nephrogram-patchy enhancement of renal parenchyma seen on CT, MRI or angio as result of small vessel occlusion, e.g. vasculitis
Spaghetti Sign-linear filling defect representing blood clot in the bladder on CT or urogram
Stripe Sign-on perfusion lung scan, a perfusion defect with a stripe of normally perfused lung at pleural surface; mitigates against PE
Saber Shin Deformity-marked anterior bowing of tibia seen in congenital syphilis, Paget disease and rickets
Saber Sheath Trachea-marked coronal narrowing and sagittal widening of intrathoracic trachea, esp in COPD
stocking glove sign
Stocking Glove Sign-In this bone scan, there is a stocking glove sign on the right hand. This represents uptake in the bony structures of the hand as a result of arterial injection.
string of pearls sign
String-of-pearls Sign-Nucs-Increased radiotracer activity on bone scan in linear pattern in several ribs representing traumatic injury versus metastatic disease which would have a scattered appearance.
six point star sign-nucs
Six-Point Star Sign-In this thyroid scan, the six point star sign represents an artifact seen as a result of septal penetration.
Swiss Cheese Appearance-multiple fenestrations in ventricular septum usually seen in a muscular VSD


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