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



B Index

Bat Wing Appearance-AKA Angel Wing-pattern of pulmonary edema which involves perihilar regions and spares cortex of lung
Berry Aneurysm-an intracranial aneurysm most often occurring in the Circle of Willis, particularly at the junction of major vessels in the anterior circulation
Blade of Grass Sign-AKA flame sign; advancing, wedge-shaped, osteolytic margin of active Paget disease of bone; usually seen in diaphysis
Beveled Edge Appearance-asymmetric erosion of the inner and outer tables of the skull usually seen with eosinophilic granuloma
Bird's Beak Sign-AKA Rat-tail Sign; irregularly marginated tapering of esophagus in achalasia
Bowler Hat Sign-cup-shaped filling defect seen on air contrast BE that represents polyp if it points toward lumen and tic if it points away
Black Pleural Line-paradoxical appearance of pleura in pulmonary microlithiasis because of innumerable dense calcifications in adjacent lung
Bird of Prey Sign-tapered barium column in sigmoid volvulus; Bird's beak sign in achalasia
Boot-shaped Heart-shape of heart in Tetralogy of Fallot due to upturned apex from RVH and concave pulmonary artery segment
Bowtie Appearance-of facets in the cervical spine on lateral view in unilateral rotatory subluxation at and above the site of rotation
Bamboo Spine-undulating contour of spine caused by bridging syndesmophytes seen in ankylosing spondylitis
Bucket Handle Tear-vertical tear in knee of mostly medial meniscus with displacement of fragment toward notch
Butterfly Vertebra-congenital sagittal cleft through center of vertebra with funnel-shaped ends on AP view of spine
Bone-within-a-Bone-inner layer of cortical new bone within an existing bone seen with osteopetrosis, Sickle Cell Dz, Thorotrast
Breast-within-a-Breast-in fibroadenolipoma
/hamartoma of breast; benign proliferation of normal breast components – fibrous, glandular, and fatty tissues – are surrounded by a thin capsule of connective tissue
Bear Paw Sign-dilated renal calyces with normal renal pelvis seen in calculus disease and  xanthogranulomatous pyelonephritis
Boutonniere Deformity-hyperextension of distal interphalangeal joint and flexion of  proximal interphalangeal joint in RA
Brim Sign-thickening of the iliopectineal line (pelvic brim) in Paget's disease
Boomerang Sign-hyperintense signal in the splenium of the corpus callosum accompanying stroke; also an MRI sign in peroneus brevis split syndrome
Box-shaped Heart-squared-off appearance of the heart in Ebstein's Anomaly due to large right atrium and dilated right ventricular outflow tract
Bite Sign-MSK-gouged-out defect due to collapse of bone in head of femur in avascular necrosis
Bulging Fissure Sign-bulging of usually minor fissure from heavy,exudative pneumonia like Klebsiella
Banana Sign-abnormal shape of the cerebellum from compression seen on MRI or antenatal US in spina bifida and other neural tube defects

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