Nephrolithiasis

  • Etiology in neonates: diuretics
  • Etiology beyond neonates: calcium oxalate most common, idiopathic in 30%, chronic urinary tract infection, urinary stasis, proximal renal tubular acidosis, interrupted enteropathic circulation, dehydration
  • Imaging: primarily radioopaque on AXR

Cases of Nephrolithiasis

CT of ureteral stone
Axial (left) and coronal (right) CT without contrast of the abdomen shows a dense calcification at the right ureteovesical junction. There is mild associated enlargement of the right kidney with mild inflammatory fat stranding around the right kidney.
AXR and US of bladder stone
AXR AP (above) shows two irregularly-shaped calcified objects projecting over the pelvis. Spinal dysraphism is noted in the sacrum. There is a cecostomy tube in the right lower quadrant. Sagittal US of the bladder (below) shows an echogenic mass within the inferior aspect of the bladder (to the right of the image) that has posterior shadowing.
US of urethral trauma
Transverse US of the prostatic urethra (upper left) shows a small round echogenic lesion with posterior shadowing in the center of the prostatic urethra which was not seen in the transverse US of the penile urethra (upper right). Sagittal US of the bladder (lower left) shows an echogenic lesion with posterior shadowing in the posterior aspect of the bladder that on transverse US of the bladder (lower right) resolved into two separate echogenic lesions with posterior shadowing.