December 31, 2011

Calcification in Lung Nodule

A spot chest radiographic view of the left lower lung zone (with a nipple marker) shows a 1-cm nodule (arrow) in the lung base just medial to the nipple marker.

Non-contrast CT confirms the presence of a nodule in the left lower lobe (arrow) that contains a central calcification.

Lung Nodule Calcification
  • Up to 6% of lung cancer have calcification. Therefore, calcium in a nodule does not exclude possibility of lung cancer
  • Suspected malignant nodule if calcium is.... eccentric, amorphous or it involves only a small portion of the nodule
  • Benign: central (>10% of cross-sectional area of nodule), diffuse and laminated calcification
  • Nodules that are nonsolid or partly solid are more often malignant
Our case: benign nodule, likely a granuloma.

Hodler J, von Schulthess GK, Zollikofer ChL. Diseases of the Heart, Chest & Breast 2011-2014. Springer-Verlag Italia 2011.

December 21, 2011

Sternoclavicular Rheumatoid Arthritis

Axial CT images of the sternoclavicular joints show erosion, indistinct cortical margins of the joints, which are quite symmetric.

  • Sternoclavicular (SC) joint is diarthrodial articulation between axial and appendicular skeleton, which is subject to same disease process that occur in other joints (degenerative arthritis, rheumatoid arthritis, infection and subluxation. Degenerative arthritis is the most common).
  • Up to 30% of patients with rheumatoid arthritis have changes in SC joints (a part of polyarticular involvement) but radiographic findings are often unremarkable.
Imaging Finding
  • Synovitis
  • Bone marrow edema and enhancement of subcortical bone (after IV contrast)Er
  • Erosion and indistinct cortical margins
  • Think infection if: unilateral, history of IVDU and immunocompromised states
1. Restrepo CS, Martinez S, Lemos DF, et al. Imaging appearance of the sternum and sternoclavicular joints. Radiographics 2009; 29:839-859.
2. Berry DJ, Steinmann SP. Adult Reconstruction, 2007.

December 11, 2011

Scrotal Pyocele

Gray-scale and color Doppler US images of the testicle shows a complex fluid collection (stars) around the testicle and marked scrotal skin thickening. The epididymis is edematous with increased flow (image not shown).

Facts: Scrotal Pyocele
  • Also known as scrotal abscess
  • Can be superficial (from infected hair follicles, wound) or intrascrotal
  • Causes: epididymitis, TB, instrumentation, neurogenic bladder, chronic catheter indwelling, spread from intraabdominal infection (i.e., appendicitis)
  • Intrascrotal abscess requires surgical drainage
  • US is the modality of choice
  • Complex-appearing fluid around the testicle
  • Scrotal skin thickening with hyperemia
  • Evidence of causes such as epididymitis or others
  • Based on imaging, it is difficult to distinguish pyocele from hematocele
1. Siegel MJ. Pediatric Sonography, 2010.
2. Resnick MI, Novick AC. Urology Secrets, 3rd ed, 2003.