Ethylene dicysteine renal scintigraphy

A 35-year-old Asian male presented with complaints of fever, right-sided pleuritic chest pain and shortness of breath of 7 days’ duration, 1 month after a right percutaneous nephrolithotomy (PCNL) by supracostal puncture. On examination, the patient was pale and tachypnaeic with pulse 120/min and blood pressure 150/100mm Hg. He had stony dullness with decreased breath sounds in the right mammary, axillary and interscapular areas. A chest radiograph demonstrated massive rightsided pleural effusion. Thoracocentesis of the right side of the chest yielded about 900ml of pleural fluid, analysis of which revealed a pleural fluid: serum creatinine ratio of 58 (normal <1), pleural fluid protein 500mg/dl and sugar 46mg/dl, with a total leucocyte count of 3000/mm, all polymorpholeucocytes. Intravenous pyelography (IVP) was noncontributory. In view of the high pleural fluid creatinine concentration, a right-sided urinothorax was suspected and the patient referred for renal scintigraphy. Radionuclide scintigraphy was performed using Tc Ethylene dicysteine (Tc EC). The initial images showed adequate tracer concentration in both kidneys, with good clearance of tracer from the left kidney (Figure 1). There was slow clearance of tracer from the right kidney, with rapid and continuously increasing tracer collection on the right side of the thorax till 2 h (Figure 2). No tracer was detected on the left side of the chest. The findings were indicative of a right-sided retroperitoneal transdiaphragmatic communication, resulting in collection of urine in the right pleural cavity (urinothorax). A right intercostal tube drain (ICTD) was inserted and antibiotic therapy started. Retrograde pyeloplasty (RGP) and double-J stenting of the right kidney was planned, but the ICTD output gradually decreased and finally stopped altogether. A repeat chest X-ray showed an expanded right lung with no residual pleural effusion even after clamping the ICTD. The drain was therefore removed and the patient discharged uneventfully.