1.By: Dr Rekha Khare MD Radiology

2. Clinical Presentation.. A 25 year young man came to thex-ray department for ultrasound exam Complaints: - rapid onset of high fever - painful mass right flank 3. Ultrasound findings.. Enlarged right kidney with dilatedpelvis with no hydrocalyx Indistinct hypoechoic inferior pole 4. U/S finding contd.. Huge heterogenous hyperechoicperinephric mass lesion all over involving inferior pole too Bulky right psoas muscle 5. CECT as further imaging Bulky right kidney with focalnon enhancing hypodense area lower pole not sparing the peripheral cortical rim (renal infarction-cortical rim sign +ve) 6. CECT finding contd.. Huge multi septate hypodensesoft tissue thickening mimicking mass in perinephric space having few small fluid collection involving inferior pole also 7. CECT findings contd.. Bulky right psoas muscle withsome hypodense lesion? collection Mild hepatomegaly 8. next image.. 9. next image.. 10. next image.. 11. next image.. 12. next image.. 13. next image.. 14. next image.. 15. next image.. 16. next image.. 17. next image.. 18. next image.. 19. next image.. 20. next image.. 21. next image.. 22. next image.. 23. next image.. 24. next image.. 25. Clinical diagnosis.. Acute pyelonephritis with severeperinephric inflammation with some fat stranding no ureteric calculus 0r obstructive pathology 26. What is perinephric space? Cone shaped retroperitonealcompartment containing kidney, adrenal, fat, fibrous bridging septa & rich net work of perirenal vessel & lymphatic 27. How PNS gets involve? From outside lesion via -lymphatic-direct - in malignancy or infectionFrom inside renal lesion -acute process, injury to the kidney,calyceal rupture in acute ureteric obstruction 28. What is perinephric stranding? It is linear areas of abnormalincreased attenuation in soft tissue/ fat- resulting from: - acute renal inflammatory or infective lesion with NO HYDRONEPHROSIS- calyceal rupture in acute ureteric obstruction with HYDRONEPHROSIS 29. D/D perinephric mass lesion.. Perinephric abscess/ urinoma/hematoma Mass/ lymphoma/ Tumour Misc.. Proliferative disease 30. Acute pyelonephritis.. It is an infection of renal parenchymausually caused by an ascending infection from lower urinary tract Most common offending pathogen E.coli It is almost always curable with antibiotic No lasting damage to kidney 31. Case review after a month.. Symptomatic relief Advised: repeat U/S & CECT 32. Ultrasound after a month. Minimal residual ill definedright renal inferior pole Perinephric space appears clear 33. CECT after a month.. Minimal residual lesion atright renal lower pole Perinephric space clear 34. next image.. 35. next image.. 36. next image.. 37. next image.. 38. next image.. 39. next image.. 40. next image.. 41. Case review after3 months.. Patient fit and fine On follow up imaging---no residual lesion on ultrasound and plain CT scan 42. NCCT image after 3 months 43. NCCT next image.. 44. NCCT next image.. 45. NCCT next image.. 46. Role of imaging.. Imaging required to exclude--obstructed kidney -previous renal pathology -mass lesion -high risk patient Acute pyelonephritis: clinico-pathological diagnosis 47. Follow up Imaging.. Not really essential Imaging changes can take3-6 months to resolve complication 48. References.. 1. Acute bacterial pyelonephritis Dr Yuranga Weerakkody and Dr Frank Gaillard et al Radiopaedia.org 2. Differential Diagnosis of Perinephric Masses on CT and MRI Antonio Westphalen, Benjamin Yeh, Aliya Qayyum, Anil Hari and Fergus V. Coakle American Journal Of Roentgenology,2004;183:1697-1702