Abstract:
Many chronic renal diseases lead to the final common state of decrease in renal size, parenchymal atrophy, sclerosis and fibrosis. The ultrasound image shows a smaller kidney, thinning of the parenchyma and its hyperechogenicity. The frequency of renal cysts increases with the progression of the disease.
A cross section study of 64 patients from out patient department, Ahmed Gasim cardiac and renal center who was suspected to have renal insufficiency, underwent renal biopsy was designed to correlate the sonographic appearance of the kidney with the clinical and laboratory findings and histological changes in various renal parenchymal diseases, patients with liver problems and those with communication problems were excluded. The collected data was analyzed blindly and independently using SPSS version 11.5 software. The most commonly associated chronic disease was systemic hypertension (26%), followed by diabetes mellitus (20%), UTI and pyelonephritis (10%) and other less common ranging from 1-7%.
There was a significant correlation between red blood count and renal size (p-value 0.017), when Red blood count is low and very low, the renal size is found to be decreased. There was no correlation between the specific sonographic appearance and the type of renal disease. There was a significant correlation between renal size and the prevalence of global sclerosis, tubular atrophy, arteriosclerosis and diffuse interstitial fibrosis in which it has been found to be decreasesd, where as it is found to be normal in cases of increased crystal level, calcification and cases associated with edema (p- value 0.005).
A significant positive correlation was also found between cortical echogenicity and the type of histological finding (P-value 0.011). Cortical thickness is found to be obviously decreased in cases of TB, malaria, hypertension and UTI & pyelonephritis, increased mainly in gout and polycystic kidney disease (p-value 0.000). Cortical thickness is found to be decreased in 72% of arteriosclerosis cases, 70% of global sclerosis and 62-63% of diffuse interstitial fibrosis and tubular atrophy respectively. It is found to be normal in 67% of edema cases, 80% in increased calcification per level pathologies and 50% in leukocytic infiltration and crystals per level conditions (p- value 0.004). Also overall significant correlation between the degree of cortical echogenicity and blood urea nitrogen and creatinine was clearly found.
Ultrasound generally does not allow for the exact diagnosis of an underlying chronic disease (renal biopsy is usually required), but it can help to determine an irreversible disease, assess prognosis and avoid unnecessary diagnostic or therapeutic procedures.
Sonography is the best screening modality to evaluate patients presenting with renal insufficiency. If hydronephrosis is present, the level and cause of the obstruction should be sought. When ultrasound cannot diagnose the level and cause of obstruction, other imaging modalities, including CT and MRI may be useful. When renovascular disease (arterial stenosis or venous thrombosis) is suspected, spectral and color Doppler can be useful in detecting abnormalities.
