Renal Lecture PDF

Renal cyst and renal mass Small kidney,renal calculi, trauma and peri renal fluid Prepared by Dr.Mahabad Naqishbandi ABHS(Radiology) This Photo by Unknown Author is licensed under CC BY-NC-ND Focal renal mass Focal renal masses are commonly identified on imaging studies. Although the most commonly e...

Renal cyst and renal mass Small kidney,renal calculi, trauma and peri renal fluid Prepared by Dr.Mahabad Naqishbandi ABHS(Radiology) This Photo by Unknown Author is licensed under CC BY-NC-ND Focal renal mass Focal renal masses are commonly identified on imaging studies. Although the most commonly encountered etiology is a benign cyst, a significant subset of renal masses may represent malignant or inflammatory etiologies. Ultrasound is a widely available, radiation-free relatively inexpensive modality that plays an important role in characterizing focal renal masses. It is used to differentiate benign cysts from solid renal neoplasms, characterize the degree of complexity of renal cysts, and identify features to help differentiate the etiologies of various lesions. Why to use ultrasound? When assessing a renal lesion the first question that a radiologist needs to address is whether it is solid or cystic. The underlying reason for this bifurcation point is that most solid lesions are malignant and treated accordingly. On the other hand, all simple cysts and even most complex cysts are benign. The ability to differentiate cysts from solid renal lesions is one of the most important strengths of ultrasound. On ultrasound, renal cysts present as spherical or ovoid anechoic lesions with thin, smooth, or imperceptible walls and posterior acoustic enhancement. How does simple cyst look like? Renal cysts When ultrasound shows multiple, echo-free, well circumscribed areas throughout the kidney, suspect multicystic kidney. This condition is usually unilateral, whereas congenital polycystic kidney disease is almost always bilateral (although the cysts may not be symmetrical). Simple cysts can be single or multiple. On ultrasound the walls are smooth When this occurs or when the outline of any cyst is irregular, further investigation is required. Hydatid cysts usually contain debris and are often loculated or septate.When calcified, the wallappears as a bright, echogenic convex line with acoustic shadowing. Hydatid cysts may be multiple or bilateral. Scan the liver for other cysts and X-ray the chest If the patient is less than 50 years old and clinically well, check the other kidney to exclude polycystic disease: congenital cysts are echo-free and without mural calcification. Both kidneys are always enlarged. Renal masses Renal Angiomyolipoma In the early stages, a renal angiomyolipoma has ultrasound characteristics that allow accurate recognition. These tumours can occur at any age and may be bilateral. Ultrasound images show a well circumscribed, hyperechogenic and homogeneous mass, and as the tumor grows there will be back wall attenuation. However, some tumors will undergo central necrosis and there will be strong back wall echoes. At this stage differentiation by ultrasound is no longer possible, but abdominal X-rays may show fat within the tumor, which is unlikely to occur in any other type of renal mass Malignant renal mass A complex non-homogeneous mass The differential diagnosis of complex masses can be very difficult, but when there is spread of a tumor beyond the kidney, there is no doubt that it is malignant. contained within the kidney. Both tumors and hematomas may show acoustic shadowing due to calcification. a complex ultrasound pattern( The differentiation of this from an abscess or a hematoma can be difficult.). Tumors can spread into the renal vein or inferior vena cava and resemble thrombosis. A rough, irregular, echogenic mass containing debris within an en- larged kidney may be malignant or a pyogenic or tuberculous abscess. The patient's clinical condition may help to differentiate Small kidney Normally, kidneys are about the size of a fist or 10 to 12 cm (about 5 inches). Kidney atrophy means that the kidney is smaller than normal. This can happen for two basic reasons. The first is that part of the kidney does not develop from birth (called a congenital hypoplasia) making a small kidney no special treatment. The second type happens after birth, which can occur in one or both kidneys. This type of kidney atrophy is due to a lower blood supply to the kidney Chronic infections blockage of the kidney can also result in kidney atrophy. ref Small Kidney normal echogenicity may be due to renal artery stenosis or occlusion, or to congenital hypoplasia. normal in shape but hyperechogenic, may indicate chronic renal disease. In renal failure, both kidneys are likely to be equally affected. A small, hyperechogenic kidney with an irregular, rather "rough" outline and variable thickness of the cortex (usually bilateral but often very asymmetrical) is probably the result of chronic pyelonephritis or infection such as tuberculosis. A single, small, normally shaped but hyperechogenic kidney may be due to end - stage renal vein thrombosis. Acute renal vein thrombosis usually causes renal enlargement, with shrinkage occurring later. Chronic obstructive nephropathy can affect one kidney in the same way, but chronic glomerulonephritis is usually bilateral. Renal Calculi Urolithiasisers to the presence of calculi anywhere along the course of the urinary tracts. Ultrasound is frequently the first investigation of the urinary tract, and although by no means as sensitive as CT, it is often able to identify calculi. Small stones and those close to the corticomedullary junction can be difficult to reliably identify. Ultrasound compared to CT KUB reference showed a sensitivity of only 24% in identifying calculi. Nearly 75% of calculi not visualized were