Diagnostic Ultrasound - Abdomen and Pelvis
Hypoechoic Kidney Acute Renal Artery Thrombosis Renal Cell Carcinoma (Left) Transverse color Doppler ultrasound of a renal transplant shows complete absence of intrarenal color flow secondary to renal artery thrombosis. The cortex ſt and pyramids st are hypoechoic. (Right) Longitudinal ultrasound of the right kidney shows an isoechoic solid mass in the upper to mid pole st extending into the sinus and causing hydronephrosis ſt. Top differential diagnoses are renal cell and urothelial carcinoma. Biopsy showed renal cell carcinoma. Differential Diagnoses: Kidney Upper Tract Urothelial Carcinoma Renal Leukemia (Left) Longitudinal ultrasound of the left kidney shows hydronephrosis and cortical thinning st. The obstruction was caused by a solid mass in the renal pelvis representing urothelial cancer. (Right) Longitudinal oblique ultrasound shows an enlarged hypoechoic kidney ſt with loss of corticomedullary differentiation and sinus echogenicity. Biopsy showed acute myeloid leukemia. Renal Lymphoma Xanthogranulomatous Pyelonephritis (Left) Longitudinal ultrasound of the left kidney ſt shows an enlarged (14 cm) hypoechoic kidney secondary to infiltrating lymphoma. Note the perirenal soft tissue rind st. (Right) Longitudinal ultrasound of the kidney shows hydronephrosis and cortical atrophy ſt with avascular soft tissue st in the renal pelvis. There were stones as well. These findings are indistinguishable from pelvic urothelial carcinoma and further evaluation is needed. 959
Hyperechoic Kidney 960 Differential Diagnoses: Kidney DIFFERENTIAL DIAGNOSIS Common • Diabetic Nephropathy • Chronic Glomerular Diseases • Hypertensive Nephrosclerosis • Acute Interstitial Nephritis • Acute Tubular Necrosis • Medullary Nephrocalcinosis • Cortical Nephrocalcinosis • Acute Pyelonephritis • Reflux Nephropathy Less Common • Vasculitis • Ischemia • Lupus Nephritis • Chronic Renal Transplant Rejection/Chronic Allograft Nephropathy • Sarcoidosis • Multicystic Dysplastic Kidney • HIV Nephropathy • Acute Cortical Necrosis Rare but Important • Emphysematous Pyelonephritis • Autosomal Recessive Polycystic Kidney Disease • Oxalosis • Alport Syndrome • Renal Amyloidosis • Renal Tuberculosis • Lithium Nephropathy • Renal Cystic Dysplasia ESSENTIAL INFORMATION Key Differential Diagnosis Issues • Increased renal echogenicity is most commonly diffuse and secondary to medical renal disease • Cortical echogenicity greater than liver is abnormal • Progresses through loss of corticomedullary differentiation (CMD) • Pyramids may be dark, later bright • Cortical echogenicity equal to sinus fat is markedly abnormal • Secondary to multiple diseases ○ Tubular, glomerular or interstitial intrinsic renal disease ○ End result of obstruction, ischemia ○ Calcification: Cortical, medullary, interstitial, vascular • Increased renal echogenicity indicates abnormal kidneys but not any particular cause • Echogenicity correlates well with interstitial disease but not with glomerular disease • Degree of echogenicity correlates poorly with severity of renal impairment • Renal biopsy indispensable in diagnosis of renal parenchymal disease • Role of ultrasound ○ Determine renal size and cortical thickness – Differentiating acute from chronic renal insufficiency ○ Exclude ureteral obstruction • Large hyperechoic kidneys: Diabetes, HIV, acute inflammation • Small hyperechoic kidneys nonspecific • Differentiate from focal areas of increased echogenicity e.g., medullary, cortical, or lesional Helpful Clues for Common Diagnoses • Diabetic Nephropathy ○ Single most important cause of renal failure in adults ○ Diabetes involves glomerulus, interstitium and vessels ○ Early: Normal or enlarged kidneys with preserved cortical thickness ○ Chronic: Small echogenic kidney with thin cortex and variable CMD ○ ↑ resistive index (RI) on Doppler studies with ↑ cortical echogenicity • Chronic Glomerular Diseases ○ Multiple pathologic entities and multiple diseases – Immunoglobulin A (IgA) disease most common type of idiopathic glomerulonephritis (GN) – Focal segmental glomerulosclerosis may be idiopathic or secondary to hypertension or reflux nephropathy – Membranous nephropathy most common cause of idiopathic nephrotic syndrome in Caucasians ○ Acute: Normal/enlarged kidney with normal or ↑ renal echogenicity ○ CMD disappears with chronic disease: Small echogenic kidney • Hypertensive Nephrosclerosis ○ 25% of end-stage renal disease ○ Renal echogenicity depends on chronicity ○ ↑ RI with ↑ cortical echogenicity • Acute Interstitial Nephritis ○ Hypersensitivity reaction to drug or infective antigen ○ Mimics acute tubular necrosis clinically ○ Kidney size may be normal or enlarged ○ Cortical echogenicity may be increased depending on severity of reaction • Acute Tubular Necrosis ○ May be normal or increased in echogenicity • Medullary Nephrocalcinosis ○ Cause: Hyperparathyroidism, renal tubular acidosis, medullary sponge kidney, vitamin D excess, gout, sarcoidosis, bone metastases ○ ↑ echogenicity of renal medullae compared to hypoechoic cortex, reversal of normal ○ Acoustic shadowing • Cortical Nephrocalcinosis ○ Focal: Caused by trauma, infarction, or infection ○ Diffuse: Due to renal cortical necrosis, kidney transplant rejection, chronic GN, Alport syndrome ○ Characterized by peripheral parenchymal calcifications and ↑ cortical echogenicity • Acute Pyelonephritis ○ Normal/swollen kidney with typically decreased echogenicity and loss of normal CMD ○ Focal areas of increased echogenicity may be seen but more commonly hypoechoic ○ Thickened urothelium and mild hydronephrosis • Reflux Nephropathy ○ Secondary to interstitial nephritis caused by reflux
- Page 930 and 931: Focal Gallbladder Wall Thickening/M
- Page 932 and 933: Echogenic Material in Gallbladder S
- Page 934 and 935: Dilated Gallbladder ○ Distended n
- Page 936 and 937: Dilated Gallbladder Mucocele/Hydrop
- Page 938 and 939: Intrahepatic and Extrahepatic Duct
- Page 940 and 941: PART III SECTION 3 Pancreas Cystic
- Page 942 and 943: Cystic Pancreatic Lesion Helpful Cl
- Page 944 and 945: Cystic Pancreatic Lesion Mucinous C
- Page 946 and 947: Solid Pancreatic Lesion ○ Usually
- Page 948 and 949: Solid Pancreatic Lesion Serous Cyst
- Page 950 and 951: Pancreatic Duct Dilatation Chronic
- Page 952 and 953: PART III SECTION 4 Spleen Focal Spl
- Page 954 and 955: Focal Splenic Lesion - Typically mu
- Page 956 and 957: Focal Splenic Lesion Pyogenic Absce
- Page 958 and 959: Focal Splenic Lesion Splenic Infarc
- Page 960 and 961: PART III SECTION 5 Urinary Tract 9
- Page 962 and 963: Intraluminal Bladder Mass Bladder C
- Page 964 and 965: Abnormal Bladder Wall □ Uterine c
- Page 966 and 967: Abnormal Bladder Wall Invasion by P
- Page 968 and 969: PART III SECTION 6 Kidney Enlarged
- Page 970 and 971: Enlarged Kidney - Nonneoplastic cau
- Page 972 and 973: Enlarged Kidney Perinephric Fluid C
- Page 974 and 975: Small Kidney ○ Pseudotumors from
- Page 976 and 977: Small Kidney Postobstructive Atroph
- Page 978 and 979: Hypoechoic Kidney • Multiple Myel
- Page 982 and 983: Hyperechoic Kidney ○ Echogenic co
- Page 984 and 985: Hyperechoic Kidney Chronic Glomerul
- Page 986 and 987: Cystic Renal Mass ○ Associated wi
- Page 988 and 989: Cystic Renal Mass Multicystic Dyspl
- Page 990 and 991: Solid Renal Mass • Horseshoe Kidn
- Page 992 and 993: Solid Renal Mass Renal Lymphoma Ren
- Page 994 and 995: Renal Pseudotumor Column of Bertin
- Page 996 and 997: Dilated Renal Pelvis • Intrarenal
- Page 998 and 999: Dilated Renal Pelvis Pyonephrosis P
- Page 1000 and 1001: PART III SECTION 7 Abdominal Wall/P
- Page 1002 and 1003: Diffuse Peritoneal Fluid Hemoperito
- Page 1004 and 1005: Solid Peritoneal Mass - Higher dens
- Page 1006 and 1007: Solid Peritoneal Mass Mimics Benign
- Page 1008 and 1009: Cystic Peritoneal Mass ○ Women of
- Page 1010 and 1011: Cystic Peritoneal Mass Pseudomyxoma
- Page 1012 and 1013: PART III SECTION 8 Prostate Enlarge
- Page 1014 and 1015: Enlarged Prostate Benign Prostatic
- Page 1016 and 1017: Focal Lesion in Prostate ○ Variab
- Page 1018 and 1019: Focal Lesion in Prostate Müllerian
- Page 1020 and 1021: PART III SECTION 9 Bowel Bowel Wall
- Page 1022 and 1023: Bowel Wall Thickening - Distal ileu
- Page 1024 and 1025: Bowel Wall Thickening Crohn Disease
- Page 1026 and 1027: Bowel Wall Thickening Clostridium D
- Page 1028 and 1029: PART III SECTION 10 Scrotum 1008
Hyperechoic Kidney<br />
960<br />
Differential Diagnoses: Kidney<br />
DIFFERENTIAL DIAGNOSIS<br />
Common<br />
• Diabetic Nephropathy<br />
• Chronic Glomerular Diseases<br />
• Hypertensive Nephrosclerosis<br />
• Acute Interstitial Nephritis<br />
• Acute Tubular Necrosis<br />
• Medullary Nephrocalcinosis<br />
• Cortical Nephrocalcinosis<br />
• Acute Pyelonephritis<br />
• Reflux Nephropathy<br />
Less Common<br />
• Vasculitis<br />
• Ischemia<br />
• Lupus Nephritis<br />
• Chronic Renal Transplant Rejection/Chronic Allograft<br />
Nephropathy<br />
• Sarcoidosis<br />
• Multicystic Dysplastic Kidney<br />
• HIV Nephropathy<br />
• Acute Cortical Necrosis<br />
Rare but Important<br />
• Emphysematous Pyelonephritis<br />
• Autosomal Recessive Polycystic Kidney Disease<br />
• Oxalosis<br />
• Alport Syndrome<br />
• Renal Amyloidosis<br />
• Renal Tuberculosis<br />
• Lithium Nephropathy<br />
• Renal Cystic Dysplasia<br />
ESSENTIAL INFORMATION<br />
Key Differential Diagnosis Issues<br />
• Increased renal echogenicity is most commonly diffuse <strong>and</strong><br />
secondary to medical renal disease<br />
• Cortical echogenicity greater than liver is abnormal<br />
• Progresses through loss of corticomedullary differentiation<br />
(CMD)<br />
• Pyramids may be dark, later bright<br />
• Cortical echogenicity equal to sinus fat is markedly<br />
abnormal<br />
• Secondary to multiple diseases<br />
○ Tubular, glomerular or interstitial intrinsic renal disease<br />
○ End result of obstruction, ischemia<br />
○ Calcification: Cortical, medullary, interstitial, vascular<br />
• Increased renal echogenicity indicates abnormal kidneys<br />
but not any particular cause<br />
• Echogenicity correlates well with interstitial disease but not<br />
with glomerular disease<br />
• Degree of echogenicity correlates poorly with severity of<br />
renal impairment<br />
• Renal biopsy indispensable in diagnosis of renal<br />
parenchymal disease<br />
• Role of ultrasound<br />
○ Determine renal size <strong>and</strong> cortical thickness<br />
– Differentiating acute from chronic renal insufficiency<br />
○ Exclude ureteral obstruction<br />
• Large hyperechoic kidneys: Diabetes, HIV, acute<br />
inflammation<br />
• Small hyperechoic kidneys nonspecific<br />
• Differentiate from focal areas of increased echogenicity<br />
e.g., medullary, cortical, or lesional<br />
Helpful Clues for Common Diagnoses<br />
• Diabetic Nephropathy<br />
○ Single most important cause of renal failure in adults<br />
○ Diabetes involves glomerulus, interstitium <strong>and</strong> vessels<br />
○ Early: Normal or enlarged kidneys with preserved cortical<br />
thickness<br />
○ Chronic: Small echogenic kidney with thin cortex <strong>and</strong><br />
variable CMD<br />
○ ↑ resistive index (RI) on Doppler studies with ↑ cortical<br />
echogenicity<br />
• Chronic Glomerular Diseases<br />
○ Multiple pathologic entities <strong>and</strong> multiple diseases<br />
– Immunoglobulin A (IgA) disease most common type of<br />
idiopathic glomerulonephritis (GN)<br />
– Focal segmental glomerulosclerosis may be idiopathic<br />
or secondary to hypertension or reflux nephropathy<br />
– Membranous nephropathy most common cause of<br />
idiopathic nephrotic syndrome in Caucasians<br />
○ Acute: Normal/enlarged kidney with normal or ↑ renal<br />
echogenicity<br />
○ CMD disappears with chronic disease: Small echogenic<br />
kidney<br />
• Hypertensive Nephrosclerosis<br />
○ 25% of end-stage renal disease<br />
○ Renal echogenicity depends on chronicity<br />
○ ↑ RI with ↑ cortical echogenicity<br />
• Acute Interstitial Nephritis<br />
○ Hypersensitivity reaction to drug or infective antigen<br />
○ Mimics acute tubular necrosis clinically<br />
○ Kidney size may be normal or enlarged<br />
○ Cortical echogenicity may be increased depending on<br />
severity of reaction<br />
• Acute Tubular Necrosis<br />
○ May be normal or increased in echogenicity<br />
• Medullary Nephrocalcinosis<br />
○ Cause: Hyperparathyroidism, renal tubular acidosis,<br />
medullary sponge kidney, vitamin D excess, gout,<br />
sarcoidosis, bone metastases<br />
○ ↑ echogenicity of renal medullae compared to<br />
hypoechoic cortex, reversal of normal<br />
○ Acoustic shadowing<br />
• Cortical Nephrocalcinosis<br />
○ Focal: Caused by trauma, infarction, or infection<br />
○ Diffuse: Due to renal cortical necrosis, kidney transplant<br />
rejection, chronic GN, Alport syndrome<br />
○ Characterized by peripheral parenchymal calcifications<br />
<strong>and</strong> ↑ cortical echogenicity<br />
• Acute Pyelonephritis<br />
○ Normal/swollen kidney with typically decreased<br />
echogenicity <strong>and</strong> loss of normal CMD<br />
○ Focal areas of increased echogenicity may be seen but<br />
more commonly hypoechoic<br />
○ Thickened urothelium <strong>and</strong> mild hydronephrosis<br />
• Reflux Nephropathy<br />
○ Secondary to interstitial nephritis caused by reflux
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