Radiology Review Manual 6th Edition

2007 Lippincott Williams & Wilkins

Urogenital Tract Differential Diagnosis of Urogenital Disorders

Renal failure

= reduction in renal function

rise in serum creatinine >2.5 mg/dL

Acute Renal Failure

= clinical condition associated with rapid steadily increasing azotemia oliguria (

drug reaction, pyelonephritis, papillary necrosis

abnormal resistive index

4. Intrarenal precipitation (hypercalcemia, urate, myeloma protein)

5. Arterial / venous obstruction 6. Acute cortical necrosis

C. POSTRENAL (5%) = result of outflow obstruction (rare)

1. Prostatism 2. Tumors of bladder, retroperitoneum, pelvis 3. Calculus

4. hydronephrosis D. CONGENITAL

bilateral renal agenesis / dysplasia / infantile polycystic kidney disease,

congenital nephrotic syndrome, congenital nephritis, perinatal hypoxia

Incidence: ATN + prerenal disease account for 75% of acute renal failure

Chronic Renal Failure (CRF)

= decrease in renal function over months / years

Incidence: end-stage renal disease in 0.01% of U.S. population; 85,000 patients/year

undergo hemodialysis; 8,000 renal transplantations/year

Etiology:

A. INFLAMMATION / INFECTION 1. Glomerulonephritis 2. Chronic pyelonephritis 3. Tuberculosis 4. Sarcoidosis

B. VASCULAR 1. Renal vascular disease 2. Bilateral renal vein thrombosis

C. DYSPROTEINEMIA 1. Myeloma 2. Amyloid 3. Cryoglobulinemia 4. Waldenstrm macroglobulinemia

D. METABOLIC 1. Diabetes 2. Gout 3. Hypercalcemia 4. Hyperoxaluria 5. Cystinosis 6. Fabry disease

E. CONGENITAL 1. Polycystic kidney disease 2. Multicystic dysplastic kidney

3. Medullary cystic disease 4. Alport syndrome 5. Infantile nephrotic syndrome

F. MISCELLANEOUS 1. Hepatorenal syndrome 2. Radiation

Musculoskeletal Manifestations of CRF

1. Renal osteodystrophy = combination of 2 HPT, osteoporosis, osteosclerosis, osteomalacia, soft-tissue and vascular calcifications

2. Aluminum toxicity (130%) o Cause: ingestion of aluminum salts phosphate-binding antacids (to control

hyperphosphatemia)

o aluminum serum level >100 ng/mL

o signs of osteomalacia (>3 insufficiency fractures with

predominant involvement of ribs)

o avascular necrosis

o lack of osteosclerosis

o less evidence of subperiosteal resorption

3. Amyloid deposition o Path: amyloid consists of 2-microglobulin

o Organs: bone, tenosynovium (carpal tunnel syndrome), vertebral disk, articular

cartilage + capsule, ligament, muscle

4. Destructive spondyloarthropathy (15%) o diskovertebral junction erosion + sclerosis

o vertebral body compression

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o disk space narrowing

o Schmorl node formation

o lack of osteophytosis

o facet involvement with subluxation

5. Tendon rupture 6. Crystal deposition disease

o Type: calcium hydroxyapatite, CPPD, calcium oxalate, monosodium urate

7. Osteomyelitis + septic arthritis 8. Avascular necrosis (in up to 40%)

Diabetes insipidus

= characterized by daily production of very large volume of dilute urine (specific gravity

a. congenital 1. Rare X-linked recessive genetic disorder with unresponsiveness of tubules

+ collecting system to vasopressin (in infants + young males) with

variable expression

2. Autosomal dominant form (rare) b. acquired = nephrogenic DI syndrome

= disorders affecting the medulla / distal nephrons:

medullary + polycystic disease, sickle cell nephropathy,

postobstructive uropathy, reflux nephropathy, chronic uremic

nephropathy, unilateral renal artery stenosis, acute tubular necrosis,

drug toxicity, analgesic nephropathy, hypokalemic +

hypercalcemic nephropathy, amyloidosis, sarcoidosis

symptoms in infancy:

vomiting secondary to hypernatremic dehydration

mental retardation

caloric growth failure (water favored over formula)

symptoms after infancy:

increased fluid intake

avoiding urination

bilateral hydroureteronephrosis

Rx: thiazide diuretics, low-salt diet, encouragement of frequent

micturition, indomethacin

Hypercalcemia

mnemonic: SHAMPOO DIRT

o Sarcoidosis

o Hyperparathyroidism, Hyperthyroidism

o Alkali-milk syndrome

o Metastases, Myeloma

o Paget disease

o Osteogenesis imperfecta

o Osteopetrosis

o D vitamin intoxication

o Immobility

o Renal tubular acidosis

o Thiazides

Polycythemia

Cause: increased level of erythropoietin (acting on erythroid stem cells) secondary to a

decrease in pO2; erythropoietin precursor is produced in juxtaglomerular epithelioid cells

of kidney + converted in blood

A. RENAL

a. intrarenal 1. Vascular impairment

2. Renal cell carcinoma (5%) 3. Wilms tumor 4. Benign fibroma 5. Simple cyst (14%) 6. Polycystic kidney disease

b. postrenal 1. Obstructive uropathy (14%)

B. EXTRARENAL

a. liver disease 1. Hepatoma 2. Regenerating hepatic cells

b. adrenal disease 1. Pheochromocytoma 2. Aldosteronoma 3. Cushing disease

C. CNS DISEASE

1. Cerebellar hemangioblastoma D. Large uterine myomas

NOT in: renal vein thrombosis, multicystic dysplastic kidney, medullary sponge kidney

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Arterial hypertension

A. PRIMARY / ESSENTIAL HYPERTENSION (8590%) B. SECONDARY HYPERTENSION

a. Renal parenchymal disease (510%) b. Potentially curable secondary hypertension (12%)

vascular

1. Renovascular disease 0.184.4%

2. Coarctation 0.6%

hormonal

1. Pheochromocytoma 0.040.2%

2. Cushing syndrome 0.3%

3. Primary aldosteronism 0.010.4%

4. Hyperthyroidism

5. Myxedema

renal

1. Unilateral renal disease

Renovascular Hypertension

= normalization of blood pressure following nephrectomy /

reestablishment of normal renal blood flow (Dx made in

retrospect)

Incidence: 15% of general population; 2nd most common

cause of potentially curable hypertension

Pathophysiology:

o usually >50% stenosis at any level in renovascular bed

leads to mildly reduced pressure in glomerular afferent

arteriole (pressure falls precipitously in >80% stenosis);

reduced pressure stimulates release of renin followed by

angiotensin-II, and aldosterone causing

a. constriction of efferent glomerular arterioles

b. increase in systemic hypertension

c. sodium retention

Cause:

1. Atherosclerosis (6090%) in individuals >50 years of age

2. Fibromuscular dysplasia (1035%) in women

11. Middle aortic syndrome, aortic dissection, dissecting

aortic aneurysm

12. Posttraumatic renovascular hypertension

. occlusion of main renal artery

a. significant stenosis by intimal flap

b. severe renal contusion

c. segmental renal artery branch injury

Renal artery stenosis is present in 77% of hypertensive

patients!

Renal artery stenosis is present in 3249% of

normotensive patients!

1520% of patients remain hypertensive after restoration of normal renal blood flow!

Clinical findings that suggest renovascular disease:

1. Onset of HTN 50 years of age

2. Hypertension refractory to therapy

3. Accelerated / malignant hypertension

4. Unexplained large increases in blood pressure above

previously controlled / baseline values 5. Symptomatic hypertension

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