Back pain and fever

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Hadeel Maksoud M.D.[2]

Abbreviations: ABG = Arterial blood gases, ANA = Antinuclear antibodies, BUN = Blood urea nitrogen, CRP = C-reactive protein, CT = Computed tomography, DRA = Dual energy radiographic absorptiometry, DRE = Digital rectal exam, ERCP = Endoscopic retrograde cholangiopancreatography, ESR = Erythrocyte sedimentation rate, HSV = Herpes simplex virus, IVP = Intravenous pyelography, KUB = Kidney, bladder, ureter, LDH = Lactate dehydrogenase, LFT = Liver function test, MRA = Magnetic resonance angiography, MRC = Magnetic resonance cholangiopancreatography, MRI = Magnetic resonance imaging, MRU = Magnetic resonance urography, NSAIDs = Non-steroidal anti-inflammatory drugs, PCR = Polymerase chain reaction, PET - FDG = Positive emission tomography - fluorodeoxyglucose, PET = Positive emission tomography, PID = Pelvic inflammatory disease, PSA = Prostatic specific antigen, PTC = Percutaneous transhepatic cholangiography, RUQ = Right upper quadrant, SPECT = Single-photon emission computed tomography, TFT = Thyroid function test, VZV = Varicella zoster virus

Classification of pain in the back based on etiology	Diease	Clinical Manifestation																	Diagnosis		Comments
		Symptoms											Signs						Lab findings	Imaging
		Onset	Duration	Quality of pain	Radiation	Stiffness	Fever	Rigors and chills	Headache	Nausea and vomiting	Syncopy	Weight loss	Motor weakness	Sensory deficit	Pulse Deficit	Heart Murmur	Bowel or bladder dysfunction	Horner's syndrome
Neurological	Arachnoiditis	Acute	Hours	Dull aching pain	Head, neck and back	+/-	+	+/-	+/-	+/-	+/-	+/-	+/-	+/-	-	-	+/-	+/-	CSF Elevated protein with normal or low glucose Culture and sensitivity May be due to TB or Meningitis Nucleic acid tests Helpful in tuberculous meningitis	Radiography Thickened nerve roots CT Narrowing of subarachnoid space Irregular collections of contrast material Thickened nerve roots MRI Study of choice shows indistinct cord outline	Usually caused by meningitis or TB
	Epidural abscess	Acute	Variable	Dull, throbbing pain	Locally	-	+/-	+/-	+/-	+/-	+/-	+/-	+/-	+/-	-	-	+/-	+/-	CBC May show leukocytosis, left shift, thrombocytopenia, and anemia ESR Elevated Culture and sensitivity To identify causative organism Immunohistochemical staining Includes gram stain, special stains for fungi and mycobacteria, also consider brucella	MRI Of choice and demonstrates fluid collection CT Demonstrates fluid collection Radiography Demonstrates osteomyelitis or vertebral collapse	LP carries risk of spread of infection
Classification of pain in the back based on etiology	Diease	Clinical Manifestation																	Diagnosis		Comments
		Symptoms											Signs						Lab findings	Imaging
		Onset	Duration	Quality of pain	Radiation	Stiffness	Fever	Rigors and chills	Headache	Nausea and vomiting	Syncopy	Weight loss	Motor weakness	Sensory deficit	Pulse Deficit	Heart Murmur	Bowel or bladder dysfunction	Horner's syndrome
Bone
	Chronic recurrent focal osteomyelitis	Chronic	Years	Dull aching pain	Local	+/-	+	+	-	-	-	+/-	-	-	-	-	-	-	CBC Leukocytosis and left shift ESR Elevated CRP Elevated Procalcitonin Elevated Culture and sensitivity To identify causative agent	Radiography Demonstrates endosteal or medullary lesion Sequestration and cavity formation MRI Bone marrow abnormalities and lytic changes CT Articular and periarticular involvement Ultrasound Soft tissue abnormalities Nuclear imaging Loss of bone density	Acute presentation is often seen in children and is associated with gait abnormalities
	Discitis	Chronic	Years	Dull aching or throbbing	Local	-	+	+/-	-	+/-	-	+/-	+/-	+/-	-	-	+/-	-	CBC May demonstrate leukocytosis ESR May be elevated CRP May be elevated Procalcitonin May be elevated Culture and sensitivity To identify causative agent	MRI Narrowing of disk space and low signalling indicates edema CT Detects lesions earlier than radiography, demonstrates hypodensity of disk and destruction of endplates and calcification of annulus Radiography Disk space narrowing with destruction of endplates and calcification of annulus Nuclear imaging Focal uptake of gallium-67 and technetium-99m in area of destruction	Most likely due to hematogenous spread of organism
	Sacroilitis	Acute or chronic	Variable	Dull aching or throbbing	Hips and legs	+/-	+	+/-	-	-	-	+/-	+/-	+/-	-	-	+/-	-	CBC May demonstrate leukocytosis ESR May be elevated CRP May be elevated Procalcitonin May be elevated Culture and sensitivity To identify causative agent	MRI Narrowing of joint space and low signalling indicates edema CT Detects lesions earlier than radiography, demonstrates hypodensity of joint space and destruction of articular surface Radiography Joint space narrowing with destruction of joint space Nuclear imaging Focal uptake of gallium-67 and technetium-99m in area of destruction	Most likely due to hematogenous spread of organism
	Vertebral compression fracture	Acute	Minutes to hours	Sudden, severe, sharp	Shoulders, arms, hips and legs	+/-	-	-	+/-	+/-	+/-	-	+/-	+/-	-	-	+/-	-	CBC Decreased hematocrit and anemia PSA To rule out prostate cancer Urine analysis To detect Bence - Jones protein Serum protein electrophoresis M spike is seen with multiple myeloma ESR May be elevated	Radiography Decreased vertebral body height CT Detects more subtle fractures and calcifications MRI Useful in those with motor weakness and sensory deficits May demonstrate hemorrhage, tumor, or infection DRA scanning Detects low bone density PET scanning To distinguish benign from malignant causes of compression	Presents as a midline back pain
	Vertebral osteomyelitis	Acute	Minutes to hours	Sudden, severe, sharp	Shoulders, arms, hips and legs	+/-	+	+/-	-	+/-	-	-	+/-	+/-	-	-	+/-	-	CBC Leukocytosis and left shift ESR Elevated CRP Elevated Procalcitonin Elevated Culture and sensitivity To identify causative agent	Radiography Demonstrates endosteal or medullary lesion Sequestration and cavity formation MRI Bone marrow abnormalities and lytic changes CT Articular and periarticular involvement Ultrasound Soft tissue abnormalities Nuclear imaging Loss of bone density	Often caused by hematogenous spread of organism
Classification of pain in the back based on etiology	Diease	Clinical Manifestation																	Diagnosis		Comments
		Symptoms											Signs						Lab findings	Imaging
		Onset	Duration	Quality of pain	Radiation	Stiffness	Fever	Rigors and chills	Headache	Nausea and vomiting	Syncopy	Weight loss	Motor weakness	Sensory deficit	Pulse Deficit	Heart Murmur	Bowel or bladder dysfunction	Horner's syndrome
Referred pain
	Appendicitis	Acute	Minutes to hours	Burning	Umbilicus and lower right quadrant	-	+	+/-	-	+	-	-	-	-	-	-	-	-	CBC Demonstrates leukocytosis and neutrophilia CRP May be elevated Urine analysis May demonstrate pyuria, hematuria, and/or proteinuria Urine 5-HIAA Maybe an early marker of appendictis Sudden increase may indicate necrosis	Ultrasound Demonstrates a non-compressible tubular structure CT Demonstrates an enlarged appendix with thickened walls and can detect abnormally located appendices MRI Useful in pregnant ladies KUB Radiography May detect an appendicolith Barium enema Demonstrates absent or incomplete filling Cecal spasm may be present Radionuclide scanning Appendiceal inflammation may be present	Pain begins around the umbilicus and then shifts to RUQ
	Cholelithiasis	Acute or subacute	Minutes or hours	Sharp	Tip of right shoulder	-	+/-	+/-	-	+	-	+/-	-	-	-	-	-	-	CBC Demonstrates polymorphnuclear leukocytosis LFT Elevated alanine aminotransferase and aspartate aminotransferases Elevated conjugated bilirubin Amylase and lipase Elevated	Radiography Radio-opaque stones may be present CT May indicate presence of gallstones in the distal common bile duct MRI May indicate presence of gallstones in the distal common bile duct Ultrasound May demonstrate gallbladder wall thickening (>5 mm) and gallbladder fluid and distention Gallstones may appear as echogenic foci that cast an acoustic shadow Scintigraphy May detect cystic duct obstruction ERCP Stones are seen as a filling defect and can be removed simultaneously PTC Similar to ERCP Used when ERCP is not feasible	May be completely asymptomatic
	Cystitis	Acute	Hours	Burning	Suprapubic	-	+/-	+/-	-	-	-	-	-	-	-	-	+/-	-	Urine analysis May demonstrate [[pyuria[[, hematuria, white blood cell casts and proteinuria Urine culture Detection of > 1000 colony-forming units/ml CBC May demonstrate leukocytosis and/or anemia	Typically no routine imaging done	Cystitis may be infectious, hemorrhagic, radiational, or sterile
	Endocarditis	Acute or subacute	Variable	Discomfort in the chest	Jaw and arms	-	+/-	+/-	-	+/-	+/-	-	-	-	+/-	+	-	-	CBC Anemia and leukocytosis may be noted Serology Decrease C3, C4, and CH50 may indicate subacute endocarditis Rheumatoid factor may be positive ESR May be elevated Urine analysis May demonstrate proteinuria and microscopic hematuria Blood culture To identify causative agent Streptococci and HACEK organisms are culture negative Organisms that grow on prosthetic valves tend to be coagulase-negative staphylococci	Echocardiography Vegetations and myocardial abscesses may be present Radiography Pyogenic emboli may be seen across the lung field Ultrasound Myocardial abscesses may be seen Valvular dysfunction may also be noted	IV drug users and those who suffer from rheumatic heart disease often present with infective endocarditis
	Myalgia	Chronic	Years	Dull aching	Variable	+/-	+/-	+/-	+/-	-	-	-	-	-	-	-	-	-	*Typically no specific lab findings A full workup should be done to exclude other etiologies, such as; Rheumatoid factor and/or anti-cyclic citrullinated peptide antibodies May indicate cause is rheumatoid arthritis CRP and ESR May be elevated CBC May indicate anemia Bone profile May be caused by a vitamin D or calcium deficiency	Typically no routine imaging done	May be associated with Hepatitis C and Lyme disease
	Nephrolithiasis	Acute	Hours	Severe, sharp	Abdomen, hips, groin, legs	-	+/-	+/-	-	+/-	-	-	-	-	-	-	-	-	CBC Mild leukocytosis may indicate infection Electrolytes Hypokalemia may indicate acute tubular necrosis Hypercalcemia or hypercalciuria may be detected Creatinine To identify potential renal injury with contrast Uric acid Uric acid stones sometimes occur with gout ABG May indicate acute tubular necrosis with hypokalemia and decreased bicarbonate	CT Visualizes calcium stones and other possible pathologies, such as hydronephrosis IVP Visualizes stones and entire urinary system KUB radiography Radio-opaque stones may be present Ultrasound For visualization of stones Plain renal tomography Can distinguish between intrarenal and extrarenal calcifications Retrograde pyelography Particularly useful for ureteric calculi visualization Nuclear renal imaging May determine a decreased renal function	Hypercalcemia may indicate primary or secondary hyperparathyroidism
	Pancreatitis	Acute or chronic	Variable	Severe, sharp or dull aching	Abdomen	-	+/-	+/-	-	+	+/-	+/-	-	-	-	-	-	-	Amylase and lipase Elevated LFT Elevated alkaline phosphatase, total bilirubin, aspartate aminotransferase, and alanine aminotransferase CBC May demonstrate leukocytosis Serum electrolytes May indicate hypo or hypercalcemia BUN and creatinine May be elevated Triglycerides Usually elevated, however, falsely lowered during acute attack	KUB radiography May demonstrate free air within abdomen, indicating a perforated viscus Ultrasound Used to visualize the pancreas and biliary tree May detect microlithiasis and periampullary lesions CT Pancreas may appear enlarged MRC May demonstrate a blockage within the biliary ducts ERCP May remove a blockage, however, can in fact cause pancreatitis	Usually caused by binge drinking or long standing gallstones that block the ampulla of Vater Vomiting is a common manifestation
	Pelvic inflammatory disease	Acute or chronic	Variable	Dullaching or throbbing	Hips, groin, legs	-	+/-	+/-	-	+/-	-	-	-	-	-	-	-	-	CBC Leukocytosis, may indicate infection with trichomoniasis Pregnancy test To rule out ectopic pregnancy STD panel To rule out gonorrhea, chlamydia, hepatitis B and C, HIV, and syphilis Urine analysis To rule out a urinary tract infection	Transvaginal ultrasound May demonstrate anechoic structures in adnexa indicating hydrosalpinx and/or pyosalpinx Laparoscopy May demonstrate adhesions (Asherman's syndrome) or gun powder lesions (Endometriosis) or an ectopic pregnancy MRI and CT May indicate hydro and/ or pyosalpinx	Inflammation may spread to perihepatic structures (Fitz-Hugh−Curtis syndrome)
	Pyelonephritis	Acute or chronic	Variable	Severe, sharp or dull aching	Groin, hips and legs	-	+	+/-	-	+/-	-	-	-	-	-	-	+/-	-	CRP Elevated ESR Elevated Urinalysis Pyuria Bacteriuria May be nitrite positive (gram negative organisms) Culture positibe (Uncomplicated: E. coli, Proteus mirabialis, Klebsiella, S. saprophyticus- Complicated: E. coli, enterococci, S.epidermidis	Ultrasound Hydronephrosis Non-contrast CT Pelvicalceal dilation Cortical involvement MRI T1: affected region(s) appear hypointense compared with the normal kidney parenchyma T2: hyperintense compared to normal kidney parenchyma T1 C+: reduced enhancement	Renal stones Obstruction Pregnancy Prolonged urinary catheterization
	Pneumonia	Acute or chronic	Variable	Variable	Chest, back and abdomen	-	+	+	+/-	+/-	+/-	+/-	-	-	-	-	-	-	CBC Leukocytosis is often demonstrated however, white blood cell count may be normal Blood culture To identify causative organism or rule out other organisms such as MRSA	Radiography Plain x-ray shows multiple patches in the lung fields CT Used to distinguish pneumonia from non-pneumonias	Hospital-acquired pneumonia is common
	Pyomyositis	Acute or chronic	Days to weeks	Dull aching or throbbing	Variable	-	+	+/-	-	-	-	-	-	-	-	-	-	-	CBC Demonstrates leukocytosis ESR Elevated Serum creatine kinase and aldolase Normal Blood culture Typically negative Culture and sensitivity May include a positive gram stain	MRI Can differentiate between osteomyelitis and pyomyositis by demonstrating early muscle inflammation or abscess formation CT May demonstrate pphypertrophy]] of muscles and/or effacement of fatty plane An enhancement in contrast may indicate abscess formation Ultrasound Useful in determining specific muscle involvement Gallium scan Useful in detecting early muscle pathology	Infectious myositis was once considered a tropical disease, however with the emergence of HIV is now prevalent in western societies too
	Waterhouse-Friderichsen syndrome	Acute	Minutes to hours	Sudden, severe, sharp	Back and/or flanks	-	+	+/-	+/-	+/-	+/-	+/-	-	-	-	-	-	-	CBC May show decreased hemotocrit, leukocytosis and rarely, eosinophilia Serum electrolytes Hyponatremia Hyperkalemia Hypercalcemia Blood urea nitrogen Elevated Creatinine Elevated Plasma glucose  Hypoglycemia Serum cortisol Decreased Plasma ACTH Elevated	CT Shows adrenal enlargement or adrenal aymmetry	Short cosyntropin (Cortrosyn) stimulation test confirms the diagnosis
Classification of pain in the back based on etiology	Diease	Clinical Manifestation																	Diagnosis		Comments
		Symptoms											Signs						Lab findings	Imaging
		Onset	Duration	Quality of pain	Radiation	Stiffness	Fever	Rigors and chills	Headache	Nausea and vomiting	Syncopy	Weight loss	Motor weakness	Sensory deficit	Pulse Deficit	Heart Murmur	Bowel or bladder dysfunction	Horner's syndrome
Tumors	Ewing's sarcoma	Chronic	Months to years	Dull aching	Variable	+/-	+/-	+/-	-	-	-	+	-	-	-	-	-	-	Tests are used to rule out other pathologies; CBC May indicate anemia Blood cultures May be positive for various organisms ESR and CRP May be elevated LDH May be elevated Cytogenetic studies May be positive for t(11;22) translocation Immunohistochemical markers May be positive for MIC2 antigen (CD99)	Radiography Periosteal reaction "onion skin" Cortical thinning Mottling MRI Skip lesions Edema Metastasis PET - FDG To identify metastatic disease
	Langerhans cell histiocytosis(eosinophilic granulomas)	Chronic	Months to years	Dull aching	Variable	-	+/-	+/-	-	-	-	-	-	-	-	-	-	-	Tests used to rule out other pathologies; CBC Reticulocyte count may be increased Positive or negative direct and indirect Coombs test Immunoglobulin levels may be elevated ESR May be elevated LFT May demonstrate elevations in total protein, albumin, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and gamma-glutamyltransferase Elevations may mean liver cirrhosis Urine analysis Decrease in urine osmolality may indicate diabetes insipidus	Radiography Single or multiple osteolytic lesions may be noted CT To identify abnormalities of the hypothalamic and/or pituitary region MRI To identify abnormalities of the hypothalamic and/or pituitary region PET - FDG More sensitive than CT or MRI to active disease
	Leukemia	Acute or chronic	Weeks to years	Aching	Variable	-	+/-	+/-	-	-	-	+	-	-	-	-	-	-	CBC Mature or immature leukocytosis Coagulation study May demonstrate elevatedprothrombin time, decreasing fibrinogen level, and presence of fibrin split products Peripheral blood smear May demonstrate blasts, ppschistocyte]]s, auer rods, and mature lymphocytosis Blood chemistry profile May demonstrate tumor lysis syndrome through elevated LDH and uric acid Blood culture To rule out infection	Typically no routine imaging studies, cytogenetic and flow cytometries aid diagnosis	Acute and chronic, lymphocytic and myeloid diagnoses are based on the presence and type of blast or mature cell
	Lymphoma	Chronic	Months to years	Aching	Variable	-	+/-	+/-	-	-	-	+	-	-	-	-	-	-	Typically no specific lab findings, however, the following routine tests are performed; CBC Serum chemistry studies, including LDH Serum beta2-microglobulin level HIV serology	Radiography May demonstrate hilar or mediastinal adenopathy Pleural or pericardial effusion Parenchymal involvement Bulky mediastinal mass CT May demonstrate enlarged lymph nodes Hepatosplenomegaly Filling defects in visceral organs Bone scan Useful in those with elevated alkaline phosphatase Gallium scan May show increased uptake MRI Signal intensity changes are noted in those with bone marrow or muscular involvement PET - FDG To distinguish between viable, active tumors and necrosis To detect early recurrence Ultrasound Useful if primary lesion is in testis	Hodgkin's lymphoma is usually focal and characterized by Reed-sternberg cells Non - hodgkin's lymphoma tends to be multifocal Biopsy provides ultimate diagnosis
	Multiple myeloma	Chronic	Years	Dull aching	Hips, groin and legs	+/-	+/-	+/-	-	-	-	+/-	-	-	-	-	+/-	-	Serum protein electrophoresis May demonstrate a M peak Serum free light chain assay and 24 - hour urine collection May detect Bence-Jones proteins CRP May be elevated Serum beta2-microglobulin May be elevated Albumin May demonstrate elevated albumin in urine LDH May be elevated Peripheral blood smear May demonstrate rouleaux formation > 50% Leukopenia Thrombocytopenia	Radiography, MRI and PET Osteolytic lesions may be demonstrated	Biopsy will demonstrate elevated plasma cells in the bone marrow
	Prostate cancer	Chronic	Months to years	Severe, sharp	Lower abdomen, hips, groin and legs	-	+/-	+/-	-	-	-	+/-	-	-	-	-	+/-	-	PSA Detection is helpful in diagnosis, usually > 10 ng/ml Acid and alkaline phosphatase Useful in detecting metastasis Serurm creatinine and LFT Useful in detecting metasstasis Urine analysis May detect hematuria or infection	Ultrasound Transrectal biopsy transrectal ultrasound may demonstrate hypoechoicity MRI May be used to guide biopsy	PSA and DRE are gold standard for screening
Classification of pain in the back based on etiology	Diease	Clinical Manifestation																	Diagnosis		Comments
		Symptoms											Signs						Lab findings	Imaging
		Onset	Duration	Quality of pain	Radiation	Stiffness	Fever	Rigors and chills	Headache	Nausea and vomiting	Syncopy	Weight loss	Motor weakness	Sensory deficit	Pulse Deficit	Heart Murmur	Bowel or bladder dysfunction	Horner's syndrome
Miscellaneous
	Herpes zoster	Acute or chronic	Variable	Severe, stabbing, electric-like	Dermatomal	-	+/-	+/-	+/-	+/-	+/-	+/-	-	+/-	-	-	-	-	Tzanck smear May demonstrate multinucleated giant cells Direct fluorescent antibody test and/or PCR Allows for differentiation between HSV and VZV	Typically no routine imaging MRI Used to exclude myelopathy or encephalopathy Lumbar puncture and cerebrospinal fluid analysis In cases of suspected meningitis, increased protein and pleocytosis will be noted
	Sickle cell anemia	Acute or chronic	Variable	Severe, sharp	Variable	+/-	+	+/-	-	-	-	-	-	-	-	-	-	-	CBC Hemoglobin level is between 5-9 g/dl Hematocrit is decreased to 17-29% Leukocytosis with predominance of neutrophils Thrombocytopenia ESR Decreased Reticulocyte count Elevated Peripheral blood smear May demonstrate target cells, elongated cells, and sickle erythrocytes Howell - Jolly bodies in an asplenic patient Hemoglobin solubility Distinguishes between sickle cell disease and sickle cell trait Hemoglobin F Percentage of Hemoglobin F is elevated LFT, renal function test and pulmonary function test To assess organ distress or failure ABG To detect oxygen saturation Urine analysis May determine an urinary tract infection with hematuria and isosthenuria Sickling test As screening for sickle hemoglobinopathies Secretory phospholipase A2 May be increased in acute chest syndrome, a complication of sickle cell disease	Radiography Osteonecrosis Dactylitis indicated by medullary expansion, cortical thinning, trabecular resorption, and bone lucency Osteomyelitis may be present and demonstrate sequestra, cortical destruction, periosteal growth and sinus formation MRI and CT In addition to findings in radiography, may detect bone marrow hyperplasia May also be useful in ruling out renal medullary carcinoma in those presenting with hematuria Nuclear imaging Used to detect early osteonecrosis through Technetium-99m bone scanning Used to detect early osteomyelitis through detection of elevation ofwhite blood cells in Indium-11 white blood cell scanning Transcranial doppler ultrasonography Abnormally high blood flow is detected in those at increased risk of stroke Abdominal ultrasound Used to exclude other pathologies such as, cholecystitis, cholelithiasis, ectopic pregnancy, nephrolithiasis, and papillary necrosis May also be used to asses the size of the liver and spleen Echocardiography Used to diagnose pulmonary hypertension based on tricuspid regurgitant jet velocity Also used to assess abnormalities of systolic and diastolic function	Sickle cell trait confers some protection against malaria
	Syringomyelia	Chronic	Years	Dull aching	Variable	+/-	+/-	-	+/-	+/-	-	-	-	-	-	-	-	-	*Typically no specific lab findings	MRI Of choice and demonstrates a syrinx (spinal cord cyst) May also be useful in assessment of CSF flow dynamics Radiography and CT May also visualize a syrinx Gadolinium scan Useful in assessment of post-operative patients and can distinguish between a tumor, scar, and disk material Myelography Used when MRI is unfruitful, and may detect widening of spinal cord and complete subarachnoid block
	Ureteropelvic junction obstruction (UPJ)	Acute	Hours to days	Dull aching	Groin, hips, legs	-	+/-	+/-	+/-	+/-	-	-	-	-	-	-	+/-	-	CBC To rule out anemia Coagulation profile To rule out bleeding Electrolyte levels To rule out nephrolithiasis BUN and serum creatinine To assess kidney function Urine culture To rule out urinary tract infection	Voiding cystourethrography May demonstrate vesicoureteral reflux Ostruction usually shows hydronephrosis without reflux Renal ultrasonography May determine kidney malformation and scarring Dilation of collecting system Annular stricturing IVP May demonstrate a hydronephrotic kidney Used to map out entire urinary system CT and MRU Provides detail about the urinary system such as; Renal vasculature Renal pelvis anatomy Location of crossing vessels Renal cortical scarring Ureteral fetal folds in the proximal ureter Doppler Used to detect cross vessels associated with obstruction MRA May demonstrate aberrant renal vessels	Congenital abrnormalities in both children and adults are usually the cause of UPJ obstruction