Urolog an.4 Seminar

 1.Role of Radiologist as specialist and consultant in  urologic pathology2.What problems could require imaging of the urinary tract3.Contrast media used in the investigation of the urinary system4.Imaging methods used in the investigation of the urinary system 5.General principles of ultrasound including doppler flow 6.General principles of X-ray plain films 7.Differences, utility and use of CT versus MRI 8.General principles of angiography including indications, utility 9.General principles of nuclear medicine 10.Radiodiagnostics of urinary system diseases: urinary retentionurinary frequencyurinary incontinence

blockage of urineabdominal massblood in the urinekidney failure

Questions in urologic radiology for medical students

Imaging can help the doctor find the cause of:

1.urinary retention—the inability to empty the bladder completely2.urinary frequency—urination eight or more times a day3.urinary urgency—the inability to delay urination4.urinary incontinence—the accidental loss of urine5.blockage of urine6.abdominal mass7.pain in the groin or lower back8.blood in the urine9.high blood pressure10.kidney failure

What problems could require imaging of the urinary tract?

Dysuria

• refers to painful urination• Difficult urination is also sometimes described 

as dysuria• It is one of a constellation of irritative bladder 

symptoms, which includes urinary frequency and haematuria

This is typically described to be a burning or stinging sensation. It is most often a result of

1. urinary tract infection2.  STD3.  bladder stones4.  bladder tumours5.  prostate disorders6.  anticholinergic drugsdrugs

Incontinence: is any involuntary leakage of urine. Common etiology are:1. Polyuria2. Prostate disorders (BPH and cancers)3. Caffeine and Cola4. Brain disorders (MS, spinal cord injuries, 

Parkinson disease, stroke)

Abnormalities of Urine Volume 

• Oliguria: is the low output of urine, It is clinically 

classified as an output below 400 ml/day • The decreased output of urine may be a sign 

of dehydration, renal failure, hypovolemic shock, multiple organ dysfunction syndrome, or urinary obstruction/urinary retention.

Anuria: absence of urine, clinically classified as below 

100ml/day Anuria can be caused by1.  total urinary tract obstruction2.  total renal artery or vein occlusion3. Shock 4. Cortical necrosis5.  severe ATN6. Rapidly progressive glomerulonephritis

Polyuria:  urine>3 L/d  Polyuria results from two potential 

mechanisms: 1. nonabsorbable solutes diuresis2. water diuresis (DI)  If the urine volume is >3 L/d and urine 

osmolality is >300 mosmol/L, then a solute diuresis is clearly present and a search for the responsible solute(s) is mandatory

METHODS OF INVESTIGATION

• ULTRASONOGRAPHY• RADIOLOGY

– Simple abdominal X-ray– Intravenous urography– Retrograde/anterograde pieloureterography– Cystography– Renal angiography– Uretrography

• NUCLEAR MEDICINE– Static studies: static renal scintigraphy– Dynamic studies: renogram 

• CT• MRI

Plain Film of the Abdomen 

• The kidneys-ureters-bladder  is often the first imaging study performed to visualize the abdomen and urinary tract– The film is taken with the patient supine and 

should include the entire abdomen from the base of the sternum to the pubic symphisis

– Can show bony abnormalities, calcification and large soft tissue masses

Urography

• Involves  instillation  of  contrast  material  to better  visualize  the  collecting  or  lumenal structures  of  the  kidneys,  ureters,  bladder, and urethra– This can be done after IV injection or direct 

instillation into the urinary tract1) Intravenous urography2) Cystography3) Voiding cystourethroography4) Retrograde urethrography

Intravenous Urography

• IVU/  intravenous  pyelogram  is  the  classic modality of imaging the entire urethelial tract from  pyelocalyceal  system  trhough  the ureters and bladder– Excellent for indentifying small urethelial lesions 

as well as the severity of obstruction from calculi– Provides anatomical and qualitative functional 

information about the kidneys

Ectopic kidney

Tumors

Cystography

• Permits imaging of an opacified urinary bladder after retrograde instillation of contrast media through a urethral or suprapubic catheter– Imaging is performed to demonstrate a suspected 

urine leak, either from traumatic bladder rupture or after bladder surgery

– Can also demonstrate a presence of a fistula between the bladder and vagina or to characterize bladder diverticuli

Tumors

Tumor

Voiding Cystourethrography

• Can be used to evaluate for abnormal anatomy and function of the lower urinary tract in both children and adults– Similar to the cystogram, instillation of contrast 

media into the bladder through a urethral cahteter is also employed

– After full distention of the bladder, the patient is instructed to void either after removing the catheter or around the catheter

Retrograde Urethrography

• Complete evaluation of the urethra includes both antegrade and retrograde urethrography– Allows visualization of the anterior male urethra – Used for evaluating a suspected traumatic 

urethral injury or urethral stricture– Can also be useful for diagnosis of a urethral 

diverticulum in females

•  

Normal RUG

Retrograde urethrogram

20mm stricture in the bulbous urethra. 

Duplicated urethra

Urethrogram confirms duplicated urethra.

ULTRASONOGRAPHY

ULTRASONOGRAPHY

ULTRASONOGRAPHY

ULTRASONOGRAPHY

RENAL ABSCESS

Doppler US

Doppler US

same patient has prostate hypertrophy. 

left image : hydronephrosis at the LK rigth image :lower ureteric calculi

Testicular torsionPresentation:15 year old boy with acute left testicular pain.

Case Discussion:US testes was performed which demonstrate the left testicle assuming an abnormal orientation and lack normal color and power Doppler flow with maintained testicular normal echogenicity, consistent with acute testicular torsion. The right testicle is within normal.

CT Scan• often used examine structures 

in  the  abdomen  and  pelvis (reproductive  organs,  liver, pancreas,  gallbladder,  spleen and  intestines). CAT Scans are a  diagnostic  tool  that urologists  use  to  detect  and diagnose:  recurrent  urinary tract  infections,  sources  of blood in the urine (hematuria), kidney  stones,  renal  cysts  and masses. Moreover,  it can help urologists  rule  out  prostate, bladder and renal cancers

CT

No Contrast

Contrast

CT

Axial image, CT showing left ureteral stone.

Benign prostatic hypertrophy

Urinary bladder diverticulum

Ectopic kidney

Ectopic kidney

Ectopic kidney

Ectopic kidney

Ectopic kidney

Cazul 2

Renal hypoplasia

Cazul 2

Hipoplazia renalaRenal hypoplasia

Trauma

CT

Tumor

CT

Tumor

CT

Hypervascular process left

kidney

Hypervascular process left

kidney

Hypervascular process left

kidney

Hypervascular process left

kidney

Parapelvical  cyst

Bosniak renal cyst classificationThe Bosniak classification system for CT evaluation of renal cysts is helpful in determining both malignant risk and required follow-up and/or treatment.

Bosniak 1simple cyst, imperceptible wall, roundedwork up : nil% malignant : ~ 0%

Bosniak 2minimally complex, a few thin (< 1mm) septa, thin Ca++; non-enhancing high-attenuation (due to  to proteinaceous or haemorrhagic fluid)  renal  lesions of  less  than 3 cm are also included in this category; these lesions are generally well marginated.work up : nil% malignant : ~ 0%

Bosniak 2Fminimally complex but requiring follow up. increased number of septa, minimally thickened or enhancing septa or wall  thick Ca++, hyperdense cyst that is:

> 3 cm diameter, mostly intrarenal (less than 25% of wall visible); no enhancementwork up : needs ultrasound / CT follow up% malignant : ~ 25 %6 

Bosniak 3indeterminate, thick or multiple septations, mural nodule, hyperdense on CT (see 2F)treatment / work up  : partial nephrectomy or RF ablation  in elderly  / poor surgical risk% malignant : ~ 54%6 Bosniak 4clearly malignant, solid mass with large cystic or necrotic component treatment: partial / total nephrectomy% malignant : ~100%

Polycystic kidney disease

Multi-Detector Computed Tomography (MDCT)

Extrarenal renal cyst expansion

Extrarenal renal cyst expansion

Extrarenal renal cyst expansion

MRI

• Can  be  generally  used  in  place  of  a  CT  scan when  renal  insufficiency  or  contrast  allergy prohibits the use of CT scan

• The  process  by  which  the  protons  realign themselves with the magnetic field is referred to as relaxation. The protons undergo 2 types of  relaxation:  T1  (or  longitudinal)  relaxation and T2 (or transverse) relaxation

MRI• In T1-weighted images (emphasizing the difference in T1 

relaxation  times  between  different  tissues),  water-containing  structures  are  dark.  T1-weighted  images  do not  show good contrast between normal and abnormal tissues.  However,  they  do  demonstrate  excellent anatomic detail.

• T2-weighted  images  emphasize  the  difference  in  T2 relaxation  times  between  different  tissues.  Because water  is  bright  in  these  images,  T2-weighted  images provide  excellent  contrast  between  normal  and abnormal  tissues,  although  with  less  anatomic  detail than T1-weighted images

MRI

Polycystic kidney disease

MRI

• renal carcinoma

MR ANGIOGRAPHY

• Left renal artery stenosis

CTMRI

Uses ionizing radiation, high-dose procedure

Uses magnetic resonance, no ionizing radiation

Excellent spatial resolution Excellent contrast resolution

Actual scanning time measured in seconds (typically <10 s)

Actual scanning time measured in minutes (typically 45 min)

Rarely requires general anesthetic in children

Frequently requires general anesthetic in children, depending on age

Table 1Comparison of advantages and disadvantages between

computed tomography (CT) and magnetic resonance (MR) imaging modalities

Excellent at showing calcification Poor at showing calcification (signal void)

Poor at showing edema or pathological changes in specific tissue types

Excellent at showing edema and pathological changes in specific tissue types

Usually requires intravenous contrast (unless looking for calcification when not required)

Usually requires intravenous administration of contrast (but certain sequences can be tailored if this is contraindicated)

No known risk of nephrogenic systemic fibrosis (NSF)

Risk of NSF (rare, but renal patients believed to be at increased risk)

Less expensive Expensive

Usually available as an emergency imaging technique

Not routinely available as an emergency technique

No significant contraindicationsContraindicated in patients with any internal ferrous objects (pacemakers, defibrillators, recent orthopedic metalware, other implanted metallic devices, metallic foreign bodies)

Open-style scanners Generally quite enclosed scanners – risk of claustrophobia

ANGIOGRAPHY

AORTOGRAPHY: LEFT RENAL ARTERY THROMBOSIS

Nuclear Medicine

• uses  the  radiation  released  by  radionuclides  (called nuclear decay) to produce images

• A radionuclide, usually technetium-99m, is combined with  different  stable,  metabolically  active compounds  to  form  a  radiopharmaceutical  that localizes  to  a  particular  anatomic  or  diseased structure (target tissue).

• tracer  goes  to  the  target  organ  and  can  then  be imaged with a gamma camera, which takes pictures of  the  radiation photons emitted by  the  radioactive tracer