Urological Investigations
Overview
Urological disease describes a wide variety of medical conditions that are associated with the filtering of urine and voiding. These include urinary tract infections, kidney stones, urinary incontinence, and erectile dysfunction. Common symptoms of urological diseases that often warrant a urological investigation are:
- Obstructive (Voiding) symptoms: Hesitancy of urination, poor urinary stream, intermittent urinary stream, terminal dribbling
- Irritative (Storage) symptoms: Burning sensation during urination, urinary urgency, increased daytime urination frequency, nocturia, urinary incontinence
- Other symptoms: Haematuria, sexual problems, pain (loin, renal, ureteric, scrotal, suprapubic, and perineal pain), renal colic, loin or pelvic swelling, fever
In order for your urologist to definitively diagnose your condition and ultimately come up with a treatment plan, they conduct a detailed history-taking, physical examination, as well as various urological investigations.
Urinalysis (Urine Tests)
A urine test or urinalysis is a test used to screen, detect, or monitor various health conditions such as urinary tract infections, kidney disease, liver disease, and diabetes. The urine sample is collected using the “clean-catch midstream” method and is sent to a laboratory for further analysis. Urinalysis examines the physical, chemical, and microscopic aspects of the urine. Urine test results may be affected by medications, supplements, and food.
Physical examination
- Colour: Reddish or brownish appearance may be caused by the presence of blood in urine and could indicate urinary tract or kidney infections.
- Odour: Urine with a sweet or fruity odour could indicate diabetic ketoacidosis. Other pathological causes of abnormal urine odour include urinary tract infections, gastrointestinal-bladder fistulas, and cystine decomposition.
- Clarity: Cloudy appearance does not necessarily be a cause for concern, but it may indicate dehydration, sexually transmitted diseases and infections, kidney stones, and diabetes.
Microscopic examination
- Cells: Elevated number of red blood cells, white blood cells, and epithelial cells can indicate various health conditions.
- Casts: Urinary casts are cylindrical structures that can be found in urine and they can be made up of white blood cells, red blood cells, kidney cells, protein, or fat. While the most common forms of casts are benign, others may indicate disease.
- Crystals: Urinary crystals are formed from chemicals concentrated in the urine and may be a sign of kidney stones.
- Bacteria: The presence of elevated bacterial count in the urine is suggestive of urinary tract infection.
A urine cytology test is run to screen or diagnose cancer. It is the microscopic examination of the patient’s urine to detect abnormal cells that may indicate cancer in the urinary tract, namely:
- Bladder cancer
- Urethral cancer
- Ureter cancer
Dipstick test
A dipstick test involves the use of a strip that changes colour when reacting to certain substances present in your urine. It tests for:
- Protein: Abnormal amount of proteins in the urine may be an indication of heart failure, kidney issues, and dehydration.
- pH: Normal urine pH is around 5.5 to 6.5. A high urine pH could indicate kidney issue and urinary tract infections while a low urine pH could indicate diabetic ketoacidosis and diarrhoea.
- Ketones: The presence of ketones in urine may indicate diabetic ketoacidosis.
- Glucose: The presence of glucose in urine may be a sign for diabetes or gestational diabetes.
- Bilirubin: The presence of bilirubin in urine may be a sign of liver or bile duct issues.
- Blood: Hematuria (blood in urine) could be a sign of kidney damage, infection, cancer, or blood disorders.
- Nitrite: A positive nitrite urine test is suggestive of urinary tract infections.
- Leukocyte esterase: The presence of leukocyte esterase could be a sign of inflammation in the urinary tract or kidneys.
- Specific gravity: The test correlates with the osmolality of urine and reveals the hydration status of the patient. It also reflects the ability of the kidneys to concentrate urine.
Urine Culture
Urine culture is used to detect the presence of bacteria colonisation in a urine sample. Sterile pyuria could indicate medical conditions such as urinary stones, transitional cell carcinoma, and urinary tuberculosis.
Blood Test
Blood tests are performed to detect certain diseases or cancers. They include full blood count, prostate-specific antigen test, urea and electrolytes test, and testosterone test.
- Full Blood Count (FBC): A full blood count may reveal anaemia due to underlying medical conditions such as haematuria, chronic renal failure, and renal cell carcinoma. An elevated white blood cell count could indicate infections and inflammatory conditions such as acute ureteric colic and disseminated malignancy.
- Prostate-specific Antigen (PSA) Blood Test: The prostate-specific antigen is produced by the prostate and can be detected in the blood. The test focuses on the detection of inflammation or abnormality of the prostate. It measures the amount of protein released from the prostate gland which increases when there is inflammation or cancer. Another possible cause is enlarged prostate. When high, more investigations may be required.
- Urea and Electrolytes Test: The test measures urea and creatinine levels in the blood and is used to monitor renal function. Creatinine is excreted by the kidneys from the metabolism of creatine and is a direct marker of renal function. High levels of creatinine could indicate issues with kidney function and efficiency.
- Testosterone/Male Hormones Blood Test: It is required to evaluate male erectile dysfunction or fertility issues. A morning test is required.
Imaging Techniques
Imaging tests are performed to determine the causes of abdominal and flank pain and are used to obtain images of internal organs and structures in the abdominal area.
- Ultrasound: An ultrasound uses high-frequency sound waves to produce images of the internal systems, organs, and foreign substances. It is often used in the investigation of renal, ureteric, bladder, prostatic, and scrotal pathology. It can also estimate prostate size and guide biopsies in the diagnosis of prostate cancer.
- Radiography: An abdominal X-ray, also called a kidney, ureter, and bladder (KUB) X-ray, uses electromagnetic energy beams that are focused on the abdominal areas to produce images of internal tissues, bones, and organs on film. It is mainly used to assess and monitor renal stones.
- Computed tomography (CT): CT scan is a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce three-dimensional images of the internal organs and tissues. It is used to detect tumours, lesions, kidney stones, and other kidney diseases.
- Magnetic resonance imaging (MRI): MRI has a better contrast resolution compared to CT scan and it can be used for soft tissue investigation. It is commonly used to image the pelvic organs and in the staging of bladder or prostate cancer.
- Intravenous pyelogram (IVP): It is an imaging test for the kidneys and ureters. It can help to show the size, shape, and structure of the kidneys, ureters, and bladder. During the test, a contrast dye is injected into the veins and monitored as it moves through the entire urinary system.
Urodynamics
Urodynamics is a combination of invasive and non-invasive tests that evaluates the function and efficiency of the lower urinary tract. It provides information on the filling and voiding phases of the lower urinary tract. It is performed due to symptoms such as frequent urination, painful urination, and urine leakage.
Urodynamic investigation evaluates the following:
- Urinary flow rate
- Assessment of bladder capacity and size of residual urine volume
- Measurement of bladder pressures using a urinary catheter during bladder filling and emptying
- Pressure or flow assessment under fluoroscopic imaging (if necessary)
Non-invasive investigations
- Bladder diary: The diary provides information on the severity of the patient’s symptoms. The bladder diary records the times of urination and voided volumes for up to 3 days. Fluid intake and types of fluid taken will be recorded as well. Urgency episodes, as well as urinary incontinence, are noted as well.
- Pad test: The pad test provides an objective assessment of the severity of urinary incontinence. It involves the wearing of pad that is weighed before and after use to estimate urinary leakage over a period of 1 to 24 hours.
- Uroflowmetry: The uroflowmetry is a screening test for the detection of bladder outlet obstruction. It involves urinating into a vessel that measures the rate of flow over time. A representative voided volume should be at least 150ml.
Invasive urodynamics
- Pressure flow studies (PFS): PFS measures the pressures inside the bladder and abdomen simultaneously. Fluid-filled lines connected to pressure transducers are inserted through the urethra and rectum. During voiding, flow rate and voiding pressures can be measured. The test provides information on urinary incontinence and bladder outflow obstruction.
- Urodynamic study/ Video-urodynamic study (UDS/VUDS): A Urodynamic Study is a real-time functional study of the bladder and the outlet and involves the infusion of saline into the bladder via a small urethral catheter. As the bladder fills and then empties, the urologist will be able to assess its storage and voiding patterns to reach a diagnosis of the patient’s issues. The aim of this study is to replicate the patient’s problem so that we can give more specific treatment. A video-UDS uses fluoroscopic imaging during the study to visualise the bladder and pelvis. This is useful in complex cases as real-time imaging of the lower urinary tract can be performed at the same time.
Cysto-urethrography
Cysto-urethrography is an imaging test that uses X-rays to diagnose issues with the bladder and urethra. During the test, a urinary catheter is used to inject contrast dye into the bladder. The contrast dye will allow the bladder to be seen more clearly during the imaging process. It can be combined with other procedures such as in a voiding cystourethrography. In this procedure, fluoroscopy is used to observe the bladder as it empties during urination. We can detect abnormalities like bladder obstruction and urethral strictures in this study.
Cystoscopy
Cystoscopy is a procedure that uses a telescope to look at the inside of the urethra and bladder. A cystoscope is a long, thin, and flexible optical instrument with a light and camera. A cystoscopy is often performed to determine the cause of symptoms such as hematuria, urinary frequency, urinary urgency, and painful urination.
Cystoscopy can be used to detect the following:
- Bladder cancer or tumour
- Polyps of normal tissue
- Bladder stones
- Scarring caused by urinary tract infections
- Abnormalities of the urinary tract
- Injury of the urinary tract
Cystoscopy can help to diagnose urological conditions such as interstitial cystitis, benign prostate hyperplasia and urethral strictures. In addition, cystoscopy can also be combined with other procedures to treat urinary tract problems.
- Removal of stones from the bladder or urethra
- Removal of abnormal tissue or tumour
- Taking a sample of tissue for biopsy
- Injecting medication into the bladder
Summary
As a patient, you may not have to undergo all these urological investigations, and instead, only specific ones that your urologist has deemed fit. Hopefully, this guide has helped better explain what these diagnostic tests are and how they help your urologist diagnose your condition and tailor a treatment to your condition and concerns.
