science

Retrograde urethrogram

Retrograde urethrogram is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Retrograde urethrogram rather than just read about it. In short: A retrograde urethrography is a routine radiologic procedure (most typically in males) used to image the integrity of the urethra. Hence a retrograde urethrogram is essential for diagnosis of urethral injury, or urethral stricture.

Key takeaways

Retrograde urethrogram belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Retrograde urethrogram to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Retrograde urethrogram from memory before moving on to harder problems.

Reference excerpt

A retrograde urethrography is a routine radiologic procedure (most typically in males) used to image the integrity of the urethra. Hence a retrograde urethrogram is essential for diagnosis of urethral injury, or urethral stricture.

Uses Some indications for retrograde urethrogram are: urethral stricture, urethral trauma, urethral fistula and congenital urethral abnormalities. There is no absolute contraindication for retrograde urethrogram. There are several relative contraindications such as: allergy to contrast agents, acute urinary tract infection, and recent instrumentation of urethra.

Procedure A low osmolar contrast agent with concentration of 200 to 300 mg per ml with volume of 20 ml can be used in this study. Warming the contrast medium before infusion into the urethra can help to reduce the chance of getting spasm of external urethral sphincter. The subject lies down in a supine position. An 8 Fr Foley catheter is connected to a 50 ml syringe. The syringe is flushed to remove any air bubbles within the Foley catheter and the syringe. The tip of the catheter is then inserted into the urethra using aseptic technique until it is parked inside the navicular fossa. The navicular fossa is located just a short distance proximal to the urethral meatus within the glans penis. The balloon of the Foley catheter is then inflated with 2 to 3 ml of water to anchor the catheter and occlude the meatus, thus preventing contrast material from leaking out from the penis. Contrast material is then injected from the syringe with fluoroscopy to visualise the flow of contrast within the penis. The catheter is gently pulled to straighten the penis over the leg of the same side to prevent the overlapping of any pathology in the posterior urethrae. Spot images are taken at 30 to 45 degrees to visualise the entire spongy urethra (penile urethra). If there is no contraindication to full urinary catheterisation such as false passage or stricture, the urinary catheter should be inserted until the urinary bladder to perform voiding cystourethrography to visualise the prostatic urethra and membranous urethra. Filling up the bladder with contrast material without full catheterisation (the end of catheter inside the urethra) is also possible if the subject is able to relax the bladder neck to allow contrast material to flow into the bladder. If a urethral injury is suspected, a retrograde urethrography should be performed before attempting to place a Foley catheter into the bladder. If there is a urethral disruption, a suprapubic catheter should be placed.

Complications Among the possible complications are: urinary tract infection, urethral trauma, and intravasation of contrast medium (contrast going into blood vessels) if excessive pressure is used to overcome a stricture.

See also Retrograde ureteral, an intervention used to remove kidney stones

References

External links New England Journal of Medicine procedure videos: Male Urethral catheterization Ohio State University Patient Education Materials: Retrograde Urethrogram Archived 2010-06-24 at the Wayback Machine

Illustrations

Worked examples

Example 1 — a first encounter with Retrograde urethrogram

Start with the simplest possible case. Write down what Retrograde urethrogram claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Retrograde urethrogram before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Retrograde urethrogram ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Retrograde urethrogram

In research: Retrograde urethrogram appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Retrograde urethrogram in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Retrograde urethrogram is common in secondary-school and first-year university syllabi. It links to neighbouring topics Medical treatment stubs, Projectional radiography, Urethra, so understanding it makes those chapters shorter.
In everyday life: Look for Retrograde urethrogram outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Retrograde urethrogram in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Retrograde urethrogram means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Retrograde urethrogram out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Retrograde urethrogram in simple terms?

Why does Retrograde urethrogram matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Retrograde urethrogram?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Retrograde urethrogram.