AIM • KMU EXAM PRACTICE

Question:

A 41-year-old man passes a hard, irregular renal calculus. Plain X-ray KUB shows the stone clearly, and no evidence of urinary infection is present. Which stone composition is most consistent with these findings?

Uric acid stone

Cystine stone

Calcium oxalate stone

Struvite stone

Pure cystine calculus

Correct Answer: Calcium oxalate stone

Explanation: Calcium oxalate calculi are commonly hard, irregular and radiopaque because of their calcium content.

Question:

A 36-year-old man with known ureteric stone initially has flank pain. Several hours later, he develops marked urinary frequency and urgency with pain extending toward the groin. Which location best explains the change in symptoms?

Distal ureter near the vesicoureteric junction

Upper renal calyx

Renal cortex

Proximal renal artery

Upper pole renal parenchyma

Correct Answer: Distal ureter near the vesicoureteric junction

Explanation: As a calculus approaches the lower ureter and vesicoureteric junction, irritation of the bladder region commonly produces frequency and urgency.

Question:

A recurrent calcium-stone former completes metabolic evaluation. Urinary citrate is persistently low, while renal function is preserved. Which preventive strategy most directly addresses this abnormality?

Long-term antimicrobial treatment

Urinary acidification therapy

Alpha-adrenergic receptor blockade

Routine ureteric stenting

Citrate supplementation to increase urinary citrate

Correct Answer: Citrate supplementation to increase urinary citrate

Explanation: Citrate binds urinary calcium and reduces calcium crystallization; replacement is therefore useful when hypocitraturia contributes to recurrence.

Question:

A 52-year-old man has recurrent stone disease associated with excessive urinary uric acid production. Adequate hydration and correction of urine pH have been addressed, but hyperuricosuria remains significant. Which additional medical approach is most appropriate?

Thiazide-type therapy

Urate-lowering therapy

Long-term ureteric stenting

Selective renal embolization

Urinary acidification therapy

Correct Answer: Urate-lowering therapy

Explanation: When excess uric acid production or hyperuricosuria contributes to recurrence, urate-lowering treatment targets the underlying metabolic abnormality.

Question:

A patient undergoes treatment for a large infection-related renal calculus. Follow-up urine cultures continue to show the same urease-producing organism. Which measure is most important for reducing further formation of the same stone type?

Increase urinary calcium excretion

Maintain persistently acidic serum pH

Begin routine alpha-blocker therapy

Eradicate the persistent urease-producing infection

Reduce renal cortical perfusion

Correct Answer: Eradicate the persistent urease-producing infection

Explanation: Persistent urease activity maintains alkaline urine and favors continued struvite precipitation, so infection control is essential to prevent recurrence.

Question:

A 45-year-old man with previous calcium stones has no major metabolic abnormality on repeat testing, but his 24-hour urinary volume remains very low. Which preventive change most directly reduces the physicochemical drive for new stones?

Increase urine volume to reduce solute supersaturation

Increase urinary ammonia production

Reduce urinary citrate excretion

Increase urinary calcium concentration

Increase crystal retention within the kidney

Correct Answer: Increase urine volume to reduce solute supersaturation

Explanation: Greater urine volume dilutes stone-forming solutes and lowers supersaturation, decreasing the likelihood of nucleation and crystal growth.

Question:

A 48-year-old man with a solitary functioning kidney presents with his first documented renal calculus. The acute episode resolves without loss of renal function. What is the most appropriate longer-term approach?

Discharge without further assessment

Use analgesia only for future attacks

Schedule routine nephrectomy

Perform detailed metabolic evaluation

Begin indefinite antimicrobial prophylaxis

Correct Answer: Perform detailed metabolic evaluation

Explanation: A solitary functioning kidney places the patient in a higher-risk group because recurrent obstruction can threaten the patient’s remaining renal function.

Question:

A 34-year-old man with acute ureteric obstruction repeatedly changes position because of severe wave-like flank pain, while abdominal examination shows no guarding or rigidity. Which mechanism best explains the characteristic pain pattern?

Renal cortical ischemia without obstruction

Ureteric contraction against an obstructing calculus

Bladder detrusor paralysis

Glomerular capillary inflammation

Renal capsular fibrosis without distension

Correct Answer: Ureteric contraction against an obstructing calculus

Explanation: Obstruction produces ureteric distension and vigorous smooth-muscle contraction, generating intermittent colicky pain and characteristic restlessness.

Question:

A patient with bilateral urinary calculi develops worsening hydronephrosis and a progressive rise in serum creatinine despite adequate analgesia. Which principle most strongly justifies active urological intervention?

All urinary calculi require immediate surgery

Hematuria alone indicates renal failure

Pain severity predicts stone composition

Radiopaque stones cannot pass spontaneously

Relieve obstruction to protect renal function

Correct Answer: Relieve obstruction to protect renal function

Explanation: Progressive renal impairment indicates that obstruction is threatening kidney function, making decompression or definitive intervention necessary.

Question:

A hemodynamically stable man sustains a penetrating flank injury. CT demonstrates a narrow injury tract extending through renal parenchyma toward the collecting system. Which mechanism best accounts for the pattern of renal damage?

Gradual metabolic crystal deposition

Isolated ureteric smooth-muscle spasm

Direct tissue disruption along the penetrating tract

Immune-mediated cortical inflammation

Progressive tubular crystal aggregation

Correct Answer: Direct tissue disruption along the penetrating tract

Explanation: Penetrating trauma can directly injure renal parenchyma, the collecting system and vessels along the path of the penetrating object.

Question:

A 29-year-old man arrives after major blunt abdominal trauma. He has flank bruising and suspected renal injury, but he is also hypotensive with compromised ventilation. What should occur before detailed renal grading?

Stabilize airway, breathing and circulation

Perform metabolic stone evaluation

Obtain a DMSA cortical scan

Analyze urinary crystal morphology

Arrange elective ureteroscopy

Correct Answer: Stabilize airway, breathing and circulation

Explanation: Renal trauma is managed within general trauma priorities; life-threatening airway, breathing and circulatory problems take precedence over anatomical renal assessment.

Question:

A stable patient with blunt renal trauma undergoes contrast-enhanced CT. A deep laceration is seen, but initial images do not clearly show whether the collecting system is disrupted. Which modification is most useful for answering this question?

Replace CT with plain KUB

Perform immediate DMSA imaging

Obtain only a non-contrast CT phase

Use a plain abdominal radiograph

Obtain delayed-phase CT images

Correct Answer: Obtain delayed-phase CT images

Explanation: Delayed CT images allow excreted contrast to enter the collecting system and can reveal urinary extravasation from collecting-system injury.

Question:

A stable patient with renal trauma is being managed non-operatively. Six hours later, which finding would most strongly raise concern that bleeding is continuing and the management plan needs reassessment?

Stable urine output with unchanged observations

Progressive fall in hemoglobin with worsening tachycardia

Improving flank tenderness with stable hemoglobin

Resolution of microscopic hematuria

Normal serum creatinine with stable vital signs

Correct Answer: Progressive fall in hemoglobin with worsening tachycardia

Explanation: A falling hemoglobin together with deteriorating vital signs suggests ongoing blood loss and requires reassessment of conservative management.

Question:

CT in a stable trauma patient demonstrates a high-grade renal injury. The surgical team decides against immediate open exploration because bleeding is controlled and the patient remains physiologically stable. Which principle best supports this decision?

Renal injury grade has no clinical value

Hematuria alone determines the need for surgery

All deep renal injuries require nephrectomy

Combine anatomical grade with hemodynamic status

Urine color is more important than CT findings

Correct Answer: Combine anatomical grade with hemodynamic status

Explanation: Trauma grade describes anatomy, but management also depends heavily on physiological stability and evidence of ongoing hemorrhage.

Question:

A patient with severe renal trauma undergoes emergency exploration for uncontrolled hemorrhage. The kidney is extensively destroyed and bleeding cannot be controlled while preserving viable tissue. Which circumstance most strongly supports nephrectomy?

Microscopic hematuria with stable blood pressure

Small subcapsular hematoma without laceration

Unsavable kidney with life-threatening bleeding

Transient flank tenderness after blunt injury

Isolated urinary extravasation in a stable patient

Correct Answer: Unsavable kidney with life-threatening bleeding

Explanation: Renal preservation is preferred when safe; nephrectomy is reserved for an unsalvageable kidney or bleeding that cannot otherwise be controlled.

Question:

A patient with a known radiopaque renal calculus undergoes fragmentation therapy. At follow-up, the clinician wants a simple investigation to compare the residual radiopaque stone burden with previous films. Which modality is most suitable for this limited purpose?

DMSA cortical scintigraphy

MAG-3 renography

Contrast renal angiography

MR urography

Plain X-ray KUB

Correct Answer: Plain X-ray KUB

Explanation: Plain KUB is useful for identifying and following known radiopaque calculi when detailed assessment of obstruction or surrounding structures is not required.

Question:

A patient with impaired renal filtration requires dynamic nuclear assessment of renal drainage. MAG-3 is selected because it remains efficiently handled by the kidney. Which characteristic best explains this advantage?

Efficient tubular extraction and secretion

Exclusive binding to renal cortical scars

Complete dependence on glomerular filtration

Selective accumulation in urinary stones

Direct visualization of ureteric epithelium

Correct Answer: Efficient tubular extraction and secretion

Explanation: MAG-3 is predominantly handled by tubular secretion and has efficient renal extraction, making it useful for dynamic functional and drainage assessment.

Question:

A dynamic renal study shows prompt tracer arrival and satisfactory renal uptake, but tracer remains within the collecting system with markedly delayed washout. Which component of renal function is most abnormal?

Renal arterial perfusion

Initial cortical tracer uptake

Tracer excretion from the collecting system

Stone mineral composition

Renal cortical morphology

Correct Answer: Tracer excretion from the collecting system

Explanation: Normal arrival and uptake with delayed washout indicates impaired urinary drainage rather than a primary perfusion or uptake abnormality.

Question:

A pregnant patient has persistent severe urinary symptoms. Ultrasound is inconclusive, and further assessment is clinically important to avoid harm from an undiagnosed urinary complication. Which principle should guide the decision about additional imaging?

Withhold all further imaging until after delivery

Use CT routinely after every inconclusive ultrasound

Use plain KUB as the routine next investigation

Use necessary imaging when maternal benefit outweighs fetal risk

Use nuclear imaging before considering MRI

Correct Answer: Use necessary imaging when maternal benefit outweighs fetal risk

Explanation: Pregnancy requires minimization of ionizing radiation, but a clinically necessary investigation should not be withheld when the expected maternal benefit justifies the fetal risk.

Question:

Two patients undergo dynamic renal scintigraphy. One study uses DTPA and the other uses MAG-3. Which statement correctly distinguishes the renal handling of these tracers?

Both tracers localize predominantly within renal cortex without excretion

DTPA reflects glomerular filtration while MAG-3 relies mainly on tubular secretion

DTPA is secreted by tubules while MAG-3 is filtered exclusively by glomeruli

Both tracers are used mainly to identify renal cortical scars

Neither tracer provides information about urinary drainage

Correct Answer: DTPA reflects glomerular filtration while MAG-3 relies mainly on tubular secretion

Explanation: DTPA is predominantly filtered by glomeruli, whereas MAG-3 is mainly handled by tubular secretion; both can contribute to dynamic functional assessment.