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On-Table (Single-Shot) IVP

The on-table (intraoperative) IVP (also called a single-shot IVP or one-shot IVP) is a rapid, portable intravenous pyelogram performed during emergency laparotomy, primarily to confirm the presence and function of a contralateral kidney before proceeding with nephrectomy in hemodynamically unstable patients who did not undergo preoperative CT imaging.[1][2] While IVP was historically the cornerstone of urologic imaging, its role has been almost entirely supplanted by CT, except in this narrow intraoperative scenario.[3][4]

Part I: Historical context — the rise and fall of IVP​

The IVP era (1930s–1990s)​

Intravenous urography (IVU / IVP) was introduced into clinical practice in the early 1930s and remained the primary imaging technique for investigation of urinary-system disorders for over 60 years.[4][5] It was the reference standard for evaluating urolithiasis (sensitivity 75–87%, specificity 92–94%),[6] hematuria workup, obstructive uropathy, congenital anomalies, renal masses / cysts / tumors, ureteral pathology and fistulas, and pre-endourological planning.[4][7][8]

The CT revolution​

Modern CT, MR and ultrasound protocols have largely replaced IVP. The appropriate modality depends on the question: suspected stones commonly need noncontrast CT, not automatically CT urography; pregnancy usually starts with ultrasound.[9][10][11] Advantages of CT over IVP:

  • Superior sensitivity for renal masses, small tumors, and calculi.
  • Cross-sectional imaging eliminates overlying bowel-gas artifact.
  • Multiphasic imaging (arterial, nephrographic, excretory) provides comprehensive evaluation.
  • IVP-like reconstructions can be generated from CT data.
  • For urolithiasis: noncontrast CT sensitivity / specificity 85–96% / 98–100% versus IVP 75–87% / 92–94%.[6]

Current ACR stone and hematuria pathways generally favor CT, ultrasound or MR as appropriate.[6][11]

Historical elective indications​

Dalla Palma’s 2001 review described these historical uses:[4]

  • Congenital anomalies of the urinary tract (duplex systems, ectopic ureters).
  • Prior to endourological procedures (providing a "roadmap").
  • Evaluation of possible fistulas.
  • Renal-transplant evaluation.
  • Genitourinary tuberculosis.
  • Ureteral pathology requiring visualization of the entire collecting system and papillae / calyces.

Part II: The on-table / single-shot IVP in trauma​

Definition and purpose​

The on-table IVP is a rapid, portable intraoperative study performed during emergency laparotomy when a renal injury is discovered and preoperative CT imaging was not obtained.[1][3][2] Its primary purpose is to confirm the presence and function of the contralateral kidney before proceeding with nephrectomy.[1][3][2]

Guideline recommendations​

The ACS Best Practices Guidelines (2025) provide the most current and specific guidance:[1]

  • Prior to exploring an injured kidney (especially without preoperative CT), palpate the contralateral kidney.
  • If the contralateral kidney is present and feels normal to palpation, exploration of the injured side can proceed.
  • If the contralateral kidney is absent or abnormal (polycystic, atrophic), give more consideration to renal salvage.
  • A single-shot, on-table IV pyelogram can be considered in this setting, primarily to confirm a functioning contralateral kidney.
  • Do not use it to exclude injury or to identify urinary extravasation alone. It lacks sufficient sensitivity for these purposes.

In rare cases when a patient reaches the operating room without preoperative CT and renal exploration or nephrectomy is being considered, AUA notes that intraoperative one-shot IVP may confirm a functioning contralateral kidney.[17] Its protocol uses 2 mL/kg IV contrast with one image at 10–15 minutes (Statements 3 and 5a discussion); the historical study’s 10-minute technique below remains separately attributed.[17]

The WSES-AAST Guidelines (2019) similarly state that IVU may be useful in unstable patients during surgery when a kidney injury is found intraoperatively or when CT scanning is not available and a urinary-tract injury is suspected (GoR 2C).[3]

The ACS Best Practices Guidelines on Imaging (2018) further specify:[2]

  • An intraoperative single-shot IVP may be used to confirm a contralateral functioning kidney if the patient is taken directly to the OR without CT and is found to require a nephrectomy.
  • Consider IVP in emergent situations if CT imaging is not available.
  • If GU-tract injury is suspected and CT is not available, consider transfer to a higher level of care.

Part III: Technique — the single-shot IVP protocol​

Standard protocol​

The technique is standardized and straightforward:[1][12]

  1. Contrast dose. The historical Morey and AUA one-shot protocols use a 2 mL/kg IV bolus.[12][17] Confirm the selected agent’s concentration and labeled dose with radiology and anesthesia before administration; Ultravist 300 adult excretory-urography labeling specifies 1 mL/kg, maximum 100 mL.[15]
  2. Timing. A single abdominal radiograph (AP KUB) is obtained 10 minutes after contrast injection.
  3. Equipment. A portable X-ray machine is brought into the operating room; the cassette is placed beneath the patient on the OR table.
  4. Interpretation. The study is interpreted immediately by the operating surgeon and/or urologist at the bedside.

Practical considerations​

  • The contrast bolus should be given as a rapid push rather than a slow drip to maximize renal opacification.
  • Before injection, ask anesthesia to review known prior iodinated-contrast reactions, confirm immediate resuscitation readiness, and monitor for hypersensitivity and hemodynamic reactions.[13][15]
  • The 10-minute delay allows contrast to be filtered by the kidneys and opacify the collecting systems.
  • A single film is obtained.
  • The cassette must be positioned to include both renal fossae to evaluate the contralateral kidney.
  • Adequate patient positioning may be challenging in the setting of an open abdomen with packs and retractors.

Contrast agents​

Use the locally available intravenous iodinated contrast formulation, with radiology/anesthesia confirmation of its concentration, injection protocol and product-specific limits. The historical trauma 2 mL/kg protocol is not the labeled dose for every contrast agent.[12]

  • Iodixanol (Visipaque), 270 or 320 mg iodine/mL: for adults with normal renal function, excretory-urography labeling specifies 1 mL/kg, maximum 100 mL. For children younger than 12 years, the 270 mg iodine/mL formulation is labeled at 1–2 mL/kg for CT or excretory urography, maximum 2 mL/kg.[13][14]
  • Iopromide (Ultravist), 300 mg iodine/mL: current US adult excretory-urography labeling specifies 1 mL/kg, maximum 100 mL, distinct from the historical high-dose trauma protocol.[15]

The 2 mL/kg/10-minute technique is directly documented in Morey’s original study.[12] The ACS 2025 PDF prints “2 mg/kg”; that apparent unit error should not be copied into a contrast prescription.[1][12]

Part IV: The landmark study — Morey et al. (1999)​

An early single-center observational study evaluating the quality and utility of the single-shot intraoperative IVP is by Morey, McAninch, et al. from San Francisco General Hospital:[12]

  • 50 patients (1990–1997) underwent single-shot intraoperative IVP for staging renal injuries when clinical instability and / or major associated injuries mandated an intraoperative study.
  • Contrast material (2 mL/kg) was injected IV and images obtained at 10 minutes.[12]
  • Study quality. Average score 3.84/5 (generally good).[12]
  • Clinical usefulness. Average score 3.96/5 (generally useful for determining urological treatment).[12]
  • In 16 patients (32%), intraoperative IVP findings safely obviated renal exploration.[12]
  • No contrast reactions were noted.
  • No complications attributable to intraoperative IVP.

The series supports feasibility in selected emergencies.[12]

Part V: Critical limitations — what the on-table IVP cannot do​

1. High false-negative rate for injury staging​

Historical IVU trauma reports describe false-negative rates of 37–75%.[3] The ACS cautions against using single-shot IVP to exclude injury or as the sole assessment of extravasation, as it lacks sufficient sensitivity in this setting.[1] EAU likewise states that the quality of a one-shot IVP is generally poor and that palpating the contralateral kidney is a pragmatic surrogate of function during emergency laparotomy.[16]

2. Cannot reliably detect ureteral injuries​

IVU is an unreliable test for ureteral injury, with false-negative rates up to 60%.[3][16] ACS and AUA state that intraoperative single-shot IV pyelography cannot reliably exclude ureteral injury. AUA calls for direct inspection when injury is suspected during laparotomy without preoperative imaging .[1][17] For suspected ureteral injury, direct inspection of the ureter during laparotomy is the recommended approach; IV injection of renally excreted dye is one possible adjunct. The ACS guideline names methylene blue or fluorescein, and also lists cystoscopic inspection of ureteral efflux, dye injected into the renal pelvis, and retrograde ureteral catheter passage.[3][1]

3. Cannot adequately stage renal-injury severity​

The on-table IVP cannot reliably differentiate between AAST grades of renal injury, identify vascular injuries, or detect contained vascular injuries (pseudoaneurysms, arteriovenous fistulas) that predict the need for intervention.[1][3]

4. Image-quality limitations​

Several factors degrade image quality in the trauma setting:

  • Hemodynamic instability reduces renal perfusion and contrast excretion.
  • Overlying bowel gas, blood, and surgical instruments obscure anatomy.
  • Patient positioning is suboptimal on the OR table.
  • Single-film technique provides limited anatomic information compared with a multi-film IVP series or CT.

5. Cannot evaluate for bladder injury​

The on-table IVP does not provide adequate bladder distension for evaluation of bladder rupture. Retrograde cystography (conventional or CT) is the diagnostic procedure of choice for bladder injuries.[3][17]

Part VI: What the on-table IVP can do​

Despite its limitations, the on-table IVP provides information in specific scenarios:

Information providedClinical utilityReliability
Contralateral kidney presenceVisible contralateral excretion demonstrates a functioning opposite kidney before nephrectomyA positive study is useful; absent opacification is inconclusive in shock
Contralateral kidney functionDemonstrates contrast excretion, confirming functional renal parenchymaModerate — may be impaired by hypotension
Bilateral contrast excretionShows excretion at the time of imagingDoes not quantify split renal function or exclude bilateral injury
Gross collecting-system disruptionMay identify major UPJ avulsion or massive extravasationLow sensitivity — cannot exclude injury
Absent renal opacificationRaises concern for absent, ectopic, poorly perfused or nonexcreting kidneyNondiagnostic for agenesis by itself
[1][2][3][4]

Part VII: Decision algorithm — when to use the on-table IVP​

The decision to perform an on-table IVP follows a specific clinical algorithm during trauma laparotomy:[1][2]

Step 1. A Zone II retroperitoneal hematoma suggests renal injury. Determine whether renal exploration is indicated before following the IVP steps below. For blunt trauma at laparotomy, ACS advises leaving a nonexpanding Zone II hematoma undisturbed when hemorrhagic shock is attributed to other injuries, then obtaining CT once the patient is stable; the 2023 EAST guideline conditionally recommends against exploring a stable Zone II hematoma identified intraoperatively even in a hemodynamically unstable adult.[1][18]

Step 2. Was preoperative CT imaging obtained?

  • Yes → confirm that the CT depicts a present, perfused contralateral kidney. If the scan is noncontrast or inadequate for that question, proceed to Step 3; otherwise on-table IVP is unnecessary.[16]
  • No → proceed to Step 3.

Step 3. Palpate the contralateral kidney.

  • Normal contralateral kidney palpated → exploration of the injured side can proceed; on-table IVP is optional (may still be performed for documentation).
  • Contralateral kidney absent, abnormal, or cannot be assessed → consider on-table IVP before opening the Zone II hematoma if it can inform management without delaying life-saving hemorrhage control.[1][3]

Step 4. Interpret the IVP.

  • Bilateral functioning kidneys → proceed with exploration / nephrectomy as indicated.
  • Contralateral kidney not opacified → interpret the film as nondiagnostic in shock, palpate the opposite kidney, and prioritize hemorrhage control. Consider renorrhaphy, partial nephrectomy, or vascular repair when bleeding is controlled and viable tissue and physiology permit.[1][16]
  • Non-diagnostic study → consider palpation alone; if nephrectomy is life-saving, proceed with clinical judgment.

Part VIII: Alternatives to the on-table IVP​

  1. Contralateral kidney palpation. It is the simplest and fastest method. The ACS guidelines state that if the contralateral kidney is present and feels normal to palpation, exploration can proceed without imaging.[1] Palpation establishes anatomy, not quantified renal function.
  2. Intraoperative ultrasound. It can confirm the presence of a contralateral kidney but does not assess function. Not widely used for this purpose in trauma.
  3. IV dye injection (methylene blue or fluorescein). For suspected ureteral injury, IV injection of renally excreted dye allows direct visualization of ureteral integrity during laparotomy. The dye is seen exiting the ureteral orifice or leaking from a ureteral laceration. A dye test supplements inspection; visible jets or a negative dye test do not exclude partial or thermal injury. Retrograde pyelography can resolve uncertainty.[3][1]
  4. Intraoperative CT (rare). Some hybrid OR suites have intraoperative CT capability, but this is not widely available and is impractical during damage-control laparotomy.
  5. Postoperative CT. If the patient survives the initial operation and is stabilized, a postoperative CT with delayed phase can be obtained to fully evaluate the urinary tract. This is the preferred approach when the clinical situation allows.[1][3]

Part IX: The on-table IVP in non-trauma surgery​

While the trauma setting is the most common indication, the on-table IVP has historical utility in other surgical contexts:

  • Ureteral assessment during complex pelvic surgery. Because single-shot IVP can miss ureteral injury, use direct inspection and, when needed, retrograde pyelography; IV indigo carmine with cystoscopic visualization of ureteral efflux can supplement inspection.[1][16]
  • Confirmation of renal function before planned nephrectomy in oncologic surgery when preoperative imaging is incomplete.
  • Low-resource settings. Where CT is unavailable, IVP remains a viable diagnostic tool for renal colic, hematuria, and obstructive uropathy.[3][4]

Part X: CT vs. IVP — comparative performance​

ParameterCT (with delayed phase)On-table IVP
Renal-injury detectionCT is the reference test in stable or stabilized patientsHistorical IVU trauma reports give a 37–75% false-negative range[3]
Injury gradingAccurate AAST grading; identifies vascular injury, contrast blush, hematoma sizeCannot reliably grade injuries
Ureteral-injury detectionDelayed-phase CT may identify leakage or obstruction; equivocal cases need further assessmentIVU false negatives up to 60%; EAU calls one-shot IVP especially unreliable[3][16]
Bladder-injury detectionRetrograde CT cystography: approximately 95% sensitivity and 100% specificity[3]Not applicable (inadequate bladder filling)
Contralateral kidney assessmentContrast-enhanced CT shows anatomy and perfusion; delayed images can show excretionVisible collecting-system contrast supports contralateral function before nephrectomy; absent opacification in shock is inconclusive[1][16]
Collecting-system extravasationDelayed-phase CT can show leakage, but excretion may be unreliable in hypovolemia[16]Poor sensitivity
Availability in ORRequires hybrid OR or patient transportPortable X-ray at bedside
Time to usable resultDepends on CT access, transport, and protocolMorey protocol: film at 10 minutes after injection, plus setup and interpretation[12]
Hemodynamic stability requiredYes (for transport)No (performed at bedside)
[1][2][3][4]

Summary — key principles​

  1. Contrast-enhanced CT with appropriate delayed images evaluates suspected renal/ureteral trauma in stable or stabilized patients. Bladder rupture requires retrograde cystography; suspected urethral injury needs urethrography or endoscopy.[3][1]
  2. The on-table IVP is reserved for hemodynamically unstable patients taken directly to the OR without preoperative CT who are found to have a renal injury requiring potential nephrectomy.[1][2]
  3. The primary purpose is to confirm a functioning contralateral kidney; it does not stage the injured kidney or exclude ureteral injury.[1]
  4. Technique. Historical one-shot protocols used a 2 mL/kg IV bolus and one film at 10 minutes (Morey)[12] or 10–15 minutes (AUA)[17]. Check the chosen contrast agent’s labeled dose and maximum before use.[12][17][15]
  5. Because historical IVU trauma reports describe 37–75% false negatives and IVP can be negative in up to 60% of ureteral injuries, a negative study should not be used to exclude injury.[1][3][16]
  6. Palpation of the contralateral kidney is the simplest alternative and is often sufficient to proceed with exploration.[1]
  7. For suspected ureteral injury during laparotomy, direct inspection with IV dye injection (methylene blue or fluorescein, per ACS 2025) is more reliable than IVP.[3][1]
  8. Elective imaging is indication-specific: CT urography for selected hematuria/urothelial questions, noncontrast CT for many stone presentations, and ultrasound or MR where appropriate.[4][9][11]

See Also​

  • Renal Trauma. Clinical context and AAST grading framework.
  • Ureteral Trauma. Direct inspection and IV dye adjuncts.
  • Bladder Trauma. Retrograde cystography is the preferred study.
  • CT Urogram. Imaging for selected renal and ureteral trauma in stable or stabilized patients; bladder and urethral injury require dedicated tests.[3]
  • Cystography. CT and fluoroscopic cystography for bladder injury.
  • Intraoperative Consultation. The operational framework for iatrogenic urinary-tract injury.

References​

1. Johnsen N, Wessells H, Archer-Arroyo K, et al. Best Practices Guidelines: Management of Genitourinary Injuries. American College of Surgeons; 2025.

2. Tominaga GT, Bernstein M, Aquino MR, et al. Best Practices Guidelines in Imaging. American College of Surgeons; 2018.

3. Coccolini F, Moore EE, Kluger Y, et al. "Kidney and uro-trauma: WSES-AAST guidelines." World J Emerg Surg. 2019;14:54. doi:10.1186/s13017-019-0274-x

4. Dalla Palma L. "What is left of i.v. urography?" Eur Radiol. 2001;11(6):931–939. doi:10.1007/s003300000801

5. Elkin M. "Stages in the growth of uroradiology." Radiology. 1990;175(2):297–306. doi:10.1148/radiology.175.2.2183276

6. Gupta RT, Kalisz K, Khatri G, et al. "ACR Appropriateness Criteria® acute onset flank pain — suspicion of stone disease (urolithiasis)." J Am Coll Radiol. 2023;20(11S):S315–S328. doi:10.1016/j.jacr.2023.08.020

7. National Library of Medicine (MedlinePlus). Intravenous pyelogram (IVP).

8. Bell EG, McAfee JG, Makhuli ZN. "Medical imaging of renal diseases — suggested indication for different modalities." Semin Nucl Med. 1981;11(2):105–127. doi:10.1016/s0001-2998(81)80041-4

9. Silverman SG, Leyendecker JR, Amis ES. "What is the current role of CT urography and MR urography in the evaluation of the urinary tract?" Radiology. 2009;250(2):309–323. doi:10.1148/radiol.2502080534

10. Choyke PL. "Radiologic evaluation of hematuria: guidelines from the American College of Radiology's Appropriateness Criteria." Am Fam Physician. 2008;78(3):347–352. PMID 18711950

11. Wolfman DJ, Marko J, Nikolaidis P, et al. "ACR Appropriateness Criteria® hematuria." J Am Coll Radiol. 2020;17(5S):S138–S147. doi:10.1016/j.jacr.2020.01.028

12. Morey AF, McAninch JW, Tiller BK, Duckett CP, Carroll PR. "Single shot intraoperative excretory urography for the immediate evaluation of renal trauma." J Urol. 1999;161(4):1088–1092. doi:10.1016/S0022-5347(01)61597-0.

13. DailyMed. Visipaque prescribing information. Sections 2.1–2.4. Accessed September 2026.

14. DailyMed. Iodixanol (Visipaque) label PDF. Accessed September 2026.

15. DailyMed. Ultravist prescribing information. Section 2.3, adult intravenous dosing. Accessed September 2026.

16. Waterloos M, Campos-Juanatey F, Hallscheidt P, et al. EAU Guidelines on Urological Trauma. Limited update, March 2026. Sections 4.1.2.b.3 and 4.2.2.b. Guideline

17. Morey AF, Broghammer JA, Hollowell CMP, et al. Urotrauma Guideline 2020: AUA Guideline. J Urol. 2021;205(1):30–35. doi:10.1097/JU.0000000000001408. Full guideline, published 2014; amended April 2017 and August 2020.

18. Abdel Aziz H, Bugaev N, Baltazar G, et al. "Management of adult renal trauma: a practice management guideline from the eastern association for the surgery of trauma." BMC Surg. 2023;23(1):22. doi:10.1186/s12893-023-01914-x