VQ/CT

About this trial

Last updated 2 years ago

Study ID

VQ/CT

Status

Recruiting

Type

Interventional

Phase

N/A

Placebo

Accepting

18+ Years

All

Not accepting

Healthy Volunteers

Trial Timing

Started 8 years ago

Both, CT scans and VQ scans, are used by doctors to look for pulmonary embolism. The most common reason to order a VQ scan is to avoid the IV dye. The IV dye used for CT scans can cause kidney problems in some patients, called contrast-induced nephropathy or "CIN." This is a kidney problem that usually does not make patients feel any differently or change how they urinate. Most of the time, it can only be found by testing blood several days later. This kind of kidney problem can be very mild and some patients will never have any symptoms, rarely these problems can be severe. Some patients can also have similar kidney problems for many other reasons (reactions to medications, blood pressure problems, etc.) and can even happen in patients that do not get IV dye. That is why doctors are not sure exactly who will have these problems or if using a test that does not use IV dye can prevent this kidney problem. The VQ scan uses a different medication through the IV that is not IV dye and has not been linked to kidney problems. The purpose of this study is to learn if using the test that does not use IV dye (the "VQ scan") instead of a CT scan in some patients can help to prevent kidney problems.

Inclusion Criteria

1. Age≥18 years

2. CTPA ordered by the treating provider to evaluate PE.

3. Pre-test probability of PE ≤20% (defined using the PE Pretest Consult Score)

4. For Randomization to CTPA or VQ imaging: Pre-imaging CIN risk ≥25% (CINRisk Score ≥2 points) • A lower-risk subset of 100 patients (CINRisk Score <2) will be enrolled and followed. These patients will complete the CTPA as ordered by their provider (not randomized). Data from this lower-risk subset, along with high-risk patients randomized to CTPA will be used will be used to validate the CINRisk Score, alone and in combination with NGAL and eGFRCYS (Study Aims 1 and 3).

Exclusion Criteria

1. History of pulmonary surgery or pulmonary infiltrate, mass or effusion on chest radiograph.

2. Clinical instability preventing randomization to CTPA or VQ imaging.

3. Pregnancy or ≤48 hours post-partum

4. Subject unavailability for reasonable follow-up including biological sample collection, serum creatinine measurement, and interview, such as an insecure residence, planned travel or absence, personal or professional obligations, incarceration, and/or other reason preventing follow-up, identified at enrollment.

5. Active renal replacement therapy (hemodialysis or peritoneal dialysis) within 30-days of enrollment or previous physician-directed plans to initiate dialysis within 30-days of the index visit.

6. Prior renal transplant or planned within 30-days of enrollment.

7. Intravascular contrast administration within 14 days prior to enrollment or planned within 7 days of enrollment.

Acute Kidney Injury in Patients Undergoing Contrast Exposure: VQ vs. CT