Renee Rutledge, MS4 Diagnostic Radiology Elective.
-
Upload
maude-nelson -
Category
Documents
-
view
217 -
download
0
Transcript of Renee Rutledge, MS4 Diagnostic Radiology Elective.
![Page 1: Renee Rutledge, MS4 Diagnostic Radiology Elective.](https://reader036.fdocuments.in/reader036/viewer/2022082506/56649ced5503460f949b976c/html5/thumbnails/1.jpg)
UTILITY OF RENAL COLIC CT IN ACUTE
FLANK PAIN
Renee Rutledge, MS4Diagnostic Radiology Elective
![Page 2: Renee Rutledge, MS4 Diagnostic Radiology Elective.](https://reader036.fdocuments.in/reader036/viewer/2022082506/56649ced5503460f949b976c/html5/thumbnails/2.jpg)
The New Gold Standard for Detecting Ureteral Calculi…
Renal colic CT first proposed for work-up of flank pain in 1995 (Smith et al), vs intravenous urography which was the gold standard at that time
Since then has been shown to have sensitivity of 97%, specificity of 96%, and accuracy of 97%.
Detects presence, size and location of stones and +/- obstruction
‘00 Case Western ED study found CT significantly increased emergency department clinician diagnostic confidence
![Page 3: Renee Rutledge, MS4 Diagnostic Radiology Elective.](https://reader036.fdocuments.in/reader036/viewer/2022082506/56649ced5503460f949b976c/html5/thumbnails/3.jpg)
Disadvantages
Radiation Dose: Estimated effective dose 8.5mSv
Cost: $1100 at OHSU Most important, estimated relative rate of
recurrence is 35.3% over 10 years...do we expose them to cost/radiation each time they have acute onset flank pain?
![Page 4: Renee Rutledge, MS4 Diagnostic Radiology Elective.](https://reader036.fdocuments.in/reader036/viewer/2022082506/56649ced5503460f949b976c/html5/thumbnails/4.jpg)
Radiation Dose
U Penn study calculated estimated effective doses for patients from renal colic CTs performed over a 6 year period
5564 studies, 144 studies on pediatric pts (age 2-17 years)
Mean effective dose of 8.5 mSv (vs 0.7 mSv for KUB) 176 pts had 3 or more exams, 19 pts had ≥6 & 1 pt
had 18! Estimated cumulative effective doses from 19.5 to 153.7 mSv. All patients with multiple examinations had a known history
of nephrolithiasis. Estimated risk of cancer induction from a 10 mSv
ionizing radiation dose is 1 in 1000 (1 in 2000 fatal) Cancer induction rate for 100mSv is 1/100!
![Page 5: Renee Rutledge, MS4 Diagnostic Radiology Elective.](https://reader036.fdocuments.in/reader036/viewer/2022082506/56649ced5503460f949b976c/html5/thumbnails/5.jpg)
Other diagnostic imaging options
Italian study compared renal colic CT vs KUB + US with the following conclusions:
Renal colic CT KUB + US -Sens 92.4% -Sens 77.1%
-Spec 96.4% -Spec 92.7% -PPV 98% -PPV 95.3% -NPV 86.9% -NPV 68% Overall accuracy of CT was better (94 vs 83%)
but... No clinically important misdiagnoses
All missed stoned passed spontaneously
![Page 6: Renee Rutledge, MS4 Diagnostic Radiology Elective.](https://reader036.fdocuments.in/reader036/viewer/2022082506/56649ced5503460f949b976c/html5/thumbnails/6.jpg)
Clinical Predictors
Elton et al conducted a study of 203 pts with proven ureteral calculi
The following four-finding prediction rule correctly classified 90% of patients presenting to the ED 1. Acute onset2. Flank pain3. Hematuria4. Positive KUB radiograph
![Page 7: Renee Rutledge, MS4 Diagnostic Radiology Elective.](https://reader036.fdocuments.in/reader036/viewer/2022082506/56649ced5503460f949b976c/html5/thumbnails/7.jpg)
Evidence Based Physical Diagnosis by Stephen McGee
Physical findings in ureterolithiasis Study of 1333 pts with acute abdominal pain Microscopic hematuria had a sensitivity of
75%, specificity of 99%, positive Likelihood Ratio of 73.1 & negative LR of 0.3
Loin tenderness had a sensitivity of only 15% but specificity of 99%, +LR 27.7, -LR 0.9
Renal tenderness had a sensitivity of 86%, specificity 76%, +LR 3.6, -LR 0.2
![Page 8: Renee Rutledge, MS4 Diagnostic Radiology Elective.](https://reader036.fdocuments.in/reader036/viewer/2022082506/56649ced5503460f949b976c/html5/thumbnails/8.jpg)
Is a +LR of 73 significant?
LR of 1 indicates no change in pre & post-test probability, the higher the positive LR & lower the negative LR the greater the “diagnostic weight”
![Page 9: Renee Rutledge, MS4 Diagnostic Radiology Elective.](https://reader036.fdocuments.in/reader036/viewer/2022082506/56649ced5503460f949b976c/html5/thumbnails/9.jpg)
Does the exact size/location of stone change treatment?
Up to 98% of stones ≤5mm pass spontaneously with supportive care such as hydration & pain control
Urgent urologic consultation warranted in pts with urosepsis, acute renal failure, anuria or intractable pain/nausea/vomiting…all noted w/o CT
Urologic intervention is indicated in pts with a stone ≥10 mm in diameter (visible on KUB) and in patients who fail to pass the stone after a trial of conservative management.
Alternative diagnoses detected with renal colic CT like ovarian pathology, pylonephritis, appendicitis and diverticulitis hopefully have other clinical/laboratory findings to point us in that direction.
![Page 10: Renee Rutledge, MS4 Diagnostic Radiology Elective.](https://reader036.fdocuments.in/reader036/viewer/2022082506/56649ced5503460f949b976c/html5/thumbnails/10.jpg)
Your call, but my humble suggestion is…
In a young patient with a high pretest probability (acute, unilateral flank pain with hematuria)…consider omitting the CT & avoiding the radiation.
In older patients with fever, leukocytosis, normal UA or other confounding factors, scan away!
![Page 11: Renee Rutledge, MS4 Diagnostic Radiology Elective.](https://reader036.fdocuments.in/reader036/viewer/2022082506/56649ced5503460f949b976c/html5/thumbnails/11.jpg)
Sources Smith, RC, AT Rosenfield, KA Choe, KR Essenmacher, M Verga, MG Glickman
& RC Lange. "Acute flank pain: comparison of non-contrast-enhanced CT and intravenous urography.." Radiology 194(1995): 789-94.
Abramson, Simeon, N Walders, KE Applegate, RC Gilkeson & MR Robbin. "Impact in the Emergency Department of Unenhanced CT on Diagnostic Confidence and Therapeutic Efficacy in Patients with Suspected Renal Colic ." American Journal of Roentgenology 175(2000): 1689-95.
Katz, SI, S Saluja, JA Brink & HP Forman. "Radiation Dose Associated with Unenhanced CT for Suspected Renal Colic: Impact of Repetitive Studies ." American Journal of Roentgenology 186(2006): 1120-24.
Catalano, Orlando, A Nunziata, F Altei & A Siani. "Suspected ureteral colic: primary helical CT versus selective helical CT after unenhanced radiography and sonography.." American Journal of Roentgenology 178(2002): 379-387.
Elton, TJ, CS Roth, TH Berquist & MD Silverstein. "A clinical prediction rule for the diagnosis of ureteral calculi in emergency departments. ." Journal of General Internal Medicine 8(1993): 57-62.
McGee, Stephen. Evidence Based Physical Diagnosis. 2nd. St Louis: Elsevier, 2007.
Segura, JW, GM Preminger, DG Assimos, SP Dretler, RI Kahn, JE Lingeman & JN Macaluso Jr. "Ureteral Stones Clinical Guidelines Panel summary report on the management of ureteral calculi. The American Urological Association.." The Journal of Urology 158(1997): 1915-21.