Kidney Stone Analysis
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Managing patients with recurrent renal calculi
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Infrared Spectrum Analysis
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Kidney Stone Analysis
Calculus (Stone) Analysis
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Sources: Bladder, kidney, prostatic, renal, or urinary
Container/Tube: Stone Analysis Collection Kit (Supply T550)
Specimen Volume: Entire dried calculi specimen
1. Prepare specimen per Kidney Stone Analysis Patient Collection Instructions in Special Instructions.
2. Transport specimen per Kidney Stone Analysis Packaging Instructions in Special Instructions.
1. Specimen source is required.
2. Specimen must be sent clean and dry.
3. Do not place stone directly in a bag. If specimen is received in a bag, either transfer stone into a screw-capped, plastic container or place bag containing stone in a screw-capped, plastic container.
Forms: If not ordering electronically, submit a General Request Form (Supply T239) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Embedded in tissue, sent with collection devices, sent in fluid-filled containers, or sent with significant non-stone debris
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
The composition of urinary stones may vary from a simple crystal to a complex mixture containing several different species of crystals. The composition of the nidus (center) may be entirely different from that of the peripheral layers.
Eighty percent of patients with kidney stones have a history of recurrent stone formation. Knowledge of stone composition is necessary to guide therapy of patients with recurrent stone formation.
Treatment of urinary calculi is complex.(1) In an overly simplified format, the following patterns are often treated as follows:
-Hyperuricuria and predominately uric acid stones: alkalinize urine to increase uric acid solubility.
-Hypercalciuria and predominately hydroxyapatite stones: acidify urine to increase calcium solubility. However, treatment also depends on urine pH and urine phosphate, sulfate, oxalate, and citrate concentrations.
-Hyperoxaluria and calcium oxalate stones: increase daily fluid intake and consider reduction of daily calcium. However, daily requirements for calcium to maintain good bone formation complicate the treatment.
-Magnesium ammonium phosphate stones (struvite): Investigate and treat urinary tract infection.
See Kidney Stones and Stone Analysis in Publications.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
The interpretation of stone analysis results is complex, and beyond the scope of this text. We refer you to chapter 25 of Smith LH: Diseases of the Kidney. Vol 1. Fourth edition. Edited by RW Schrier, CW Gottscholk. Boston, MA, Little, Brown and Company, 1987.
Calcium oxalate stones:
-Production of calcium oxalate stones consisting of oxalate dihydrate indicate that the stone is newly formed and current urine constituents can be used to assess the importance of supersaturation.
-Production of calcium oxalate stones consisting of oxalate monohydrate indicate an old (>2 months since formed) stone and current urine composition may not be meaningful.
Magnesium ammonium phosphate stones (struvite):
-Production of magnesium ammonium phosphate stones (struvite) indicates that the cause of stone formation was infection.
-Treatment of the infection is the only way to inhibit further stone formation.
-Certain herbal and over-the-counter preparations (eg, Mah Jung) contain high levels of ephedrine and guaifenesin. Excessive consumption of these products can lead to the formation of ephedrine/guaifenesin stones.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
No significant cautionary statements
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Lieske JC, Segura JW: Evaluation and medical management of kidney stones. In Essential Urology: A Guide to Clinical Practice. Edited by JM Potts. Totowa, NJ, Humana Press, 2004, pp 117-152
2. Lieske JC: Pathophysiology and evaluation of obstructive uropathy. In Smith's Textbook of Endourology. Second edition. Edited by AD Smith, B Gopal Badlani, D Bagley, et al. Hamilton, Ontario, Canada, BC Decker Inc., 2007, pp 101-106
Method Description Describes how the test is performed and provides a method-specific reference
Representative specimens are taken from all identifiable layers of the calculus. Each specimen is weighed and crushed into a fine powder. An infrared spectrum of each specimen is recorded and the resulting spectrum compared against reference spectra of all known calculus components. This procedure allows for accurate analyses of complex crystal mixtures as well as the hydration state of each crystal type.(Hesse A, Bach D: Stone analysis by infrared spectroscopy. In Urinary Stones: Critical and Laboratory Aspects. Edited by GA Rose. Baltimore, MD, University Park Press, 1982)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday; 8 a.m. - 8 p.m./Continuously
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|8596||Kidney Stone Analysis||40787-4|
|2440||1st Constituent:||In Process|
|2441||2nd Constituent:||In Process|
|2442||3rd Constituent:||In Process|
|2443||Nidus, Major||In Process|
|2444||Nidus, Minor||In Process|
|2445||Shell, Major||In Process|
|2446||Shell, Minor||In Process|