Note 3 - Fair Value Measurement	3 Months Ended
Note 3 - Fair Value Measurement	Mar. 31, 2019
Notes to Financial Statements
Fair Value Disclosures [Text Block]	3. Fair value measurement As a basis for determining the fair value of certain of the Company’s financial instruments, the Company utilizes a three -tier value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1—Observable inputs such as quoted prices in active markets for identical assets or liabilities. Level 2—Observable inputs, other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. This hierarchy requires the Company to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value. The carrying amount of certain of the Company’s financial instruments, including cash, accounts receivable, prepaid expenses and other assets, accounts payable, and accrued liabilities approximate fair value due to their short term nature. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the entire fair value measurement requires management to make judgments and consider factors specific to the asset or liability. The Company had a term loan outstanding under an agreement with MidCap Financial Trust, or MidCap, at March 31, 2018. The amount outstanding on the term loan was reported at its carrying value in the accompanying balance sheet at that date. The estimated fair value of the term loan , based upon market rates at the time for similar borrowings, as measured using Level 2 inputs, approximated the carrying amount as presented on the consolidated balance sheets. In connection with the sale of the U.S. Laboratory Services Business to Quest on November 6, 2018, approximately $32.3 million of the gross proceeds received pursuant to the Transaction, was paid directly to MidCap to repay the outstanding indebtedness under an agreement with MidCap Financial Trust, or the MidCap Agreement, which included prepayment and exit fees of approximately $2.3 million (see Note 8. Loans payable ).

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.