GOODWILL AND OTHER INTANGIBLE ASSETS

The following table presents goodwill balances and the movements for each of our reportable segments during the six months ended April 30, 2019:



	Life Sciences and Applied Markets		Diagnostics and Genomics			Agilent CrossLab			Total
	(in millions)
Goodwill as of October 31, 2018	$	803	$	1,607		$	563		$	2,973
Foreign currency translation impact	—		(2		)	(1		)	(3		)
Goodwill arising from acquisitions and adjustments	153		(11		)	—			142
Goodwill as of April 30, 2019	$	956	$	1,594		$	562		$	3,112

The components of other intangible assets as of April 30, 2019 and October 31, 2018 are shown in the table below:



	Purchased Other Intangible Assets
	Gross Carrying Amount		Accumulated Amortization and Impairments		Net Book Value
	(in millions)
As of October 31, 2018
Purchased technology	$	947	$	683	$	264
Trademark/Tradename	151		88		63
Customer relationships	107		63		44
Third-party technology and licenses	28		19		9
Total amortizable intangible assets	1,233		853		380
In-Process R&D	111		—		111
Total	$	1,344	$	853	$	491
As of April 30, 2019
Purchased technology	$	1,026	$	720	$	306
Trademark/Tradename	153		95		58
Customer relationships	127		71		56
Third-party technology and licenses	28		21		7
Total amortizable intangible assets	1,334		907		427
In-Process R&D	111		—		111
Total	$	1,445	$	907	$	538

On November 14, 2018, we acquired 100 percent of the stock of ACEA Biosciences (“ACEA”), a developer of cell analysis tools, for approximately $250 million in cash. The financial results of ACEA have been included within our financial results from the date of the close. The purchase accounting for this acquisition is substantially complete and will be finalized during 2019, as we assess the tax impact and finalize the intangibles valuation of the acquisition.

During the six months ended April 30, 2019, we recorded additions to goodwill of $153 million related primarily to the ACEA acquisition within the life sciences and applied markets business. In the second quarter of fiscal year 2019, we recorded a measurement period adjustment to goodwill of $11 million for deferred tax assets related to pre-acquisition net operating losses of Advanced Analytical Technologies, Inc. During the six months ended April 30, 2019, we recorded additions to other intangible assets of $102 million related to the ACEA acquisition.

In general, for United States federal tax purposes, goodwill from asset purchases is deductible, however any goodwill created as part of a stock acquisition is not deductible.

Each quarter we review the events and circumstances to determine if impairment of indefinite-lived intangible assets and goodwill is indicated. There were no indicators of impairments of indefinite-lived intangible assets or goodwill during the three and six months ended April 30, 2019 and 2018, respectively.

Amortization expense of intangible assets was $26 million and $55 million for the three and six months ended April 30, 2019, respectively. Amortization expense of intangible assets was $26 million and $52 million for the three and six months ended and April 30, 2018, respectively.

Future amortization expense related to existing finite-lived purchased intangible assets for the remainder of fiscal year 2019 and for each of the five succeeding fiscal years and thereafter is estimated below:



Estimated future amortization expense:
(in millions)
Remainder of 2019	$	53
2020	$	94
2021	$	81
2022	$	65
2023	$	55
2024	$	46
Thereafter	$	33