UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

SCHEDULE 13G/A

(Amendment No. 2)

(Rule 13d-102)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO

RULES 13d-1(b), (c) AND (d) AND AMENDMENTS THERETO FILED

PURSUANT TO RULE 13d-2(b)

MGC Diagnostics Corporation

(Name of Issuer)

Common Stock, $0.10 Par Value

(Title of Class of Securities)

552768103

(CUSIP Number)

December 31, 2017

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

☐ Rule 13d-1(b)

☒ Rule 13d-1(c)

☐ Rule 13d-1(d)

CUSIP No. 552768103 13G/A

1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Bradley Louis Radoff
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a)  ☐        (b)  ☐
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION United States of America
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5	SOLE VOTING POWER 0
		6	SHARED VOTING POWER 0
		7	SOLE DISPOSITIVE POWER 0
		8	SHARED DISPOSITIVE POWER 0
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 0
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* ☐
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 0.0%
12	TYPE OF REPORTING PERSON* IN

* SEE INSTRUCTIONS BEFORE FILLING OUT

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SCHEDULE 13G/A

This Amendment No. 2 to the Schedule 13G (this “Amendment”) is being filed on behalf of Bradley Louis Radoff relating to Common Stock, $0.10 Par Value (the “Common Stock”), of MGC Diagnostics Corporation, a Minnesota corporation (the “Issuer”), purchased by Mr. Radoff. This Amendment is being filed to report that the Reporting Persons no longer own shares of Common Stock of the Issuer.

Item 1(a) Name of Issuer.

MGC Diagnostics Corporation

Item 1(b) Address of Issuer’s Principal Executive Offices.

350 Oak Grove Parkway

Saint Paul, Minnesota 55127-8599

Item 2(a) Name of Person Filing.

Mr. Bradley Louis Radoff

Item 2(b) Address of Principal Business Office, or, if none, Residence

1177 West Loop South

Suite 1625

Houston, Texas 77027

Item 2(c) Place of Organization.

Mr. Radoff is a U.S. citizen.

Item 2(d) Title of Class of Securities.

Common Stock, $0.10 Par Value (the “Common Stock”)

Item 2(e) CUSIP Number.

552768103

Item 3 Reporting Person.

The person filing is not listed in Items 3(a) through 3(j).

Item 4 Ownership.

The Reporting Persons own 0 shares of Common Stock of the Issuer.

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Item 5 Ownership of Five Percent or Less of a Class.

If this statement is being filed to report the fact that as of the date hereof the Reporting Persons have ceased to be the beneficial owners of more than five percent of the class of securities, check the following ☒.

Item 6 Ownership of More Than Five Percent on Behalf of Another Person.

Inapplicable.

Item 7 Identification and Classification of the Subsidiary which Acquired the Security Being Reported On by the Parent Holding Company.

Inapplicable.

Item 8 Identification and Classification of Members of the Group.

Inapplicable.

Item 9 Notice of Dissolution of Group.

Inapplicable.

Item 10 Certification.

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

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SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: February 14, 2018

/s/ Bradley Louis Radoff

Bradley Louis Radoff

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