Thank you, Howard. I'm now going to briefly review our fourth quarter and full year 2011 performance and attempt to highlight what I believe to be some material items. I will also give some further explanation of certain items in our financial statements as well as provide some insights into some of the metrics that drove our fourth quarter performance.
Lastly, I will provide 2012 financial guidance levels.
In my discussion, I will use the term adjusted EBITDA, which is a non-GAAP financial measure. The company defines adjusted EBITDA as earnings before interest, taxes, depreciation and amortization, each from continuing operations, and excludes losses or gains on the disposal of equipment, other income or loss, loss on debt extinguishments, bargain purchase gains and nonequity cash compensation. Or I should say, noncash equity compensation, excuse me. Adjusted EBITDA includes equity earnings in unconsolidated operations and subtracts allocations of earnings to noncontrolling interest in subsidiaries and is adjusted for noncash or extraordinary and onetime events taking place during the period. A full quantitative reconciliation of adjusted EBITDA to net income or loss attributable to RadNet, Inc. common shareholders is included in our earnings release.
With that said, I'd now like to review our fourth quarter and full year 2011 results. For the 3 months ended December 31, 2011, RadNet reported revenue and adjusted EBITDA of $164.8 million and $32.3 million, respectively. Revenue increased $18.6 million or 12.8% over the prior year's same quarter and adjusted EBITDA increased $2.1 million or 7% over the prior year's same quarter. The increase in revenue and adjusted EBITDA from the fourth quarter of last year was both the result of procedural volume increases from acquired entities as well as same-center procedural volumes.
Fourth quarter 2011 same-center procedural volumes increased 4.6% as compared with the fourth quarter of 2010 and we benefited from the contribution of the CML acquired operations, which we purchased in November of 2011. It contributed approximately $11 million of revenue and over $1 million of EBITDA for the quarter.
For the fourth quarter of 2011, as compared with the prior year's fourth quarter, aggregate MRI volume increased 19.7%, CT volume increased 18.8% and PET/CT volume increased 7.6%.
Overall volume, taking into account routine imaging exams inclusive of x-ray, Ultrasound, Mammography and other exams increased 18.2% over the prior year's fourth quarter.
In the fourth quarter of 2011, we performed 1,020,129 total procedures, the first time in our company's history we exceeded 1 million procedures in any quarter. The procedures were consistent with our multi-modality approach whereby 77.9% of all the work we did by volume was from routine imaging. Our procedures in the fourth quarter of 2011 were as follows: 125,675 MRIs as compared with 105,022 MRIs in the fourth quarter of 2010; 94,374 CT's as compared with 79,448 CTs in the fourth quarter of 2010; 5,490 PET/CTs as compared with 5,101 PET/CTs in the fourth quarter of 2010; and 794,590 routine imaging exams, which include nuclear medicine, ultrasound, Mammography, x-ray and other exams as compared with 673,209 all those exams in the fourth quarter of 2010.
Net income for the fourth quarter of 2011 was $4.5 million or 12%, excuse me, $0.12 per share compared to net income of $3.3 million or $0.09 per share reported for the 3-month period ended December 31, 2010, based upon a weighted average number of shares outstanding of 38.1 million and 37.8 million for these periods in 2011 and 2010, respectively. This represents an improvement in net income for the quarter of approximately $1.2 million.
Excluding non-cash gains from the mark-to-market of our interest rate swaps of $1.7 million, a $306,000 noncash charge to interest expense related to the amortization of accumulated unrealized losses on interest rate swaps, gains from the disposal or sale of equipment of $312,000 and noncash stock compensation of $611,000, RadNet would have reported net income of $3.5 million or $0.09 per share, per fully diluted share for the fourth quarter of 2011, compared with net income of $3.2 million or $0.08 per share for the fourth quarter of 2010, excluding those same noncash losses and expenses.
Also affecting net income in the fourth quarter of 2011 were certain other noncash expenses and nonrecurring items, including $421,000 of severance paid in connection with employee reductions related to cost savings initiatives and $754,000 of noncash deferred financing expense related to the amortization of financing fees paid as part of our new credit facilities and senior unsecured notes.
With regards to some specific income statement accounts, overall GAAP interest expense for the fourth quarter of 2011 was $13.5 million. This compares with GAAP interest expense in the fourth quarter of 2010 of $12.9 million. The increase is attributable to increased borrowings we had under the revolver in 2011, which was primarily the result of our purchase of the CML assets in November. The fourth quarter of 2011 bad debt expense was 5.7% of our revenue compared with 5.9% for the fourth quarter of 2010.
I'll now discuss full year results. For the full year of 2011, RadNet reported revenue and adjusted EBITDA of $619.8 million and $115.5 million, respectively. Revenue increased $68 million or 12.3% over 2010 and adjusted EBITDA increased $9.3 million or 8.8% over 2010. For the year ended December 31, 2011 as compared to 2010, MRI volume increased 17.6%, CT volume increased 11% and PET/CT volume increased 3.2%. Overall volume, taking into account routine imaging exams inclusive of x-ray, ultrasound, Mammography and other exams, increased 13.1% for the 12 months of 2011 over 2010.
In 2011, we performed 3,748,830 total procedures. The procedures were consistent with our multi-modality approach, whereby 77.9% of all the work we did by volume was from routine imaging. Our procedures in 2011 were as follows: 460,473 MRIs as compared with 391,566 MRIs in 2010; 345,864 CTs as compared with 311,647 CTs in 2010; 21,427 PET/CTs as compared with 20,769 PET/CTs in 2010; and 2,921,066 routine imaging exams, which include nuclear medicine, ultrasound, Mammography, x-ray and other exams as compared with 2,591,037 of all these exams in 2010.
Net income for 2011 was $0.19 per share compared to a net loss of negative $0.35 per share in 2010 based upon a weighted average number of basic -- of diluted shares outstanding of 38.8 million and 36.9 million shares in 2011 and 2010, respectively. Affecting net income in 2011 were certain noncash expenses and nonrecurring items including, noncash gains from the mark-to-market of our interest rate swaps of $5.4 million; $3.1 million of noncash employee stock compensation expense resulting from the vesting of certain options and warrants; $2.9 million of noncash deferred financing expense related to the amortization of financing fees paid as part of our existing credit facilities; $1.4 million of severance paid in connection with the headcount reductions related to cost savings initiatives from previously announced acquisitions; $2.2 million gain on the disposal or sale of certain capital equipment and $1.1 million noncash charge to interest expense related to the amortization of accumulated, unrealized losses on interest rate swaps related to the company's credit facilities.
With regards to some specific income statement accounts, overall GAAP interest expense in 2011 was $52.8 million. Adjusting for the noncash impacts from items such as amortization of financing fees, losses or gains related to the fair value adjustments on interest rate hedges and accrued interest, cash interest expense was $47.3 million in 2011. This compares with GAAP interest expense in 2010 of $48.4 million and cash paid for interest of $40.4 million.
For 2011, bad debt expense was 5.6% of our revenue compared with an overall blended rate of 6% for the full year of 2010.
With regards to our balance sheet, as of December 31, 2011, we had $556.4 million of net debt, which is total debt less our cash balance and we were drawing $58 million on our revolving credit facility of $121 million. This is an increase in our net debt of $52.4 million compared with December 31, 2010. This increase was primarily due to borrowings we made under our revolving credit facility to purchase the U.S. operations of CML HealthCare, which we completed in November 2011.
Since December 31, 2010, accounts receivable increased approximately $32.3 million, primarily the result of accounts receivable assumed from acquisitions, increased revenue, credentialing holds and billings we have held back in conjunction with negotiations we had with private payors throughout 2011, some of which were the result of the bundling of CT codes related to the abdomen and pelvis.
Our net days sales outstanding or DSOs increased to 62.6 days at December 31, 2011 from 54 days as of that date one year ago. Our accounts payable and accrued expenses increased $20.5 million to $103.1 million during 2011. Much of this increase is attributable to acquired entities and to the increased size of our business.
Throughout 2011, we repaid $18.8 million of notes and leases payable, had cash capital expenditures net of asset dispositions of $39.7 million and entered into notes and leases payable of $26,000.
I will now discuss how RadNet performed relative to our 2011 guidance, which we released exactly one year ago. With respect to revenue, our guidance level was $575 million to $605 million. Our actual results were $619.8 million, exceeding the high end of the guidance range. For adjusted EBITDA, our guidance was $110 million to $120 million. Our actual results were $115.5 million. For capital expenditures, our guidance range was $35 million to $40 million, our actual results were $39.7 million. For cash interest expense, our guidance range was $45 million to $49 million, our actual results were $47.3 million. And finally, for free cash flow generation, our guidance range was $25 million to $35 million and our actual results were $28.5 million.
We are pleased to have met or exceeded each guidance level we set for 2011. We believe these 2011 performance objectives, which were set at levels above 2010 results were accomplished partly through capturing market share from our local competitors, most of which are smaller and less-capitalized, single-center or small group operators. Our size, economies of scale and efficiency have continued to separate us from much of the rest of the industry.
At this time, I'd like to review our 2012 fiscal year guidance levels, which we released this morning at our earnings press release. For our 2012 fiscal year, we announced our guidance ranges as follows: for revenue, our 2012 guidance range is $660 million to $700 million. For adjusted EBITDA, our range is $120 million to $130 million. For capital expenditures, our range is $35 million to $40 million. For cash interest expense, our guidance range is $46 million to $51 million and for free cash flow, our guidance range is $25 million to $35 million.
As reflected in our guidance, we are optimistic about 2012. Despite our assumption that the operating environment may continue to be affected by a broader -- a difficult, broader economy, we are predicting increasing aggregate procedural volumes, revenue and EBITDA. At the midpoint of our guidance ranges, we are anticipating 9.7% top line growth and 8.2% EBITDA growth. We will benefit in 2012 from the full year contribution of the CML transaction, which we completed in November of 2011 and the numerous capital investments we made and projects we began in 2011.
Throughout our 2012 -- though our 2012 guidance incorporates previously discussed reimbursement cuts for Medicare and certain others from private health plans, the midpoint of our guidance reflects only modest volume increases, which result in flat same-center revenue as compared with 2011. We also should benefit from cost savings and productivity measures we implemented throughout 2011 designed to lower salaries, professional fees and information technology expenses. All in all, we're excited about the prospects of 2011.
I'd now like to turn the call back to Dr. Berger, who will make some closing remarks.