Scannings. News from Wake Radiology, Village Radiology, Raleigh MRI & Wake Radiology Oncology Services

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1 Scannings SUMMER 2000 Inside: Perfusion/Diffusion Community Service Breast Cancer Golf Festival Managed Care Update Open MRI Hours Web Site Survey Jon Simpson Awarded News from, Village Radiology, Raleigh MRI & Oncology Services WAKE RADIOLOGY PROVIDES IMAGING SERVICES TO FRANKLIN REGIONAL MEDICAL CENTER Consultants began serving Franklin Regional Medical Center in Louisburg, NC on April 19. The new contract now places physicians in six hospitals including WakeMed in Raleigh, Western WakeMed in Cary, Johnston Memorial Hospital in Smithfield, Maria Parham Hospital in Henderson and Good Hope Hospital in Erwin. The contract also makes Wake Radiology one of the largest health care providers in the Triangle and the largest radiology practice in the state. Franklin Regional Medical Center is a 90-bed facility located approximately 35 miles north of Raleigh in Louisburg, NC. The medical center also has become a part of the teleradiology network. We are pleased to add this facility to our network of imaging facilities, said managing partner Dr. Robert E. Schaaf. Consultants and Diagnostic Imaging currently serve six counties through 16 locations. In addition to the hospital locations, seven imaging centers serve North Raleigh, Northwest Raleigh, West Raleigh, Cary, Garner and Chapel Hill (through Village Radiology Consultants), as well as Raleigh MRI Center, and Oncology Services in Cary. DIABETES, GLUCOPHAGE AND RADIOGRAPHIC CONTRAST-INDUCED RENAL FAILURE PROFILED William G. Way, M.D. Diabetics are at risk of developing radiographic contrast-induced renal failure (RCIRF) if they have pre-existing renal insufficiency. Recent documentation of normal renal function in diabetic patients is therefore recommended before routine intravenous administration of iodinated contrast for diagnostic examinations. Fortunately, diabetics with normal renal function are at no greater risk of RCIRF than non-diabetics. In both groups, the risk of RCIRF is relatively low. Lactic acidosis is a rare but serious metabolic complication that can occur with the administration of Glucophage R (metformin) to patients with impaired renal function. When it occurs, it is fatal in approximately 50% of patients. The risk of lactic acidosis increases with the degree of William G. Way, M.D. impairment of renal function. According to the manufacturer s guidelines, patients with serum creatinine levels above the upper limit of normal for their age should not be treated with Glucophage R. The manufacturer s guideline clearly stated that Glucophage should be withheld for 48 hours subsequent to the [intravenous contrast-enhanced radiologic] procedure and reinstituted only after renal function has been re-evaluated and found to be normal. This may require that the patient s BUN and creatinine be checked 48 hours after the procedure to ensure there has been no deterioration in renal function as a consequence of contrast administration. (These guidelines do NOT apply to the intrathecal administration of iodinated contrast for myleography nor to the intravenous administration of MR contrast.) We routinely seek out data regarding renal function in all diabetic patients scheduled for examinations that might require iodinated intravenous contrast administration so that this information is available to us at the time the study is to be performed. Furthermore, we carefully scrutinize each individual case to determine if the intravenous administration of iodinated contrast is warranted. Diabetics on Glucophage R at the time of their examination can safely receive iodinated contrast material if renal function is normal at the time of contrast administration, but it still must be withheld afterward (continued on Page 4)

2 NEW MR AND CT TECHNOLOGIES ASSIST IN DIAGNOSTIC IMAGING William T. Djang, M.D. and William G. Way, M.D. strongly supports our obligation to provide the most up-to-date medical imaging services to our patients and referring physicians. We continue to implement the latest imaging advances in order to provide the best medical care available. Here we describe two advanced techniques now available, Diffusion MR Imaging and 3-D CT Angiography. Diffusion MR Imaging for Detecting Acute Strokes William T. Djang, M.D. Diffusion MR sequences provide the most sensitive and earliest method of detecting acute strokes. Diffusion MR scanning reveals abnormalities within minutes of acute ischemia, long before standard MR T2 or T1 weighted images become positive (3-6 hours) and much earlier than CT (6 hours to days). We perform diffusion MR scans routinely on most patients seen for brain scans at our Raleigh MRI and WakeMed MR locations. With modern high-field strength systems, diffusion imaging can be performed in less William G. Way, M.D. than one minute of additional scan time. Diffusion imaging is based on the diffusion mobility of water. Diffusion refers to the random motion of molecules within their local environment. Water molecules may freely diffuse within large CSF filled spaces or extracellular water compartments, for example, but encounter limited diffusion capability within highly structured intracellular environments such as within axons surrounded by myelin sheaths. Diffusion scans are specifically designed to demonstrate the net diffusion of water molecules within each voxel of imaged tissue. As with most spin-echo techniques, increasing motion reduces signal intensity. With diffusion scans, even small differences in the random movement of water molecules (and here we are talking about micron dimensions) between normal and abnormal brain can be detected. Most often, diffusion-weighted images (DWI) are displayed and photographed, with areas of free diffusion demonstrating motion-related diminished signal intensity while areas of restricted diffusion appear bright. Simply stated, water molecules that diffuse freely result in diminished signal intensity on DWI. Alternatively, voxels containing molecules with restricted diffusion result in less loss of signal intensity compared to free extracellular water and thus appear bright. Why do acute infarcts appear bright on DWI? Here we have to look at physiology. The brain does not store its own energy sources. With an acute stroke, the cessation of blood supply and therefore glucose and oxygen delivery causes an immediate disruption in cellular metabolism, and cell membrane permeability is affected. Sodium and water are able to enter ischemic cells, causing cell swelling (ischemic edema). In this case, previous extracellular (and freely diffusable) water molecules are now intracellular, and these water molecules now experience constrained diffusion by organelles and other cellular components. This relative restricted or reduced diffusion is manifested by bright signal intensity relative to adjacent brain. In fact, areas of acute infarction are often so conspicuously abnormal that they show up as light bulbs compared to adjacent uninvolved brain. The actual physics of diffusion and its detection are actually slightly more complicated. The diffusion coefficient of water in brain tissue is direction dependent, reflecting the organized structure of the brain architecture. Diffusion images are therefore usually obtained in 3 perpendicular planes. The signal intensity on diffusion images is also partially affected by the underlying T2 characteristics of tissue, therefore corresponding T2 images of the brain should be analyzed with the diffusion images to avoid the so called T2 shine through artifact. Occasionally, actual diffusion coefficient (ADC) maps must be calculated and displayed to avoid false positive interpretation of T2 shine-through as real diffusion abnormality. So called susceptibility artifacts are encountered near bone and air interfaces. Although diffusion imaging is exquisitely sensitive in detecting acute stroke, its role is not limited to ischemic conditions. Often, tumors such as dermoids may have imaging characteristics similar to CSF on standard MRI sequences. These lesions, however, can be easily distinguished from other abnormalities by their different diffusion characteristics. The early detection of stroke as well as the determination of the size and location of the lesion may have important therapeutic implications. In the future, diffusion may be combined with perfusion imaging (a newer investigational technique) to assess the potential for preventing stroke progression (so called salvage of ischemic but not yet infarcted tissue). 3D CT Angiography Breakthrough CT angiography, or CTA, is an exciting new breakthrough in diagnostic imaging. With CTA, high resolution angiograms can be now be performed utilizing CT. This exam requires only intravenous contrast administration, as opposed to invasive traditional catheter angiography. Additionally, the computer generated 3D images can be manipulated in real time on a dedicated computer workstation, allowing greater understanding of spatial relationships between vessels and adjacent anatomic structures. This technique is rapidly gaining acceptance as a replacement for conventional diagnostic angiography in certain selected situations. CTA capitalizes on the enhanced capabilities of current state-ofthe-art high speed spiral (helical) CT scanners to acquire large anatomic data sets during the brief period of peak arterial contrast enhancement following the rapid intravenous bolus administration of iodinated contrast. This non-invasive technique allows one to generate an angiogram-like image through manipulation of the volumetric CT data set on a commercial computer workstation specially designed for this purpose. In some instances, it has been proven superior to conventional angiography in its ability to display vascular anatomy and pathology, in part due to the unlimited number of views or projections that can be generated from the volumetric data set and additionally because of the superior spatial resolution of CT. Because the acquisition of the base data set is always done in the same manner, this technique minimizes the operator-dependant nature of alternative modalities such as ultrasound. It provides data similar to that of Magnetic Resonance Angiography (MRA) with the added advantage of showing additional anatomic structures that are not seen by MRA such as intimal calcification, a feature that may be critical in certain clinical situations. The test is well-tolerated by most patients and requires far less time to perform than does conventional angiography. This test, which can be performed on an outpatient basis, is also obviously much less expensive than conventional angiography. Relative contraindications to this examination include contrast allergy and impaired renal function. Claustrophobia is generally not an issue due to the speed with which this study can be performed in virtually any state-of-the-art diagnostic spiral CT scanner. 2 (continued on Page 4)

3 COMMUNITY SERVICE ALWAYS THE FOCUS AT WAKE RADIOLOGY WR PARTNERS WITH WAKE MED AS HEALTH EDUCATION SPONSOR FOR THE 2000 BLUE CROSS BLUE SHIELD BREAST CANCER GOLF FESTIVAL From its inception in 1953, has focused on a strong commitment to community service. That commitment is evident this year in the key roles played with the Blue Cross Blue Shield Breast Cancer Golf Festival, the American Cancer Society s Red Sword Ball, the health education support of the NC Answer Cancer campaign and many others. The practice also has been a key contributor to special facilities such as WakeMed s Children s Emergency Center and the Alice Aycock Poe Center for Health Education through which school children from across the state received information about all aspects of health. An even deeper and longer community service role has been with for the past 46 years in its service to the indigent community of Wake and surrounding counties. The physicians of through their work at WakeMed and other hospital locations have provided imaging services to those individuals who are not insured or are unable to provide for their own health care. Perhaps as important as s work with the community at large is its commitment to provide good health care to its own employee community. Now nearly 200 strong, Wake Radiology employees enjoy benefits and programs that are consistent with the practice's overall policy toward community service. Employees are encouraged to participate in their own local communities. As a practice we feel we have been extremely fortunate to have the strong relationship we have with the medical community and with our patients, says Dr. Robert Schaaf. We feel compelled to return our good fortune to our various communities whenever possible. For its fourth consecutive year, has taken its place as one of the key supporters of health education in the breast cancer education and research arena through the BCBS Breast Cancer Golf Festival. This year the practice shares health education sponsorship duties with WakeMed. This sponsorship pays for 16 health education organizations such as Save Our Sisters, the Poe Center for Health Education and Race for the Cure to be present at the annual fund-raising golf tournament at Pine Needles in Southern Pines. And to provide information about a variety of preventive and treatment services to corporate golfers on the course. Each health education organization is given a tented exhibit space on one hole at each of the two tournament courses, Pine Needles and Mid Pines. As golfers arrive at a tee, they are provided with information and sometimes exercises to test their knowledge, by the health education providers. The practice of placing this information on the tournament courses began following the Festival of Women s Health at the 1996 U.S. Women s Open Championship. This annual fund-raising program has raised more than $500,000 in funds for breast cancer education and research in North Carolina. was the first sponsor of the original Festival of Women s Health and has participated in the tournaments since. Consultants celebrate the new Siemens Somatom Plus-4 CTScanner at Good Hope Hospital in February. From left to right: Don Annis, Good Hope CEO; Bruce Gomedella, hospital board member; NC House Representative Leslie Cox; Dr. Jay Parikh, orthopedic physician; Dr. Robert Schaaf, managing partner, ; Dr. Kerry Weinrich, ; NC House Representative Teddy Byrd. 3

4 DIABETES (continued from Page 1) according to the guidelines above. If data regarding renal function is NOT available for a diabetic on Glucophage R, one can withhold Glucophage R for 48 hours and then safely administer IV contrast without risking the development of lactic acidosis. Unfortunately, the risk of causing further deterioration of any degree of unrecognized renal impairments still remains. We will make every attempt to notify you, our referring physicians, when intravenous contrast has been administered to one of your diabetic patients on Glucophage R. Your patients will also be instructed to contact you regarding their oral hypoglycemic therapy following radiologic examination. We apologize in advance for any inconvenience this may cause you or your diabetic patient. Our Protocol Regarding Glucophage R (metformin) 1. Recent documentation of renal function is mandatory before the intravenous administration of iodinated contrast to diabetics taking Glucophage. a. If normal, it is safe to administer the IV contrast. b. If abnormal, Glucophage R should be withheld for at least 48 hours after which contrast can then be safely administered without risk of lactic acidosis. Be aware that diabetics with pre-existing renal impairment are at significant risk for further deterioration of renal function after the intravenous administration of iodinated radiographic contrast material. As such, they should be well-hydrated prior to any study for which it is required and they should withhold diuretics, ACEinhibitors, and NSAID for 24 hours prior to the examination. One should also consider alternative means for diagnosis (US, MRI, etc.) when available. 2. If a patient with impaired function who is on Glucophage R requires a contrast-enhanced study emergently, it should be done only after consultation with the referring physician. Every effort should be made to hydrate that patient to the maximum extent possible prior to the administration of contrast without compromising the patient s care. 3. After contrast has been administered, Glucophage R must be withheld at least 48 hours after which it shall become the responsibility of the referring MD to consider resuming therapy. Out-patients shall be informed of this both verbally by the technologist performing the examination and in writing. The radiologist shall write orders in the chart of an in-patient to the same effect when iodinated contrast has been administered to a diabetic taking Glucophage R. 4. The following information will be included on the written radiologic report for the purpose of notifying the referring physician with regard to this issue. WARNING: Glucophage R is contraindicated in patients with renal insufficiency due to potential development of the rare, but serious, metabolic complication of lactic acidosis. The intravenous administration of iodinated contrast material can result in contrastinduced renal insufficiency. This is particularly true for diabetic patients with compromised renal function. Radiographic contrast-induced renal failure may take up to 48 hours to become manifest through serum analysis. According to the manufacturer s guidelines, Glucophage R should be withheld for 48 hours subsequent to the [contrast-enhanced radiologic] procedure and reinstituted only after renal function has been re-evaluated and found to be normal. This may require that you recheck your patient s creatinine level before resuming Glucophage R therapy. We have instructed your patient to temporarily discontinue Glucophage R and to contact you in 2 days about resuming it. NEW MR AND CT TECHNOLOGIES (continued from Page 2) Because the exam requires the enhanced vessels to be higher in density than adjacent structures, evaluation of vessels within bone structures (such as the intrapetrous carotid artery) is not practical. At present, CT angiography is being successfully applied to the evaluation of the circle of Willis, the carotid arteries, the thoracic aorta, the abdominal aorta and iliac vessels, and the renal arteries with a high degree of accuracy. In the circle of Willis, CTA can identify aneurysms, vascular occlusions, and variant vascular anatomy. CTA can clarify potential abnormalities revealed by MR angiography or even ambiguous findings on conventional angiographic studies. In the neck, it can be used to identify and characterize the extent and severity of atherosclerotic disease. In the chest, CTA can be used to characterize the size and extent of aneurysms, to evaluate congenital vascular anomalies, and to identify the presence and location of an intimal flap in the setting of dissection. In the setting of chest trauma, the role of CTA in the evaluation of the aorta for possible intimal tear remains to be determined. In the abdomen, CTA has been successfully employed to determine the size and configuration of abdominal aortic aneurysms and to characterize the extent and severity of associated iliac disease. It is accurate in identifying the number and location of renal veins and accessory renal arteries, features that are critical for preoperative planning. CTA has been successfully used in the preoperative assessment of renal transplant donor candidates and in preoperative planning for nephrectomy. It is also a useful technique for evaluating patients with uncontrolled hypertension in search of renal artery stenosis as the etiology. At present, offers CT Angiography at WakeMed. Ordering a CT Angiogram is quite easy. Simply call or to request a CTA of the vascular structure you wish to have evaluated: circle of Willis, cervical carotid arteries, thoracic aorta, renal arteries, or abdominal aortic aneurysm (which routinely includes CTA of the iliac vessels for complete preoperative characterization). Because relatively large volumes of IV contrast are used for these examinations, we ask that relatively recent BUN and creatinine levels be available for review at the time the examination is to be performed. Patient preparation for CTA is no different than that for any other diagnostic CT examination requiring the administration of iodinated contrast material. We routinely request that all patients undergoing CTA be hydrated with 32 oz. of water p.o. over the 6-12 hours preceding their exam and we ask that they not eat 6 hours prior to their study so as to minimize the incidence of vomiting that may occasionally occur with the administration of IV contrast. No bowel prep is necessary. Neither oral nor rectal contrast is administered as they are not necessary for diagnosis and may actually interfere with image processing. In most circumstances, patients who have undergone recent UGI or BE may have to wait several days after these studies so as to avoid beam hardening artifact that may occur with retained barium in the bowel. While the present applications of CTA are exciting, the future of CTA is even brighter. With the latest multi-array CT scanners that will soon be available, we hope to provide even higher resolution CT angiograms covering greater anatomic distances. This may potentially eliminate the need for conventional angiography in the evaluation of peripheral vascular disease. CTA is proving to be a complementary tool to MRA, which also continues to develop. CTA has clearly arrived and is rapidly taking hold as a valuable tool in the diagnosis and characterization of vascular disease. Please feel free to contact one of our radiologists if you have questions regarding CTA, MRA, conventional angiography, or other imaging modality. 4

5 WAKE RADIOLOGY PARTICIPATING MANAGED CARE PLANS OPEN MRI SERVICES AVAILABLE ON SATURDAY AHA (American Healthcare Alliance) Alliance PPO (a MAMSI product) Blue Cross and Blue Shield all plans CCN CIGNA Healthcare of NC, Inc. (HMO and PPO) CIGNA Healthcare (Connecticut General) PPN/PPO and PPN/POS (formerly Healthsource Provident) Doctors Health Plan First Health (through Health Care Savings network only) Generations Health Care Savings Healthsource North Carolina, Inc. HealthStar Jefferson Pilot PPO MAMSI Life & Health MedCost all plans Medicaid Medicare Optimum Choice of the Carolinas, Inc. (OCCI, a MAMSI product) United HealthCare of North Carolina, Inc. United HealthCare Insurance Company Open MRI services will be available two Saturdays a month beginning in July at Village Radiology Consultants in Chapel Hill. This office is located at 110 S. Estes Drive. For appointments or information please call or toll free at Aetna US Healthcare Contract In November 1998, signed a participating provider contract with Aetna US Healthcare. Unfortunately, that contract is still NOT executed. We continue to try to be a participating provider, but at this time we are considered non-participating. We apologize for any inconvenience this may have caused your patients and office staff. One Health Plan Contract Effective June 30, 2000 will no longer participate with One Health Plan of North Carolina. We apologize for any inconvenience this may cause you or your patients. Note: Patients who are in a plan that we do not participate with can be seen on an out-of-network basis. A patient can choose this option with a higher deductible and/or higher co-insurance. We will be glad to contact the insurer to get eligibility and benefit coverage if requested. continues to align its managed care contracts with those of its referring physicians. If there are additional plans that we should consider, please call Michele Jackson at or fax to WAKE RADIOLOGY WEB SITE SURVEY As the largest radiology practice in North Carolina, is committed to providing the highest quality of service. This commitment guides our practice today as we work within a rapidly changing specialty and healthcare environment. Through our web site, we are able to provide current and detailed information about our staff, services, radiological examinations, imaging locations, frequently asked questions, and managed care plan participation. In an effort to provide the best possible service, we ask you to take a moment to answer the short questions listed on the reply card enclosed in this issue of Scannings. The information collected from this survey will enable us to improve our web site and better serve your electronic needs. Your response is greatly appreciated. WAKE RADIOLOGY S JOHN SIMPSON RECEIVES MARIE CURIE AWARD Jon Simpson, BS, CNMT at Wake Radiology was awarded the 1999 Marie Curie Award for Innovation from ADVANCE magazine, a publication for Radiological Professionals. Simpson's article dealing with New 3 Phase Bone Scan Imaging appeared in the magazine and was selected from all reader submissions as the most innovative for the year, and the article that most advanced the field in the particular area of expertise. 5

6 WAKE RADIOLOGY LOCATIONS North Raleigh Office West Raleigh Office Northwest Raleigh Office 3821 Merton Drive 4301 Lake Boone Trail, # Creedmoor Road, #200 Raleigh, NC Raleigh, NC Raleigh, NC (919) (919) (919) (919) FAX (919) FAX (919) FAX Garner Office Cary Office Chapel Hill Office 800 Benson Road, # Ashville Avenue, #100 Village Radiology Consultants Garner, NC Cary, NC S. Estes Drive (919) (919) Chapel Hill, NC (919) FAX (919) FAX (919) (919) FAX Raleigh MRI Center Open MRI Oncology Services 3811 Merton Drive Village Radiology Consultants 300 Ashville Avenue, #110 Raleigh, NC S. Estes Drive Cary, NC (919) Chapel Hill, NC (919) (919) FAX (919) (919) FAX (919) FAX SCANNINGS is a quarterly publication of, Village Radiology, Oncology Services, and Raleigh MRI MEDICAL EDITOR David Ling, M.D. WAKE RADIOLOGY MANAGING PARTNER Robert E. Schaaf, M.D. WAKE RADIOLOGY ADMINISTRATOR William H. Johnson WAKE RADIOLOGY DIAGNOSTIC IMAGING, INC Haworth Drive Raleigh, NC diagnostic imaging, inc Haworth Drive Raleigh, NC Presorted First Class US Postage PAID Permit 2483 Raleigh, NC Printed on Recycled Paper