Volume 2 Number 1 Spring 96

Master List Volume 2 Number 1 Spring 1996

IN THIS ISSUE

What's New In UAB Radiology

Filmless Ultrasound

FAQs

Carotid Ultrasound

Frequently Called Radiology Phone Numbers

What's New in UAB Radiology - Filmless Ultrasound

The long-promised era of filmless radiology has begun at UAB! In mid- December, under the leadership of Chief of Ultrasound, Michelle Robbin, M.D., the Aegis™ electronic image review and storage system (Acuson, Inc., Mountain View, CA) was installed simultaneously at the University Hospital and The Kirklin Clinic. This system is networked so that examinations performed at either location are immediately accessible at both the hospital and clinic reading rooms.

On the day of installation, we made dramatic changes in our traditional practice habits. First, we stopped routinely filming ultrasound examinations. This is possible because we now archive all of our studies on electronic media (Magneto-optical). This will save tens of thousands of dollars per year in film and film processing costs, film jackets, and film library storage and management, and will assure rapid access to any sonogram done within UAB Radiology. Images can still be filmed when needed for conferences or review remotely from our labs.

Carotid Angiogram. See FAQS. This angiogram shows a nearly
pinpoint opening in the Internal
Carotid Artery indicating a greater than 80 percent stenosis.

Carotid Ultrasound. See FAQS.
The ultrasound image shows a dramatic increase from the normal blood flow verlocity in the internal Carotid Artery. The "noisy" pattern of the tracing indicates turbulent flow beyond a marked stenosis.

Second, we stopped recording preliminary reports in handwritten log books. However, those clinicians who have depended on those books need not be concerned. We are now recording impressions and findings directly into the computer system. At a glance of the patient list, the most important findings are evident, and more complete descriptions are found in a "comments" section. Moreover, the results are legible! This provides us with an easily accessible database for research and clinical purposes.

Third, a unique enhancement to our filmless operation is a real-time monitoring system built by UAB Biomedical Engineering to specifications outlined by our Ultrasound section. This permits us to monitor the real-time activity instantaneously on any one of our ultrasound scanners at either University Hospital or The Kirklin Clinic. This creates the opportunity to provide primary high-quality interpretations immediately and remotely. Consultations between radiologists and among clinicians and radiologists will be facilitated.

This innovation is only one early project among many to implement our long-term plan to automate image management and interpretation in Radiology. We plan to move forward aggressively as technological advances and our resources allow. For 1996, we will be installing a revolutionary digital upright chest x-ray machine at University Hospital, and are already receiving vendors' quotations on a system to make all x-ray acquisition in the Emergency Department all-electronic. Our strategy is to implement systems which are user-friendly, will add functions which enhance patient care, and will provide substantial long-term returns on investment. We invite you to call us and visit our facility. We welcome your comments and questions.

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FAQs - Carotid Ultrasound

In recent years, among the most powerful interventions to prevent strokes have been those that treat the seriously stenotic internal carotid artery. Carotid endarterectomy has been proven to be effective in decreasing the incidence of strokes in symptomatic patients with greater than 70 percent diameter stenoses. Two year stroke risk was 26 percent for those treated medically and only 9 percent for surgical treatment. Major or fatal stroke risk was 13.1 percent and 2.5 percent respectively. At UAB, our overall surgical stroke rates are only 2-3 percent. The proof of the value of surgical revascularization has led to research in other procedures such as carotid stenting and angioplasty, including work here at UAB.

Carotid ultrasound has become the primary diagnostic method for evaluating suspected carotid stenosis because of its accessibility, low expense relative to angiography, and its high accuracy (90 to 95 percent). The following are frequently asked questions about carotid ultrasound done by the UAB Department of Radiology: Why and how to request a carotid ultrasound:

Q: What are indications for carotid ultrasound?

Symptoms possibly attributable to carotid stenosis such as stroke or transient ischemic attack, or findings such as a cervical bruit. Carotid ultrasound may also be done to follow the results of prior carotid endarterectomy or other intervention, or known atherosclerotic disease. We also commonly study the carotid arteries in patients about to undergo major cardiac surgery.

Q: Is screening of asymptomatic patients indicated?

The consensus is that widespread screening is not indicated. However, screening for asymptomatic patients is generally accepted in the presence of a carotid bruit or a bruit/transmitted murmur. Some are beginning to advocate studying patients at high risk for atherosclerosis. An ongoing controversial study (the Asymptomatic Carotid Atherosclerosis Study (ACAS)) has demonstrated a moderate decrease in strokes in surgically treated asymptomatic patients with greater than 60% stenoses.

Q: Are there any reasons to perform an examination immediately?

If there is a reasonable clinical suspicion of acute carotid thrombosis which may benefit from acute intervention, an urgent scan is appropriate. The common sense guidelines for performing any diagnostic test depends upon whether the patient can tolerate a small delay while undergoing the diagnostic test and if urgent therapy will follow a positive result.

Q: How do I request an examination?

For inpatients, a request may be entered in the routine manner in the PIN system. For outpatients, please call The Kirklin Clinic Patient Communication Office (PCO) at 205-731-9380. We routinely provide same day or next day service if needed. These studies are performed during regular working hours. If you are not satisfied, or if there is any emergency, please call one of the ultrasound technologists or radiologists directly at The Kirklin Clinic ultrasound (205-801-7890), or University Hospital ultrasound (205-934-1383). Staff radiologists are always on call for difficult after-hours cases.

Q: How is the examination done?

The carotid ultrasound is a technically demanding examination with several potential sources of serious error for the inexperienced operator. Our studies are done by ultrasound technologists and are monitored and interpreted by staff radiologists specializing in ultrasound. All of our technologists are experienced at carotid ultrasound. Additionally, two of five technologists at the University Hospital and one of two at TKC are registered vascular technologists (RVT). Both of our laboratories are accredited by the Intersocietal Commission on Accreditation of Vascular Laboratories (ICAVL).

The quality of equipment is also critical to obtaining an accurate result. All of our units have sophisticated color Doppler imaging capability. The examination includes the common, internal and external carotid arteries and the vertebral arteries. There is also a detailed analysis of the Doppler waveform and of color and gray-scale images. A routine examination requires about 30 minutes plus patient transport.

Q: How do I get the results?

Results are available on PIN as soon as the final revisions are approved. Most inpatient charts will have a preliminary handwritten report in the progress note section. For patients visiting their clinic after our study, reports are faxed directly to their clinic at the completion of the examination. Additionally, the preliminary interpretation is then logged on our ultrasound electronic image archiving stations. Therefore, results for any examination done in either of our laboratories are available for reviewing images and reports in both of our reading rooms (TKC and UH). Please see the What's New in Radiology column in this issue for more on this system.

Interpreting the interpretation:

Q: What criteria are applied?

For many years, we have applied criteria for categorizing stenoses based upon the work of Strandness, et al in the late 1970s and early 1980s. Although these criteria have been very successful, recent work has indicated the need for refining these criteria and further subcategorizing stenoses to correspond to the greater than 60 percent and greater than 70 percent levels studied by large multiinstitutional trials.

The criteria are based on such findings as the maximum velocity of blood flow in the carotid arteries, the ratio of velocities between various vessels, and the visual appearances. A complete discussion can be obtained by requesting a pre-print of a chapter on this subject with associated references, written by Lincoln Berland, M.D., and Therese Weber, M.D., of the UAB Radiology Department.

Q: What are the limitations of US?

A very small percentage of patients with short necks, marked obesity, or anomalously high carotid bifurcations may have technically suboptimal examinations. However, there are no objective physical criteria which can be used to screen such subjects prior to the examination. If the study is suboptimal, this will be mentioned in the report. Cardiac disease or other vascular problems can lead to abnormal waveforms and velocity values. However, when such a history is available, or other evidence is observed in the nature of the Doppler signals, the radiologist can often take these factors into account. Heavily calcified plaques may obscure the portion of the artery at which the observation of flow may be most useful. However, this obstacle is surprisingly uncommon.

Q: Can ultrasound detect atherosclerotic plaque ulceration?

No. All clinical-pathological studies have shown that the sonographic depiction of presumed ulceration is not sufficiently sensitive or specific for clinical application.

Q: What is the importance of the appearance of plaques?

This is controversial. Some reports suggest an association between a heterogeneous appearance of plaque and internal plaque hemorrhage which is associated with a higher risk of embolism. We make such observations sparingly, only when the appearance is striking.

Q: Can US reliably detect occlusion?

One known error is mistaking the bifurcation of the external carotid artery for the bifurcation of the common carotid in the presence of an occluded (and invisible) internal carotid. However, this error is rare in experienced hands. More commonly, it is difficult to determine with certainty whether an apparently occluded internal carotid artery has minimal residual flow. Only in the latter situation may intervention still be indicated.

What should I do about an abnormal result?

Q: Will an angiogram be necessary?

Opinions are changing on this subject, and the practice at UAB remains variable. Some surgeons now accept a good quality ultrasound as definitive, and will operate without further studies. Others believe that angiographic corroboration is essential, partly because of the ability to evaluate the precise status of more proximal and distal vessels that cannot be seen with ultrasound. Some researchers are advocating the use of MR flow imaging associated with ultrasound to largely replace angiography.

Q: When should a patient be referred for intervention for carotid disease?

Few are comfortable treating stenoses less than 60-70 percent. Disease less severe than this can be followed clinically and sonographically, particularly if asymptomatic. Patients who are candidates for an interventional procedure, with symptoms consistent with carotid disease and stenoses greater than 60 percent by sonographic criteria may be referred for specialty evaluation.

For further information, enumeration of our laboratories' diagnostic criteria, or a more complete discussion, please contact Dr. Berland at 934-7978 or by e-mail at lberland@rad.uab.edu .

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Frequently Called UAB Department of Radiology Phone Numbers

Day Shift

Monday-Friday

General, GI, and GU

4-5135

Myelography

4-6078 or 4-5135

Vascular and Interventional

4-5135

Neuro Angiography

4-7134

CT

4-6078

Ultrasound

4-1383

MRI

4-3069

Evenings

Monday-Friday

CT

4-4831

MRI

4-2796 (Until 8:30 p.m.)

All Other Exams

4-5135

Nights

CT

4-4831 or Beeper 1646

All Other Exams

4-4431

Weekends

CT

4-4831

All Other Exams

4-5135

All Kirklin Clinic Scheduling Information

731-9380

Kirklin Clinic Department of Radiology

801-8750

Visions is published quarterly by the University of Alabama Hospital Department of Radiology. Professor and Chairman: Robert J. Stanley, M.D. Vice-Chairman for Operations and Academic Affairs: Robert E. Koehler, M.D. Vice Chairman for Planning and Administration: Lincoln Berland, M.D. Director of Outpatient Services: Peter Dempsey, M.D. Visions Staff-Managing Editor: Margaret Ard. Editors/Writers: Lincoln Berland, M.D. Kay Hamrick, M.D. Robert Lopez, M.D. UAB Office of Marketing and Media Relations Staff- Editor: Rhonda Gregg. Art Director: Jason Bickell. Please direct questions, comments, and suggestions as follows: Attention Angie French or Lincoln Berland, M.D. Fax: 975-7213 Address: NHB 623B EMAIL: lberland@uabmc.edu

Q: What are indications for carotid ultrasound?	Symptoms possibly attributable to carotid stenosis such as stroke or transient ischemic attack, or findings such as a cervical bruit. Carotid ultrasound may also be done to follow the results of prior carotid endarterectomy or other intervention, or known atherosclerotic disease. We also commonly study the carotid arteries in patients about to undergo major cardiac surgery.
Q: Is screening of asymptomatic patients indicated?	The consensus is that widespread screening is not indicated. However, screening for asymptomatic patients is generally accepted in the presence of a carotid bruit or a bruit/transmitted murmur. Some are beginning to advocate studying patients at high risk for atherosclerosis. An ongoing controversial study (the Asymptomatic Carotid Atherosclerosis Study (ACAS)) has demonstrated a moderate decrease in strokes in surgically treated asymptomatic patients with greater than 60% stenoses.
Q: Are there any reasons to perform an examination immediately?	If there is a reasonable clinical suspicion of acute carotid thrombosis which may benefit from acute intervention, an urgent scan is appropriate. The common sense guidelines for performing any diagnostic test depends upon whether the patient can tolerate a small delay while undergoing the diagnostic test and if urgent therapy will follow a positive result.
Q: How do I request an examination?	For inpatients, a request may be entered in the routine manner in the PIN system. For outpatients, please call The Kirklin Clinic Patient Communication Office (PCO) at 205-731-9380. We routinely provide same day or next day service if needed. These studies are performed during regular working hours. If you are not satisfied, or if there is any emergency, please call one of the ultrasound technologists or radiologists directly at The Kirklin Clinic ultrasound (205-801-7890), or University Hospital ultrasound (205-934-1383). Staff radiologists are always on call for difficult after-hours cases.
Q: How is the examination done?	The carotid ultrasound is a technically demanding examination with several potential sources of serious error for the inexperienced operator. Our studies are done by ultrasound technologists and are monitored and interpreted by staff radiologists specializing in ultrasound. All of our technologists are experienced at carotid ultrasound. Additionally, two of five technologists at the University Hospital and one of two at TKC are registered vascular technologists (RVT). Both of our laboratories are accredited by the Intersocietal Commission on Accreditation of Vascular Laboratories (ICAVL). The quality of equipment is also critical to obtaining an accurate result. All of our units have sophisticated color Doppler imaging capability. The examination includes the common, internal and external carotid arteries and the vertebral arteries. There is also a detailed analysis of the Doppler waveform and of color and gray-scale images. A routine examination requires about 30 minutes plus patient transport.
Q: How do I get the results?	Results are available on PIN as soon as the final revisions are approved. Most inpatient charts will have a preliminary handwritten report in the progress note section. For patients visiting their clinic after our study, reports are faxed directly to their clinic at the completion of the examination. Additionally, the preliminary interpretation is then logged on our ultrasound electronic image archiving stations. Therefore, results for any examination done in either of our laboratories are available for reviewing images and reports in both of our reading rooms (TKC and UH). Please see the What's New in Radiology column in this issue for more on this system.
Interpreting the interpretation: Q: What criteria are applied?	For many years, we have applied criteria for categorizing stenoses based upon the work of Strandness, et al in the late 1970s and early 1980s. Although these criteria have been very successful, recent work has indicated the need for refining these criteria and further subcategorizing stenoses to correspond to the greater than 60 percent and greater than 70 percent levels studied by large multiinstitutional trials. The criteria are based on such findings as the maximum velocity of blood flow in the carotid arteries, the ratio of velocities between various vessels, and the visual appearances. A complete discussion can be obtained by requesting a pre-print of a chapter on this subject with associated references, written by Lincoln Berland, M.D., and Therese Weber, M.D., of the UAB Radiology Department.
Q: What are the limitations of US?	A very small percentage of patients with short necks, marked obesity, or anomalously high carotid bifurcations may have technically suboptimal examinations. However, there are no objective physical criteria which can be used to screen such subjects prior to the examination. If the study is suboptimal, this will be mentioned in the report. Cardiac disease or other vascular problems can lead to abnormal waveforms and velocity values. However, when such a history is available, or other evidence is observed in the nature of the Doppler signals, the radiologist can often take these factors into account. Heavily calcified plaques may obscure the portion of the artery at which the observation of flow may be most useful. However, this obstacle is surprisingly uncommon.
Q: Can ultrasound detect atherosclerotic plaque ulceration?	No. All clinical-pathological studies have shown that the sonographic depiction of presumed ulceration is not sufficiently sensitive or specific for clinical application.
Q: What is the importance of the appearance of plaques?	This is controversial. Some reports suggest an association between a heterogeneous appearance of plaque and internal plaque hemorrhage which is associated with a higher risk of embolism. We make such observations sparingly, only when the appearance is striking.
Q: Can US reliably detect occlusion?	One known error is mistaking the bifurcation of the external carotid artery for the bifurcation of the common carotid in the presence of an occluded (and invisible) internal carotid. However, this error is rare in experienced hands. More commonly, it is difficult to determine with certainty whether an apparently occluded internal carotid artery has minimal residual flow. Only in the latter situation may intervention still be indicated.
What should I do about an abnormal result? Q: Will an angiogram be necessary?	Opinions are changing on this subject, and the practice at UAB remains variable. Some surgeons now accept a good quality ultrasound as definitive, and will operate without further studies. Others believe that angiographic corroboration is essential, partly because of the ability to evaluate the precise status of more proximal and distal vessels that cannot be seen with ultrasound. Some researchers are advocating the use of MR flow imaging associated with ultrasound to largely replace angiography.
Q: When should a patient be referred for intervention for carotid disease?	Few are comfortable treating stenoses less than 60-70 percent. Disease less severe than this can be followed clinically and sonographically, particularly if asymptomatic. Patients who are candidates for an interventional procedure, with symptoms consistent with carotid disease and stenoses greater than 60 percent by sonographic criteria may be referred for specialty evaluation.

Frequently Called UAB Department of Radiology Phone Numbers
Day Shift	Monday-Friday
General, GI, and GU	4-5135
Myelography	4-6078 or 4-5135
Vascular and Interventional	4-5135
Neuro Angiography	4-7134
CT	4-6078
Ultrasound	4-1383
MRI	4-3069
Evenings	Monday-Friday
CT	4-4831
MRI	4-2796 (Until 8:30 p.m.)
All Other Exams	4-5135
Nights
CT	4-4831 or Beeper 1646
All Other Exams	4-4431
Weekends
CT	4-4831
All Other Exams	4-5135
All Kirklin Clinic Scheduling Information	731-9380
Kirklin Clinic Department of Radiology	801-8750