Stroke MARCH-APRIL 1976 VOL. NO. 2stroke.ahajournals.org/content/strokeaha/7/2/109.full.pdf ·...
6
Stroke A Journal of Cerebral Circulation MARCH-APRIL 1976 VOL. 7 NO. 2 Comparison of Computerized Tomography and Radionuclide Imaging in "Stroke" .99 MOKHTAR H . GADO, M.D., R. EDWARD COLEMAN, M.D., ANTHONY L. MERLIS, M.D., PHILIP O. ALDERSON, M.D., AND KIL SOO LEE, M.D. SUMMARY Forty patients were studied by computerized tomog- raphy and by radionuclide brain imaging. The final diagnosis was in- farction in 29 patients, intracerebral hematoma in seven, acute SAH in one, and old cerebrovascular accidents in three. CT was far superior to RN in detecting intracerebral hematomas and dis- tinguishing them from cerebral infarction. The results of CT and RN tests were comparable regarding the percentage of abnormalities. However, the results in the same patients were not identical in 55% of the cases, indicating a complementary role for the two tests. There was no relationship between the frequency of abnormalities on CT and the time lapse after the onset of cerebral infarction. RN uptake was not seen in patients with old cerebrovascular accidents. SINCE THE INTRODUCTION of computerized tomog- raphy (CT) as a noninvasive technique for brain imaging, several reports have discussed its usefulness in patients with stroke. The purpose of this communication is to compare CT and radionuclide brain scanning in patients with cerebrovascular disease. Methods There were 40 patients with a final diagnosis of cerebro- vascular accident. Each patient was examined by CT and radionuclide (RN) brain imaging. There were 29 cases of re- cent infarction (28 in the cerebral hemisphere and one in the cerebellum), seven cases of intracerebral hemorrhage, and one with subarachnoid hemorrhage (SAH). The diagnosis of cerebral infarction was made on clinical grounds. The diagnosis of intracerebral hematoma was confirmed by sur- gery in three cases and by autopsy in two. There were two cases in this series in which the diagnosis of a hematoma was based on the CT scan. The interval between the onset of symptoms and the diagnostic imaging in this group of patients is shown in table 1. The time lapse between CT and RN brain imaging was less than one week in the same patient, with a mean of 1.8 days. As shown in table 1, CT was done in the first two days in 15 patients, between two and seven days after the onset in 13 patients, between seven and 21 days in six patients, and more than 21 days after the onset in six patients. RN studies were done in the first two days in 18 patients, between two and seven days after the episode in 13 patients, between seven and 21 days in four patients, and more than 21 days after the episode in five From the Neuroradiology Section and the Division of Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway, St. Louis, Missouri 63110. Supported in part by Neuroradiology Training Grant NIH-5-T01-NS0- 522-08. Reprint requests to Dr. Gado, Associate Professor, Chief, Neuroradiology Section. patients. Three patients admitted for evaluation of late se- quelae of a cerebrovascular accident that had occurred one year earlier are included in the last column of table 1. In this study there was a slight inadvertent selection of patients resulting in a slight artificial bias in the results. During the greater part of the period covered in this study there was a single CT unit in operation at our institute. As a result of the inevitable waiting list, some patients with a negative RN study were not studied by CT. It is quite possible, therefore, that a group of patients with negative isotope studies and positive CT was inadvertently omitted from the study. This will be discussed later. CT scans were performed with an EMI scanner, using the standard technique. The x-ray tube was operated at 120 KVP and 33 mA with 13 mm collimation of the beam. The scan was done at a plane of 20° above the orbitomeatal plane. The image consisted of an 80 X 80 matrix in the studies of the first 17 patients. The remaining 23 patients were studied by the 160 X 160 matrix. The RN brain scan was performed utilizing a scintillation camera and the intravenous injection of Mm Tc-pertech- netate (15 to 20 mCi in 1 to 4 cc of saline). A rapid sequence study was performed at the time of the injection, using a high sensitivity parallel hole collimator. Static brain imag- ing was performed approximately 30 minutes after injection using a high resolution parallel hole collimator. When necessary, delayed images (two to four hours) were ob- tained. Results Of the 29 patients with recent infarction, 16 patients (55%) showed abnormality on the CT scan and 20 (69%) showed abnormality on RN brain imaging (table 2). The ab- normality on CT consisted of decreased density of the brain tissue (fig. 1). None of the patients had evidence of brain swelling on CT. Twenty of the patients showed increased up- 109 by guest on June 19, 2018 http://stroke.ahajournals.org/ Downloaded from
Transcript of Stroke MARCH-APRIL 1976 VOL. NO. 2stroke.ahajournals.org/content/strokeaha/7/2/109.full.pdf ·...
StrokeA Journal of Cerebral Circulation
MARCH-APRIL 1976VOL. 7 NO. 2
Comparison of Computerized Tomography andRadionuclide Imaging in "Stroke".99
MOKHTAR H . GADO, M.D., R. EDWARD C O L E M A N , M.D., ANTHONY L. MERLIS, M.D.,
PHILIP O. ALDERSON, M.D., AND KIL SOO LEE, M.D.
SUMMARY Forty patients were studied by computerized tomog-raphy and by radionuclide brain imaging. The final diagnosis was in-farction in 29 patients, intracerebral hematoma in seven, acute SAHin one, and old cerebrovascular accidents in three. CT was farsuperior to RN in detecting intracerebral hematomas and dis-tinguishing them from cerebral infarction. The results of CT and RN
tests were comparable regarding the percentage of abnormalities.However, the results in the same patients were not identical in 55% ofthe cases, indicating a complementary role for the two tests. Therewas no relationship between the frequency of abnormalities on CTand the time lapse after the onset of cerebral infarction. RN uptakewas not seen in patients with old cerebrovascular accidents.
SINCE THE INTRODUCTION of computerized tomog-raphy (CT) as a noninvasive technique for brain imaging,several reports have discussed its usefulness in patients withstroke. The purpose of this communication is to compareCT and radionuclide brain scanning in patients withcerebrovascular disease.
Methods
There were 40 patients with a final diagnosis of cerebro-vascular accident. Each patient was examined by CT andradionuclide (RN) brain imaging. There were 29 cases of re-cent infarction (28 in the cerebral hemisphere and one in thecerebellum), seven cases of intracerebral hemorrhage, andone with subarachnoid hemorrhage (SAH). The diagnosis ofcerebral infarction was made on clinical grounds. Thediagnosis of intracerebral hematoma was confirmed by sur-gery in three cases and by autopsy in two. There were twocases in this series in which the diagnosis of a hematoma wasbased on the CT scan. The interval between the onset ofsymptoms and the diagnostic imaging in this group ofpatients is shown in table 1. The time lapse between CT andRN brain imaging was less than one week in the samepatient, with a mean of 1.8 days. As shown in table 1, CTwas done in the first two days in 15 patients, between twoand seven days after the onset in 13 patients, between sevenand 21 days in six patients, and more than 21 days after theonset in six patients. RN studies were done in the first twodays in 18 patients, between two and seven days after theepisode in 13 patients, between seven and 21 days in fourpatients, and more than 21 days after the episode in five
From the Neuroradiology Section and the Division of Nuclear Medicine,Mallinckrodt Institute of Radiology, Washington University School ofMedicine, 510 South Kingshighway, St. Louis, Missouri 63110.
Supported in part by Neuroradiology Training Grant NIH-5-T01-NS0-522-08.
Reprint requests to Dr. Gado, Associate Professor, Chief, NeuroradiologySection.
patients. Three patients admitted for evaluation of late se-quelae of a cerebrovascular accident that had occurred oneyear earlier are included in the last column of table 1. In thisstudy there was a slight inadvertent selection of patientsresulting in a slight artificial bias in the results. During thegreater part of the period covered in this study there was asingle CT unit in operation at our institute. As a result of theinevitable waiting list, some patients with a negative RNstudy were not studied by CT. It is quite possible, therefore,that a group of patients with negative isotope studies andpositive CT was inadvertently omitted from the study. Thiswill be discussed later.
CT scans were performed with an EMI scanner, using thestandard technique. The x-ray tube was operated at 120KVP and 33 mA with 13 mm collimation of the beam. Thescan was done at a plane of 20° above the orbitomeatalplane. The image consisted of an 80 X 80 matrix in thestudies of the first 17 patients. The remaining 23 patientswere studied by the 160 X 160 matrix.
The RN brain scan was performed utilizing a scintillationcamera and the intravenous injection of MmTc-pertech-netate (15 to 20 mCi in 1 to 4 cc of saline). A rapid sequencestudy was performed at the time of the injection, using ahigh sensitivity parallel hole collimator. Static brain imag-ing was performed approximately 30 minutes after injectionusing a high resolution parallel hole collimator. Whennecessary, delayed images (two to four hours) were ob-tained.
Results
Of the 29 patients with recent infarction, 16 patients(55%) showed abnormality on the CT scan and 20 (69%)showed abnormality on RN brain imaging (table 2). The ab-normality on CT consisted of decreased density of the braintissue (fig. 1). None of the patients had evidence of brainswelling on CT. Twenty of the patients showed increased up-
109
by guest on June 19, 2018http://stroke.ahajournals.org/
Dow
nloaded from
110 STROKE VOL. 7, No. 2, MARCH-APRIL 1976
TABLE 1 Time Interval Between Cerebrovascular Accidentand Imaging Studies
CTRN
0-2
1518
Days2-7
1313
7-21
64
>21
65
Total
4040
take on radionuclide imaging (fig. 2). Rapid sequence scin-tigraphy was done on 14 of these patients and showeddecreased vascularity in three, a flip-flop phenomenon (fig.3) in one, and normal results in ten. There was no increaseduptake in eight patients with recent infarction. Rapid se-quence scintigraphy was done on four of them and showeddecreased vascularity in three, all of whom had a positiveCT. There were three cases in which both the CT and radio-nuclide study were negative. Rapid sequence scintigraphywas done on one of these and it also was negative (table 3).
Of the three patients evaluated one year after a cerebro-vascular accident, none showed increased uptake on radio-nuclide images. Rapid sequence scintigraphy was done ontwo of them and showed a flip-flop phenomenon in both. CTwas positive in all three cases.
The results of RN and CT studies were analyzed in rela-tion to the time interval between the scan and the onset ofsymptoms in the 29 patients with cerebral infarction (table4). The studies were divided into four groups in which thetime interval was 0 to 2 days, 2 to 7 days, 7 to 21 days, andgreater than 21 days, respectively. Radionuclide imagingshowed an increase in the percentage of detectable cases in
the two to seven day-interval and a further increase in the 7to 21 day-interval. A decline was noted after 21 days. CTshowed, on the other hand, little difference in the incidenceof positive results between the three groups in this smallsample.
Unlike thromboembolic cerebral infarction, intra-cerebral hematomas were detected by CT in all sevenpatients included in this series (table 2). In all cases thenature of the lesion was also determined, as distinct from in-farction, by its high density (fig. 4). The RN studies showedan increased uptake, indistinct from infarction, in twopatients only. The remaining five patients showed normalRN studies.
Discussion
CEREBRAL INFARCTION
The changes shown on CT scan in patients with infarctionhave been described by New et al.1 and Paxton and Am-brose.2 These authors point to a series of changes based uponthe natural history of cerebral infarction. CT obtained in the
FIGURE 1 Cerebral infarction in the territory of the left middlecerebral artery (MCA). CT scan shows decreased density in the leftcerebral hemisphere in the distribution of the MCA.
FIGURE 2 Cerebral infarction in the territory of the left MCA. RNbrain images: anteroposterior view (top), left lateral view (bottom).There is increased uptake of the radionuclide by the brain in the dis-tribution of the left MCA.
by guest on June 19, 2018http://stroke.ahajournals.org/
Dow
nloaded from
COMPUTERIZED TOMOGRAPHY AND RADIONUCLIDE IMAGING/Garfo et al. Ill
TABLE 2 Cerebrovascular Accidents: Results of RadionuclideImages and CT Scans
Diagnosis
Recent cerebralinfarction
Recent intracerebralhematoma
Acute SAHOld cerebrovascular
accidents
n
29
7
13
CTT abnormal
16 (55%)
7 (100%)
13
Radionuclide imagingabnormal*
20 (69%)
2 (28%)
00
•Does not include results of rapid sequence scintigraphy.SAH = subarachnoid hemorrhage.
first few days after the ictus shows a diffuse low density areainvolving the cortex and white matter with little or no mid-line displacement. Studies done more than ten days after theinitial episode show a more clearly defined low density area.After a month or more some patients show a well-definedcystic area with CSF density. New1 ascribes the earlychanges, within hours or days after the onset of infarction, toaccompanying cerebral edema. He suggests that necrosisand phagocytosis result in the appearance ten days later of amore well-defined margin and lower density of the lesion ascompared to the edema of the earlier stage. He postulatesthat if the area of necrosis is small, the lesion may becomedifficult to detect. When it is large, a remaining cavity withCSF density is seen at the site of an old infarct.
The incidence of abnormal findings on CT in patients withcerebral infarction was reported to be 48% by Baker et al.3
and 49% by Paxton and Ambrose.2 Our results show aslightly higher figure of 55% in recent infarction. None ofour studies showed evidence of deformity of the ventricularsystem due to cerebral swelling. Davis and Pressman4 alsofound that the majority of patients with cerebral infarctionshowed no such swelling.
The frequency of abnormal RN studies in patients withcerebral infarction studied during the first week after theonset of symptoms5" has been reported to vary between20% and 40%. Welch et al.12 in a study of 169 radionuclidestudies in patients with thromboembolic cerebral infarctionreported 32% positive studies during the first week after theictus and 52% positive findings in studies done later than oneweek after the ictus. They also indicated a 27% incidence ofabnormal studies in the first two days after the episode. Ourresults of RN imaging show the same trend but the figures inour series are higher due to an artificial bias as indicatedearlier. They are higher than our previously publisheddata.12
TABLE 3 Recent Infarction: Results of Radionuclide Imagesand CT Scans*
No. of casesCRAG (n.)CRAG result +
CT +RN +
10615
CT -RN +
10835
*CT = computerized tomography.RN = radionuclide static images.CRAG = rapid sequence scintigraphy.+ = positive.— = negative.
CT +RN -
6330
CT -RN -
3101
M
Silli
fife:
FIGURE 3 Occlusion of right internal carotid artery. Rapidsequence scintigraphy showing arterial phase (top), capillary phase(middle), and venous phase (bottom). There is decreased activity inthe right hemisphere in the arterial phase. In the venous phase, thereis increased activity in the right hemisphere suggesting collateralflow to the right hemisphere. This has been referred to as the "flip-flop" phenomenon.
by guest on June 19, 2018http://stroke.ahajournals.org/
Dow
nloaded from
112 STROKE VOL. 7, No. 2, MARCH-APRIL 1976
It appears, therefore, that the percentage of abnormalitieson CT in recent infarction is comparable to RN brain imag-ing. While this is the case, if one compares the results of thetwo tests in the same patient, one finds that patients with
negative CT are not necessarily those who have negative RNimaging, and vice versa. Table 3 shows that in 29 patientswith recent infarction, the results of the two tests were notidentical in 16 (55%). The significance of this observation isevident. While the two tests yield a comparable percentageof abnormalities, their roles in detection of a lesion are com-plementary rather than alternative.
The three patients evaluated one year after the episodeshowed abnormalities on CT while the RN images showedno increased uptake. Patients with old strokes are prone tohave new strokes. A positive RN uptake would be related tothe recent stroke whereas a positive CT could be the result ofeither the recent or the old stroke, another indication for thecomplementary role of the two tests. Our results show norelationship between the incidence of abnormalities on CTand the time lapse after the episode.
INTRACEREBRAL HEMATOMA
Previous reports have demonstrated the high efficacy ofCT in detecting fresh intracerebral hematomas.1-2 The highx-ray attenuation characteristics of clotted blood enable CTscanning to detect 100%2 of intracerebral hematomas and todistinguish them from infarction. Our results in this smallseries and our experience are in agreement with these find-ings. Moreover, we have studied three patients with intra-cerebral hematoma (one of them not included in this series)in whom the clinical diagnosis was one of thromboembolicinfarction. It was only after CT that the nature of the lesionwas determined.
The results of RN brain imaging in patients with intra-cerebral hematoma in previous reports6' "• 1S~1B show a widerange (107o to 60%) of incidence of abnormal scans. In ourexperience12 abnormal RN images were seen in 43% ofpatients with intracerebral hematoma. The results in thecurrent study show a lower percentage (28%) and confirmthe superiority of CT over RN imaging in this group ofpatients.
Conclusions
The incidence of abnormalities on CT in cases of cerebralinfarction is comparable to those of RN imaging. In intra-cerebral hematoma CT is far superior to RN studies.
TABLE 4 Relationship of Findings on Radionuclide and CTStudies lo Time Interval After Onset of Cerebral Thromboem-bolic Infarction
FIGURE 4 Right intracerebral hematoma. CT scan showsincreased density caused by high x-ray absorbency of clotted bloodin the deep portion of the right cerebral hemisphere. The blood clotextended into the lateral ventricle.
Time interval
Radionuclide imaging0-2 days2-7 days7-21 days>21 days*
CT scan0-2 days2-7 days7-21 days>21 days*
Total (no.)
32101345
328
1266
Abnormalscans (no.)
206932
19574
3
% Abnormalstudies
6340697540
5963586650
•Includes three patients evaluated one year after a cerebrovascular ac-cident.
by guest on June 19, 2018http://stroke.ahajournals.org/
Dow
nloaded from
NEUROGENIC REGULATION OF CBF FOLLOWING ISCHEMIA/Zervas et al. 113
The distinction between intracerebral hematoma andcerebral infarction can be made only by CT.
Three observations in this study indicate complementaryroles for RN brain imaging and CT in evaluation of patientswith stroke. (1) While the percentages of abnormalities onboth tests were comparable in recent infarction, the resultsin the same patients were not identical in 55% of the cases.(2) In patients with a recent and an old stroke a positive RNuptake would be the result of the recent insult, while on CTboth types of lesions show similar abnormalities. (3) Hemo-dynamic changes on rapid sequence studies weredemonstrated in 38% of 18 patients on whom the test wasdone.
References
1. New PFJ, Scott WR, Schnur JA, et al: Computerized axial tomographywith the EMI scanner. Radiology 110:109-123, 1974
2. Paxton R, Ambrose J: The EMI scanner. A brief review of the first 650patients. Br J Radiol 47:530-565, 1974
3. Baker HL Jr, Campbell JK, Houser OD, et al: Computer assisted tomog-raphy of the head. An early evaluation. Mayo d i n Proc 49:17-27 (Jan)1974
4. Davis DO, Pressman BD: Computerized tomography of the brain.Radiol Clin North Am 12:297-313 (Aug) 1974
5. Tow RE, Wagner HN, Deland FH, et al: Brain scanning in cerebralvascular disease. JAMA 207:105-108, 1969
6. Glasgow JL, Currier RD, Goodrich JK, et al: Brain scans at varied inter-vals following CVA. J Nud Med 6:902-916, 1965
7. Morrison RT, Afifi AK, Van Allen MW, et al: Scintiencephalographyfor the detection and localization of non-neoplastic intracranial lesions. JNucl Med 6:7-15, 1965
8. Brown A, Zingesser L, Scheinberg LC: Radioactive mercury-labeledchlormerodrin scans in cerebrovascular accidents. Neurology17:405-411, 1967
9. Oeconomos D: Gammaencephalography in cerebral vascular accidents.Prog Brain Res 30:201-209, 1968
10. Marshall J, Popham MG: Radioactive brain scanning in the managementof cerebrovascular disease. J Neurol Neurosurg Psychiat 33:201-204,1970
11. Molinari GF, Pircher F, Heyman A: Serial brain scanning usingtechnetium 99m in patients with cerebral infarction. Neurology17:627-636, 1967
12. Welch DM, Coleman RE, Hardin WB, et al: Brain scanning in cerebralvascular disease. A reappraisal. Stroke 6:136-141 (Mar-Apr) 1975
13. Sharma SM, Quinn JL: Brain scans in autopsy proved cases of intra-cerebral hemorrhage. Arch Neurol 28:270-271, 1973
14. Ojemann RG, Aronow S, Sweet WH: Scanning with positron-emittingisotopes in cerebrovascular disease. Acta Radiol Diagn 5:894-905, 1966
15. Overton MC III, Haynie TP, Snodgrass SR: Brain scans in non-neo-plastic intracranial lesions. JAMA 191:431-436, 1965
Neurogenic Regulation of CerebralBlood Flow Following Ischemia
NICHOLAS T. ZERVAS, M.D., HIROSHI HORI, M.D.,
MAKATO NAGORO, M.D., AND RICHARD WURTMAN, M.D.
SUMMARY To elicit evidence concerning neurogenic control,regional cerebral blood flow determined by measurement of corticaltemperature was examined in monkeys. Following three hours oftemporary occlusion of the MCA, pressure autoregulation waspreserved in all control animals. Presumptive partial chemical sym-pathectomy, produced by the administration of either L-alpha-
methyl-tyrosine or 3-alpha-dimethyl-tyrosine methyl ester HCI, wasassociated with loss of pressure autoregulation following 1.5 hours ofocclusion of the MCA on only the side of the occlusion. Failure ofpressure autoregulation in the treated animals implies that sym-pathetic control was a partial requirement of proper postischemicpressure autoregulation.
Introduction
THE NORADRENERGIC NERVE TERMINALS of thecervical sympathetic trunk arborize extensively in the adven-titia of cerebral arteries and arterioles.1 One would an-ticipate that these neural elements should participate in theregulation of the cerebral circulation. However, numerousconflicting reports have generated an unresolved controver-sy regarding the importance of these cerebral sympatheticfibers (see discussion below).
Since the normal state may not offer a satisfactory sub-strate from which to elicit evidence of neurogenic control,
From the Department of Neurosurgery, Beth Israel Hospital and HarvardMedical School, Boston, Massachusetts; and the Department of Nutritionand Food Sciences, Massachusetts Institute of Technology, Cambridge,Massachusetts.
These studies were supported in part by the US Public Health Services(NS-10459, GM-2019, and HL-15365).
Reprint requests to Dr. Zervas, Beth Israel Hospital, 330 BrooklineAvenue, Boston, Massachusetts 02215.
we examined regional cerebral blood flow (rCBF) in animalswith transient cerebral ischemia. Sympathetic function wasaltered by interference with the synthesis of norepinephrine.Ischemia was produced by temporary ligation of the middlecerebral artery (MCA). Pressure autoregulation (PAR) wasthen studied to determine whether impairment of autonomicfunction would modify the control of the cerebral circula-tion. In the normal state regional or total CBF remainsrelatively constant within moderate limits of systemicarterial blood pressure. However, if systolic pressure isgreater than 140 mm Hg2 or less than 70 mm Hg,3 CBF mayincrease or decrease, respectively. PAR is said to bepreserved if CBF does not change in response to fluctuationsof mean arterial blood pressure (MABP) within this range.In the studies described below, MABP was raised by 20 mmHg for very short periods to determine whether control ofCBF was impaired in these ischemic chemically denervatedanimals. The results will be discussed in the light of recentdiscussions of sympathetic nerve-blood flow interactions.
by guest on June 19, 2018http://stroke.ahajournals.org/
Dow
nloaded from
M H Gado, R E Coleman, A L Merlis, P O Alderson and K S LeeComparison of computerized tomography and radionuclide imaging in "stroke".
Print ISSN: 0039-2499. Online ISSN: 1524-4628 Copyright © 1976 American Heart Association, Inc. All rights reserved.
is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231Stroke doi: 10.1161/01.STR.7.2.109
1976;7:109-113Stroke.
http://stroke.ahajournals.org/content/7/2/109World Wide Web at:
The online version of this article, along with updated information and services, is located on the
http://stroke.ahajournals.org//subscriptions/
is online at: Stroke Information about subscribing to Subscriptions:
http://www.lww.com/reprints Information about reprints can be found online at: Reprints:
document. Permissions and Rights Question and Answer available in the
Permissions in the middle column of the Web page under Services. Further information about this process isOnce the online version of the published article for which permission is being requested is located, click Request
can be obtained via RightsLink, a service of the Copyright Clearance Center, not the Editorial Office.Stroke Requests for permissions to reproduce figures, tables, or portions of articles originally published inPermissions:
by guest on June 19, 2018http://stroke.ahajournals.org/
Dow
nloaded from
