Vascular Displacement Diagnosed by Cerebral Radionuclide Angiography 1
Nuclear Medicine
Walter P. Maynard, M.D. and Fred S. Mishkin, M.D. Findings were reviewed in twelve patients who had both contrast and radionuclide cerebral angiograms interpreted as showing displacement of the anterior or middle cerebral arteries on either study. The radionuclide angiogram detected 3 of 8 displacements of the anterior cerebral artery and 9 of 10 displacements of the middle cerebral artery. In two cases the radionuclide study suggested displacement of the middle cerebral artery when in fact it was occluded in one and normal in the other. Radionuclide angiographic detection of major cerebral artery displacement provides valuable interpretative data, particularly when the middle cerebral artery is involved. INDEX TERMS:
Cerebral blood vessels, displacement. Cerebral blood vessels. radionu-
elide studies Radiology 117:361-364, November 1975
• 99 m Tc-pertechnetate into an antecubital vein after administration of 200 mg of oral potassium perchlorate.
of the cerebral radionuclide angiogram in detecting cerebral abnormalities by differences in relative regional perfusion has been well documented (1). Less has been said of the usefulness of the cerebral radionuclide angiogram in detecting cerebral mass lesions that cause displacement of the intracerebral arterial vessels. We have encountered cerebral mass lesions that caused displacement of the major cerebral arteries on the cerebral radionuclide angiogram that correlated with the findings of the contrast angiogram. This prompted us to review and correlate all similar cases with the findings of the contrast angiogram to determine the clinical usefulness of this observation.
T
HE EFFICACY
RESULTS
T ABLE I summarizes the results. Nine of ten patients showing displacement of a major cerebral artery on contrast angiography showed similar changes on the radionuclide study, while a 1-cm shift of the anterior cerebral artery due to a central sylvian hemorrhage in CASE 12 was not detected by the radionuclide study. Two patients who were thought to have displacement of the middle cerebral artery showed no displacement on contrast angiography, although one had complete occlusion of the middle cerebral artery. Figure 1 shows typical findings in a patient with elevation of the middle cerebral artery (CASE 1). Figure 2 shows a shift of the anterior and middle cerebral arteries in a patient with a recurrent right subdural hematoma (CASE 6). A more striking example of shift of the anterior cerebral artery is shown in Figure 3 (this patient is not included in the series).
MA TERIAL AND METHODS
All cerebral radionuclide angiograms and contrast angiograms obtained from May 1972 to November 1974 that were reported as demonstrating arterial displacement on either study were reviewed. A total of twelve patients had undergone both procedures. Three additional patients in the contrast angiogram group and three additional patients from the cerebral radionuclide angiogram group were excluded from the study because of the lack of both examinations. In all cases except one, the cerebral radionuclide angiogram preceded the contrast angiogram, and in all cases the procedures were performed within two days of each other except in one instance in which a delay of 4 days occurred. All studies were carried out with an Anger camera.f the bolus passage monitored with a persistence scope, the entire study recorded on videotape and the arterial and venous phases imaged on 4 X 5- in. radiographic film. A standard anterior flow study was conducted with the intravenous injection of a bolus of 357 tLCi/kg
DISCUSSION
Even though the number of patients in our series is small and it is acknowledged that contrast angiography is a more specific and sensitive method of detecting cerebral arterial displacement, our study suggests that potentially useful information concerning the presence or absence of cerebral arterial vascular displacement can be obtained from the cerebral radionuclide angiogram. This potentially valuable information may be lost when a vertex flow study is performed. Our data suggest that shifts of the middle cerebral artery are more easily detected than anterior cerebral ar-
1 From the Department of Radiology, Division of Nuclear Medicine. Charles R. Drew Postgraduate Medical School and the Martin Luther King, Jr. General Hospital of Los Angeles County, Los Angeles, Calif. 90059. Accepted for publication in May 1975. 2 Searle Radiographies Pho/Gamma HP. dk
361
Table I:
Flow Study and Rectilinear Scan
Final Diagnosis
Patient Data MCA* Displacement Patient 1 35-year-old woman with trauma to (R) face with fracture of zygomatic arch
Displacement of Cerebral Arteries in Twelve Patients Angiogram Medial displacement of insular group of (R) MCA. Insular surface 32 mm from inner table. Sylvian point 37 mm from inner table. Major branch of MCA 9 mm above clinoparietal line. Elevation of sylvian triangle on left. Sylvian point 41 mm from inner table. Insular surface 34 mm from inner table. No displacement from clinoparietal line. Elevation of (L) MCA. Major branch of MCA 27 cm below clinoparietal line. Insular surface 44 mm from inner table. Sylvian point 49 mm from inner table.
Cerebral contusion
Elevated (R) MCA group. I ncreased activity (R) temporal lobe and over (R) convexity.
Patient 2 34-year-old man sustained trauma to head 1 week previously
Inflammatory temporal lobe hematoma surgically removed
Elevated (L) MCA. Increased activity (L) temporal lobe.
Patient 3 72-year-old woman with confusion
Temporal lobe brain tumor
Elevation and medial displacement of the (L) MCA. Increased activity (L) temporal lobe.
Cerebral contusion
Elevated (L) MCA. Increased activity in (L) temporal lobe and over (L) parietal convexity.
Patient 5 48-year-old woman semicomatose with (R) hemiparesis
Chronic (L) subdural hematoma drained surgically
Elevated (L) MCA. Decreased flow over (L) convexity. Increased activity (L) convexity and (L) temporal lobe.
Patient 6 44-year-old man who had previous craniotomy after auto accident. Recent fall with (L) hemiparesis and headache
Acute right subdural hematoma surgically drained
Medial displacement of (R) MCA and right to left displacement of ACA. I ncreased activity over (R) convexity.
Patient 7 32-year-old man beaten up with basilar skull fracture. Headaches, confusion and focal seizures. Previous craniotomy
Right epidural hematoma surgically removed
Elevated (R) MCA. I ncreased activity (R) temporal lobe and over right convexity.
Patient 8 - 64-year-old woman with sudden onset of (L) sided weakness
Intracerebral hematoma surgically evacuated
Right to left shift of ACA. Increased activity (R) frontoparietal region.
Patient 9 10-year-old boy with sudden loss of consciousness
Ruptured intracranial aneurysm with intracerebral hematoma
Lateral displacement of (R) MCA. Right to left shift of ACA. No delayed scan.
No intracranial mass at autopsy
Decreased perfusion of (L) MCA with possible elevation of (R) MCA. Normal delayed scan. Downward and lateral displacement of (R) MCA. Normal delayed scan.
Normal. Insular surface 30 mm from inner table. Sylvian point 39 mm from inner table. Vessels of MCA below clinoparietal line 3 mm. Occlusion of right MCA 2 cm distal to bifurcation. 12 mm right to left pericallosal shift.
Decreased perfusion in distribution (R) MCA. Normal delayed scan.
10 mm right to left shift of pericallosal artery and superolateral displacement of the (R) sylvian point. Surface of insula 20 mm from inner table. Sylvian point 30 mm from inner table. Inferior group of MCA 9 mm above clinoparietal line.
MCA and ACA ** Displacement Patient 4 25-year-old man struck on head
False Positives Patient 10 46-year-old man with seizures, right-sided hemiparesis Patient 11 65-year-old woman found comatose with bloody spinal fluid False Negatives Patient 12 51-year-old woman with hypertension and abrupt onset of left hemiparesis
Acute occlusion of (R) MCA with cerebral edema Intracerebral clot surgically evacuated
*MCA = middle cerebral artery. ** ACA = anterior cerebral artery. (L) = left; (R) = right.
362
Medial displacement of su rface of (L) insular group 38 mm from inner table. Sylvian point 48 mm from inner table. Major inferior branch of MCA 11 mm above clinoparietal line. 1 cm left to right shift of pericallosal artery. Elevation and medial displacement of left insular group of (L) MCA. Sylvian point 45 mmfrom inner table. I nsular surface 44 mm from inner table. MCA major inferior branches on clinoparietal line. 9 mm left to right sh itt of peri" callosal artery. 8 mm right to left shift of ACA. Medial displacement of (R) MCA. 2.2 cm avascular cresent over right convexity. Insular surface 42 mm from inner table. Sylvian point 47 mm from inner table. Major inferior branch of MCA 14 mm above clinoparietal line. Elevated (R) MCA. 18 mm right to left shift of pericallosal artery. Sylvian point 45 mmfrom inner table. Insular surface 31 mm from inner table. MCA major inferior branch 9 mm above clinoparietal line. 13 mm right to left shift of midline vessels. Depression sylvian vessels of (R) MCA 12 mm below c1inoparietal line. Sylvian point 40 mrn from inner table. Insular surface 32 mm from inner table. Aneurysm of (R) MCA with intracerebral hematoma. 9 mm right to left shift of pericallosal. Lateral displacement of (R) MCA. Sylvian point 41 mm from inner table. MCA group 25 mm above c1inoparietal line.
Vol. 117
VASCULAR DISPLACEMENT DIAGNOSED BY RADIONUCLIDE ANGIOGRAPHY
363
Nuclear Medicine
Fig. 1. CASE 2. Left temporal lobe hematoma. Arterial phase (A) shows elevation of left middle cerebral artery (arrows), midline anterior cerebral artery act ivity . Straight sagittal sinus on venous phase (B) shows head is straight. Delayed left lateral im age (C) shows abnormality in posterior left temporal lobe. Left carotid angiogram (D) shows elevation of left middle cerebral artery.
Fig. 2. CASE 6. Recurrent subdural hematoma. Arterial phase (A) shows medial displacement of right middle cerebral artery, right to left bowing ofproximal portion of anterior cerebral vessels. Venous phase (B) shows compressed superficial vessels (arrows) and straight sagittal sinus . Delayed anterior image (C) shows slight increase in activity over right convexity. Right carotid angiogram (D) shows avascular region of subdural hematoma, bowing of anterior cerebral artery and right to left shift of internal cerebral ve in.
tery shifts. We were unable to detect five of eight shifts of the anterior cerebral artery, while we detected nine of ten shifts of the middle cerebral artery . This is probably due to the lack of a separate opposite symmetrical anterior cerebral artery that can be used for comparison. However, if there is complete occlusion of the mid-
die cerebral artery, the middle cerebral artery may appear asymmetrical and mimic a shift as was the case with Patient 11. This was probably due to misinterpretation of activity from the posterior cerebral artery. The smallest mid:ine shift detected was 8 mm while the five undetected were 9, 10, 10, 12 and 18 mm. We
November 1975
WALTER P. MAYNARD AND FRED S. MISHKIN
364
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Fig. 3. Metastatic breast carcinoma, left frontal lobe. Arterial phase (A)shows marked bowingof anterior cerebral vessels. Venous phase (8) shows large blush of activity in left hemisphere (arrow) and straight sagittal sinus indicating no rotation. Delayed anterior image (C) shows uptake in largesingle lesionwhich was resected . have no good objective way of evaluating the least displacement of the middle cerebral artery group detectable by the radionuclide angiogram. Standard measurements used for evaluating displacement include the relat ionship of the sylvian po int and insular surface to the inner table of the skull and the relationship of the lower main middle cerebral artery branch to the clinoparietal line . These measurements are given in TABLE I, but do not convey the impression of displacement gained by viewing the total information. Our series is too small to allow prediction of a threshold of major vessel shift detectability by cerebral radionuclide angiography. The ma in source of difficulty in detecting vascular displacement is determining whether the findings are secondary to rotation or jf an actual shift is present. Rotation can be assessed in the arterial phase by observing the cerebral hemispheres for symmetry of size, the hemisphere toward which the head is rotated appearing smaller. Furthermore, the sagittal sinus serves as a convenient guide . In a nonrotated venous phase the sagittal sinus is straight. If there is rotation, the sinus will
appear bowed. There are exceptions to these observations in a small percentage of normal patients who have bowed sagittal sinuses. As with the contrast angiogram, the size and location of the lesion are important factors in determining if there will be detectable arterial vascular displacement. We made no attempt to quantitate size of the lesions in this study except for the fact that they were large. Lesions that are located in the frontal , temporal and central sylvian areas will probably be responsible for the majority of the detectable arterial shifts. REFERENCE 1. Cowan RJ, Maynard CD, Meschan I, et al: Value of the routine use of the cerebral dynamic radioisotope study. Radiology 107: 111-116, Apr 1973
Fred S. Mishkin, M.D. Department of Radiology Martin Luther King, Jr. General Hospital 12021 South Wilmington Avenue LosAngeles, Calif. 90059
Nuclear Medicine
Walter P. Maynard, M.D. and Fred S. Mishkin, M.D. Findings were reviewed in twelve patients who had both contrast and radionuclide cerebral angiograms interpreted as showing displacement of the anterior or middle cerebral arteries on either study. The radionuclide angiogram detected 3 of 8 displacements of the anterior cerebral artery and 9 of 10 displacements of the middle cerebral artery. In two cases the radionuclide study suggested displacement of the middle cerebral artery when in fact it was occluded in one and normal in the other. Radionuclide angiographic detection of major cerebral artery displacement provides valuable interpretative data, particularly when the middle cerebral artery is involved. INDEX TERMS:
Cerebral blood vessels, displacement. Cerebral blood vessels. radionu-
elide studies Radiology 117:361-364, November 1975
• 99 m Tc-pertechnetate into an antecubital vein after administration of 200 mg of oral potassium perchlorate.
of the cerebral radionuclide angiogram in detecting cerebral abnormalities by differences in relative regional perfusion has been well documented (1). Less has been said of the usefulness of the cerebral radionuclide angiogram in detecting cerebral mass lesions that cause displacement of the intracerebral arterial vessels. We have encountered cerebral mass lesions that caused displacement of the major cerebral arteries on the cerebral radionuclide angiogram that correlated with the findings of the contrast angiogram. This prompted us to review and correlate all similar cases with the findings of the contrast angiogram to determine the clinical usefulness of this observation.
T
HE EFFICACY
RESULTS
T ABLE I summarizes the results. Nine of ten patients showing displacement of a major cerebral artery on contrast angiography showed similar changes on the radionuclide study, while a 1-cm shift of the anterior cerebral artery due to a central sylvian hemorrhage in CASE 12 was not detected by the radionuclide study. Two patients who were thought to have displacement of the middle cerebral artery showed no displacement on contrast angiography, although one had complete occlusion of the middle cerebral artery. Figure 1 shows typical findings in a patient with elevation of the middle cerebral artery (CASE 1). Figure 2 shows a shift of the anterior and middle cerebral arteries in a patient with a recurrent right subdural hematoma (CASE 6). A more striking example of shift of the anterior cerebral artery is shown in Figure 3 (this patient is not included in the series).
MA TERIAL AND METHODS
All cerebral radionuclide angiograms and contrast angiograms obtained from May 1972 to November 1974 that were reported as demonstrating arterial displacement on either study were reviewed. A total of twelve patients had undergone both procedures. Three additional patients in the contrast angiogram group and three additional patients from the cerebral radionuclide angiogram group were excluded from the study because of the lack of both examinations. In all cases except one, the cerebral radionuclide angiogram preceded the contrast angiogram, and in all cases the procedures were performed within two days of each other except in one instance in which a delay of 4 days occurred. All studies were carried out with an Anger camera.f the bolus passage monitored with a persistence scope, the entire study recorded on videotape and the arterial and venous phases imaged on 4 X 5- in. radiographic film. A standard anterior flow study was conducted with the intravenous injection of a bolus of 357 tLCi/kg
DISCUSSION
Even though the number of patients in our series is small and it is acknowledged that contrast angiography is a more specific and sensitive method of detecting cerebral arterial displacement, our study suggests that potentially useful information concerning the presence or absence of cerebral arterial vascular displacement can be obtained from the cerebral radionuclide angiogram. This potentially valuable information may be lost when a vertex flow study is performed. Our data suggest that shifts of the middle cerebral artery are more easily detected than anterior cerebral ar-
1 From the Department of Radiology, Division of Nuclear Medicine. Charles R. Drew Postgraduate Medical School and the Martin Luther King, Jr. General Hospital of Los Angeles County, Los Angeles, Calif. 90059. Accepted for publication in May 1975. 2 Searle Radiographies Pho/Gamma HP. dk
361
Table I:
Flow Study and Rectilinear Scan
Final Diagnosis
Patient Data MCA* Displacement Patient 1 35-year-old woman with trauma to (R) face with fracture of zygomatic arch
Displacement of Cerebral Arteries in Twelve Patients Angiogram Medial displacement of insular group of (R) MCA. Insular surface 32 mm from inner table. Sylvian point 37 mm from inner table. Major branch of MCA 9 mm above clinoparietal line. Elevation of sylvian triangle on left. Sylvian point 41 mm from inner table. Insular surface 34 mm from inner table. No displacement from clinoparietal line. Elevation of (L) MCA. Major branch of MCA 27 cm below clinoparietal line. Insular surface 44 mm from inner table. Sylvian point 49 mm from inner table.
Cerebral contusion
Elevated (R) MCA group. I ncreased activity (R) temporal lobe and over (R) convexity.
Patient 2 34-year-old man sustained trauma to head 1 week previously
Inflammatory temporal lobe hematoma surgically removed
Elevated (L) MCA. Increased activity (L) temporal lobe.
Patient 3 72-year-old woman with confusion
Temporal lobe brain tumor
Elevation and medial displacement of the (L) MCA. Increased activity (L) temporal lobe.
Cerebral contusion
Elevated (L) MCA. Increased activity in (L) temporal lobe and over (L) parietal convexity.
Patient 5 48-year-old woman semicomatose with (R) hemiparesis
Chronic (L) subdural hematoma drained surgically
Elevated (L) MCA. Decreased flow over (L) convexity. Increased activity (L) convexity and (L) temporal lobe.
Patient 6 44-year-old man who had previous craniotomy after auto accident. Recent fall with (L) hemiparesis and headache
Acute right subdural hematoma surgically drained
Medial displacement of (R) MCA and right to left displacement of ACA. I ncreased activity over (R) convexity.
Patient 7 32-year-old man beaten up with basilar skull fracture. Headaches, confusion and focal seizures. Previous craniotomy
Right epidural hematoma surgically removed
Elevated (R) MCA. I ncreased activity (R) temporal lobe and over right convexity.
Patient 8 - 64-year-old woman with sudden onset of (L) sided weakness
Intracerebral hematoma surgically evacuated
Right to left shift of ACA. Increased activity (R) frontoparietal region.
Patient 9 10-year-old boy with sudden loss of consciousness
Ruptured intracranial aneurysm with intracerebral hematoma
Lateral displacement of (R) MCA. Right to left shift of ACA. No delayed scan.
No intracranial mass at autopsy
Decreased perfusion of (L) MCA with possible elevation of (R) MCA. Normal delayed scan. Downward and lateral displacement of (R) MCA. Normal delayed scan.
Normal. Insular surface 30 mm from inner table. Sylvian point 39 mm from inner table. Vessels of MCA below clinoparietal line 3 mm. Occlusion of right MCA 2 cm distal to bifurcation. 12 mm right to left pericallosal shift.
Decreased perfusion in distribution (R) MCA. Normal delayed scan.
10 mm right to left shift of pericallosal artery and superolateral displacement of the (R) sylvian point. Surface of insula 20 mm from inner table. Sylvian point 30 mm from inner table. Inferior group of MCA 9 mm above clinoparietal line.
MCA and ACA ** Displacement Patient 4 25-year-old man struck on head
False Positives Patient 10 46-year-old man with seizures, right-sided hemiparesis Patient 11 65-year-old woman found comatose with bloody spinal fluid False Negatives Patient 12 51-year-old woman with hypertension and abrupt onset of left hemiparesis
Acute occlusion of (R) MCA with cerebral edema Intracerebral clot surgically evacuated
*MCA = middle cerebral artery. ** ACA = anterior cerebral artery. (L) = left; (R) = right.
362
Medial displacement of su rface of (L) insular group 38 mm from inner table. Sylvian point 48 mm from inner table. Major inferior branch of MCA 11 mm above clinoparietal line. 1 cm left to right shift of pericallosal artery. Elevation and medial displacement of left insular group of (L) MCA. Sylvian point 45 mmfrom inner table. I nsular surface 44 mm from inner table. MCA major inferior branches on clinoparietal line. 9 mm left to right sh itt of peri" callosal artery. 8 mm right to left shift of ACA. Medial displacement of (R) MCA. 2.2 cm avascular cresent over right convexity. Insular surface 42 mm from inner table. Sylvian point 47 mm from inner table. Major inferior branch of MCA 14 mm above clinoparietal line. Elevated (R) MCA. 18 mm right to left shift of pericallosal artery. Sylvian point 45 mmfrom inner table. Insular surface 31 mm from inner table. MCA major inferior branch 9 mm above clinoparietal line. 13 mm right to left shift of midline vessels. Depression sylvian vessels of (R) MCA 12 mm below c1inoparietal line. Sylvian point 40 mrn from inner table. Insular surface 32 mm from inner table. Aneurysm of (R) MCA with intracerebral hematoma. 9 mm right to left shift of pericallosal. Lateral displacement of (R) MCA. Sylvian point 41 mm from inner table. MCA group 25 mm above c1inoparietal line.
Vol. 117
VASCULAR DISPLACEMENT DIAGNOSED BY RADIONUCLIDE ANGIOGRAPHY
363
Nuclear Medicine
Fig. 1. CASE 2. Left temporal lobe hematoma. Arterial phase (A) shows elevation of left middle cerebral artery (arrows), midline anterior cerebral artery act ivity . Straight sagittal sinus on venous phase (B) shows head is straight. Delayed left lateral im age (C) shows abnormality in posterior left temporal lobe. Left carotid angiogram (D) shows elevation of left middle cerebral artery.
Fig. 2. CASE 6. Recurrent subdural hematoma. Arterial phase (A) shows medial displacement of right middle cerebral artery, right to left bowing ofproximal portion of anterior cerebral vessels. Venous phase (B) shows compressed superficial vessels (arrows) and straight sagittal sinus . Delayed anterior image (C) shows slight increase in activity over right convexity. Right carotid angiogram (D) shows avascular region of subdural hematoma, bowing of anterior cerebral artery and right to left shift of internal cerebral ve in.
tery shifts. We were unable to detect five of eight shifts of the anterior cerebral artery, while we detected nine of ten shifts of the middle cerebral artery . This is probably due to the lack of a separate opposite symmetrical anterior cerebral artery that can be used for comparison. However, if there is complete occlusion of the mid-
die cerebral artery, the middle cerebral artery may appear asymmetrical and mimic a shift as was the case with Patient 11. This was probably due to misinterpretation of activity from the posterior cerebral artery. The smallest mid:ine shift detected was 8 mm while the five undetected were 9, 10, 10, 12 and 18 mm. We
November 1975
WALTER P. MAYNARD AND FRED S. MISHKIN
364
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Fig. 3. Metastatic breast carcinoma, left frontal lobe. Arterial phase (A)shows marked bowingof anterior cerebral vessels. Venous phase (8) shows large blush of activity in left hemisphere (arrow) and straight sagittal sinus indicating no rotation. Delayed anterior image (C) shows uptake in largesingle lesionwhich was resected . have no good objective way of evaluating the least displacement of the middle cerebral artery group detectable by the radionuclide angiogram. Standard measurements used for evaluating displacement include the relat ionship of the sylvian po int and insular surface to the inner table of the skull and the relationship of the lower main middle cerebral artery branch to the clinoparietal line . These measurements are given in TABLE I, but do not convey the impression of displacement gained by viewing the total information. Our series is too small to allow prediction of a threshold of major vessel shift detectability by cerebral radionuclide angiography. The ma in source of difficulty in detecting vascular displacement is determining whether the findings are secondary to rotation or jf an actual shift is present. Rotation can be assessed in the arterial phase by observing the cerebral hemispheres for symmetry of size, the hemisphere toward which the head is rotated appearing smaller. Furthermore, the sagittal sinus serves as a convenient guide . In a nonrotated venous phase the sagittal sinus is straight. If there is rotation, the sinus will
appear bowed. There are exceptions to these observations in a small percentage of normal patients who have bowed sagittal sinuses. As with the contrast angiogram, the size and location of the lesion are important factors in determining if there will be detectable arterial vascular displacement. We made no attempt to quantitate size of the lesions in this study except for the fact that they were large. Lesions that are located in the frontal , temporal and central sylvian areas will probably be responsible for the majority of the detectable arterial shifts. REFERENCE 1. Cowan RJ, Maynard CD, Meschan I, et al: Value of the routine use of the cerebral dynamic radioisotope study. Radiology 107: 111-116, Apr 1973
Fred S. Mishkin, M.D. Department of Radiology Martin Luther King, Jr. General Hospital 12021 South Wilmington Avenue LosAngeles, Calif. 90059
