472
TECHNICAL NOTES
February 1976
with additional acrylic compound. This applicator is now polished and trimmed until it can be easily inserted and removed, and the alignment is again verified (Figs. 1 and 2). The innermost part of the applicator may also be trimmed to fit the contour of an irregular lesion and then lined with lead to form a "lead cut-out" around the lesion. THE COLLIMATING TUBE A lead tube for collimating the intraoral beam is made to fit the applicator, and a lead diaphragm is soldered around this tube to protect the circumoral tissues. The tube is made to project 2 cm beyond the diaphragm to keep the treatment cone from sliding out of alignment with the intraoral lead tube (Fig. 3). TREATMENT SET-UP
Fig. 3. Diagram showing the x-ray unit, treatment cone (~), lead diaphragm (--), and intraoral applicator (t).
THE APPLICATOR A thin-walled acrylic tube is made by molding the material around a piece of brass pipe of a size that will fit comfortably in the patient's mouth. Thin dental acrylic impressions are then made of the upper and lower gingivae. While the patient wears these, the acrylic tube is introduced into the open mouth and aimed at the lesion. When a satisfactory alignment has been achieved, the tube is joined to the oral impression securely, removed from the patient, and the bond reinforced
A Simple Aid for Catheterizing the Left Common Carotid Artery 1 Franklin J. Miller, Jr., M.D., Linda C. Coleman, M.D., and Daniel W. Hottenstein, M.D. A rapid, simple technique to engage the left common carotid artery by means of the injection of flushing solution is presented. INDEX TERMS:
Angiography, technique • Carotid Arteries, catheterization
Radiology 118:472-473, February 1976
The use of small (5F) catheters is commonplace for cerebral angiography. Smaller catheters lower morbidity, but there is some loss of torque control at the tip. Several techniques involving variously shaped catheters to engage difficult arch vessels have been reported (1, 2). Vines recently reported the use of coughing or swallowing as a mechanism to advance a guide wire into the right and left carotid arteries (3). Occasionally, one will experience difficulty engaging a left common carotid artery, which arises from the aortic arch very near the origin of the brachiocephalic artery. Pulling on
The plastic applicator is lubricated and inserted into the oral cavity. When alignment with the lesion has been verified, the lead collimating tube is inserted into the applicator until the protective diaphragm rests on the patient's lips, and finalIy, the unit treatment cone is brought in contact with the diaphragm and the head of the patient is strapped to the unit to maintain the treatment distance. When combined with external teletherapy, transoral irradiation should be administered first, since the severe mucositis usually seen towards the end of the treatment interferes with the insertion of the applicator. We have used this method in 10 patients with lesions of the gingiva, floor of the mouth, and palate, and the immediate results have been satisfactory. We have no long-term follow-up on these cases. ACKNOWLEDGMENT: We wish to thank Raul Ruiz, Chief Technician, Oncologic Hospital, for preparing the applicators. 1 From the Departments of Radiotherapy, Saint Peter's Hospital (E. P.), Albany, N. Y., and Mayaguez Medical Center (I. R.), Mayaguez, P.R. Accepted for' publication in September 1975. elk
the catheter usually results in the tip moving quickly from the brachiocephalic vessel into the left subclavian and bypassing the left carotid orifice in this anatomical variation. We have found that a rapid hand injection of flushing solution is a helpful maneuver to engage the artery in this situation. We perform femoral-cerebral angiography in the standard fashion using a 5F polyetheylene catheter. We puncture the right or left femoral artery and then advance the catheter over an 0.089-cm (0.035 in.) "J" guide wire. If several attempts at engaging the orifice of the left carotid artery are unsuccessful, the saline injection technique is used. To perform this maneuver, the contrast-filled catheter is placed into the brachiocephalic artery and a hand-flush of 7-10 ml of heparinized normal saline is given. The necessary pressure can quickly be determined by observing the tip, which usually flips into the left carotid orifice but will engage the subclavian artery if too much pressure is applied. After engaging the left carotid orifice, an 0.81-cm (0.32 in.) guide wire is then ad, vanced into the left carotid artery and catheterization is completed. The entire maneuver is accomplished in only a few seconds.
473
TECHNICAL NOTES
Vol. 118
This maneuver is simple to perform, requires no additional equipment, and adds no risk to the procedure. It has been useful in 20 of the last 30 cases in which this technique was tried and has saved not only time but catheter exchanges. REFERENCES 1. Newton TH, Potts DG: Radiology of the Skull and Brain. St. Louis, Mo., Mosby, 1974, pp 920-938 2. Simmons CR, Tsao EC, Thompson JR: Angiographic ap-
Technical Notes
proach to the difficult aortic arch: a new technique for transfemoral cerebral angiography in the aged. Am J Roentgenol 119:605-612, Nov 1973 3. Vines FS, Bonstelle CT: Guide-wire manipulation for cerebral angiography. Radiology 113:728-729, Dec 1974 1 From the Department of Radiology, Milton S. Hershey Medical Center College of the Pennsylvania State University College of Medicine, Hershey, Pa. 17033. Revised edition accepted for publication in October 1975. elk
Proper Shielding Method for Dynamic Vertex Cranial Imaging 1 Arnold H. Deutchman, Ph.D., and Lawrence R. Fulmer, M.D. The shielding requirements for dynamic vertex cranial imaging with a scintillation camera have led to the development of a new shielding device which eliminates Compton scattered false counts by shielding both the camera detector and the cranium from extracranial activity and has proved to be effective and easy to use in actual clinical practice. INDEX TERMS: Brain, radionuclide studies. Radiations, protective and therapeutic agents and devices • Radionuclide Imaging, apparatus and equipment
Radiology 118:473-474, February 1976
Dynamic vertex cranial imaging with 99mTc and a scintillation camera is degraded by nontarget photons because the injected dose is not entirely localized in the head. In a typical vertex bolus study, only 20 % of the 20-mCi dose reaches the cerebral hemispheres before recirculation, and most of the remainder is found highly concentrated in the heart and lungs. At the same time the bolus passes through the initial arterial and capillary phases of the cerebral circulation, a large amount of activity still remains in the arm and shoulder on the injected side. In both cases the large extracranial pools of activity can contribute large numbers of extraneous counts, either directly (if the nontarget activity is in the field of view of the camera) or indirectly (by nontarget photons scattering in the skull) (1). This causes considerable degradation of sequential static images and will invalidate any quantitative analysis of regional cerebral perfusion made using digital computer systems. MATERIALS AND METHODS Compton scattering can be eliminated by the use of a device shielding the detector and the patient's head from photons originating extracranially (Fig. 1). The shield consists of a lead-backed steel assembly that resembles a wide-brimmed top hat. The annular portion is oval and slightly larger than the cross-sectional area of the average head in the cantho-meatal plane. The brim is square and large enough to cover the detector. The annular portion extends both above and below the brim, so that when the brim is aligned with the canthomeatal plane it extends about 5 cm above and 10 cm below the plane. completely shielding the heaci. The shield is insert-
Fig. 1.
New cranial shielding device in use.
ed in a square frame holder which is strapped to the detector head with rubber straps. Three shield inserts have been constructed with different cross-sectional areas to fit virtually every patient. A rubber Penrose drain filled with lead shot is placed in the insert, after the patient is positioned, to fill any gaps left between the patient's head and the shielding. RESULTS In order to test the effectiveness of the shield, an unshielded nonradioactive patient was placed in the proper position under a scintillation camera. A 92 X t-ern Tygon tube was filled with 11.2 mCi of 99mTc pertechnetate. The tube was draped across the patient's shoulders and arms so that it remained out of the field of view of the detector, simulating extracranial pools of radioactivity. A full-width half-maximum (FWHM) energy window was chosen and a 30-second image containing 200,000 counts was recorded. Figure 2, A clearly shows a distinct outline of the patient's head formed by photons which became directionalized by Compton scattering in the skull and were still recorded as photopeak unscattered photons. A typical set of sequential 1-second images obtained during a routine vertex bolus study is shown in Fig. 2, B. A large amount of neck and shoulder activity obscures the areas perfused by the posterior cerebral arteries and, as was shown, a significant number of counts in the hemisphere are due to
TECHNICAL NOTES
February 1976
with additional acrylic compound. This applicator is now polished and trimmed until it can be easily inserted and removed, and the alignment is again verified (Figs. 1 and 2). The innermost part of the applicator may also be trimmed to fit the contour of an irregular lesion and then lined with lead to form a "lead cut-out" around the lesion. THE COLLIMATING TUBE A lead tube for collimating the intraoral beam is made to fit the applicator, and a lead diaphragm is soldered around this tube to protect the circumoral tissues. The tube is made to project 2 cm beyond the diaphragm to keep the treatment cone from sliding out of alignment with the intraoral lead tube (Fig. 3). TREATMENT SET-UP
Fig. 3. Diagram showing the x-ray unit, treatment cone (~), lead diaphragm (--), and intraoral applicator (t).
THE APPLICATOR A thin-walled acrylic tube is made by molding the material around a piece of brass pipe of a size that will fit comfortably in the patient's mouth. Thin dental acrylic impressions are then made of the upper and lower gingivae. While the patient wears these, the acrylic tube is introduced into the open mouth and aimed at the lesion. When a satisfactory alignment has been achieved, the tube is joined to the oral impression securely, removed from the patient, and the bond reinforced
A Simple Aid for Catheterizing the Left Common Carotid Artery 1 Franklin J. Miller, Jr., M.D., Linda C. Coleman, M.D., and Daniel W. Hottenstein, M.D. A rapid, simple technique to engage the left common carotid artery by means of the injection of flushing solution is presented. INDEX TERMS:
Angiography, technique • Carotid Arteries, catheterization
Radiology 118:472-473, February 1976
The use of small (5F) catheters is commonplace for cerebral angiography. Smaller catheters lower morbidity, but there is some loss of torque control at the tip. Several techniques involving variously shaped catheters to engage difficult arch vessels have been reported (1, 2). Vines recently reported the use of coughing or swallowing as a mechanism to advance a guide wire into the right and left carotid arteries (3). Occasionally, one will experience difficulty engaging a left common carotid artery, which arises from the aortic arch very near the origin of the brachiocephalic artery. Pulling on
The plastic applicator is lubricated and inserted into the oral cavity. When alignment with the lesion has been verified, the lead collimating tube is inserted into the applicator until the protective diaphragm rests on the patient's lips, and finalIy, the unit treatment cone is brought in contact with the diaphragm and the head of the patient is strapped to the unit to maintain the treatment distance. When combined with external teletherapy, transoral irradiation should be administered first, since the severe mucositis usually seen towards the end of the treatment interferes with the insertion of the applicator. We have used this method in 10 patients with lesions of the gingiva, floor of the mouth, and palate, and the immediate results have been satisfactory. We have no long-term follow-up on these cases. ACKNOWLEDGMENT: We wish to thank Raul Ruiz, Chief Technician, Oncologic Hospital, for preparing the applicators. 1 From the Departments of Radiotherapy, Saint Peter's Hospital (E. P.), Albany, N. Y., and Mayaguez Medical Center (I. R.), Mayaguez, P.R. Accepted for' publication in September 1975. elk
the catheter usually results in the tip moving quickly from the brachiocephalic vessel into the left subclavian and bypassing the left carotid orifice in this anatomical variation. We have found that a rapid hand injection of flushing solution is a helpful maneuver to engage the artery in this situation. We perform femoral-cerebral angiography in the standard fashion using a 5F polyetheylene catheter. We puncture the right or left femoral artery and then advance the catheter over an 0.089-cm (0.035 in.) "J" guide wire. If several attempts at engaging the orifice of the left carotid artery are unsuccessful, the saline injection technique is used. To perform this maneuver, the contrast-filled catheter is placed into the brachiocephalic artery and a hand-flush of 7-10 ml of heparinized normal saline is given. The necessary pressure can quickly be determined by observing the tip, which usually flips into the left carotid orifice but will engage the subclavian artery if too much pressure is applied. After engaging the left carotid orifice, an 0.81-cm (0.32 in.) guide wire is then ad, vanced into the left carotid artery and catheterization is completed. The entire maneuver is accomplished in only a few seconds.
473
TECHNICAL NOTES
Vol. 118
This maneuver is simple to perform, requires no additional equipment, and adds no risk to the procedure. It has been useful in 20 of the last 30 cases in which this technique was tried and has saved not only time but catheter exchanges. REFERENCES 1. Newton TH, Potts DG: Radiology of the Skull and Brain. St. Louis, Mo., Mosby, 1974, pp 920-938 2. Simmons CR, Tsao EC, Thompson JR: Angiographic ap-
Technical Notes
proach to the difficult aortic arch: a new technique for transfemoral cerebral angiography in the aged. Am J Roentgenol 119:605-612, Nov 1973 3. Vines FS, Bonstelle CT: Guide-wire manipulation for cerebral angiography. Radiology 113:728-729, Dec 1974 1 From the Department of Radiology, Milton S. Hershey Medical Center College of the Pennsylvania State University College of Medicine, Hershey, Pa. 17033. Revised edition accepted for publication in October 1975. elk
Proper Shielding Method for Dynamic Vertex Cranial Imaging 1 Arnold H. Deutchman, Ph.D., and Lawrence R. Fulmer, M.D. The shielding requirements for dynamic vertex cranial imaging with a scintillation camera have led to the development of a new shielding device which eliminates Compton scattered false counts by shielding both the camera detector and the cranium from extracranial activity and has proved to be effective and easy to use in actual clinical practice. INDEX TERMS: Brain, radionuclide studies. Radiations, protective and therapeutic agents and devices • Radionuclide Imaging, apparatus and equipment
Radiology 118:473-474, February 1976
Dynamic vertex cranial imaging with 99mTc and a scintillation camera is degraded by nontarget photons because the injected dose is not entirely localized in the head. In a typical vertex bolus study, only 20 % of the 20-mCi dose reaches the cerebral hemispheres before recirculation, and most of the remainder is found highly concentrated in the heart and lungs. At the same time the bolus passes through the initial arterial and capillary phases of the cerebral circulation, a large amount of activity still remains in the arm and shoulder on the injected side. In both cases the large extracranial pools of activity can contribute large numbers of extraneous counts, either directly (if the nontarget activity is in the field of view of the camera) or indirectly (by nontarget photons scattering in the skull) (1). This causes considerable degradation of sequential static images and will invalidate any quantitative analysis of regional cerebral perfusion made using digital computer systems. MATERIALS AND METHODS Compton scattering can be eliminated by the use of a device shielding the detector and the patient's head from photons originating extracranially (Fig. 1). The shield consists of a lead-backed steel assembly that resembles a wide-brimmed top hat. The annular portion is oval and slightly larger than the cross-sectional area of the average head in the cantho-meatal plane. The brim is square and large enough to cover the detector. The annular portion extends both above and below the brim, so that when the brim is aligned with the canthomeatal plane it extends about 5 cm above and 10 cm below the plane. completely shielding the heaci. The shield is insert-
Fig. 1.
New cranial shielding device in use.
ed in a square frame holder which is strapped to the detector head with rubber straps. Three shield inserts have been constructed with different cross-sectional areas to fit virtually every patient. A rubber Penrose drain filled with lead shot is placed in the insert, after the patient is positioned, to fill any gaps left between the patient's head and the shielding. RESULTS In order to test the effectiveness of the shield, an unshielded nonradioactive patient was placed in the proper position under a scintillation camera. A 92 X t-ern Tygon tube was filled with 11.2 mCi of 99mTc pertechnetate. The tube was draped across the patient's shoulders and arms so that it remained out of the field of view of the detector, simulating extracranial pools of radioactivity. A full-width half-maximum (FWHM) energy window was chosen and a 30-second image containing 200,000 counts was recorded. Figure 2, A clearly shows a distinct outline of the patient's head formed by photons which became directionalized by Compton scattering in the skull and were still recorded as photopeak unscattered photons. A typical set of sequential 1-second images obtained during a routine vertex bolus study is shown in Fig. 2, B. A large amount of neck and shoulder activity obscures the areas perfused by the posterior cerebral arteries and, as was shown, a significant number of counts in the hemisphere are due to
