Search

Takayasu's Arteritis is a progressive occlusive disease of the aortic arch and its branches. It may need several bypass procedures along with or without endovascular techniques. Case Descriptions. A twenty-six year old woman who had a history of Takayasu's Arteritis, and had a Gore-Tex Dacron Y-graft from the ascending aorta to the right subclavian and right common carotid arteries 18 years before, is presented. She presented with recurrent hemispheric ischemia and transient ischemic attacks and severe long segment stenosis in the left common carotid artery. She was successfully treated with a saphenous vein graft bypass from the left vertebral artery to the common carotid artery. The stenosis of the brachiocephalic graft was succesfully treated by angioplasty. Three months follow up showed stenosis of the left VA immediately proximal to the proximal anastomosis which was managed successfully with angioplasty. Conclusions. The surgical treatment of Takayasu's Arteritis with bypass procedures needs a complex overview and follow up. A regular follow up is mandatory for evaluation and planning of appropriate management, in view of the progressive nature of the disease process.

OBJECTIVE: In the treatment of patients with cranial base tumors, unclippable aneurysms, or medically intractable ischemia, it may be necessary to use high-flow bypass grafts. The indications, surgical techniques and complications are discussed. METHODS: During a 10-year period, 99 saphenous vein grafts and 3 radial artery grafts were performed for 101 patients, i.e., 72 with neoplasms, 23 with aneurysms, and 6 with ischemia. Clinical follow-up monitoring of the patients was by direct examination or telephone interview, with a mean follow-up period of 41.2 months (range, 5-147 mo). Radiological follow-up monitoring was by magnetic resonance imaging, magnetic resonance angiography, or three-dimensional computed tomographic angiography, with a mean follow-up period of 32 months (range, 1-120 mo). During the follow-up period, there was one late graft occlusion and one graft stenosis. RESULTS: The use of intraoperative angiography improved the patency rate from 90 to 98% and reduced the incidence of perioperative stroke from 13 to 9.5%. Ninety-two percent of the patients were in excellent or good neurological condition at the time of discharge from the hospital, compared with 95% before surgery. The perioperative mortality rate was 2%. Other complications included three intracranial hematomas, rupture of a vein graft in a patient with Marfan's syndrome, and five tumor resection-related problems. The long-term survival rates for patients who received grafts were excellent for patients with benign tumors, fair to poor for patients with malignant tumors, good for patients with aneurysms, and excellent for patients with ischemia. CONCLUSION: The results of saphenous vein and radial artery grafting have been greatly improved by the use of intraoperative angiography, improvements in surgical techniques, and improved perioperative treatment.

Glossopharyngeal (that is, cranial nerve IX) schwannomas are extremely rare nerve sheath tumors that frequently mimic the more common vestibular schwannoma in their clinical as well as radiographic presentation. Although rare in adults, this tumor has not been reported in a child. The authors report the case of a 10-year-old boy who presented with several months of unilateral hearing loss. He was found to have a large right cerebellopontine angle tumor. Given the boy's primary complaint of hearing loss and the appearance of the lesion on imaging, the tumor was initially believed to be a schwannoma of the vestibular nerve. It was found intraoperatively, however, to originate from the glossopharyngeal nerve. To the authors' knowledge, this is the first reported case of a glossopharyngeal schwannoma in a child.

Objective The posteroinferior cerebellar artery (PICA) usually arises from the intradural segment of the vertebral artery (VA). The extradural origin of the PICA is infrequent. Its preoperatory identification is important in surgical strategy during the exposure of the VA. Methods During an anatomic prosection, the VA was exposed at the craniocervical junction in cadaveric adult specimens. The extradural origin of the PICA was encountered bilaterally in one specimen and on one side in a second specimen. An anatomic study with histological and radiographic correlation was performed. Results Perforating branches originate from the PICA. They supply the middle and inferior third of the olive and the lateral aspect of the medulla. The PICA has cortical branches that lead to the cerebellum. Injury to the PICA can produce an infarction of these neural structures that can be asymptomatic or cause major neurological deficits. Radiographic results obtained using a lateral projection provided the most reliable delineation of the extradural origin of the PICA. When this artery originates at, or posterior to, the posterior aspect of the occipital condyle, an extradural origin is likely. Conclusion Bilateral selective vertebral angiography should be performed with special attention to the relationships of PICA origins before any surgical exposure of the VA at the craniocervical junction, unless magnetic resonance angiography provides this information without question. A thorough understanding of the relative dominance of the VAs and PICAs, the location of the PICA origin, and the collateral circulation of the posterior fossa are prerequisites to surgery in this region. The preoperative identification of an extradural PICA is important in planning surgical strategy and in avoiding complications during operations near the foramen magnum.

A modified foramen magnum decompression procedure, designed to respect the subarachnoid spaces as much as possible, was prospectively evaluated in eight consecutive patients with a progressive clinical syndrome related to hydrosyringomyelia-Chiari I complex. This evaluation included quantitative clinical and magnetic resonance follow-up of at least 1 year in the first six patients and 6 months for the last two. Magnetic resonance scans at 6 months or more confirmed a persistent reduction of the hydrosyringomyelic cavity in all cases, which was associated with obvious subjective improvement. All patients have maintained this improvement. The operative technique and methods of clinical and radiological follow-up are discussed.

We retrospectively analyzed pre- and postoperative sonographic and medical records of 335 children who had surgical or endoscopic treatment at the ureterovesical junction, in order to determine normal and atypical sonographic appearances. Normal sonographic findings after ureteral reimplantation include thickening of the posterior bladder wall, pseudodiverticular sacculations, bladder asymmetry, and transitory hydroureteronephrosis. Short-term or persistent (lasting more than 1 month) hydroureteronephrosis, urinoma, hematoma, bladder lithiasis, and diverticula were abnormal findings, occurring in 17% of the patients. After partial ureteronephrectomies, visualization of the residual ureter on sonograms was not possible in cases without complications; in one patient, reflux of fluid dilated the residual ureter and made the ureter visible on sonograms. After endoscopic incisions, the masslike appearance of a collapsed ureterocele was observed. Submucosally injected Teflon always appeared as a curvilinear hyperechoic area with an acoustic shadow. Marked acute or persistent hydroureteronephrosis or ectopic intracavitary Teflon particles were observed in 2% of patients. Granuloma formation was considered likely in 5% of the patients when the area of injected Teflon material was longer than 12 mm on sonograms. Submucosally injected collagen appeared less echogenic than Teflon and showed no acoustic shadowing. The various normal sonographic appearances after treatment must be known in order to distinguish them from significant abnormalities. In patients with anatomic anomalies, such as short-term or persistent hydroureteronephrosis, urinoma, hematoma, and lithiasis, complementary uroradiologic examinations may be necessary to clarify the diagnosis.

The great morbidity and mortality associated with pseudoaneurysms complicating pancreatic pseudocysts stress the need for their early detection. The authors report the use of colour Doppler sonography in the detection of pseudoaneurysms within pancreatic pseudocysts, emphasizing not only the value of this modality in the initial diagnosis, but also its value in monitoring the success of transcatheter embolization. Colour Doppler should be used systematically in the evaluation of pancreatic pseudocysts.

Objective: Management of cranial base tumors requires an interdisciplinary approach. Supraselective angiography and embolization is an important adjunct to cranial base surgery. Though successful embolization facilitates resection, the morbidity of this procedure remains poorly defined. Therefore, we set out to define the morbidity associated with embolization of skull base meningiomas, thus allowing for informed decision making when considering this adjunct to tumor resection. Methods: A retrospective analysis was performed on our experience with embolization of 167 cranial base meningiomas. Cranial base meningiomas were defined as tumors originating from the olfactory groove, tuberculum sella, medial sphenoid wing, petro-clival region or foramen magnum. Results: 280 feeding vessels were embolized with an average of 1.7 vessels per lesion. In 91% of patients embolized, good to excellent embolization was achieved without permanent neurological sequelae. In 20 patients no embolization was attempted due to the risk of new neurologic deficits or lack of an appropriate vessel for embolization. Twenty-one patients (12.6%) had transient worsening of their neurologic exam or a medical complication requiring hospitalization. Fifteen patients (9%) experienced permanent neurologic deficits or medical morbidity as a result of embolization. Four of the patients who experienced major complications had a decline in previously compromised cranial nerve function. Conclusions: Embolization of cranial base tumors is an important part of the therapeutic armamentarium for the treatment of cranial base lesions. Recognition of the morbidity of this procedure will allow for the most appropriate use of this powerful adjunct to cranial base surgery.

Review of 500 consecutive MRI studies was undertaken to assess the frequency and the appearances of cystic pineal glands. Cysts were encountered in 2.4% of cases. Follow-up examination demonstrated no change in these cysts and they were considered to be a normal variant. Size, MRI appearances and signs associated with this condition are reported in order to establish criteria of normality.

To assess the effectiveness of a protocol consisting of 4 cycles of high-dose intra-arterial cisplatin infusions followed by radiation therapy for improving chemotherapy response rates, organ preservation, and survival in patients with advanced-stage untreated and previously treated squamous cell carcinoma of the head and neck.A prospective study of sequentially enrolled patients treated in an academic medical center. The Kaplan-Meier method was used for survival analysis.Fifty-eight nonpregnant adults, 18 years of age or older, with measurable untreated or recurrent advanced biopsy-proven squamous cell carcinoma of the head and neck.Response rate to targeted intra-arterial cisplatin infusions, organ preservation, and survival.Fifty-eight patients (44 men and 14 women) were followed up for at least 2 years (median duration of follow-up, 27 months). Twenty-nine (67%) of the 43 previously untreated patients had a complete response to intra-arterial cisplatin therapy. Of the untreated patients, 28 are alive and disease free after a median follow-up time of 30 months. Five of the patients with recurrent disease had a complete response to intra-arterial cisplatin therapy. There were 4 survivors after a median follow-up time of 17.5 months. Of note, there were no deaths or serious complications related to the treatment in either group.High-dose intra-arterial cisplatin therapy provides a high complete and partial response rate (91%). The combination of high-dose intra-arterial cisplatin and radiation therapy is effective in improving survival and organ preservation rates in patients with previously untreated, advanced squamous cell carcinoma of the head and neck. This treatment protocol is much less effective for recurrent disease.

The authors report the unusual presentation of a mycotic aneurysm of the superior gluteal artery in a patient with unsuspected bacterial endocarditis. The diagnosis of this atypically large lesion, the therapeutic considerations, and the technical aspects of the endovascular occlusion are discussed.

The outcomes of 114 patients with meningiomas operated at the University of Pittsburgh were analyzed. Cerebrospinal fluid leakage was the most frequent complication, observed in 25 patients (21%). Complications were more frequent in patients who had recurrent (previously operated) tumors and patients with extensive tumors. Our current analysis also indicates that patients with prior radiotherapy (usually external beam) have unacceptably high complication rates after microsurgery. Early results indicate that regrowth rates are much higher in patients with incomplete resection (20%) than those with gross total excision (5%). Of the 114 patients, 108 returned to independent living and/or their previous occupation.

The outcomes of 114 patients with meningiomas operated at the University of Pittsburgh were analyzed. Cerebrospinal fluid leakage was the most frequent complication, observed in 25 patients (21%). Complications were more frequent in patients who had recurrent (previously operated) tumors and patients with extensive tumors. Our current analysis also indicates that patients with prior radio-therapy (usually external beam) have unacceptably high complication rates after microsurgery. Early results indicate that regrowth rates are much higher in patients with incomplete resection (20%) than those with gross total excision (5%). Of the 114 patients, 108 returned to independent living and/or their previous occupation.

The great morbidity and mortality associated with pseudoaneurysms complicating pancreatic pseudocysts stress the need for their early detection. The authors report the use of colour Doppler sonography in the detection of pseudoaneurysms within pancreatic pseudocysts, emphasizing not only the value of this modality in the initial diagnosis, but also its value in monitoring the success of transcatheter embolization. Colour Doppler should be used systematically in the evaluation of pancreatic pseudocysts.

Acute disseminated encephalomyelitis (ADEM) is a rare demyelinating condition of the central nervous system, usually developing after a viral infection or vaccination. We report a case of ADEM predominantly affecting the spinal cord in an 8-year old boy evaluated by MRI. The radiographic picture consisted of multiple focal lesions of the spinal cord, a left posterior thalamic lesion and a subcortical right posterior parietal lesion. These lesions regressed several weeks after corticosteroid treatment. The clinical presentation, the laboratory results and the radiological findings suggest the diagnosis of ADEM secondary to viral infection by Coxsackie B.

PURPOSE: To evaluate the use of postembolization gadolinium-enhanced MR imaging as a means to judge the efficacy of tumor embolization. METHODS: Fifteen patients with meningiomas were prospectively studied. The following data were evaluated for each tumor: the percentage of vascular supply to the tumor arising from the internal and external carotid arteries; the percentage of the tumor embolized as judged by angiography, by MR imaging, and by CT scanning; the estimated blood loss according to the surgeon; and histologic evidence of necrosis as seen by the neuropathologist. RESULTS: The data reveal an excellent correlation between the amount of tumor embolized as estimated by MR and both the estimated blood loss at time of surgery and the presence of histological necrosis in the specimen. CONCLUSIONS: Postembolization gadolinium-enhanced MR is an excellent means to evaluate the efficacy of an embolization and offers certain advantages over CT and angiography. One important advantage of this technique lies in the fact that it can be performed immediately postembolization.

Gadolinium enhancement may be normal in the vertebral endplates adjacent to previously operated intervertebral discs. To determine the frequency of this finding and to differentiate this normal healing process from early lesions due to focal infection, we studied 135 patients who had undergone surgery for herniated lumbar disc, and compared them with 249 unoperated patients with radicular symptoms and 15 with known spondylodiscitis. Hypointense foci which enhanced with gadolinium were identified in the endplates of 25 (18.5%) of the operated patients, 9 of whom required a second operation for recurrent disc herniation, at which time the absence of infection was confirmed. Gadolinium enhancement within the endplates adjacent to the operated disc occurs during normal healing after surgery. Care should be taken before invoking a diagnosis of focal infection or secondary spondylodiscitis.

We report a cavernous sinus meningioma encasing the cavernous internal carotid artery in a patient with congenital agenesis of the contralateral internal carotid artery and cavernous sinus hypoplasia.

The authors report a case of simultaneously occurring neurofibroma and schwannoma of the sciatic nerve and discuss the complementary aspects of MR and US. The schwannoma was well-defined and showed distal enhancement on sonographic evaluation, whereas the neurofibroma was ill-defined; both tumors were hypoechoic. T1- and T2-weighted MR images revealed similar signal characteristics of the two tumors, but intense enhancement following administration of gadolinium-DTPA distinguished the schwannoma from the neurofibroma.

16535 Background: Aggressive chemotherapy combined with radiation increases organ preservation and provides locoregional control in advanced head and neck (H&N) cancer. Intra-arterial (IA) cisplatin can provide higher dose intensity but does not control distant disease. We evaluated a program that consisted of intra-arterial and intravenous chemotherapy combined with chemoradiotherapy. Methods: The course of 23 patients treated with four weekly IA doses of cisplatin (150 mg/m2) with IV sodium thiosulfate rescue, then two cycles IV paclitaxel (175 mg/m2, day 1), ifosfamide (1,000 mg/m2 and mesna 600 mg/m2, days 1–3), and cisplatin (60 mg/m2, day 1) (TIP), and followed by radiation to 70 Gy combined with weekly paclitaxel (30 mg/m2) and amifostine (740 mg/m2 TIW) was analyzed. One patient received one cycle of cisplatin/5-FU and one cycle of TIP instead of 2 cycles of TIP. Endpoints were recurrence free survival (RFS) and overall survival (OS). Results: Of twenty-three patients, 20 were men. The median age was 57 years (range 45–70) and median follow-up was 6.1 years (range 4.1–7.9). Eighteen had long smoking histories. Seventeen completed treatment (74%). Of the 6 who did not complete the program, two had resistant tumors, one had an adverse reaction to IA therapy, and three were noncompliant. Of 23 patients, 14 are alive, 13 without evidence of disease recurrence; one patient recurred and was salvaged by surgery. Five patients recurred and died of metastatic H&N cancer. One patient recurred, was salvaged with surgery and later died of lung cancer without evidence of H&N cancer. The RFS is 56.5% and the OS is 60.8%. Adverse events were infrequent and included 1 patient who had facial swelling during IA therapy and 2 patients who developed osteonecrosis of the mandible, one while continuing to smoke 6 months after therapy and the other 3 years after therapy following tooth extraction. Conclusions: A program consisting four doses of intra-arterial cisplatin followed by two cycles of IV TIP and chemoradiotherapy is effective in treating locally advanced SCC of the H&N and was generally well tolerated. No significant financial relationships to disclose.

The femoral artery approach to cerebral angiography has become well accepted. Some patients, however, are not candidates for femoral catheterization because of severe arteriosclerosis. One hundred cerebral angiograms were performed in 88 severely arteriosclerotic patients, using No. 5 French polyethylene catheters and the axillary approach. The technique, degree of success, patient population, and their complications are described. This approach allows selective vertebral and internal carotid artery injections. Only one serious complication occurred, thrombosis of the axillary artery. Because of the time saved, this technique is often preferable to the femoral approach in severely arteriosclerotic patients.

Based upon dissections of 150 human brains in which the arteries of interest were selectively injected, we have evaluated the origin, course, and each cortical branch of the cerebral arteries to see if it would be possible to precisely define their vascular territories. This work was especially detailed for the anterior and middle cerebral arteries. It was quite evident that each cortical branch of a cerebral artery has a characteristic vascular territory which is relatively fixed, despite variations from one hemisphere to another or from one brain to another. The limits of these territories are equally precise.

The terms fissure and sulcus as they are classically defined are: a fissure separates one lobe from another, while a sulcus is within a lobe and delimits gyri.

During the development of the embryo, the first vein to appear in the posterior fossa is, according to PADGET (1956), the primitive ventral metencephalic vein since, at this stage, the cerebellar hemisphere is merely represented by a cerebellar plate. This ventral metencephalic vein, homologous to the trigeminal vein of lower vertebrates, will eventually become the petrosal vein. The proximal end of the ventral metencephalic vein becomes incorporated into the petrous crest to form the superior petrosal sinus. The primitive ventral myelencephalic vein, also called the vagal vein (PADGET, 1956), anastomoses superiorly with the ventral metencephalic vein and drains the medulla oblongata. The inferior petrosal sinus is derived from the proximal end of the ventral myelencephalic vein.

A simple in vitro experiment showed that the 5-F angiographic catheter can be visualized on sonograms. Subsequent in vivo imaging showed that small catheters can be seen sonographically in many locations. Ultrasound is proposed as an effective presurgical procedure in order to determine whether a catheter fragment remains near an arterial puncture or has embolized distally.

Until recently the achievement of diagnostically adequate resolution in the basal subarachnoid cisterns has remained a difficult problem for computed tomography (CT). Artifacts frequently degrade image quality and preclude subtle diagnosis (Fig. 17.1.A & 17.2.A).

The basal cerebral vein described by ROSENTHAL in 1824 has been the subject of many investigations.

The aqueduct of Sylvius represents the communication between the third and fourth ventricles. It is 15 to 18 mm long and 1 to 2 mm in diameter. Its shape is like the neck of a swan. Posteriorly, its relations are, from superiorly to inferiorly, the posterior commissure, the superior and inferior colliculi and the anterior medullary velum. Its floor is the midbrain, and contains the nuclei of the third and fourth cranial nerves (Fig. 153).

Iatrogenic neurological deficit constitutes the greatest risk during therapeutic embolization in the vascular territories of the carotid and vertebral arteries. Constant monitoring of the patient's neurological status is therefore essential. The authors discuss the use of medical hypnosis to circumvent general anesthesia and to reduce chemical sedation to a minimum. Their experience with this technique is presented.

The vertebral arteries, basilar trunk and their branches provide the vascular supply to the brainstem and cerebellum. The anatomy of these arteries has been studied by STOPFORD (1917), FOIX and HILLEMAND (1925) and LAZORTHES, POULHES and ESPAGNO (1950).

The deep cerebral venous system may be said to consists of the two internal cerebral veins and their tributaries—the subependymal, deep medullary, superior striate and choroidal veins. The basal cerebral vein, sometimes included in the deep venous system, is described elsewhere (Part 1, Chap. 4, p. 128).

1. Cerebral Hemisphere.- 1. Fissures and Sulci (G. S.).- I. Anatomic Study of the Fissures and Sulci of the External Surface of the Cerebral Hemisphere.- 1. Principal or Interlobar Fissures.- 2. Sulci of the External Surface.- a) Sulci of the Frontal Lobe.- b) Sulci of the Parietal Lobe.- c) Sulci of the Occipital Lobe.- d) Sulci of the Temporal Lobe.- II. Anatomic Study of the Fissures and Sulci of the Internal Surface of the Cerebral Hemisphere.- 1. Fissures of the Internal Surface.- 2. Sulci of the Internal Surface.- III. Anatomic Study of the Fissures and Sulci of the Inferior Surface of the Cerebral Hemisphere.- 1. Fissure of the Inferior Surface-Sylvian Fissure.- 2. Sulci of the Inferior Surface.- a) Sulci of the Orbital Surface of the Frontal Lobe.- b) Sulci of the Inferior Surface of the Temporal and Occipital Lobes.- IV. Radiologic Study of Fissures and Sulci.- 2. Lateral Ventricles (G. S.).- I. Anatomic Study of the Lateral Ventricles.- 1. Frontal Horn of the Lateral Ventricle.- 2. Body of the Lateral Ventricle.- 3. Atrium of the Lateral Ventricle.- 4. Occipital Horn of the Lateral Ventricle.- 5. Temporal Horn of the Lateral Ventricle.- II. Radiologic Study of the Lateral Ventricles.- 1. Frontal Horn of the Lateral Ventricle.- 2. Body of the Lateral Ventricle.- 3. Atrium of the Lateral Ventricle.- 4. Occipital Horn of the Lateral Ventricle.- 5. Temporal Horn of the Lateral Ventricle.- 3. Cortical Arteries (G. S.).- A. Anterior Cerebral Artery.- I. Anatomic Study of the Anterior Cerebral Artery.- Branches of the Anterior Cerebral Artery.- a) Branch to the Orbital Surface of the Frontal Lobe.- b) Branches to the Internal Surface of the Frontal Lobe.- c) Branch to the Paracentral Lobule.- d) Branches to the Internal Aspect of the Parietal Lobe.- e) Branches to the Corpus Callosum.- II. Radiologic Study of the Anterior Cerebral Artery.- B. Middle Cerebral Artery.- I. Anatomic Study of the Middle Cerebral Artery.- 1. Patterns of Division of the Middle Cerebral Artery within the Sylvian Fissure.- 2. Frontal Branches of the Middle Cerebral Artery.- 3. Parietal Branches of the Middle Cerebral Artery.- 4. Temporal and Temporo-Occipital Branches of the Middle Cerebral Artery.- 5. Insular Branches.- II. Radiologic Study of the Middle Cerebral Artery.- C. Anterior Choroidal Artery.- I. Anatomic Study of the Anterior Choroidal Artery.- II. Radiologic Study of the Anterior Choroidal Artery.- D. Posterior Cerebral Artery.- I. Anatomic Study of the Posterior Cerebral Artery.- II. Radiologic Study of the Posterior Cerebral Artery.- 4. Basal Cerebral Vein (Y. P. H.).- A. Normal Anatomy.- I. First Segment of the Basal Cerebral Vein and Its Tributaries.- 1. Deep Middle Cerebral Vein.- 2. Inferior Striate Veins.- 3. Olfactory Vein.- 4. Fronto-Orbital Veins.- 5. Anterior Cerebral and Pericallosal Veins.- 6. Veinlets from the Optic Chiasm, Optic Tract, and Adjacent Structures.- II. Second Segment of the Basal Cerebral Vein and Its Tributaries>.- 1. Peduncular Vein.- 2. Inferior Ventricular Vein.- III. Third Segment of the Basal Cerebral Vein and Its Tributaries.- 1. Lateral Mesencephalic Vein.- 2. Lateral Atrial Vein.- 3. Medial Temporal and Occipitotemporal Cortical Veins.- 4. Posterior Longitudinal Hippocampal Vein.- 5. Posterior Thalamic Veins.- B. Anatomic Variations.- 2. Mesencephalic Region, Diencephalic Region, and Basal Ganglia.- 1. Third Ventricle and Suprasellar Cisterns (G. S.).- I. Anatomic Study of the Third Ventricle and Suprasellar Cisterns.- 1. Third Ventricle.- 2. Suprasellar Cisterns.- II. Radiologic Study of the Third Ventricle and Suprasellar Cisterns.- 2. Aqueduct of Sylvius (G. S.).- I. Anatomic Study of the Aqueduct of Sylvius.- II. Radiologic Study of the Aqueduct of Sylvius.- 3. Arteries of the Basal Ganglia and the Posterior Choroidal Arteries (G. S.).- I. Anatomic Study of the Perforating Arteries of the Basal Ganglia and of the Posterior Choroidal Arteries.- 1. Perforating Branches of the Carotid System.- a) Perforating Branches of the Anterior Cerebral Artery.- b) Perforating Branches of the Middle Cerebral Artery.- c) Perforating Branches of the Anterior Choroidal Artery.- 2. Perforating Branches of the Vertebrobasilar System.- a) Arteries to the Inferior Surface of the Thalamus.- b) Arteries to the Posterior Surface of the Thalamus.- c) Arteries to the Superior Surface of the Thalamus.- II. Radiologic Study of the Perforating Arteries of the Basal Ganglia and of the Posterior Choroidal Arteries.- 4. Deep Cerebral Veins (Y. P. H.).- A. Internal Cerebral and Great Cerebral Veins.- B. Subependymal Veins of the Lateral Ventricle.- I. Medial Group of theSubependymal Veins.- 1. Septal Vein.- 2. Posterior Septal Vein.- 3. Medial Atrial Vein.- 4. Transverse Hippocampal Subependymal Veins.- II. Lateral Group of the Subependymal Veins.- 1. Thalamostriate Vein.- 2. Direct Lateral Vein.- 3. Inferior Ventricular Vein.- C. Choroidal Veins of the Lateral Ventricle.- D. Veins of the White Matter of the Cerebral Hemisphere-Medullary Veins.- E. Veins of the Grey Matter of the Cerebral Hemisphere.- 3. Posterior Fossa.- 1. Fourth Ventricle and Cisterns of the Posterior Fossa (G. S.).- I. Anatomic Study of the Fourth Ventricle.- 1. Floor of the Fourth Ventricle.- 2. Roof of the Fourth Ventricle t2.- II. Anatomic Study of the Posterior Fossa Cisterns.- 1. Cisterns Anterior to the Brainstem.- a) Medullary Cistern.- b) Pontine Cistern.- c) Cerebellopontine Angle Cistern.- 2. Cistern Posterior to the Medulla and Below the Inferior Vermis-Cisterna Magna.- 3. Cisterns Posterior to the Tectum and Superior to the Cerebellum.- 4. Cisterns Around the Cerebral Peduncles.- III. Radiologic Study of Posterior Fossa, Fourth Ventricle and Cisterns of the Posterior Fossa.- 2. Arteries of the Vertebrobasilar System (G. S.).- I. Anatomic Study of the Arteries of the Vertebrobasilar System.- 1. Intracranial Segment of the Vertebral Artery.- 2. Basilar Trunk.- 3. Arteries of the Brainstem.- a) Arteries of the Medulla.- b) Arteries of the Pons.- c) Arteries of the Cerebral Peduncles.- 4. Arteries of the Cerebellum.- a) Superior Cerebellar Artery-SCA.- b) Anterior Inferior Cerebellar Artery-AICA.- c) Posterior Inferior Cerebellar Artery-PICA.- II. Radiologic Study of the Arteries of the Vertebrobasilar System.- 1. Basilar Trunk and Its Branches.- 2. Anterior. Inferior Cerebellar Artery-AICA.- 3. Superior Cerebellar Artery-SCA.- 3. Veins of the Posterior Fossa (Y. P. H.).- I. Superior or Galenic Draining Group.- 1. Mesencephalic Tributaries.- 2. Cerebellar Tributaries.- II. Anterior or Petrosal Draining Group.- 1. Tributaries Related to the Anterior Aspect of the Brain Stem.- 2. Tributaries Related to the Wing of the Precentral Cerebellar Fissure.- 3. Tributaries Related to the Posterolateral Fissure.- 4. Tributaries Related to the Cerebellomedullary Fissure.- 5. Tributaries Related to the Cerebellar Hemisphere.- III. Posterior or Tentorial Draining Group.- IV. Intercommunications Among the Superior, Anterior and Posterior Draining Groups and Between the Supra- and Infratentorial Veins.- V. Circulation Times of Veins of the Posterior Fossa.- References.

Knowledge of the radiologic anatomy of the posterior fossa has certainly benefited from recent investigations into the arterial supply and venous drainage of its structures, and from studies of the anatomy of the fourth ventricle and cisterns of the posterior fossa.

The vascularization of the lentiform nucleus, the caudate nucleus, the thalamus and the internal capsule is provided by perforating arteries which arise from the anterior, middle and posterior cerebral arteries and the anterior choroidal arteries. The carotid branches supply the nuclei of telencephalic origin (caudate and lentiform) while the vertebrobasilar branches supply the diecephalic nuclei (thalamus).

Gas myelography is a useful technique in the evaluation of the spinal canal and its contents. Although it has been greatly simplified and the high-resolution imaging greatly improved, morbidity remains a problem. Removal of the gas at the end of the examination through the lumbar route significantly decreases morbidity. This can be achieved through the same needle if the examination is performed via a lumbar puncture. Insertion of a second needle in the lumbar region may be necessary if the cervical or cisternal puncture is employed for gas introduction.