PERSISTENT TRIGEMINAL ARTERY TERMINATING IN THE POSTERIOR INFERIOR CEREBELLAR ARTERY

OBJECTIVE

Persistent trigeminal arteries are rare and represent a remnant of the fetal carotid-basilar circulation. They typically extend from the internal carotid artery to the basilar artery. An unusual case of a patient with a trigeminal artery originating from the internal carotid artery and terminating as the dominant hemispheric branch of the posterior inferior cerebellar artery is presented.

CLINICAL PRESENTATION

A 66-year-old woman presented to the emergency department with pulsatile tinnitus, increasing left eye pain, proptosis, conjunctival injection, diplopia, and decreased visual acuity. Conventional contrast-enhanced computed tomographic and magnetic resonance imaging demonstrated findings consistent with a left carotid-cavernous fistula. The patient underwent an emergency diagnostic cerebral angiogram. Besides an indirect carotid-cavernous fistula on the left side, a right-sided persistent trigeminal artery terminating as the dominant hemispheric trunk of the posteroinferior cerebellar artery was incidentally noted. The vermian branch of the right posteroinferior cerebellar artery arose from the ipsilateral vertebral artery, whereas duplicate superior cerebellar arteries supplied the left posteroinferior cerebellar artery region.

INTERVENTION

The patient was treated for the indirect carotid-cavernous fistula with detachable platinum coils and N-butyl cyanoacrylate, resulting in the resolution of her symptoms.

CONCLUSION

We report a case of a persistent trigeminal artery supplying only the cerebellar hemisphere. The clinical significance of this anomaly relates to its role in endovascular therapeutic and surgical complications and the paradoxical lesions in the cerebellum that occur as a result of carotid disease. We also discuss the Saltzman classification of persistent trigeminal arteries and their variants.

Linkage to chromosome 2q36.1 in autosomal dominant Dandy-Walker malformation with occipital cephalocele and evidence for genetic heterogeneity

We previously reported a Vietnamese-American family with isolated autosomal dominant occipital cephalocele. Upon further neuroimaging studies, we have recharacterized this condition as autosomal dominant Dandy-Walker with occipital cephalocele (ADDWOC). A similar ADDWOC family from Brazil was also recently described. To determine the genetic etiology of ADDWOC, we performed genome-wide linkage analysis on members of the Vietnamese-American and Brazilian pedigrees. Linkage analysis of the Vietnamese-American family identified the ADDWOC causative locus on chromosome 2q36.1 with a multipoint parametric LOD score of 3.3, while haplotype analysis refined the locus to 1.1 Mb. Sequencing of the five known genes in this locus did not identify any protein-altering mutations. However, a terminal deletion of chromosome 2 in a patient with an isolated case of Dandy-Walker malformation also encompassed the 2q36.1 chromosomal region. The Brazilian pedigree did not show linkage to this 2q36.1 region. Taken together, these results demonstrate a locus for ADDWOC on 2q36.1 and also suggest locus heterogeneity for ADDWOC.

Coil embolization of posttraumatic pseudoaneurysm of the ophthalmic artery causing subarachnoid hemorrhage

✓The authors report a unique case of subarachnoid hemorrhage caused by a traumatic pseudoaneurysm of the ophthalmic artery, which was successfully treated with coil embolization. Clinical and imaging features, as well as the relevant literature, are described.

Pulsatility Imaging of Saccular Aneurysm Model by 64-Slice CT with Dynamic Multiscan Technique

The feasibility of imaging pulsatility in an aneurysm model with the high-resolution dynamic multiscan technique of 64-slice computed tomography (CT) was studied. A pulsatile aneurysm phantom was constructed and imaged with dynamic multiscan technique. The aneurysm model was filled with iodinated contrast material (250 Hounsfield Units) and was scanned with use of a gantry rotation time of 0.33 seconds, slice thickness of 1.2 mm, effective coverage of 24 mm, and total imaging time of 4 seconds. Images were reconstructed at 50-msec intervals. The visualization of wall motion was qualitatively evaluated by direct comparison of four-dimensional images versus phantom motion. Pulsatility imaging without perceptible artifact or need for cardiac gating was achieved with the use of this technique.

Primary treatment of an indirect carotid cavernous fistula by injection of N-butyl cyanoacrylate in the dural wall of the cavernous sinus

BACKGROUND

Carotid cavernous fistulae are abnormal communications between the carotid artery system and the cavernous sinus. Endovascular treatment is the treatment of choice, but because of their heterogeneous etiology and anatomy, an appropriate treatment plan must be tailored for each patient.

CASE DESCRIPTION

A 77-year-old diabetic woman presented with rapid onset of right eye pain, conjunctivitis, and chemosis. Angiography revealed an indirect CCF located in the posterior wall of the right cavernous sinus. N-Butyl cyanoacrylate was injected directly into the fistula site in the dural wall via a microcatheter, resulting in a cure.

CONCLUSION

We describe an unconventional treatment of an indirect CCF from an IPS approach. One type D(2) CCF was treated successfully using only N-butyl cyanoacrylate injected directly at the fistula site. This was achieved by microcatheterization of the fistula in the posterior wall of the right cavernous sinus.

Spinal arteriovenous malformations associated with Klippel-Trenaunay-Weber syndrome: a literature search and report of two cases

SUMMARY

Patients with Klippel-Trenaunay-Weber syndrome present with venous varices, cutaneous capillary malformations, and tissue hypertrophy, usually involving an extremity. A small but important subset also harbors arteriovenous malformations (AVMs) of the spine. We report 2 such cases, 1 with 3 concurrent spinal arteriovenous fistulas. These cases and our review of the literature emphasize the importance of screening the spine for AVMs. In addition, it is also important to investigate for the presence of multiple spinal AVMs.

Extradural spinal meningioma as a source of plasmacytoid cells. A case report

BACKGROUND

Meningiomas, tumors that often affect middle-aged and elderly people, occasionally arise in the spine, typically at the thoracic level. The cytologic findings in meningiomas include whorls and syncytial clusters of bland-looking cells with scattered, psammomatous calcifications and intranudclear cytoplasmic inclusions. However, in many cases, not all these findings are seen, and in rare cases, unusual cytomorphologic features are observed.

CASE

A case of spinal meningioma was located in the extradural compartment and composed predominantly of singly scattered cells with a plasmacytoid appearance, demonstrated on fine needle aspiration biopsy smear preparations. The cell block showed more typical features of meningioma, and the diagnosis was supported by the results of immunohistochemical staining.

CONCLUSION

The diagnosis of spinal meningioma is readily made by employing magnetic resonance imaging. The diagnosis can be difficult to confirm pathologically when atypical histologic findings are present, as in this case, with prominent plasmacytoid features. Sections from the cell block and immunohistochemical stains as well as clinical and radiologic findings were extremely helpful in arriving at the final diagnosis.

MR angiographic evaluation of platinum coil packs at 1.5T and 3T: an in vitro assessment of artifact production: technical note

Susceptibility artifact from platinum coil packs impairs the visibility of perianeurysmal soft tissues at conventional 3D time-of-flight MR angiography. These artifacts limit the evaluation for residual-recurrent aneurysm and parent vessel stenosis. Reducing the echo time can decrease the artifact and improve perianeurysmal visualization. The purpose of this study was to assess quantitatively the effect of decreasing the echo time on artifact production at different field strengths and coil pack densities.

Rheolytic catheter thrombectomy, balloon angioplasty, and direct recombinant tissue plasminogen activator thrombolysis of dural sinus thrombosis with preexisting hemorrhagic infarctions

We describe the case of a 28-year-old obtunded woman who presented with bilateral anterior parietal lobe cortical hemorrhages associated with thrombosis of the superior sagittal sinus, both transverse and sigmoid sinuses, and multiple cortical veins draining into the sagittal sinus. Initial heparin therapy was not effective. A combination of AngioJet rheolytic catheter thrombectomy, balloon angioplasty, and continuous direct superior sagittal sinus recombinant tissue plasminogen activator infusion led to venous recanalization with a successful clinical outcome, without worsening of the preexisting intracranial hemorrhages.

Radiation Doses in Interventional Radiology Procedures: The RAD-IR Study

PURPOSE

To present the physics data supporting the validity of the clinical dose data from the RAD-IR study and to document the performance of dosimetry-components of these systems over time.

MATERIALS AND METHODS

Sites at seven academic medical centers in the United States prospectively contributed data for each of 12 fluoroscopic units. All units were compatible with International Electrotechnical Commission (IEC) standard 60601-2-43. Comprehensive evaluations and periodic consistency checks were performed to verify the performance of each unit's dosimeter. Comprehensive evaluations compared system performance against calibrated ionization chambers under nine combinations of operating conditions. Consistency checks provided more frequent dosimetry data, with use of each unit's built-in dosimetry equipment and a standard water phantom.

RESULTS

During the 3-year study, data were collected for 48 comprehensive evaluations and 581 consistency checks. For the comprehensive evaluations, the mean (95% confidence interval range) ratio of system to external measurements was 1.03 (1.00-1.05) for fluoroscopy and 0.93 (0.90-0.96) for acquisition. The expected ratio was 0.93 for both. For consistency checks, the values were 1.00 (0.98-1.02) for fluoroscopy and 1.00 (0.98-1.02) for acquisition. Each system was compared across time to its own mean value. Overall uncertainty was estimated by adding the standard deviations of the comprehensive and consistency measurements in quadrature. The authors estimate that the overall error in clinical cumulative dose measurements reported in RAD-IR is 24%.

CONCLUSION

Dosimetric accuracy was well within the tolerances established by IEC standard 60601-2-43. The clinical dose data reported in the RAD-IR study are valid.

Basilar artery herniation into the sphenoid sinus resulting in pontine and cerebellar infarction: demonstration by three-dimensional time-of-flight MR angiography

We report a unique case of basilar artery herniation into the sphenoid sinus caused by a traumatic skull base fracture, with persistent patency of the basilar artery. Clinical and imaging features, as well as the relevant literature, are described.

Temporary balloon occlusion to test adequacy of collateral flow to the retina and tolerance for endovascular aneurysmal coiling

Two carotid ophthalmic artery aneurysms with incorporation of the artery into the neck were referred for endovascular assessment. Temporary balloon occlusion at the aneurysm neck was performed in an attempt to assess the adequacy of collateral flow to the retina. During inflation, the patients reported visual deterioration that resolved upon deflation, which indicates that collateral blood flow was insufficient. The patients were referred for surgical clipping to ensure preservation of the ophthalmic artery.

Intracranial chondrosarcoma: a case report and review of the literature

OBJECTIVE AND IMPORTANCE

Chondrosarcomas rarely occur intracranially away from the skull base. We present a case of a supratentorial dural-based, low-grade classic chondrosarcoma and emphasize salient imaging findings that assist in its diagnosis.

CLINICAL PRESENTATION

A 23-year-old female presented with new onset seizures. Multiple radiographic imaging studies identified a large left frontal mass with radiological findings that suggested the correct diagnosis.

INTERVENTION

The patient underwent a left frontal craniotomy and gross total resection of the lesion and associated dura.

CONCLUSION

Intracranial chondrosarcomas away from the skull based are extremely rare malignancies. As with other extra-axial masses, they often grow to a relatively large size before generating symptoms. Careful analysis of CT, MR, and angiographic imaging characteristics should suggest the correct diagnosis.

Radiation doses in interventional radiology procedures: the RAD-IR study: part II: skin dose

PURPOSE

To determine peak skin dose (PSD), a measure of the likelihood of radiation-induced skin effects, for a variety of common interventional radiology and interventional neuroradiology procedures, and to identify procedures associated with a PSD greater than 2 Gy.

MATERIALS AND METHODS

An observational study was conducted at seven academic medical centers in the United States. Sites prospectively contributed demographic and radiation dose data for subjects undergoing 21 specific procedures in a fluoroscopic suite equipped with built-in dosimetry capability. Comprehensive physics evaluations and periodic consistency checks were performed on each unit to verify the stability and consistency of the dosimeter. Seven of 12 fluoroscopic suites in the study were equipped with skin dose mapping software.

RESULTS

Over a 3-year period, skin dose data were recorded for 800 instances of 21 interventional radiology procedures. Wide variation in PSD was observed for different instances of the same procedure. Some instances of each procedure we studied resulted in a PSD greater than 2 Gy, except for nephrostomy, pulmonary angiography, and inferior vena cava filter placement. Some instances of transjugular intrahepatic portosystemic shunt (TIPS) creation, renal/visceral angioplasty, and angiographic diagnosis and therapy of gastrointestinal hemorrhage produced PSDs greater than 3 Gy. Some instances of hepatic chemoembolization, other tumor embolization, and neuroembolization procedures in the head and spine produced PSDs greater than 5 Gy. In a subset of 709 instances of higher-dose procedures, there was good overall correlation between PSD and cumulative dose (r = 0.86; P <.000001) and between PSD and dose-area-product (r = 0.85, P <.000001), but there was wide variation in these relationships for individual instances.

CONCLUSIONS

There are substantial variations in PSD among instances of the same procedure and among different procedure types. Most of the procedures observed may produce a PSD sufficient to cause deterministic effects in skin. It is suggested that dose data be recorded routinely for TIPS creation, angioplasty in the abdomen or pelvis, all embolization procedures, and especially for head and spine embolization procedures. Measurement or estimation of PSD is the best method for determining the likelihood of radiation-induced skin effects. Skin dose mapping is preferable to a single-point measurement of PSD.