Ming-Shiang Yang

Alternative option in the treatment of very small ruptured intracranial aneurysms

BACKGROUND To evaluate the safety and protective effect of relative undersized coil with loose coil core in the clinical dilemma condition--very small (43.0 mm) ruptured intracranial aneurysm. METHODS We studied 12 patients (4 men, 8 women) who had suffered from acute ruptured small intracranial aneurysms (2-3 mm in size, with SAH presentation). All subjects underwent a single coil embolization procedure. An undersized coil (equivalent to the neck size or 0.5 mm smaller than the aneurysm diameter) was chosen as the embolizer. Based on the postembolization angiogram, subjects were divided into 2 groups. One was labeled as the initial complete obliteration group (NR) and the other as the incomplete obliteration group (SR). Fisher exact test and the Wilcoxon rank sum test were used to for statistical analysis. RESULTS The technical success rate was 100% without any procedure-related complication. The follow-up interval ranged from 6 to 32 months. No episode of rebleeding or coil migration could be defined in the admissive and following period. Loose coil core were seen in all patients. The total recurrent rate was 8.3% (1/12); only one patient suffered from recurrent lesion in SR group. CONCLUSION The preliminary result showed that under-sized coil packing with loose coil core could provide the protective effect and prevent from further rebleeding for very small ruptured aneurysms. It should be considered as an alternative option in the treatment of acute ruptured very small aneurysms when other conventional strategies are not feasible.

Spontaneous Spinal and Intracranial Subdural Hematoma

Subdural hematoma (SDH) of the spine following intracranial hemorrhage is extremely rare. We present a 35-year-old woman who suffered from headache and dizziness initially, and then lower back pain, lower limb weakness and paraparesis gradually developed within 1-2 weeks. Magnetic resonance imaging revealed intracranial and spinal SDH. No vascular abnormality was seen by brain and spinal angiography. Platelet count, prothrombin time, activated partial thromboplastin time, and inflammatory markers, including C-reactive protein, were normal. A diagnosis of spontaneous spinal and intracranial SDH was then confirmed surgically. Postoperative recovery was uneventful.

Intraspinal Extradural Ganglion Cyst of the Cervical Spine

Intraspinal ganglion cyst is an uncommon lesion, which occurs most frequently in the lower lumbar region; occurrence in the cervical region is extremely rare. We report a case of ganglion cyst in the cervical region and describe its clinical pathological and radiological findings. A 59-year-old man presented with sudden lower limbs weakness and numbness below the nipple level. Magnetic resonance imaging revealed an intraspinal extradural lobulated cystic lesion at the level of C6-7 in contact with the left facet joint and posterior erosion of the spinal process at C7. The spinal cord was severely compressed by this lesion which was hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging and short T1 inversion recovery. The cyst wall was strongly enhanced after contrast injection. Intraoperatively, the mass was found to arise from the capsule of the C6-7 facet joint. The excised cyst contained jelly-like fluid. The patients neurologic symptoms had fully recovered 20 days after the operation. The histopathologic analysis was consistent with ganglion cyst. Ganglion cyst of the cervical region is extremely rare, but must be considered in the differential diagnosis of intraspinal extradural compressive syndromes.

Gastrointestinal stromal tumors: computed tomographic features and prediction of malignant risk from computed tomographic imaging.

Background: Gastrointestinal stromal tumors (GISTs) are specific, generally Kit (CD117)‐positive, mesenchymal tumors of the gastrointestinal tract encompassing a majority of tumors previously considered gastrointestinal smooth muscle tumors. Our aim was to characterize the computed tomographic findings and predict malignant risk from computed tomography for the evaluation of GISTs. Methods: The computed tomographic images of 39 patients with pathologically and immunohistochemically proven GISTs were reviewed by 2 radiologists, and the final interpretations were reached by consensus. Images were assessed for the size, contour, growth pattern, boundary, degree of enhancement, and necrosis of the tumors. The presence of calcification within the lesions, abdominal lymphadenopathy, ascites, and bowel obstruction were also recorded. Categorical variables were compared using Fishers exact test. Univariate and multivariate logistic regression analyses were used for selection of significant predictors of high‐risk malignancy. In addition, the relationships between computed tomographic features and tumor size were assessed by means of nonparametric univariate analysis with the Mann–Whitney U test and Kruskal–Wallis test. Results: Both old age and larger tumor size (≥ 5 cm) were statistically significant in the univariate logistic analysis for high‐risk malignant tumors (p < 0.25). However, in multivariate logistic regression, only larger tumor size (≥ 5 cm) was found to have final statistical significance for high‐risk malignant GISTs (p < 0.05). In addition, more exophytic growth pattern (p < 0.01), more lobulated appearance (p < 0.01), good enhancement (p < 0.05), and more necrosis (p < 0.01) of masses were more often observed in larger GISTs than small ones on computed tomography. Conclusion: Larger tumor size (≥ 5 cm) was found to have a predictive value with respect to high‐risk malignant GISTs.

Imaging Characteristics of Familial Wolfram Syndrome

Wolfram syndrome is a rare diffuse neurodegenerative disorder also known as DIDMOAD due to its characteristics of diabetes insipidus, diabetes mellitus, optic nerve atrophy and deafness. It is also associated with a wide variety of abnormalities of the central nervous system, urinary tract and endocrine glands. It may be familial or sporadic. Imaging findings include absence of the short T1 nature of the pituitary posterior lobe, atrophy of the optic nerve, chiasma, and tracts. Atrophy of the brain stem and cerebellum has also been reported. We describe a 15-year-old boy and an 11-year-old girl with Wolfram syndrome who were siblings from a diabetes mellitus family. They received regular insulin control at our hospital and had symptoms of frequent urinary tract infection and diabetes insipidus. Magnetic resonance imaging revealed marked pons and cerebellar atrophy. Optic nerve and chiasma atrophy was also noted.

Iatrogenic and fatal arterial air embolism during the CT scan.

Systemic and fatal arterial air embolism during the computed tomography (CT) scan is rarely reported in English-based literature. Iatrogenic air embolism happening during the CT scan is often related to the injector, usually venous air embolism and asymptomatic. We report one fatal and extensive systemic arterial air embolism because of one error that happened during a brain CT scan. The mechanism is different from the reported cases in the literature. The possible mechanism and pathogenesis are well discussed to alert clinicians and prevent the recurrence of such complication.

Angioplasty as the First-Line Therapeutic Option for Venous Hypertension with Outlet Obstruction of Dural Sinus

We describe a nonconventional endovascular approach to the treatment of pseudotumor cerebri with venous outlet stricture or obstruction. In three patients presenting with acute visual loss, angiograms showed sinus occlusion and stasis of contrast material, with an increased pressure gradient in the venous system. We used venous sinus angioplasty as the first therapeutic option. This treatment was effective, and symptoms and signs of all three patients subsided quickly. In our initial and limited experience, sinus balloon angioplasty appeared to be a good first-line treatment for patients with pseudotumor cerebri, sinus outlet obstruction and acute vision loss. We prefer to use sinus stent placement as a second-line option when initial attempts are unsuccessful, especially in pediatric and young-adult patients, as illustrated in our cases.

Characterization of focal brain lesions by gradient-echo arterial spin-tagging perfusion imaging.

A simple gradient-echo arterial spin tagging (GREAST) technique allows for quick assessment of regional tissue perfusion without the need for exogenous contrast agent. The purpose of this prospective study was to validate GREAST imaging in characterizing the regional perfusion status of focal brain lesions by comparing with relative cerebral blood volume (rCBV) maps obtained by using echo-planar imaging (EPI)–based dynamic susceptibility contrast MR imaging. Thirty-two patients whose nonenhanced brain MR images showed 34 focal brain lesions during routine examination were selected to immediately undergo GREAST and dynamic susceptibility contrast MR imaging to evaluate regional perfusion of the lesions. The Pearson correlation coefficient was used to test the relative quantification of local perfusion with the two imaging methods. Qualitative perfusion measurements agreed in 23 (79%) of 29 lesions for which GREAST and dynamic susceptibility contrast MR imaging were successful. On rCBV maps, six focal lesions with local hemorrhage were underestimated. In three patients with metal surgical implants, lesions could not be measured because of susceptibility artifacts and distortion on EPIs. After these lesions were excluded, the Pearson correlation coefficient between relative quantitative perfusion measurements on GREAST images versus rCBV maps was about 0.90 (p value = 0.000). The success rate of GREAST imaging was 94% (30 of 32 patients), higher than that of dynamic susceptibility contrast MR imaging (72%, or 23 of 32 patients). GREAST imaging was comparable to rCBV mapping for the relative quantification of regional perfusion of focal brain lesions. This technique may be useful in routine MR examination for characterizing the regional perfusion of brain focal lesions.

Avoiding Unnecessary Orchiectomy-MRI Features in a Case of Multiple Benign Fibrous Scrotal Pseudotumors

We report a surgically confirmed case of scrotal fibrous pseudotumors. A 21-year-old man presented with multiple painless palpable masses in the left scrotum which had progressively enlarged over the previous 6 months. Magnetic resonance imaging (MRI) showed multiple tumor nodules at the scrotal wall. Characteristic of fibrous tumors, they were isosignal with the testis in Ti-weighted images (T1WI) and had low signal intensity in T2-weighted images (T2WI). Gadolinium injection revealed an inhomogeneous but obvious enhancement compared with the testis. We think the MRI picture is highly suggestive of this rare non-neoplastic entity. Awareness of the MRI features of the fibrous pseudotumor is important and could prevent unnecessary orchiectomy.

Unusual Sonographic Feature of Congenital Pulmonary Sequestration

The ultrasonographic appearance of fetal pulmonary sequestration has been typically described as a hyperechoic mass in the thoracic cavity. We present the case of a 33-year-old woman at 24 weeks of gestation, with an echolucent cyst in the thorax of the fetus. No other congenital anomalies were noted. Color Doppler sonography failed to identify any aberrant vessel supplying the mass. After the termination of pregnancy on the patients request, autopsy and detailed histologic examination were carried out. The reports showed an extralobar pulmonary sequestration with macrocystic appearance, simulating type I congenital cystic adenomatoid malformation proposed by Stocks classification. We suggest that the hypoechogenicity in this type of pulmonary sequestration may result from the retention of fluid in the obstructed bronchial tree. Literature on the sonographic features of pulmonary sequestration is also reviewed.