Chung-Chuan Hsu

Cubital tunnel syndrome : Diagnosis by high-resolution ultrasonography

The purpose of this study was to evaluate the morphologic changes in the ulnar nerve in cubital tunnel syndrome with high‐resolution ultrasonography. The mean values of the short axis (cm) x long axis (cm) at the arm, epicondyle, and forearm levels were 0.057 +/‐ 0.01, 0.068 +/‐ 0.019, and 0.062 +/‐ 0.01 in control group; 0.069 +/‐ 0.04, 0.139 +/‐ 0.06, and 0.066 +/‐ 0.023 in the symptomatic side in patients with cubital tunnel syndrome; and 0.063 +/‐ 0.029, 0.068 +/‐ 0.029, and 0.057 +/‐ 0.012 in the normal side in patients with cubital tunnel syndrome. No significant difference was found in the area (short axis x long axis) of the ulnar nerve at the arm, epicondyle and forearm levels between the left and right ulnar nerve in the control group and between the control group and the normal side in symptomatic patients. However, the mean value of the area of the ulnar nerve at the epicondyle level in symptomatic patients was significantly larger than that of the control group and that of the contralateral side in patients, and the P value was less than 0.001. High resolution ultrasonography can detect morphologic changes in the ulnar nerve accurately, and it could therefore be useful as a screening and even follow‐up modality in patients with cubital tunnel syndrome.

Alternative and effective treatment of shoulder ganglion cyst: ultrasonographically guided aspiration.

The therapeutic effect of ultrasonographically guided aspiration of a ganglion cyst of the shoulder is evaluated. Fifteen patients (nine male, six female) with chronic shoulder pain were enrolled in this study. Each patient was referred to rule out rotator cuff lesion. The ultrasonographic examination showed an anechoic cystic lesion in the shoulder region in every patient and abnormality of the rotator cuff in only four patients. Under ultrasonographic guidance, an 18 gauge needle was inserted into the cyst to aspirate the fluid. Initial sonographic imaging showed the cyst, which appeared as a localized fluid accumulation and was located between the deltoid muscle and the subscapularis tendon in seven patients, between the deltoid muscle and the biceps tendon in one patient, below the coracoacromial ligament in five patients, and over suprascapular notch area in one patient. The ganglion cysts ranged in size from 3.5 to 30 mm. The amount of aspirated fluid in each cyst varied from 0.4 to 12 ml (mean, 2.6 ml +/‐ 3.1) with a clear or light yellowish color and a jelly‐like appearance. No major complications occurred during or after this procedure. The symptom (pain) was improved after sonographically guided aspiration in each patient. Follow‐up study showed complete relief of pain in four patients, marked improvement in nine patients, and mild improvement but still persistent shoulder pain in two patients. Duration of follow‐up study ranged from 2 to 24 months (mean, 6.4 months +/‐ 6.9). The success rate for sonographically guided aspiration was 86% on the basis of marked symptom improvement or relief. Ultrasonographically guided aspiration of shoulder ganglion cysts is an effective procedure in the management of shoulder pain caused by ganglion cysts.

Evaluation of ocular arterial changes in glaucoma with color Doppler ultrasonography.

The purpose of this study was to evaluate hemodynamic changes of the retrobulbar vasculature caused by different intraocular pressures with color Doppler ultrasonography. Fifty normal eyes in 25 patients, 13 patients with normal tension glaucoma, and 19 patients with acute glaucoma and increased intraocular pressure (greater than 30 mm Hg) were enrolled in this study. In 15 of 19 patients with acute glaucoma patients, follow‐up color Doppler ultrasonography was also undertaken after laser peripheral iridectomy when the intraocular pressure had returned to normal. The peak systolic velocity, end diastolic velocity, resistive index, time average maximum velocity, and pulsatility index were compared in different vessels, including the central retinal artery, lateral posterior ciliary artery, medial posterior ciliary artery, and ophthalmic artery in each orbit. The peak systolic velocity, end diastolic velocity, and time average maximum velocity of the central retinal artery were significantly lower (P<0.01) in acute glaucoma patients than in the control group. The resistive index and pulsatility index of the central retinal artery were significantly higher (P<0.01) in acute glaucoma patients than in the control group. The end diastolic velocity of the lateral and medial posterior ciliary arteries was significantly lower in patients with acute glaucoma than in the control group, and the resistive index and pulsatility index of both of these arteries were significantly higher (P<0.001) in patients with acute glaucoma than in the control group. However, no statistical significantly differences were found in the peak systolic velocity or time average maximum velocity in either of the posterior ciliary arteries; similarly, no statistically significant differences were noted in any of the parameters in the ophthalmic artery between the control group and the group with acute glaucoma. The pulsatility index of the central retinal artery and of the lateral and medial posterior ciliary arteries was significantly lower (P<0.01) in acute glaucoma patients after laser therapy than in acute glaucoma patients before laser therapy. The resistive index of both posterior ciliary arteries was also significantly lower (P<0.004) in acute glaucoma patients after laser therapy than before laser therapy. All parameters for all vessels examined among the normal subjects, the patients with normal tension glaucoma, and the patients with acute glaucoma after laser therapy when the intraocular pressure had returned to normal showed no statistically significant differences. Color Doppler ultrasonography is a good modality for both imaging and studying the hemodynamics of the perioptic nerve vessels.

Triangular fibrocartilage of wrist: presentation on high resolution ultrasonography.

This study consisted of two parts. Part I is for detection of the normal triangular fibrocartilage by high resolution ultrasonography and Part II is a preliminary study to evaluate high resolution ultrasonography in the diagnosis of tears of the triangular fibrocartilage. Normally, the triangular fibrocartilage was seen in all cases in Part I as an inverse triangular structure of homogeneous hyperechogenicity on transverse and oblique sagittal scans at the level of the distal radioulnar joint. At its waist it measured from 2.3 to 4.2 mm (mean, 3.0 +/‐ 0.5 mm) on oblique sagittal scan and from 2.5 to 3.7 mm (mean, 3.2 +/‐ 0.4 mm) on transverse scan. Under normal conditions, the triangular fibrocartilage is thicker than 2.5 mm on both transverse and oblique sagittal sections with a confidence level of 95%. In Part II, eight of the 47 wrists were found to be hypoechoic in the triangular fibrocartilage region, which proved to be tears by arthrography. Six cases showed a homogeneous hyperchoic triangular fibrocartilage measuring from 1.8 to 2.8 mm (mean, 2.3 +/‐ 0.5 mm) in transverse section and from 0 to 2.2 mm (mean 1.2 +/‐ 1.1 mm) in oblique sagittal section; five of these proved to be tears by arthrography. In contrast, 33 wrists had a homogeneous hyperechoic triangular fibrocartilage measuring from 2.5 to 4 mm (mean, 3.1 +/‐ 0.4 mm) and 2.5 to 4.2 mm (mean, 3.1 +/‐ 0.6 mm) on transverse and oblique sagittal sections, respectively; 27 proved to be normal triangular fibrocartilage by arthrography. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 68.4%, 96.4%, 92.9%, 81.8%, and 85.1%, respectively. HRUS can display the normal triangular fibrocartilage as a homogeneous hyperechoic and inverted triangular structure. The torn triangular fibrocartilage appears as a hypoechoic region or as thinning (< 2.5 mm) of the hyperechoic structure on either transverse or oblique sagittal section. HRUS has an acceptable accuracy in the diagnosis of triangular fibrocartilage tear.

Verifying complete obliteration of carotid artery-cavernous sinus fistula: role of color Doppler ultrasonography.

The purpose of this study was to evaluate the role of color Doppler ultrasonography in verifying obliteration of carotid artery‐cavernous sinus fistula before and after therapeutic embolization or gamma knife radiosurgery. Before treatment, carotid artery‐cavernous sinus fistula showed the following data on color Doppler ultrasonography: (1) increased blood flow in the common carotid artery (220 to 1264 ml/min with mean+/‐SD of 728+/‐378 ml/min); internal carotid artery (435 to 1097 ml/min with mean+/‐SD of 834+/‐216 ml/min) in fistulas of the direct type; and external carotid artery (85 to 257 ml/min with mean+/‐SD of 170+/‐75 ml/min) in fistulas of the indirect type in comparison to the contralateral side; (2) reverse pulsatile flow or spiculated wave form with turbulent flow in the engorged superior ophthalmic vein on the lesion side in all patients. All of the above abnormal hemodynamic changes became normal in six patients immediately after first embolization, in two patients with balloon embolization combined with subsequent direct embolization by direct puncture through the superior orbital fissure or internal carotid artery embolization, and in five patients after gamma knife radiosurgery at 4, 4, 8, 9, and 9 months, respectively. Color Doppler ultrasonography might be a good modality in long‐term follow‐up of carotid artery‐cavernous sinus fistula after gamma knife radiosurgery and embolization.