Percutaneous Radiofrequency Ablation for Benign Nodules of the Thyroid Gland

PURPOSE: We wanted to evaluate the efficacy and safety of using ultrasound guided percutaneous radiofrequency ablation for the benign nodules of the thyroid gland. MATERIALS AND METHODS: We studied 148 patients with benign thyroid nodules (200 total nodules) that were confirmed histopathologically, and we performed ultrasound guided radiofrequency ablation. The radiofrequency ablation was done 1 to 5 times per one nodule, and follow-up ultrasonography was performed one to nineteen months after the ablation procedures. The physical changes and the decrease of volume of the nodules were evaluated, and the complications related to radiofrequency ablation were observed. RESULTS: The mean initial nodule volume was 0.01-95.61 ml (mean; 6.83+/-SD of 10.63 ml) and the nodule volume after radiofrequency ablation was decreased to 0.00-46.56 ml (mean; 1.83+/-SD of 4.69 ml). The mean volume reduction rate was 73.2%. Reduction of more than 50% was noted in 90% of all cases. For 180 nodules (90%), the decrease was 50% or more, in 20 nodules (10%), the decrease was 49% or less. On gray-scale ultrasonogram obtained after ablation, the echogenicity of the nodules changed to darker, and on the doppler-sonogram, the vascular flow within the nodules disappeared in all cases. Most patients complained pain during or right after the procedure, but the pain was transient and subsided after medication. Two patients developed hoarseness that was improved in 1 week and 2 months, respectively. CONCLUSION: Sonoguided percutaneous radiofrequency ablation can be one of the treatments for benign nodules of the thyroid gland.

Patterns and Significance of Peripheral Calcifications of Thyroid Tumors seen on Ultrasound

PURPOSE: We wanted to analyze the peripheral calcification patterns of thyroid tumors that were seen on ultrasound and we also wanted to evaluate the clinical usefulness of the peripheral calcifications of the thyroid tumors. MATERIALS AND METHODS: We retrospectively analyzed 21 peripheral calcifications of the thyroid tumors of 18 patients; these were histopathologically confirmed by fine needle aspiration biopsy, automated gun biopsy and surgery. The peripheral calcification patterns were categorized into three types: type 1, peripheral nodular calcification, type 2, peripheral smooth rim calcification, and type 3, peripheral irregular rim calcification. The histopathologic results obtained during surgery, fine needle aspiration or automated gun biopsy were compared. RESULTS: Of the total 21 peripheral calcifications of thyroid tumors, 5 cases showed as being type 1 (24%), 3 cases showed as being type 2 (14%) and 13 cases showed as being type 3 (62%). Of the total 21 peripheral calcifications of the thyroid tumors, 18 were histopathologically confirmed as papillary carcinoma (86%). Among the type 1 peripheral calcification patterns, 3 cases were coincidentally diagnosed as papillary carcinoma and 2 cases were follicular neoplasm on the preoperative biopsy results and on the surgical results. Two cases of type 2 peripheral calcifications (67%) and three cases of type 3 peripheral calcifications (23%) were diagnosed as benign lesions upon preoperative biopsy, but the postoperative results were papillary carcinoma. CONCLUSION: Peripheral calcifications of thyroid tumors are important feature that suggest malignancy together with the microcalcification and peripheral calcifications of the type 2 and type 3 patterns, and these lesions may be difficult to accurately diagnose with using only biopsy.

Imaging of the Ventriculoperitoneal Shunt-Related Complications in Infants and Children With Hydrocephalus

PURPOSE: To evaluate the frequency and imaging findings of various ventriculo-peritoneal shunt-relatedcomplications in pediatric patients with hydrocephalus. MATERIALS AND METHODS: We retrospectively reviewed 246plain radiographs, three shuntograms, 53 ultrasounds, 133 CT scans, and 24 MR images obtained before and after theventriculo-peritoneal shunt procedure in 33 pediatric patients with hydrocephalus. Using preoperative images, theetiology of the hydrocephalus was assessed. Changes in the size and shape of the ventricles, the location andcontinuity of shunt apparatus, and the presence of any abnormal enhancement, hemorrhage, edema or tissue loss, orother findings of complications, were analyzed on postoperative images; the frequency and imaging findings ofshunt-related complications such as shunt malfunction, infection, hemorrhage or isolated ventricle, andcomplications caused by overdrainage, were thus evaluated. The frequency of such complications was analyzedaccording to the etiology of the hydrocephalus, and in addition, medical records were reviewed and correlated withimaging findings. RESULTS: In 18 of the 33 patients(54%), a total of 31 complications was detected. These werepresent in four of five cases (80%) of hydrocephalus caused by meningitis and ventriculitis, seven of twelve (58%)intraventricular hemorrhage, two of four (50%) unknown cases, three of nine (33%) congenital malformations, one oftwo (50%) tumors, and one (100%) congenital infection. Shunt malfunction was most common(n=15), and wasaccompanied by findings of enlarged ventricles, periventricular and peritubal edema, and abnormal location of theshunt tube. Symptoms and signs of increased intracranial pressure were also noted. Subdural hemorrhage andinfection were present infour cases each;findings of infection were enhancement of the ventricular wall, meninges,and parenchyma, as well as sonographically noted intraventricular septation and increased ventricular wall echo.Isolated lateral ventricle (n=4) or 4th ventricle (n=1) was persistently distended in spite of the presence of ashunt tube within the other ventricle. Collapsed ventricles, thick calvarium, and symptoms of increasedintracranial pressure were helpful in the diagnosis of slit ventricle syndrome(n=1). Immediate postoperativeintraventricular and parenchymal hemorrhage were noted in one case each. CONCLUSION: Shunt-related complicationswere found on postoperative images in 54% of pediatric patients with hydrocephalus; the frequency was highest incases of hydrocephalus caused by infection. Shunt malfunction occurred most frequently and each complication hadvarious imaging findings. For the diagnosis of post-operative shunt-related complication, continuous follow-upstudies are therefore necessary.

Imaging of the Ventriculoperitoneal Shunt-Related Complications in Infants and Children With Hydrocephalus

PURPOSE: To evaluate the frequency and imaging findings of various ventriculo-peritoneal shunt-relatedcomplications in pediatric patients with hydrocephalus. MATERIALS AND METHODS: We retrospectively reviewed 246plain radiographs, three shuntograms, 53 ultrasounds, 133 CT scans, and 24 MR images obtained before and after theventriculo-peritoneal shunt procedure in 33 pediatric patients with hydrocephalus. Using preoperative images, theetiology of the hydrocephalus was assessed. Changes in the size and shape of the ventricles, the location andcontinuity of shunt apparatus, and the presence of any abnormal enhancement, hemorrhage, edema or tissue loss, orother findings of complications, were analyzed on postoperative images; the frequency and imaging findings ofshunt-related complications such as shunt malfunction, infection, hemorrhage or isolated ventricle, andcomplications caused by overdrainage, were thus evaluated. The frequency of such complications was analyzedaccording to the etiology of the hydrocephalus, and in addition, medical records were reviewed and correlated withimaging findings. RESULTS: In 18 of the 33 patients(54%), a total of 31 complications was detected. These werepresent in four of five cases (80%) of hydrocephalus caused by meningitis and ventriculitis, seven of twelve (58%)intraventricular hemorrhage, two of four (50%) unknown cases, three of nine (33%) congenital malformations, one oftwo (50%) tumors, and one (100%) congenital infection. Shunt malfunction was most common(n=15), and wasaccompanied by findings of enlarged ventricles, periventricular and peritubal edema, and abnormal location of theshunt tube. Symptoms and signs of increased intracranial pressure were also noted. Subdural hemorrhage andinfection were present infour cases each;findings of infection were enhancement of the ventricular wall, meninges,and parenchyma, as well as sonographically noted intraventricular septation and increased ventricular wall echo.Isolated lateral ventricle (n=4) or 4th ventricle (n=1) was persistently distended in spite of the presence of ashunt tube within the other ventricle. Collapsed ventricles, thick calvarium, and symptoms of increasedintracranial pressure were helpful in the diagnosis of slit ventricle syndrome(n=1). Immediate postoperativeintraventricular and parenchymal hemorrhage were noted in one case each. CONCLUSION: Shunt-related complicationswere found on postoperative images in 54% of pediatric patients with hydrocephalus; the frequency was highest incases of hydrocephalus caused by infection. Shunt malfunction occurred most frequently and each complication hadvarious imaging findings. For the diagnosis of post-operative shunt-related complication, continuous follow-upstudies are therefore necessary.

Usefulness of US-Guided Automated Gun Biopsy of Nonpalpable Breast Lesions

PURPOSE: To evaluate the clinical usefulness of ultrasonography (US) - guided automated gun biopsy of nonpalpable breast lesions. MATERIALS AND METHODS: In 30 nonpalpable breast lesions over 0.6cm and detected on US, we performed US-guided biopsy using an 18-gauge automated biopsy gun. Two to four specimens were obtained from each lesion. We analyzed the site, size and depth of the lesions, and the length and histopathologic results of the specimens. In four lesions, surgical biopsy and gun biopsy results were compared. RESULTS: In 29 of 30 lesions (96.7%), specimens were adequate for histopathologic diagnosis, and this was as follows: one case of infiltrating ductal carcinoma, 13 of fibrocystic disease, 10 of fibrocystic disease versus fibroadenoma and one of fibroadenoma. There was also one reactive hyperplasia of LN, and one fatty one and two normal tissues, and inthese four lesions, agreement between gun and surgical biopsy results was 100%. The only complication was minor bleeding, which was controlled by compression. CONCLUSION: US-guided automated gun biopsy is a clinically useful and safe procedure for evaluating nonpalpable breast lesions detected on US.