Revisiting Rupture of Benign Thyroid Nodules after Radiofrequency Ablation: Various Types and Imaging Features

BACKGROUND: To evaluate the imaging features, clinical manifestations, and prognosis of patients with thyroid nodule rupture after radiofrequency ablation (RFA).METHODS: The records of 12 patients who experienced thyroid nodule rupture after RFA at four Korean thyroid centers between March 2010 and July 2017 were retrospectively reviewed. Clinical data evaluated included baseline patient characteristics, treatment methods, initial presenting symptoms, imaging features, treatment, and prognosis.RESULTS: The most common symptoms of post-RFA nodule rupture were sudden neck bulging and pain. Based on imaging features, the localization of nodule rupture was classified into three types: anterior, posterolateral, and medial types. The anterior type is the most often, followed by posterolateral and medial type. Eight patients recovered completely after conservative treatment. Four patients who did not improve with conservative management required invasive procedures, including incision and drainage or aspiration.CONCLUSION: Thyroid nodule rupture after RFA can be classified into three types based on its localization: anterior, posterolateral, and medial types. Because majority of thyroid nodule ruptures after RFA can be managed conservatively, familiarity with these imaging features is essential in avoiding unnecessary imaging workup or invasive procedures.

Core Needle Biopsy of the Thyroid: 2016 Consensus Statement and Recommendations from Korean Society of Thyroid Radiology

Core needle biopsy (CNB) has been suggested as a complementary diagnostic method to fine-needle aspiration in patients with thyroid nodules. Many recent CNB studies have suggested a more advanced role for CNB, but there are still no guidelines on its use. Therefore, the Task Force Committee of the Korean Society of Thyroid Radiology has developed the present consensus statement and recommendations for the role of CNB in the diagnosis of thyroid nodules. These recommendations are based on evidence from the current literature and expert consensus.

Effects of mirodenafil on the hemodynamics in hypertensive patients taking amlodipine

While phosphodiesterase type 5 inhibitors have been used for erectile dysfunction with acceptable safety profile, they can induce orthostatic hypotension in patients taking antihypertensive drugs with blood pressure lowering effect. This study evaluated the hemodynamic effects of 100 mg mirodenafil in hypertensive patients taking an amlodipine. Thirteen hypertensive patients who were taking 5 or 10 mg of amlodipine once daily participated in a randomized, double-blind, placebo-controlled, crossover study. A single oral dose of mirodenafil 100 mg or placebo was administered at 4.5 hour after administration of amlodipine. The maximal change in systolic and diastolic blood pressure (ΔmaxSBP and ΔmaxDBP) and pulse rate (ΔmaxPR) were compared between mirodenafil and placebo periods. Twelve patients completed this study and were included analysis. The values of ΔmaxPR in standing and supine position were significantly greater in the mirodenafil period (13.25±7.12 and 11.17±4.86 beats/minute) when compared to the placebo (8.50±4.72 and 6.58±3.90 beats/minute). The ΔmaxSBP and ΔmaxDBP in standing position appeared to be lower in the mirodenafil period, but they were not statistically different from those in the placebo period (ΔmaxSBP = -7.42±5.6 vs -4.42±5.37 mmHg and ΔmaxDBP = -7.17±5.72 vs -3.50±3.37 mmHg). Both ΔmaxSBP and ΔmaxDBP in standing and supine position were not significantly different between mirodenafil and placebo. This study demonstrated that mirodenafil exerted minimal hemodynamic effects in the patients taking amlodipine, that is unlikely associated with a clinically significant hypotensive event.

Ultrasonographic Classification of the Metastases to the Thyroid Gland / 대한갑상선학회지

BACKGROUND AND OBJECTIVES: To classify the metastases to the thyroid gland arising from non-thyroidal malignancies on ultrasound (US). MATERIALS AND METHODS: We enrolled 45 consecutive patients with metastases to the thyroid gland from 2005 to 2012. We classified metastases into 4 types; type I: diffuse non-mass forming lesion, type II: a solitary suspicious nodule, type III: multiple suspicious nodules, and type IV: nodule(s) with no suspicion. We subcategorized type I into two subtypes; type IA: diffusely infiltrative lesion, type IB: diffuse micronodulation. RESULTS: The most frequent primary malignancy of thyroid metastases was lung cancer. The patients with thyroid metastases were 26 (57.8%) in type I; type IA: 16 (35.6%), type IB: 10 (22.2%), 14 (31.1%) in type II, 3 (6.7%) in type III and 2 (4.4%) in type IV. Type I metastasis included 18 of 25 patients with lung cancer and all 3 patients with stomach cancer. Thirty patients (73.3%) having type IA, II or III revealed malignant findings on US, in contrast, 12 (26.7%) patients having type IB or IV revealed no suspicious findings. CONCLUSION: Type I (diffuse non-mass forming lesion) was the most common in thyroid metastases. A quarter of thyroid metastases revealed no suspicious findings on US. Thyroid metastases can be considered as a differential diagnosis, when diffuse non-mass forming lesions or nodules with no suspicion are revealed on thyroid US.

Comparison between Ultrasonography and Computed Tomography for Detecting the Pyramidal Lobe of the Thyroid Gland: A Prospective Multicenter Study

OBJECTIVE: To compare the detection rates of the pyramidal lobe of the thyroid gland (TPL) using ultrasonography (US) and computed tomography (CT) in a prospective multi-center study. MATERIALS AND METHODS: We enrolled 582 patients who underwent neck CT at six institutions. Each radiologist prospectively evaluated the presence and features of TPLs on thyroid US. Radiologists were divided into two groups according to their previous experience in detecting TPL on US or CT. The same radiologist also retrospectively assessed CT findings, blinded to the corresponding US findings. RESULTS: The pyramidal lobe of the thyroid glands were detected in 230 cases (39.5%) on US and in 276 cases (47.6%) on CT. The TPL detection rate at the six institutions ranged from 22.0% to 59% for US and from 34.1% to 59% using CT. There were significant differences between US and CT in the detection rate, length, anteroposterior diameter, volume, and superior extent of TPL (p < or = 0.027). The TPL detection rates on both US and CT (p < 0.001) differed significantly according to the experience level of the radiologists. When the CT result was used as a reference standard, the sensitivity, specificity, positive and negative predictive values, as well as the accuracy of US for TPL detection were 72.6%, 91.5%, 89.3%, 77.3%, and 82.1%, respectively. CONCLUSION: Our prospective multicenter study revealed that US could detect TPL with relatively high diagnostic accuracy compared to CT. Because the detection rate of TPL varied significantly according to the radiologists' level of experience, careful inspection is necessary to avoid imaging pitfalls and ensure appropriate evaluation of TPL on both US and CT.

Core Needle Biopsy of Thyroid Nodules: Consensus Statement and Recommendations

Core needle biopsy is a complementary diagnostic method of fine needle aspiration for patients with thyroid nodules. The Task Force Committee of the Korean Society of Thyroid Radiology has developed recommendations for diagnosis of thyroid nodules and recurrent thyroid cancers using core needle biopsy. These recommendations are based on evidence from the current literature and expert consensus.

Hyperechoic Cervical Lymph Nodes after Injection of Silicone into the Face: A Case Report

Lymph nodes (LNs) containing echogenic deposits is a specific ultrasonographic (US) finding of pathologic LNs. Here, I reported on a case of hyperechoic cervical lymph nodes after injection of silicone into the face. US showed globally or partially hyperechoic cervical LNs with hyperechoic tapering trails. This is the first description of ultrasonographic findings and the pathologic correlation for LNs affected by migration of liquid injectable silicone into the neck.

Image Reporting and Characterization System for Ultrasound Features of Thyroid Nodules: Multicentric Korean Retrospective Study

OBJECTIVE: The objective of this retrospective study was to develop and validate a simple diagnostic prediction model by using ultrasound (US) features of thyroid nodules obtained from multicenter retrospective data. MATERIALS AND METHODS: Patient data were collected from 20 different institutions and the data included 2000 thyroid nodules from 1796 patients. For developing a diagnostic prediction model to estimate the malignant risk of thyroid nodules using suspicious malignant US features, we developed a training model in a subset of 1402 nodules from 1260 patients. Several suspicious malignant US features were evaluated to create the prediction model using a scoring tool. The scores for such US features were estimated by calculating odds ratios, and the risk score of malignancy for each thyroid nodule was defined as the sum of these individual scores. Later, we verified the usefulness of developed scoring system by applying into the remaining 598 nodules from 536 patients. RESULTS: Among 2000 tumors, 1268 were benign and 732 were malignant. In our multiple regression analysis models, the following US features were statistically significant for malignant nodules when using the training data set: hypoechogenicity, marked hypoechogenicity, non-parallel orientation, microlobulated or spiculated margin, ill-defined margins, and microcalcifications. The malignancy rate was 7.3% in thyroid nodules that did not have suspicious-malignant features on US. Area under the receiver operating characteristic (ROC) curve was 0.867, which shows that the US risk score help predict thyroid malignancy well. In the test data set, the malignancy rates were 6.2% in thyroid nodules without malignant features on US. Area under the ROC curve of the test set was 0.872 when using the prediction model. CONCLUSION: The predictor model using suspicious malignant US features may be helpful in risk stratification of thyroid nodules.

Erratum: Image Reporting and Characterization System for Ultrasound Features of Thyroid Nodules: Multicentric Korean Retrospective Study

On page 110, the author (Won-Jin Moon)'s affiliation has been incorrectly marked as 6Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University, Seoul 143-729, Korea. The correct affiliation is 5Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 143-729, Korea.

Desmoplastic Fibroma of Bone in a Toe: Radiographic and MRI Findings

Desmoplastic fibroma is a rare benign primary bone tumor that is histologically similar to the soft tissue desmoid tumor. It most often involves the mandible, large long bone or iliac bone. Desmoplastic fibroma in a toe has been extremely rarely reported. Authors report a rare case of desmoplastic fibroma of bone occurring in the distal phalanx of a foot, with descriptions of the radiographic and MRI findings, correlation of the radiologic and pathologic findings, and discussion on the differential diagnosis of the tumor.

Carcinoma Mixed within Milk of Calcium in a Breast: a Case Report

Milk of calcium located in the breast is typically a benign entity. However, carcinoma may incidentally arise adjacent to or even within milk of calcium. Consequently, the characteristics of all observed calcific particles should be carefully analyzed. In this study, we report a case of carcinoma presented as malignant microcalcifications mixed within milk of calcium in a breast.

Spontaneous Disappearance of Microcalcifications in Breast Papillary Carcinoma: Case Report

Spontaneous disappearance of breast calcification has rarely been reported. The majority of cases of spontaneously resolving calcifications have been concerned with benign processes. We report here on breast papillary carcinoma that showed spontaneously resolving microcalcifications without newly developed parenchymal changes on the follow-up mammogram.

MRI Findings of Cavernous Hemangioma of the Uterus: A Case Report

Hemangioma is the most common soft tissue tumor in the body. Though it may occur anywhere in the body, hemangioma of the uterus is a very rare tumor. Hemangioma is almost asymptomatic, but it is sometimes clinically important because it can cause massive hemorrhage and this is a life-threatening condition. We report here on the magnetic resonance imaging and pathologic findings of cavernous hemangioma of the uterus in a 32-year-woman with menorrhagia.

Osteoma of the Middle Ear: Case Report

Osteomas of the middle ear are exceedingly rare benign neoplasms. To date, only 21 cases have been reported in the literature. They arise from the promontory, the pyramidal process and the ossicles, and they are usually asymptomatic or cause some conductive hearing loss. We report here the CT & pathologic findings in a 38-year-old woman with a benign osteoma of the middle ear along with chronic otitis media.

In Vitro of Quantitative MR Imaging of Early Degenerative Changes in Human Articular Cartilage

PURPOSE: To assess the applicability of quantitative MR microscopy for the detection of glycosaminoglycan (GAG) depletion as an early sign of degeneration in the articular cartilage of humans treated by trypsin. MATERIALS AND METHODS: Four cartilage-bone blocks were obtained from the patient who had suffered from osteoarthritis of the knee and underwent a total knee replacement arthroscopy. Each articular cartilage segment was resected as to a round disk shape (8 mm in diameter) with a remnant of subchondral bone 1 mm in thickness. Four different culture solutions were prepared, and these solutions were 0.2 mg/ml of trypsin solution (group 1), 1 mM of Gd (DTPA) 2-mixed trypsin solution (group 2), phosphate buffered saline (PBS) (group 3), and 1 mM of Gd (DTPA) 2-mixed PBS (group 4). The cartilages were cultured and then MR imagings were performed every hour for 5 hrs, and we continued the additional cultures of 24 hrs, 36 hrs and 48 hrs. Three imaging sequences were used: T1-weighted spin echo (TR/TE, 450/22), proton density turbo spin echo with fat suppression (TR/TE, 3000/25), and CPMG (Carr-Purcell-Meiboom-Gill) (TR/TE/TI, 760/21-168, 360). MR imaging data were analyzed with pixel-by-pixel comparisons in all groups. RESULTS:The GAG loss in the articular cartilage was increased proportionately to the culture duration. Mean changes of T1 relaxation time were 1.2% for group 1, -1.9% for group 3, -54.7% for group 2 and -64.2% for group 4 (p<0.05). When comparing by linear profile on the T1-weighted images, SNR increased and T1 relaxation time decreased for group 2 and 4, as the culture duration increased (p<0.05). On the correlation analysis, there is significant correlation between GAG loss and Gd (DTPA) 2-enhancement for group 2 (p=0.0431), but there was no significant difference for group 4 (p=0.0918). More enhancement with Gd (DTPA) 2-was noted for group 2 than for group 4. Group 2 showed a diffuse enhancement in all the layers of cartilage, but for group 4, prominent enhancement was noted only in the superficial layer. CONCLUSION: Early degenerative changes of the articular cartilage were not noted on the T1-weighted images, turbo spin echo with fat suppresison and T1, T2, or the rho relaxometry by a 1.5 T machine. Only Gd (DTPA) 2- enhancement was useful in the detection of early degeneration of the articular cartilage.

Gd(DTPA)2--enhanced, and Quantitative MR Imaging in Articular Cartilage

PURPOSE: Early degeneration of articular cartilage is accompanied by a loss of glycosaminoglycan (GAG) and the consequent change of the integrity. The purpose of this study was to biochemically quantify the loss of GAG, and to evaluate the Gd(DTPA)2--enhanced, and T1, T2, rho relaxation map for detection of the early degeneration of cartilage. MATERIALS AND METHODS: A cartilage-bone block in size of 8mmx10 mm was acquired from the patella in each of three pigs. Quantitative analysis of GAG of cartilage was performed at spectrophotometry by use of dimethylmethylene blue. Each of cartilage blocks was cultured in one of three different media: two different culture media (0.2 mg/ml trypsin solution, 1mM Gd (DTPA)2- mixed trypsin solution) and the control media (phosphate buffered saline (PBS)). The cartilage blocks were cultured for 5 hrs, during which MR images of the blocks were obtained at one hour interval (0 hr, 1 hr, 2 hr, 3 hr, 4 hr, 5 hr). And then, additional culture was done for 24 hrs and 48 hrs. Both T1-weighted image (TR/TE, 450/22 ms), and mixed-echo sequence (TR/TE, 760/21-168ms; 8 echoes) were obtained at all times using field of view 50 mm, slice thickness 2 mm, and matrix 256x512. The MRI data were analyzed with pixel-by-pixel comparisons. The cultured cartilage-bone blocks were microscopically observed using hematoxylin & eosin, toluidine blue, alcian blue, and trichrome stains. RESULTS: At quantitation analysis, GAG concentration in the culture solutions was proportional to the culture durations. The T1-signal of the cartilage-bone block cultured in the Gd(DTPA)2- mixed solution was significantly higher (42% in average, p0.05). However the focal increase in T1 relaxation time at superficial and transitional layers of cartilage was seen in Gd(DTPA)2- mixed culture. Toluidine blue and alcian blue stains revealed multiple defects in whole thickness of the cartilage cultured in trypsin media. CONCLUSION: The quantitative analysis showed gradual loss of GAG proportional to the culture duration. Microimagings of cartilage with Gd(DTPA)2--enhancement, relaxation maps were available by pixel size of 97.9x195 micrometer. Loss of GAG over time better demonstrated with Gd(DTPA)2--enhanced images than with T1, T2, rho relaxation maps. Therefore Gd(DTPA)2--enhanced T1-weighted image is superior for detection of early degeneration of cartilage.

Cholecystogastric Fistula and the Transmigration of the Gallstone / 대한소화기내시경학회지

The internal biliary fistula between the gallbladder or bile duct and intestinal tract is a rare disease. Because symptoms and signs of biliary fistula are not specific, these patients are commonly investigated with computed tomography, endoscopic retrograde cholangiopancreatography (ERCP) and barium study. Among them, a cholecystogastric fistula is a very rare type of biliary fistula. We recently experienced a case of cholecystogastric fistula and transmigration of the gallstone to the stomach. A 53-year-old woman was transferred with the impression of gallbladder cancer. On evaluating the cause of right upper abdominal pain and nausea, we confirmed the cholecystogastric fistula with gastroscopy, upper GI series and ERCP. Cholecystectomy and the repair of the fistula was done.

PTBD Spiral CT Cholangiography: Utility in Patients with Extrahepatic Biliary Obstruction

PURPOSE: The purpose of this study is to assess the utility of PTBD spiral CT cholangiography, after infusion of contrast media through a PTBD tube, for evaluation of a biliary lesion after emergency PTBD due to severe jaundice. MATERIALS AND METHODS: Forty patients with emergency PTBD due to extrahepatic biliary obstruction were transferred to our clinic and prospectively studied. The causes of obstruction were 17 extrahepatic cholangiocarcinomas (including three Klatskin's tumors), seven pancreatic head carcinomas, six calculous diseases of the common bile duct, six periampullary lesions, two ampulla of Vater carcinomas, one gall bladder carcinoma with invasion of the common hepatic duct, and one cholangitis. Diagnosis was on the basis of pathologic, radiologic, and clinical findings. Pre-contrast CT scanning was performed. After the infusion of contrast media (iothalamate : normal saline=1:10) through a PTBD tube, spiral CT scans were obtained. After IV infusion of contrast media (Ultravist, 100cc), early- and delayed-phase spiral CT scans were obtained at 45 and 210 seconds, respectively, with an interscan interval of 5mm. 3-D CT cholangiograms were then reconstituted. Spiral CT without infusion of contrast media through a PTBD tube and PTBD spiral CT cholangiography were performed in 14 cases. The level of extrahepatic biliary obstruction was categorized as either upper, middle, or lower third. In 21 surgically confirmed cases, we evaluated the accuracy with which the level and cause of obstruction was determined; levels and causes during surgery and by as seen on PTBD cholaniography were compared. RESULTS: The levels of obstruction diagnosed on PTBD spiral CT cholangiography and on 3-D CT cholangiography corresponded in all cases to the levels during surgery and on PTBD cholangiography [upper third (n=7), middle third (n=12), lower third (n=21)], and the level diagnosed on spiral CT without infusion of contrast media through a PTBD tube corresponded to the level during surgery in ten of 14 cases. The cause of obstruction diagnosed on PTBD spiral CT cholangiography corresponded to pathologic findings in 19 of 21 cases. In 15 cases, 3-D CT cholangiography was diagnostically helpful. CONCLUSION: PTBD spiral CT cholangiography is a useful diagnostic method for determining the level and cause of biliary obstruction.

Contrast Enhanced Two-Phase Spiral CT of Urinary Bladder

PURPOSE: To determine optimal scan time for the early phase of two-phase spiral CT and to evaluate its usefulness in the detection and assessment of extension of urinary bladder lesions. MATERIALS AND METHODS: In four normal adults, we performed dynamic scanning and obtained time-density curves for internal and external iliac arteries and veins, and the wall of the urinary bladder. Sixty patients with 68 lesions of the urinary bladder or prostate underwent precontrast and two-phase spiral CT scanning. After injection of 100ml of noninonic contrast material, images for the early and delayed phases were obtained at 60 seconds and 5 minutes, respectively. We measured CT H.U. of the wall, the lesion, and lumen of urinary bladder as seen on axial scanning, in each image in which the lesion was best shown. For the detection of bladder lesions and assessment of their extension, precontrast, early-, and delayed phase images were compared. RESULTS: Dynamic study of normal adults showed maximum enhancement of bladder wall between 60 and 100 seconds. The difference of CT H.U. between bladder wall and the lesion was greatest in the early phase. The best detection rate (98.5%) was seen during this phase, and for the detection of bladder lesion, this same phase was superior or equal (66/68,97.1%) to the delayed phase. The precontrast image was also superior or equal (31/68,45.6%) to that of the delayed phase. For the assessment of extension of bladder lesion, the early phase was superior (36/68,52.9%) to the delayed phase, and precontrast image was superior (1/68, 1.5%) to that of the delayed phase. For determining the stage of bladder cancer, the early phase was most accurate if the stages was below B2 or D, while for stage C, the delayed phase was most accurate. CONCLUSION: In two-phase spiral CT scanning, we consider the optimal time for the early phase to be between 60 and 100 seconds after injection of contrast material. For the detection and assessment of extension of urinary bladder lesion, the early phase was superior to the late phase, and for evaluation of the ureter, the delayed phase was useful. The precontrast image was inferior to that of the delayed phase. We suggest that for the detection and assessment of extension of urinary bladder lesion without scanning of the precontrast image, two-phase spiral CT is reliable.

Quantitative CT of Lung in Healthy Koreans :Evaluation with PULMO-CT

PURPOSE: Spirometric gating quantitative CT, PULMO-CT, is an objective method for the measurement of pulmonary parenchymal attenuation at a constant level of inspiration. In order to obtain a normal value for quantitative CT of the lung, the authors therefore used PULMO-CT to evalvate the lung density of healthy koreans with different respiratiory status. MATERIALS AND METHODS: Twenty healthy Korean volunteers, 18 men and 2 women, ranging in age from 24 to 27 years and with normal chest radiography, were evaluated using the PULMO-CT option of Somatom Plus(Siemens, Erlangen, Germany). Spirometric gating HRCT images, at levels of 50% and 20% of vital capacity, were obtained at the level of the tracheal carina and at 5cm above and below this point. The images were analyzed by semiautomatic programs and the results were evaluated using the Student t-test. RESULTS: The mean attenuation value of lung parenchyma at 50% of vital capacity was -791HU27.1 and at 20% was -700HU+/-42.9. The difference in lung attenuation was 91HU and was statistically significant(p<0.001). The for 58% of participants, the highest reading for of lung attenuation at 50% of vital capacity was between -899HU and -800HU, and for 20.3% of participants, this reading was between -799HU and -700HU. At 20% of vital capacity, the largest proportion of participants(43.8%) had a reading of between -799HU and -700HU; the reading of 35.2% was higher than -699HU. CONCLUSION: Respiratory status significantly affects the quantitative accessment of pulmonary parenchyma; in order to determine, during quantitative HRCT, the parameters of a pathologic condition, lung parenchyma of differing respiratory status must be evaluated.