Feasibility Study of Synthetic Diffusion-Weighted MRIin Patients with Breast Cancer in Comparison withConventional Diffusion-Weighted MRI

Objective@#To investigate the clinical feasibility of synthetic diffusion-weighted imaging (sDWI) at different b-values in patientswith breast cancer by assessing the diagnostic image quality and the quantitative measurements compared with conventionaldiffusion-weighted imaging (cDWI). @*Materials and Methods@#Fifty patients with breast cancer were assessed using cDWI at b-values of 800 and 1500 s/mm2 (cDWI800and cDWI1500) and sDWI at b-values of 1000 and 1500 s/mm2 (sDWI1000 and sDWI1500). Qualitative analysis (normal glandulartissue suppression, overall image quality, and lesion conspicuity) was performed using a 4-point Likert-scale for all DWI setsand the cancer detection rate (CDR) was calculated. We also evaluated cancer-to-parenchyma contrast ratios for each DWI setin 45 patients with the lesion identified on any of the DWI sets. Statistical comparisons were performed using Friedman test,one-way analysis of variance, and Cochran’s Q test. @*Results@#All parameters of qualitative analysis, cancer-to-parenchyma contrast ratios, and CDR increased with increasingb-values, regardless of the type of imaging (synthetic or conventional) (p< 0.001). Additionally, sDWI1500 provided better lesionconspicuity than cDWI1500 (3.52 ± 0.92 vs. 3.39 ± 0.90, p< 0.05). Although cDWI1500 showed better normal glandular tissuesuppression and overall image quality than sDWI1500 (3.66 ± 0.78 and 3.73 ± 0.62 vs. 3.32 ± 0.90 and 3.35 ± 0.81, respectively;p< 0.05), there was no significant difference in their CDR (90.0%). Cancer-to-parenchyma contrast ratios were greater insDWI1500 than in cDWI1500 (0.63 ± 0.17 vs. 0.55 ± 0.18, p< 0.001). @*Conclusion@#sDWI1500 can be feasible for evaluating breast cancers in clinical practice. It provides higher tumor conspicuity,better cancer-to-parenchyma contrast ratio, and comparable CDR when compared with cDWI1500.

Apparent Sparganosis Presenting as a Palpable Neck Mass: A Case Report and Review of Literature

Sparganosis is an uncommon human parasitic infection caused by plerocercoid cysts of the genus Spirometra. Sparganosis of the neck is a rare condition, thus making it difficult to diagnose. It is often initially misdiagnosed as a lymphadenopathy or a soft tissue tumor. Herein, we describe a rare case of apparent sparganosis presenting as a palpable mass in the left neck of a 53-year-old female patient. Imaging studies played a key role in the diagnosis. In this case report, we emphasize that sparganosis should be considered in the differential diagnosis of a palpable superficial mass. We also stress the importance of meticulous radiological review in the context of appropriate clinical suspicion.

Solitary intraventricular hemorrhage without subarachnoid hemorrhage due to aneurysmal rupture: a case report

The presence of primary intraventricular hemorrhage (IVH) without vascular lesion is very rare. We experienced solitary IVH without subarachnoid hemorrhage due to aneurysmal rupture in a 58-year-old man treated with coil embolization, which contributed to his good prognosis. After 33 days of hospitalization, he had mild right hemiplegic symptoms remaining, and he was transferred to a rehabilitation institute for further treatment. In cases of primary IVH, computed tomography angiography seems worthwhile for making a differential diagnosis, although the possibility of IVH due to cerebral aneurysmal rupture is very low. Endovascular intervention is a good option for diagnosis and treatment.

Möbius Syndrome Demonstrated by the High-Resolution MR Imaging: a Case Report and Review of Literature

Möbius syndrome is a rare congenital condition, characterized by abducens and facial nerve palsy, resulting in limitation of lateral gaze movement and facial diplegia. However, to our knowledge, there have been few studies on evaluation of cranial nerves, on MR imaging in Möbius syndrome. Herein, we describe a rare case of Möbius syndrome representing limitation of lateral gaze, and weakness of facial expression, since the neonatal period. In this case, high-resolution MR imaging played a key role in diagnosing Möbius syndrome, by direct visualization of corresponding cranial nerves abnormalities.

Ultrasonographic Interval Changes in Solid Thyroid Nodules after Ultrasonography-Guided Fine-Needle Aspiration

OBJECTIVE: None of the previous studies have investigated the interval change in ultrasonography (US) features of solid thyroid nodules (STNs) after US-guided fine-needle aspiration (US-FNA). This study aimed to assess the prevalence and characteristics of US interval changes in STNs after US-FNA. MATERIALS AND METHODS: This study included 257 STNs in 257 patients in whom thyroid US and initial US-FNA had been performed by two radiologists from January 2015 to June 2015. One of the radiologists performed single needle puncture in all cases, whereas the other radiologist used double or triple needle punctures. Follow-up US examinations were performed after 12.0 ± 6.0 months. We evaluated the prevalence and characteristics of post-FNA US interval changes through a retrospective analysis. In addition, multiple factors were correlated with post-FNA US interval changes. RESULTS: The number of needle punctures was one (n = 91), two (n = 163), and three (n = 3). Of the 257 STNs (mean diameter, 11.9 mm) in 257 patients, 35 (13.6%) showed an interval change in US features on follow-up US. Among them, 17 STNs (6.6%) showed newly developed malignant US features, including hypoechogenicity (n = 5), microcalcifications (n = 2), a spiculated margin (n = 4), hypoechogenicity with a spiculated margin (n = 5), and microcalcifications with non-parallel orientation (n = 1). Between patients who showed presence and absence of US interval changes, there were no significant differences in patient age, sex, nodule size, dichotomization, and location, Korean Thyroid Imaging Reporting and Data System categorization after FNA, practitioners involved, number of needle punctures, cytological findings, and interval between FNA and US follow-up (p > 0.05). CONCLUSION: Awareness of US interval changes after US-FNA of STNs may be helpful for the management of STNs.

Fine-Needle Aspiration Cytology of Carcinosarcoma in the Salivary Gland: An Extremely Rare Case Report

Carcinosarcoma of the salivary gland is an extremely rare tumor that is composed of both malignant epithelial and mesenchymal components. Diagnosing carcinosarcoma with fine-needle aspiration cytology is challenging because of its overlapping cytomorphologic characteristics with other high-grade malignant salivary gland tumors. Among the many features, including pleomorphic oncocytoid epithelial components, necrotic background, and mitoses, recognizing the singly scattered atypical spindle cells is most essential in carcinosarcoma. We present a case of a 66-year-old male patient with characteristic features of carcinosarcoma, who was successfully treated by wide local excision and subsequent radiation therapy.

Korean Thyroid Imaging Reporting and Data System features of follicular thyroid adenoma and carcinoma: a single-center study

PURPOSE: This study aimed to assess the diagnostic efficacy of Korean Thyroid Imaging Reporting and Data System (K-TIRADS) features for distinguishing follicular thyroid adenoma (FTA) from follicular thyroid carcinoma (FTC). METHODS: From January 2013 to July 2016, 46 follicular neoplasms in 45 patients who underwent preoperative thyroid ultrasonography (US) and thyroid surgery were included. The US features of each thyroid nodule were retrospectively evaluated by a single radiologist using a picture archiving and communication system. The diagnostic indices of K-TIRADS for follicular neoplasms were calculated according to whether K-TIRADS category 4 lesions were excluded or classified as benign or malignant. RESULTS: Of the 46 follicular neoplasms (mean size, 3.1±1.6 cm), 37 were FTAs (mean size, 3.1±1.7 cm) and nine were FTCs (mean size, 3.0±1.5 cm). A statistically significant difference was found between FTAs and FTCs regarding the margin (P=0.035), while no significant differences were observed in the composition, echogenicity, shape, orientation, calcification, or vascularity of the lesions (P<0.05). The FTAs belonged to K-TIRADS categories 3 (n=22) and 4 (n=15), while the FTCs belonged to K-TIRADS categories 3 (n=4), 4 (n=4), and 5 (n=1). However, there was no statistically significant difference in the distribution of K-TIRADS categories between FTAs and FTCs (P=0.184). CONCLUSION: K-TIRADS features were not helpful for distinguishing FTA from FTC, although follicular neoplasms showed a high prevalence of K-TIRADS categories 3 and 4.

Splenial Lesions of the Corpus Callosum: Disease Spectrum and MRI Findings

The corpus callosum (CC) is the largest white matter structure in the brain, consisting of more than 200–250 million axons that provide a large connection mainly between homologous cerebral cortical areas in mirror image sites. The posterior end of the CC is the thickest part, which is called the splenium. Various diseases including congenital to acquired lesions including congenital anomalies, traumatic lesions, ischemic diseases, tumors, metabolic, toxic, degenerative, and demyelinating diseases, can involve the splenium of the CC and their clinical symptoms and signs are also variable. Therefore, knowledge of the disease entities and the imaging findings of lesions involving the splenium is valuable in clinical practice. MR imaging is useful for the detection and differential diagnosis of splenial lesions of the CC. In this study, we classify the disease entities and describe imaging findings of lesions involving the splenium of the CC based on our experiences and a review of the literature.

MR Findings of Seizure-Related Cerebral Cortical Lesions during Periictal Period

PURPOSE: This study investigated the MRI, MR angiography (MRA) and MR perfusion findings of seizure-related cerebral cortical lesions during the periictal period. MATERIALS AND METHODS: From a retrospective review of the institutional database between 2011 and 2014, a total of 21 patients were included in this study. Two radiologists assessed periictal MRI, including MRA and MR perfusion, in patients with seizure-related cortical lesions. The parameters examined include: location of cortical abnormality, multiplicity of the affected cortical region, cerebral vascular dilatation, perfusion abnormality and other parenchymal lesions. RESULTS: All patients showed T2 hyperintense cerebral cortical lesions with accompanying diffusion restriction, either unilateral (18/21, 85.7%) or bilateral (3/21, 14.3%). Of the 21 patients enrolled, 10 (47.6%) had concurrent T2 hyperintense thalamic lesions, and 10 (47.6%) showed hippocampal involvement. Of the 17 patients (81%) who underwent MRA, 13 (76.5%) showed vascular dilatation with increased flow signal in the cerebral arteries of the affected cortical regions. On MR perfusion, all 5 patients showed cortical hyperperfusion, corresponding to the region of cortical abnormalities. CONCLUSION: Seizure-related cerebral cortical lesions are characterized by T2 and diffusion hyperintensities, with corresponding cerebral hyperperfusion and vascular dilatation. These findings can be helpful for making an accurate diagnosis in patients with seizure.

MR Findings of Seizure-Related Cerebral Cortical Lesions during Periictal Period

PURPOSE: This study investigated the MRI, MR angiography (MRA) and MR perfusion findings of seizure-related cerebral cortical lesions during the periictal period. MATERIALS AND METHODS: From a retrospective review of the institutional database between 2011 and 2014, a total of 21 patients were included in this study. Two radiologists assessed periictal MRI, including MRA and MR perfusion, in patients with seizure-related cortical lesions. The parameters examined include: location of cortical abnormality, multiplicity of the affected cortical region, cerebral vascular dilatation, perfusion abnormality and other parenchymal lesions. RESULTS: All patients showed T2 hyperintense cerebral cortical lesions with accompanying diffusion restriction, either unilateral (18/21, 85.7%) or bilateral (3/21, 14.3%). Of the 21 patients enrolled, 10 (47.6%) had concurrent T2 hyperintense thalamic lesions, and 10 (47.6%) showed hippocampal involvement. Of the 17 patients (81%) who underwent MRA, 13 (76.5%) showed vascular dilatation with increased flow signal in the cerebral arteries of the affected cortical regions. On MR perfusion, all 5 patients showed cortical hyperperfusion, corresponding to the region of cortical abnormalities. CONCLUSION: Seizure-related cerebral cortical lesions are characterized by T2 and diffusion hyperintensities, with corresponding cerebral hyperperfusion and vascular dilatation. These findings can be helpful for making an accurate diagnosis in patients with seizure.

Skull Base Dermoid Cyst in the Right Infratemporal Fossa Diagnosed Using the Dixon Technique: a Case Report and Review of Literature

Dermoid cysts are benign congenital tumors composed of keratinizing squamous epithelium and dermal derivatives. They account for less than 1% of all intracranial tumors and are rarely exhibited at the base of the skull. To the best of our knowledge, only one case report has presented computed tomography and conventional T1-weighted magnetic resonance (MR) findings that revealed an infratemporal dermoid cyst. In the present study, we report an unusual case of a dermoid cyst in the right infratemporal fossa, which was incidentally detected by MR imaging with the Dixon technique. This article also highlights the importance of meticulous radiological review and the usefulness of the Dixon technique in everyday clinical practice.

Skull Base Dermoid Cyst in the Right Infratemporal Fossa Diagnosed Using the Dixon Technique: a Case Report and Review of Literature

Dermoid cysts are benign congenital tumors composed of keratinizing squamous epithelium and dermal derivatives. They account for less than 1% of all intracranial tumors and are rarely exhibited at the base of the skull. To the best of our knowledge, only one case report has presented computed tomography and conventional T1-weighted magnetic resonance (MR) findings that revealed an infratemporal dermoid cyst. In the present study, we report an unusual case of a dermoid cyst in the right infratemporal fossa, which was incidentally detected by MR imaging with the Dixon technique. This article also highlights the importance of meticulous radiological review and the usefulness of the Dixon technique in everyday clinical practice.

Susceptibility Vessel Sign for the Detection of Hyperacute MCA Occlusion: Evaluation with Susceptibility-weighted MR Imaging

PURPOSE: Susceptibility vessel sign (SVS) on gradient echo image, which is caused by MR signal loss due to arterial thrombosis, has been reported in acute middle cerebral artery (MCA) infarction. However, the reported sensitivity and diagnostic accuracy of SVS have been variable. Susceptibility-weighted imaging (SWI) is a newly developed MR sequence. Recent studies have found that SWI may be useful in the field of cerebrovascular diseases, especially for detecting the presence of prominent veins, microbleeds and the SVS. The purpose of this study was to evaluate the diagnostic values of SWI for the detection of hyperacute MCA occlusion. MATERIALS AND METHODS: Sixty-nine patients (37 males, 32 females; 46-89 years old [mean, 69.1]) with acute stroke involving the MCA territory underwent MR imaging within 6 hours after the symptom onset. MR examination included T2, FLAIR (fluid-attenuated inversion recovery), DWI, SWI, PWI (perfusion-weighted imaging), contrast-enhanced MR angiography (MRA) and contrast-enhanced T1. Of these patients, 28 patients also underwent digital subtraction angiography (DSA) within 2 hours after MR examination. Presence or absence of SVS on SWI was assessed without knowledge of clinical, DSA and other MR imaging findings. RESULTS: On MRA or DSA, 34 patients (49.3%) showed MCA occlusion. Of these patients, SVS was detected in 30 (88.2%) on SWI. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of SWI were 88.2%, 97.1%, 96.8%, 89.5% and 92.8%, respectively. CONCLUSION: SWI was sensitive, specific and accurate for the detection of hyperacute MCA occlusion.

Nontraumatic Intracystic Hemorrhage of Arachnoid Cyst: CT and MR Findings

Arachnoid cysts (AC) are intraarachnoidal cerebrospinal fluid collections, and account for 1% of all intracranial space-occupying lesions. Intracystic hemorrhage of the AC can occur spontaneously, but this is an extremely rare event. Herein, we present a case of hemorrhagic AC in a nontraumatic patient in the left middle cranial fossa. We also performed relevant literature review on this disease.

Is Diffusion-Weighted MRI Useful for Differentiation of Small Non-Necrotic Cervical Lymph Nodes in Patients with Head and Neck Malignancies?

OBJECTIVE: To evaluate the usefulness of measuring the apparent diffusion coefficient (ADC) in diffusion-weighted magnetic resonance imaging to distinguish benign from small, non-necrotic metastatic cervical lymph nodes in patients with head and neck cancers. MATERIALS AND METHODS: Twenty-six consecutive patients with head and neck cancer underwent diffusion-weighted imaging (b value, 0 and 800 s/mm2) preoperatively between January 2009 and December 2010. Two readers independently measured the ADC values of each cervical lymph node with a minimum-axial diameter of > or = 5 mm but < 11 mm using manually drawn regions of interest. Necrotic lymph nodes were excluded. Mean ADC values were compared between benign and metastatic lymph nodes after correlating the pathology. RESULTS: A total of 116 lymph nodes (91 benign and 25 metastatic) from 25 patients were included. Metastatic lymph nodes (mean +/- standard deviation [SD], 7.4 +/- 1.6 mm) were larger than benign lymph nodes (mean +/- SD, 6.6 +/- 1.4 mm) (p = 0.018). Mean ADC values for reader 1 were 1.17 +/- 0.31 x 10-3 mm2/s for benign and 1.25 +/- 0.76 x 10-3 mm2/s for metastatic lymph nodes. Mean ADC values for reader 2 were 1.21 +/- 0.46 x 10-3 mm2/s for benign and 1.14 +/- 0.34 x 10-3 mm2/s for metastatic lymph nodes. Mean ADC values between benign and metastatic lymph nodes were not significantly different (p = 0.594 for reader 1, 0.463 for reader 2). CONCLUSION: Measuring mean ADC does not allow differentiating benign from metastatic cervical lymph nodes in patients with head and neck cancer and non-necrotic, small lymph nodes.

Angioarchitecture of Spinal Dural Arteriovenous Fistula - Evaluation with 3D Rotational Angiography / 신경중재치료의학

PURPOSE: The complex angioarchitecture of spinal dural arteriovenous fistulas (SDAVFs) sometimes preclude angiographic analyses or superselective procedures. Therefore, the effectiveness of 3 dimensional rotational angiography (3DRA) as a detailed imaging technique for SDAVFs was evaluated. MATERIALS AND METHODS: Of 57 patients with spinal vascular malformations, recent 13 SDAVF patients underwent 3DRA. The advantage of 3DRA compared to digital subtraction angiography (DSA) in imaging SDAVF was assessed. Angioarchitecture of SDAVF was focused on location, number, and course of feeders and draining vein. Appropriate angled views were also selected to reveal the segmental artery and feeders. RESULTS: 3DRA technique provided additional information for imaging evaluation of SDAVFs compared to DSA; the presence of multiple feeders, including their transdural portions, as well as their courses. The contralaterally angled anterior-oblique-caudal (spider) view showed the radicular feeder by separating the intercostal artery and the dorsal muscular branch. The bottom-to-up (tunnel) view was useful for revealing the location (ventral vs. dorsal) including sharp medial turn of the dural feeder. The dual mode, which displays both vessels and bones, revealed the course of the feeders and the fistula related to the spinal bony column. CONCLUSION: Because spinal vasculature overlaps in DSA, 3DRA revealed additional information for evaluations of the number and transdural course of fistular feeders in SDAVFs, and it offers working angles to obtain appropriate views.

Mercury exposure from dental amalgam: a 6 month follow-up / 대한구강보건학회지

OBJECTIVES: Dental amalgam is a widely used filling material for oral cavity. The released mercury vapor from amalgam could have systemic adverse effects potentially. The purpose of this study is to evaluate the relationship between dental amalgam and urinary mercury levels in children during a 6-month timespan. METHODS: A total of 525 elementary school children participated in this study. Oral examination was carried out from one dentist. Urine samples collected at baseline and at 6 month were analyzed for mercury and creatinine excretion. Additionally, general characteristics of subjects were surveyed by a questionnaire. The statistical analysis was performed using the SPSS 18.0. RESULTS: Greater amalgam surfaces were associated to higher urinary mercury levels; this tendency was similar at the 6-month observation after the correct baseline data. In the multivariable model, urinary mercury excretion was only associated with amalgam surfaces positively. CONCLUSIONS: Even a small amount of mercury uptake from dental amalgam has been associated to increase the mercury concentration of urine.

The Use of Protection Device in Landmark-wire Technique of Symptomatic Subclavian Artery Occlusion with Combined Approach via Trans-femoral vs. Trans-brachial Arteries: Technical note / 신경중재치료의학

PURPOSE: Since we reported about a landmark technique to reopen an occluded subclavian artery, we have faced difficulty in using protection devices in the vertebral artery to protect against thromboembolism from the reversed steal phenomenon after angioplasty and stenting. Therefore, we are presenting an optimal solution in using a protection device while recanalizing the occluded subclavian artery. MATERIALS AND METHODS: Among 21 cases of stenting for subclavian artery steno-occlusion, we applied the landmark technique at the opposite end of an occluded segment in 4 patients and used a protection device in two patients. Because the embolic protection device was placed in the vertebral artery via the brachial artery, optimal angioplasty and stenting via the brachial route were limited. Therefore, angioplasty via the trans-brachial approach was needed to be followed by stenting through a trans-femoral approach. We estimated the safe and optimal steps for placement and retrieval of the protection devices in addition to stenting. RESULTS: The procedure was safely performed when a stent was introduced via the femoral artery and a protection device was used via the brachial artery. However, in cases when a guidewire wasn't passed via the transfemoral route, simultaneous use of two systems via the brachial route could cause friction of devices or trapping of protection devices in a stent. When a protection device was trapped in a deployed stent, we retrieved the protection device with a 4F angiocatheter by selectively rotating the catheter tip. To avoid such procedural difficulty, we recommend using a transbrachial angioplasty followed by trans-femoral stenting while placing the protection device in the vertebral artery via the trans-brachial route. CONCLUSION: If a guidewire is not passed through using a trans-femoral approach while performing the landmark technique, changing the stenting route from brachial to the femoral artery can be useful after securing the lumen in the occluded subclavian artery after angioplasty via the brachial artery.

Direct Percutaneous Alcohol Sclerotherapy for Venous Malformations of Head and Neck Region without Fluoroscopic Guidance: Technical Consideration and Outcome / 신경중재치료의학

PURPOSE: Alcohol is not used directly to the vascular lesion without mixing with the contrast agent because alcohol itself cannot be seen on the fluoroscopy. Since we have used alcohol for the venous malformations in the head and neck area, we realized that alcohol can be safely and effectively used without using fluoroscopy. We present the method of direct sclerotherapy using absolute alcohol without using fluoroscopy. MATERIALS AND METHODS: After obtaining and carefully analyzing direct puncture venogram, we used this technique in 22 patients who underwent alcohol sclerotherapy. Because fluoroscopy was not used during alcohol injection, the angiotable can be placed outside of C-arm so that alcohol was comfortably injected without any obstacle around the patients. Venogram can also be obtained between the injections to detect whether there is any dangerous venous outflow drainage such as the superior ophthalmic vein to the cavernous sinus. To control the venous outflow, local compression to the draining vein was applied. The result and complication such as skin necrosis, infection, and nerve injury were evaluated during mean follow-up period of 13 months (range, 1-63 months). RESULTS: The frequency of sclerotherapy was one in 16 and 2-5 in 6 patients. The volume of alcohol used per treatment session ranged from 2 to 18 mL (mean, 8.5 mL). There was the minimum change in 1 (4.5%), moderately decreased lesion in 12 (54.5%), and markedly decreased lesion in 9 (41%) patients. The patients did not reveal any complications during 12.9 months follow-up period. CONCLUSION: Direct puncture alcohol sclerotherapy without using fluoroscopy can be a safe and effective technique for treating venous malformation of the head and neck areas. In addition, the procedure can be performed in the comfortable position because biplane fluoroscopy would not be necessary.

Bilateral Extraocular Muscle Metastasis of Nasal Rhabdomyosarcoma Mimicking a Thyroid Associated Orbitopathy: A Case Report

Metastases to the orbit usually affect the intraorbital fat and bone than the extraocular muscles. Metastasis to the extracoular muscles commonly occurs unilaterally, and diffuse enlargement of the bilateral extraocular muscles due to metastasis is extremely rare. In this report, we will describe a case of diffuse metastasis to the bilateral extraocular muscles from nasal rhabdomyosarcoma masquerading as thyroid associated orbitopathy. We will also discuss about the MR imaging findings helpful for differential diagnosis from thyroid associated orbitopathy.