Mucoepidermoid carcinoma of the breast: A case report and literature review focused on radiological findings.

RATIONALE: Mucoepidermoid carcinoma (MEC) of the breast is a rare entity, with an estimated incidence of only 0.2% to 0.3% of all primary breast tumors. The radiological features of breast MEC have scarcely been investigated mainly because of its rarity. In this article, we present a case of breast MEC diagnosed at our hospital and review the literature, focusing on radiological findings and radiologic-pathologic correlations that could improve clinical management of this entity. To the best of our knowledge, our study is the first review of the literature that focuses on the radiological features of breast MEC. PATIENT CONCERNS: A 47-year-old premenopausal woman presented with a painless palpable mass in the right breast. DIAGNOSIS: Mammography and ultrasonography revealed a mass with suspicious malignant features, which was categorized as Breast Imaging Reporting and Data System category 4c. A 14-gauge core-needle biopsy revealed an intermediate-grade MEC of the breast. The patient underwent breast magnetic resonance imaging and chest computed tomography for preoperative evaluation. Postoperative histopathological examination confirmed a diagnosis of intermediate-grade MEC. The clinical staging was T2N0M0. INTERVENTIONS: The patient underwent breast-conserving surgery, adjuvant chemotherapy, radiotherapy, and hormonal therapy. OUTCOMES: No evidence of recurrence has been reported over 37 months. LESSONS: The imaging characteristics of breast MEC were variable, and there were no specific radiological features for diagnosis. The presence of cystic components on radiological imaging is likely to be an indicator of a low-grade tumor and better prognosis, although the number of reported cases is limited.

Monitoring Radiation Doses during Diagnostic and Therapeutic Neurointerventional Procedures: Multicenter Study for Establishment of Reference Levels.

PURPOSE: To assess patient radiation doses during diagnostic and therapeutic neurointerventional procedures from multiple centers and propose dose reference level (RL). MATERIALS AND METHODS: Consecutive neurointerventional procedures, performed in 22 hospitals from December 2020 to June 2021, were retrospectively studied. We collected data from a sample of 429 diagnostic and 731 therapeutic procedures. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time (FT), and total number of image frames (NI) were obtained. RL were calculated as the 3rd quartiles of the distribution. RESULTS: Analysis of 1160 procedures from 22 hospitals confirmed the large variability in patient dose for similar procedures. RLs in terms of DAP, CAK, FT, and NI were 101.6 Gy·cm2, 711.3 mGy, 13.3 minutes, and 637 frames for cerebral angiography, 199.9 Gy·cm2, 3,458.7 mGy, 57.3 minutes, and 1,000 frames for aneurysm coiling, 225.1 Gy·cm2, 1,590 mGy, 44.7 minutes, and 800 frames for stroke thrombolysis, 412.3 Gy·cm2, 4,447.8 mGy, 99.3 minutes, and 1,621.3 frames for arteriovenous malformation (AVM) embolization, respectively. For all procedures, the results were comparable to most of those already published. Statistical analysis showed male and presence of procedural complications were significant factors in aneurysmal coiling. Male, number of passages, and procedural combined technique were significant factors in stroke thrombolysis. In AVM embolization, a significantly higher radiation dose was found in the definitive endovascular cure group. CONCLUSION: Various RLs introduced in this study promote the optimization of patient doses in diagnostic and therapeutic interventional neuroradiology procedures. Proposed 3rd quartile DAP (Gy·cm2) values were 101.6 for diagnostic cerebral angiography, 199.9 for aneurysm coiling, 225.1 for stroke thrombolysis, and 412.3 for AVM embolization. Continual evolution of practices and technologies requires regular updates of RLs.

A rare case of thyroglossal duct cyst extending to the sublingual space: A case report.

RATIONALE: Thyroglossal duct cyst (TGDC) is the most common congenital anomaly of midline neck masses. A thyroglossal duct cyst is especially difficult to diagnose and is treated differently when it appears in the sublingual area. Here, we report a rare case of TGDC extending to the sublingual space. PATIENT CONCERNS: A 42-year-old female presented with a history of neck swelling in the submental region. DIAGNOSIS: The final pathologic diagnosis was a TGDC. INTERVENTIONS: Sistrunk operation was performed. OUTCOMES: Recurrence of the disease has not been seen for the past year. LESSION: Clinical awareness of the thyroglossal duct cyst in the sublingual area or on the oral floor area is important for an accurate diagnosis and the appropriated management.

Adverse effect of smoking on cross-sectional area of small pulmonary vessel and arterial stiffness in healthy smokers without COPD.

INTRODUCTION: Because it induces systemic inflammation, smoking is a risk factor of atherosclerosis and pulmonary hypertension. The brachial-ankle pulse wave velocity (baPWV) and cross-sectional area (CSA) of small pulmonary vessels can be useful markers to assess early changes of arterial stiffness and pulmonary vascular alteration in smokers. OBJECTIVES: This study aimed to explore association between the CSA of small pulmonary vessel and arterial stiffness in healthy male smokers. METHODS: We enrolled 90 male non-smokers and 90 male smokers (age: 51.5 ± 9.7 years and 52.1 ± 7.9 years, respectively). All subjects underwent chest computed tomography (CT), pulmonary function test and baPWV measurement. We evaluated the total CSAs less than 5 mm2 using ImageJ software and divided by the total lung area (%CSA<5). We compared the association between baPWV and %CSA<5 in two groups as well as correlations among the amount of smoking, baPWV and %CSA<5. Multiple linear regression analysis using %CSA<5 as the dependent variable was also performed. RESULTS: The mean baPWV and mean %CSA<5 were significantly different between the smokers and non-smokers. The pack-years was significantly correlated with %CSA<5 (r = -0.631, P < 0.001) and baPWV (r = 0.534, P < 0.001) in smokers. In multiple linear regression analysis, age, pack-years, FEV1 /FVC and baPWV were associated with %CSA<5, regardless of body mass index, blood pressure and heart rate. CONCLUSIONS: There is a dose-response relationship between cigarette smoking and the CSA of small pulmonary vessels and arterial stiffness, respectively. Arterial stiffness, age, pack-years and mild airflow impairment are independent predictors of small pulmonary vascular destruction in smokers.

Preoperative localization of the sensorimotor cortex and measurement of tumor perfusion in a single acquisition using ASL technique.

Resting state fMRI (rs-fMRI) using arterial spin labelling (ASL) technique was performed for the preoperative localization of the sensorimotor cortex in a patient with lymphoma and the results were compared to those of task-based (tb) and rs-fMRI studies using blood oxygenation level-dependent (BOLD) sequence. Rs-fMRI using ASL showed similar results in the regions of the sensorimotor network to those of tb- and rs-fMRI fMRI using BOLD. ASL technique has a potential in clinical practice because all of brain perfusion imaging, cerebral blood flow measurement, and rs-fMRI study can be performed at a single acquisition.

Intracranial Venous Reflux Caused by Occlusion of the Brachiocephalic Vein Mimicking Dural Arteriovenous Fistula.

BACKGROUND: High signal intensity of cerebral venous sinuses on magnetic resonance angiography (MRA) indicates high flow of shunt from arterial blood, suggesting dural arteriovenous fistula (dAVF). Herein, we describe the cases of 2 patients with intracranial venous reflux caused by brachiocephalic vein occlusion (BVO) mimicking dAVF on MRA. CASE DESCRIPTION: Case 1 was a 71-year-old woman who had received arteriovenous graft (AVG) surgery for hemodialysis and presented with headache. MRA depicted high signal intensities in the left jugular vein, inferior petrosal sinus, and ophthalmic vein suggesting intracranial dAVF. However, cerebral angiography revealed intracranial venous reflux through the jugular vein caused by BVO. After balloon angioplasty with stenting for BVO, normal venous drainage was restored and her symptoms resolved. Case 2 was a 62-year-old woman who had received AVG for hemodialysis and was hospitalized due to seizure. MRA revealed high signal intensities of the left transverse-sigmoid sinus and jugular vein, and it was suspected that they were associated with BVO. She did not receive immediate intervention because of her septic condition. The patient ultimately died of fatal intracranial hemorrhage and subarachnoid hemorrhage. CONCLUSIONS: Central venous occlusion may occur in patients with end-stage renal disease who are receiving AVG for hemodialysis. Intracranial venous reflux resulting from BVO can induce various neurologic disorders including intracranial venous hypertension or hemorrhage. Prompt recognition and implementation of endovascular treatment can be beneficial in cases of symptomatic central venous occlusion.

Visual loss due to optic nerve infarction and central retinal artery occlusion after spine surgery in the prone position: A case report.

RATIONALE: Visual loss after spine surgery in the prone position is a serious complication. Several cases of central retinal artery occlusion with ophthalmoplegia after spine surgery have been reported in patients with ophthalmic arteries fed by the internal carotid artery (ICA) in a normal manner. PATIENT CONCERNS: A 74-year-old man developed visual loss after undergoing a spinal decompression and fusion operation in the prone position that lasted approximately 5 hours. DIAGNOSES: We detected an extremely rare case of visual loss due to optic nerve infarction and central retinal artery occlusion through fundoscopic examination, fluorescein angiogram, brain magnetic resonance imaging, and magnetic resonance angiography. The patient's visual loss may have been caused by compromised retrograde collateral circulation of the ophthalmic artery from branches of the external carotid artery in the presence of proximal ICA occlusion after a spinal operation in the prone position. INTERVENTIONS: To recover movement of the left extraocular muscles, the patient received intravenous injections of methylprednisolone for 3 days and then oral prednisolone for 6 days. OUTCOMES: Twenty days after the treatment, the motion of the left extraocular muscles was significantly improved. However, recovery from the left visual loss did not occur until 4 months after the operation. LESSONS: In high-risk patients with retrograde collateral circulation of the ophthalmic artery from the external carotid artery due to proximal ICA occlusion, various measures, including the use of a head fixator to provide a position completely free of direct compression of the head and face, should be considered to decrease the risk of postoperative visual loss.

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.

Differentiation of small intrahepatic mass-forming cholangiocarcinoma from small liver abscess by dual source dual-energy CT quantitative parameters.

PURPOSE: To investigate the use of dual source dual-energy CT (DECT) quantitative parameters compared with the use of conventional CT for differentiating small (≤3cm) intrahepatic mass-forming cholangiocarcinoma (IMCC) from small liver abscess (LA) during the portal venous phase (PVP). MATERIAL AND METHODS: In this institutional review board-approved, retrospective study, 64 patients with IMCCs and 52 patients with LAs who were imaged in PVP using dual-energy mode were included retrospectively. A radiologist drew circular regions of interest in the lesion on the virtual monochromatic images (VMI), color-coded iodine overlay images, and linear blending images with a linear blending ratio of 0.3 to obtain CT value, its standard deviation, slope (k) of spectral curve and normalized iodine concentration (NIC). Two radiologists assessed lesion type on the basis of qualitative CT imaging features. RESULTS: CT values on VMI at 50-130keV (20keV-interval), k, and NIC values were significantly higher in IMCCs than in LAs (p<0.0001). The best single parameter for differentiating IMCC from LA was CT value at 90keV, with sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 89.1%, 86.5%, 87.9%, 89.1%, and 86.5%, respectively. The best combination of parameters was CT value at 90keV, k, and NIC, with values of 87.5%, 84.6%, 83.6%, 87.5%, and 84.6%, respectively. Compared with CT value at linear blending images, CT value at 90keV showed greater sensitivity (89.1% vs 60.9%, p<0.0001) and similar specificity (86.5% vs 84.6%, p=1.0000), and combined CT value at 90keV, k, and NIC showed greater sensitivity (87.5% vs 60.9%, p<0.0001) and similar specificity (84.6% vs 84.6%, p=1.0000). Compared with qualitative analysis, CT value at 90keV showed greater sensitivity (89.1% vs 65.6%, p=0.0059) and specificity (86.5% vs 69.2%, p=0.0352), and combined CT value at 90keV, k, and NIC showed greater sensitivity (87.5% vs 65.6%, p=0.0094) and similar specificity (84.6% vs 69.2%, p >0.05). CONCLUSION: Quantitative analysis of dual source dual-energy CT quantitative parameters showed greater accuracy than quantitative and qualitative analyses of conventional CT for differentiating small IMCCs from small LAs on single PVP scan.

Patient Radiation Exposure During Diagnostic and Therapeutic Procedures for Intracranial Aneurysms: A Multicenter Study.

PURPOSE: To assess patient radiation doses during cerebral angiography and embolization of intracranial aneurysms across multi-centers and propose a diagnostic reference level (DRL). MATERIALS AND METHODS: We studied a sample of 490 diagnostic and 371 therapeutic procedures for intracranial aneurysms, which were performed at 23 hospitals in Korea in 2015. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time and total angiographic image frames were obtained and analyzed. RESULTS: Total mean DAP, CAK, fluoroscopy time, and total angiographic image frames were 106.2 ± 66.4 Gy-cm(2), 697.1 ± 473.7 mGy, 9.7 ± 6.5 minutes, 241.5 ± 116.6 frames for diagnostic procedures, 218.8 ± 164.3 Gy-cm(2), 3365.7 ± 2205.8 mGy, 51.5 ± 31.1 minutes, 443.5 ± 270.7 frames for therapeutic procedures, respectively. For diagnostic procedure, the third quartiles for DRLs were 144.2 Gy-cm(2) for DAP, 921.1 mGy for CAK, 12.2 minutes for fluoroscopy times and 286.5 for number of image frames, respectively. For therapeutic procedures, the third quartiles for DRLs were 271.0 Gy-cm(2) for DAP, 4471.3 mGy for CAK, 64.7 minutes for fluoroscopy times and 567.3 for number of image frames, respectively. On average, rotational angiography was used 1.5 ± 0.7 times/session (range, 0-4; n=490) for diagnostic procedures and 1.6 ± 1.2 times/session (range, 0-4; n=368) for therapeutic procedures, respectively. CONCLUSION: Radiation dose as measured by DAP, fluoroscopy time and image frames were lower in our patients compared to another study regarding cerebral angiography, and DAP was lower with fewer angiographic image frames for therapeutic procedures. Proposed DRLs can be used for quality assurance and patient safety in diagnostic and therapeutic procedures.

Initial factors affecting the clinical outcome after successful recanalization via MR-based mechanical thrombectomy in patients with acute ischemic stroke due to basilar artery occlusion.

BACKGROUND AND PURPOSE: To determine the initial factors, including patient characteristics, stroke etiology and severity, time factors, and imaging findings, that could affect the clinical outcome of patients with acute ischemic stroke (AIS) caused by basilar artery occlusion (BAO) where successful recanalization was achieved via mechanical thrombectomy. METHODS: Between March 2011 and December 2014, 35 patients with AIS caused by BAO received MRI/MR angiography-based mechanical thrombectomies, and recanalization was achieved with a Thrombolysis In Cerebral Infarction score of >2b. The patients were divided into a good outcome group (n=19), defined as those with a modified Rankin Scale (mRS) score of 0-2 at 3 months after stroke onset, and a poor outcome group (n=16), defined as a mRS score of 3-6. The differences between the groups were analyzed. RESULTS: Initial National Institutes of Health Stroke Scale (NIHSS) score (good vs poor: 17.9±8.9 vs 27.6±8.5, p=0.003), posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) based on initial diffusion-weighted images (DWI) (good vs poor: 7.8±1.6 vs 5.4±1.8, p=0.001), pc-ASPECTS based on contrast staining on the post-thrombectomy control CT (good vs poor: 9.2±1.5 vs 6.3±2.2, p<0.001), and presence of contrast staining in the brainstem on that CT (good vs poor: 15.8% vs 81.6%, p<0.001) were significantly different between the groups. CONCLUSIONS: Patients with AIS caused by BAO with a lower initial NIHSS score, fewer lesions on initial DWI, and less contrast staining on the post-thrombectomy control CT have higher probabilities of a good clinical outcome after successful recanalization via a mechanical thrombectomy.

Comparison of Solitaire thrombectomy and Penumbra suction thrombectomy in patients with acute ischemic stroke caused by basilar artery occlusion.

BACKGROUND AND PURPOSE: Acute ischemic stroke (AIS) caused by basilar artery occlusion (BAO) is a very severe neurological disease with a high mortality rate and poor clinical outcomes. In this study, we compared our experience of mechanical thrombectomy using the Solitaire stent (Solitaire thrombectomy) and manual aspiration thrombectomy using the Penumbra reperfusion catheter (Penumbra suction thrombectomy) in patients with AIS caused by BAO. MATERIALS AND METHODS: Between March 2011 and December 2011, 13 patients received Solitaire thrombectomy. In January 2012, the Korean Food and Drug Administration banned the use of the Solitaire stent as a thrombectomy device, and a further 18 patients received Penumbra suction thrombectomy until December 2013. We compared parameters between patients treated with each device. RESULTS: Successful recanalization rates (Thrombolysis in Cerebral Infarction (TICI) score ≥2b: 84.6% vs 100%, p=0.168) and clinical outcomes (judged by the modified Rankin Scale scores recorded at 3 months: 3.6±2.6 vs 3.2±2.6, p=0.726) were not significantly different between the two groups. However, complete recanalization rates (TICI score of 3: 23.1% vs 72.2%, p=0.015) and total procedure times (101.9±41.4 vs 62.3±34.8 min, p=0.044) were significantly higher, and shorter, respectively, in patients treated by Penumbra suction thrombectomy. CONCLUSIONS: The two thrombectomy devices were associated with similar recanalization rates and clinical outcomes in patients with AIS caused by BAO. However, Penumbra suction thrombectomy seemed to allow more rapid and complete recanalization than Solitaire thrombectomy.

Carotid stent infection: a rare but potentially fatal complication of carotid artery stenting.

Infections involving endovascular devices are rare and, to our knowledge, only three cases of infection with an inserted carotid stent have ever been reported. A 68-year-old man underwent carotid artery stenting (CAS) of the left proximal internal carotid artery. Two days after CAS the patient developed a high fever and investigation showed that the inserted carotid stent was infected. The infection could not be controlled despite adequate antibiotic therapy. Eventually a rupture of the carotid artery occurred and the patient underwent emergency resection of the left carotid bifurcation in addition to stent removal and reconstruction with a saphenous vein interposition graft. The patient recovered fully without any neurological sequelae.

Emergency carotid artery stenting in patients with acute ischemic stroke due to occlusion or stenosis of the proximal internal carotid artery: a single-center experience.

BACKGROUND: The feasibility, safety and effectiveness of emergency carotid artery stenting (eCAS) in patients with acute ischemic stroke (AIS) due to proximal internal carotid artery (ICA) stenosis or occlusion are still controversial. In this study we analyzed our experience with eCAS in patients with AIS. METHODS: Twenty-two eCAS procedures for proximal ICA stenosis or occlusion were performed in 22 patients at our institution between January 2011 and November 2013. The mean time from stroke symptom onset to presentation was 204 min (range 50-630 min) and the mean initial score on the National Institutes of Health Stroke Scale (NIHSS) was 12.55 (range 5-23). Ten patients had total occlusion of the proximal ICA and the remaining 12 patients had near total occlusion or severe stenosis (mean degree 90.7%, range 80-100%). Eleven patients also had tandem occlusion on the more distal intracranial arteries. RESULTS: Successful stent insertion was achieved in all patients and additional thrombectomy using a Solitaire stent or Penumbra aspiration catheter achieved a Thrombolysis In Cerebral Infarction grade of more than 2a in all patients with distal tandem occlusion. Procedure-related complications occurred in one patient (cerebral hyperperfusion syndrome) who recovered successfully. The mean NIHSS score at discharge was 3.55 (range 0-18). The mean modified Rankin Scale score at 3 months was 1 ± 1.67 (range 0-6). CONCLUSIONS: eCAS in patients with AIS due to proximal ICA stenosis or occlusion appears to be a technically feasible and effective method for achieving good clinical outcomes.

Upregulation of human mammaglobin reduces migration and invasion of breast cancer cells.

Little is known about the biological role of human mammaglobin (hMAM) that is considered as a promising marker for breast cancer. Here, we investigated hMAM's role related to migration and invasion of human breast cancer cells (hBCC). Compared to normal cells, hBCC have high MAM mRNA expression levels. Of the hBCC tested, MAM mRNA expression levels were higher in noninvasive than in invasive cells. Overexpression of hMAM in breast cancer cells decreased migration and invasion, whereas knockdown of hMAM increased both. Taken together, these results suggest that metastasis of hBCC could be controlled by hMAM expression levels.

Two-phase computed tomography study of warthin tumor of parotid gland: differentiation from other parotid gland tumors and its pathologic explanation.

OBJECTIVE: The objective of this study was to define the radiological characteristics of 2-phase computed tomography (CT) of parotid gland Warthin tumors (WTs) with a pathologic basis for these findings. METHODS: We prospectively enrolled 116 patients with parotid gland tumor who underwent preoperative 2-phase CT scans(scanning delays of 30 and 120 seconds). The attenuation changes and enhancement patterns were analyzed according to pathology. We also evaluated size-matched samples of WTs and pleomorphic adenoma by staining CD31, vascular endothelial growth factor-receptor 2, collagen IV, and smooth muscle actin. RESULTS: Computed tomography numbers in WTs were significantly higher than those in other tumors in early-phase scans and lower in delayed scans. Pathologically, CD31(+) blood vessel area was significantly higher in WTs than in pleomorphic adenomas. In addition, WTs had an extensive capillary network and many leaky blood vessels. CONCLUSIONS: The enhancement pattern of early fill-in and early washout is the typical finding of WTs on 2-phase CT scans, which may be attributed pathologically to abundant blood vessel and extensive capillary network.

A case of spontaneous spinal epidural hematoma mimicking a stroke.

INTRODUCTION: For intravenous (IV) thrombolytic therapies to be effective, a correct diagnosis of acute ischemic stroke must be made within 3 hours from the onset of symptoms, a relatively short window period. However, obtaining a diagnosis in the time frame is not easy; a wide variety of conditions mimic a stroke, including seizures, migraine, and even a spinal mass, and often these are diagnosed as acute ischemic stroke and receive thrombolytic therapy. CASE REPORT: A patient presented suffering progressive and fluctuating painful triparesis coupled with acute onset dissociated sensory loss. The patient complained of dysarthria and transient altered mentality at the onset of symptoms; therefore, we suspected an ischemic infarction of the brainstem and spinal cord accompanied by vertebral artery dissection. As the time at diagnosis was 2 hours 30 minutes after symptom onset, we started IV thrombolytic treatment using recombinant tissue plasminogen activator. Magnetic resonance imaging during the recombinant tissue plasminogen activator infusion revealed a spontaneous spinal epidural hematoma (SSEH) of the cervical and thoracic spine, leading the patient to undergo an emergency surgery. CONCLUSIONS: SSEH is an uncommon clinical condition, and a manifestation of SSEH with anterior spinal artery syndrome is also rare. Furthermore, an emergency operation after IV thrombolytic treatment is an extraordinary situation.

Diagnostic value of peritumoral minimum apparent diffusion coefficient for differentiation of glioblastoma multiforme from solitary metastatic lesions.

OBJECTIVE: In glioblastoma multiforme, the peritumoral region may be infiltrated with malignant cells in addition to vasogenic edema, whereas in a metastatic deposit, the peritumoral areas comprise predominantly vasogenic edema. The purpose of this study was to determine whether the minimum apparent diffusion coefficient (ADC) can be used to differentiate glioblastoma from solitary metastasis on the basis of cellularity levels in the enhancing tumor and in the peritumoral region. MATERIALS AND METHODS: Seventy-three patients underwent conventional MRI and diffusion-weighted imaging (DWI) before undergoing treatment. The minimum ADC was measured in the enhancing tumor, peritumoral region, and contralateral normal white matter. To determine whether there was a statistical difference between metastasis and glioblastoma, we analyzed patient age and sex, minimum ADC value, and ADC ratio of the two groups. A receiver operating characteristic (ROC) curve analysis was used to determine the cutoff value of the minimum ADC that had the best combination of sensitivity and specificity for distinguishing between glioblastoma and metastasis. RESULTS: The mean minimum ADC values and mean ADC ratios in the peritumoral regions of glioblastomas were significantly higher than those in metastases. However, the mean minimum ADC values and mean ADC ratios in enhancing tumors showed no statistically significant difference between the two groups. According to ROC curve analysis, a cutoff value of 1.302 × 10(-3) mm(2)/s for the minimum peritumoral ADC value generated the best combination of sensitivity (82.9%) and specificity (78.9%) for distinguishing between glioblastoma and metastasis. CONCLUSION: Although the characteristics of solitary metastasis and glioblastoma multiforme may be similar on conventional MRI, DWI can offer diagnostic information to distinguish between the tumors.

Role of ultrasonography in predicting malignancy in patients with thyroid nodules.

The use of ultrasonography (USG) has become an essential part of endocrine surgical practice. We evaluated the value of USG in predicting malignancy of thyroid nodules. The accuracy of USG in 857 patients who underwent fine-needle aspiration (FNA) with or without surgery was analyzed in a prospective setting. The diagnostic accuracy of USG was compared to that of FNA and of combined models in 153 operated patients. The malignancy-predicting value of USG in follicular neoplasms and its relation to nodule size were also investigated. Sensitivity, specificity, and overall accuracy (OA) of USG were 84.9%, 95.5%, and 93.7%, respectively. In operated patients, USG had accuracy comparable to that of FNA and combined models (sensitivity 93.3%, specificity 90.6%, OA 92.0%) regardless of nodule size but showed a significant rate of indeterminate results (29.4%). For follicular neoplasms, the sensitivity, specificity, and OA of USG were 100%, 95.4%, and 96.1%, respectively, with indeterminate results for three malignant nodules (42.8%). This acceptable malignancy-predicting value of USG in thyroid nodules supports the potential role of USG for predicting malignancy in selected patients with thyroid nodules. However, the high rate of indeterminate results precludes it from being a standard independent diagnostic method for the present time.

Effect of occupational manganese exposure on the central nervous system of welders: 1H magnetic resonance spectroscopy and MRI findings.

This study investigated the relationship between long-term occupational manganese (Mn) exposure on the regional Mn concentration in the brain, neuronal loss, and neurobehavioral effects on welders. 1H MRS of the basal ganglia (BG) was performed on 20 male welders and 10 age- and gender-matched, non-office, control workers in a shipyard to assess the metabolic change, and the N-acetylaspartate (NAA)/creatine (Cr), choline (Cho)/Cr and NAA/Cho ratios, by the level of Mn exposure. We also assessed the signal intensity of T1-weighted image of magnetic resonance imaging (MRI) on globus pallidus (GP) compared to that of the frontal white matter (pallidal index, PI). The welders had significantly higher signal intensity than the controls. PI showed a significant dose-response relationship with cumulative exposure index (CEI) (r=0.54, p=0.002). CEI and PI showed different relationships with NAA/Cr according to smoking status, and the correlation was evident only in non-smokers (r=-0.73 and -0.57, respectively). There were no significant differences between the welders and the controls in NAA/Cr, Cho/Cr, and NAA/Cho ratios obtained from BG. CEI was positively correlated with simple reaction time. PI was positively correlated with mean sway (MSWAY), sway area (SWAYA), and sway intensity (SWAYI), and negatively correlated with maximum frequency (MAXF). After categorizing the subjects into two groups according to NAA/Cr ratio level, the low NAA/Cr ratio group showed significantly lower score on digit span backward and significantly higher score on MSWAY, SWAYA and SWAYI in regression analysis than the high NAA/Cr ratio group. We speculated that the NAA/Cr ratio of MRS in BG seems to reflect the cumulative effect of Mn exposure on the human brain. Due to uneven distribution of smoking among the welders and the controls, in addition to the small number of subjects in our study, our findings are needed further studies with a larger number of subjects.