A hidden pathophysiology of endolymphatic hydrops: case report of a patient with spontaneous intracranial hypotension presenting with sudden sensorineural hearing loss with vertigo.

Spontaneous intracranial hypotension (SIH) is characterized by decreased cerebrospinal fluid (CSF) volume due to leakage through the dural membrane. We present the case of a patient with SIH manifested by fluctuating low-frequency hearing loss, tinnitus, and vertigo. In this patient, endolymphatic hydrops in the cochlea and saccule were visualized by means of a special sequence of inner ear magnetic resonance imaging scans, with a gadolinium-based contrast agent administered intravenously. Endolymphatic hydrops is a potential underlying pathophysiology of SIH-associated hearing impairment. We hypothesize that SIH may be a rare cause of endolymphatic hydrops.

Imaging characteristics of slow-growing soft tissue chondroma of the tongue: A case report.

INTRODUCTION: Extraskeletal soft tissue chondroma (STC) is a rare benign tumor. Soft-tissue chondromas rarely occur in the oral cavity. In this study, we aimed to confirm a slow-growing tongue mass using magnetic resonance imaging. PATIENT CONCERNS: A 60-year-old woman presented with a painful, slow-growing tongue mass that had persisted for 17 years. Intraoral examination revealed a pedunculated mass covered with mucosa on the right side of her tongue. DIAGNOSIS: CT and MRI revealed a lobulated heterogeneously enhancing mass without calcification. Compared with previous images obtained 17 years prior, the mass presented slow growth, more prominent enhancement, and lobulated contour. Histopathological examination confirmed the presence of STC. INTERVENTIONS: Excision of the mass surrounding normal tissue was performed under general anesthesia. OUTCOMES: During 1-year follow-up period, no recurrence was observed. CONCLUSIONS: In this study, STC lesions were slow-growing, and changed from weakly homogeneous enhancement and clean margins to markedly heterogeneous enhancement and lobulated margins over time.

Fulminant Disseminating Fatal Granulomatous Amebic Encephalitis: The First Case Report in an Immunocompetent Patient in South Korea.

Central nervous system infections caused by free-living amoeba are very rare, but often fatal. The typical image findings of amebic meningoencephalitis are non-specific, showing ring-like enhancement. We report the first case of fulminant disseminating fatal granulomatous amebic encephalitis caused by Balamuthia mandrillaris in an immunocompetent patient in South Korea. Our case exhibited two interesting features: one was the unusual clinical course and the other was additional image findings. Magnetic resonance imaging revealed a rim-enhancing lesion with intralesional blooming dark signal intensity on susceptibility weighted imaging and low signal intensity on diffusion weighted images and on apparent diffusion coefficient maps. Differential diagnosis was started from a tumor or non-tumorous lesion, and diagnosis was difficult due to the rarity of the disease. Following the clinical and diagnostic courses of our case, we recommend inspecting image findings of granulomatous amebic encephalitis for early diagnosis.

Pulmonary toxicities of molecular targeted antineoplastic agents: a single-center 10-year experience.

BACKGROUND/AIMS: A better understanding of cancer cell biology has led to the discovery and development of several new targeted agents for cancer. These drugs are widely used in cancer treatment and have good toxicity profiles. However, some patients are extremely sensitive to these drugs and can develop severe toxicities. Among the toxicities, pulmonary complications are infrequent with most targeted therapies. This study aimed to identify the radiologic pulmonary complications in various targeted therapies and to analyze the characteristics of patients with pulmonary toxicity. METHODS: We retrospectively reviewed the medical records and chest image findings of 644 patients who were treated with targeted antineoplastic agents at Soonchunhyang University Hospital between May 2005 and September 2014. RESULTS: Of these 644 patients, 90 (14.0%) developed pulmonary complications as noted on chest computed tomography. Among these patients, 15 (2.3%) developed drug-related pulmonary toxicities. Treatment with targeted agents was discontinued in all patients, while 11 patients were simultaneously treated with glucocorticoids. Three patients died of drug-related pulmonary toxicity. CONCLUSION: During targeted therapy, clinicians should assess for pulmonary toxicities and symptoms that occur with dyspnea. If drug-induced pulmonary toxicities are suspected, imaging studies should be performed immediately, and the possibility of variable radiological patterns should be considered. Discontinuing the use of implicated causative agents and treatment with glucocorticoids resulted in an improvement in both symptoms and imaging findings, but some patients still experienced fatal pulmonary toxicities.

Susceptibility-Weighted Imaging as a Distinctive Imaging Technique for Providing Complementary Information for Precise Diagnosis of Neurologic Disorder.

Various sequences have been developed for MRI to aid in the radiologic diagnosis. Among the various MR sequences, susceptibility-weighted imaging (SWI) is a high-spatial-resolution, three-dimensional gradient-echo MR sequence, which is very sensitive in detecting deoxyhemoglobin, ferritin, hemosiderin, and bone minerals through local magnetic field distortion. In this regard, SWI has been used for the diagnosis and treatment of various neurologic disorders, and the improved image quality has enabled to acquire more useful information for radiologists. Here, we explain the principle of various signals on SWI arising in neurological disorders and provide a retrospective review of many cases of clinically or pathologically proven disease or components with distinctive imaging features of various neurological diseases. Additionally, we outline a short and condensed overview of principles of SWI in relation to neurological disorders and describe various cases with characteristic imaging features on SWI. There are many different types diseases involving the brain parenchyma, and they have distinct SWI features. SWI is an effective imaging tool that provides complementary information for the diagnosis of various diseases.

Differentiation of postoperative changes and residual tumors in dynamic contrast-enhanced sella MRI after transsphenoidal resection of pituitary adenoma.

To establish magnetic resonance imaging (MRI) features that differentiate residual tumors from postoperative surgical changes following the transsphenoidal approach of a pituitary adenoma.We analyzed residual enhancements at the tumor bed in 52 patients who underwent dynamic contrast-enhanced sella MRI within 48 hours after surgery and at 6 to 28 months. Patients were divided into 2 groups defined by either peripheral or nodular enhancement patterns. For each group, we measured the maximum thickness of the residual enhancing portion and compared differences in the residual tumor and postoperative changes.Among the tumors examined in the 52 patients, 19 residual tumors showed nodular (n = 16) and peripheral (n = 3) enhancement patterns, and 33 postoperative changes showed nodular (n = 3) and peripheral (n = 30) enhancement patterns. The mean residual tumor thickness was 7.1 mm (range, 2.9-16.8 mm) and 1.9 mm (range, 1.0-7.4 mm) in the postoperative change. Receiver operating characteristic curve analysis revealed that a 3.9-mm thickness was associated with 89% sensitivity, 97% specificity, and 94% accuracy for diagnosis of residual tumor.On immediate postoperative MRI, residual enhancement with greater than 3.9-mm thickness and nodular pattern suggest residual pituitary adenoma tumor.

Dual-energy CT with virtual monochromatic images and metal artifact reduction software for reducing metallic dental artifacts.

Background Metallic dental prostheses may degrade image quality on head and neck computed tomography (CT). However, there is little information available on the use of dual-energy CT (DECT) and metal artifact reduction software (MARS) in the head and neck regions to reduce metallic dental artifacts. Purpose To assess the usefulness of DECT with virtual monochromatic imaging and MARS to reduce metallic dental artifacts. Material and Methods DECT was performed using fast kilovoltage (kV)-switching between 80-kV and 140-kV in 20 patients with metallic dental prostheses. CT data were reconstructed with and without MARS, and with synthesized monochromatic energy in the range of 40-140-kiloelectron volt (keV). For quantitative analysis, the artifact index of the tongue, buccal, and parotid areas was calculated for each scan. For qualitative analysis, two radiologists evaluated 70-keV and 100-keV images with and without MARS for tongue, buccal, parotid areas, and metallic denture. The locations and characteristics of the MARS-related artifacts, if any, were also recorded. Results DECT with MARS markedly reduced metallic dental artifacts and improved image quality in the buccal area ( P < 0.001) and the tongue ( P < 0.001), but not in the parotid area. The margin and internal architecture of the metallic dentures were more clearly delineated with MARS ( P < 0.001) and in the higher-energy images than in the lower-energy images ( P = 0.042). MARS-related artifacts most commonly occurred in the deep center of the neck. Conclusion DECT with MARS can reduce metallic dental artifacts and improve delineation of the metallic prosthesis and periprosthetic region.

CT, MRI, and 18F-FDG PET/CT findings of malignant peripheral nerve sheath tumor of the head and neck.

Background Malignant peripheral nerve sheath tumor (MPNST) is a highly malignant tumor and rarely occurs in the head and neck. Purpose To describe the imaging features of MPNST of the head and neck. Material and Methods We retrospectively analyzed computed tomography (CT; n = 14), magnetic resonance imaging (MRI; n = 16), and 18F-FDG PET/CT (n = 5) imaging features of 18 MPNSTs of the head and neck in 17 patients. Special attention was paid to determine the nerve of origin from which the tumor might have arisen. Results All lesions were well-defined (n = 3) or ill-defined (n = 15) masses (mean, 6.1 cm). Lesions were at various locations but most commonly the neck (n = 8), followed by the intracranial cavity (n = 3), paranasal sinus (n = 2), and orbit (n = 2). The nerve of origin was inferred for 11 lesions: seven in the neck, two in the orbit, one in the cerebellopontine angle, and one on the parietal scalp. Attenuation, signal intensity, and enhancement pattern of the lesions on CT and MRI were non-specific. Necrosis/hemorrhage/cystic change within the lesion was considered to be present on images in 13 and bone change in nine. On 18F-FDG PET/CT images, all five lesions demonstrated various hypermetabolic foci with maximum standard uptake value (SUVmax) from 3.2 to 14.6 (mean, 7.16 ± 4.57). Conclusion MPNSTs can arise from various locations in the head and neck. Though non-specific, a mass with an ill-defined margin along the presumed course of the cranial nerves may aid the diagnosis of MPSNT in the head and neck.

Prognostic CT findings of diplopia after surgical repair of pure orbital blowout fracture.

PURPOSE: Diplopia is a common sequela of blowout fracture even after proper surgical management. We investigated the prognostic factors of diplopia after surgery of pure blowout fracture. MATERIALS AND METHODS: We retrospectively reviewed CT images of 181 patients with pure orbital blowout fracture who underwent at least six months of postoperative follow-up. We evaluated the following CT factors: (1) fracture site (orbital floor, medial wall of the orbit, or both), (2) fracture type (closed flap, open flap), (3) fracture size, (4) volume of herniated orbital soft tissue, (5) ratio of volume of herniated orbital soft tissue to fracture size, (6) number of points of contact between extraocular muscle (EOM) and bony edge, (7) presence of EOM thickening, (8) EOM swelling ratio, (9) presence of displacement of EOM, (10) presence of deformity of EOM, (11) presence of tenting of EOM, and (12) presence of entrapment of EOM. The associations between diplopia at six months after surgical repair and various risk factors were analyzed using logistic regression models for univariable and multivariable analyses. RESULTS: EOM tenting and deformity and ratio of volume of herniated orbital soft tissue to fracture size were found to be statistically significant risk factors of diplopia at six months after repair on univariable analysis (all P < 0.05). Patients who showed EOM tenting or deformity on CT images had 5.22 and 10.85 times greater probability of diplopia after surgery, respectively (P-value, <0.001 and 0.026; 95% confidence interval of odds ratio, 2.071-13.174 and 1.323-88.915, respectively). On the other hand, ratio of volume of herniated orbital soft tissue to fracture size was not significant on multivariable analysis (P = 0.472). CONCLUSION: The prognosis of patients was predicted by CT evaluation. Patients who have tenting or deformity of EOM on CT scan are more likely to have postoperative diplopia.

Diagnostic role and correlation with staging systems of PIVKA-II compared with AFP.

BACKGROUND/AIMS: Alpha-fetoprotein (AFP) and protein-induced by vitamin K absence or antagonist (PIVKA-II) are representative markers of hepatocellular carcinoma (HCC). The aim of this study was to evaluate the usefulness of PIVKA-II when compared with AFP for detecting HCC. Furthermore, we evaluated the correlation between PIVKA-II and HCC staging. METHODOLOGY: One hundred patients with liver cirrhosis (LC) and 227 with HCC were analyzed between January 2004 and March 2006. To compare the diagnostic value of PIVKA-II and AFP, Receiver operating characteristic curve was constructed. RESULTS: The area under the curve indicated a better accuracy for PIVKA-II than AFP in diagnosis of HCC (0.829 vs. 0.712). The positive rates of PIVKA-II in patients with tumor size larger than 5 cm, 3-5 cm, and less than 3 cm were higher than that of AFP (96%, 83%, 74% vs. 65%, 57%, 48%, respectively). In addition, there seems to be correlation between PIVKA-II and staging systems, Tumor Node Metastasis, Cancer of the Liver Italian Program score and Japan Integrated Staging score (p<0.05). CONCLUSIONS: The results of this study show that a PIVKA-II is a useful marker for detecting HCC, especially in small HCC and may have correlations with known staging systems.

Thymosin Alpha-1 in Combination with Pegylated Interferon and Ribavirin in Chronic Hepatitis C Patients Who have Failed to Prior Pegylated Interferon and Ribavirin Treatment.

Combination therapy with inteferon-alpha and ribavirin is an approved therapy for patients with chronic hepatitis C. However, even with the use of pegylated interferon, response rates are still poor in many difficult-to-treat groups, especially with genotype 1 and high viral loads. Retreatment of these patients remains challenging. Newer combinations are being investigated to optimize chances of attaining a sustained response in these groups. Thymosin alpha 1 is a polypeptide with immunomodulatory properties that has been suggested to increase response rates in patients with chronic hepatitis C. Herein, we describe two cases of retreatment patients with chronic hepatitis C who have failed prior pegylated interferon and ribavirin therapy. They received triple combination therapies of thymosin alpha 1, pegylated interferon and ribavirin and achieved sustained virological responses. These cases support that thymosin-alpha 1 may increase the efficacy of pegylated interferon plus ribavirin in the treatment of non-responders to previous combination therapy.