Submental Ectopic Thyroid in a Patient with an Orthotopic Thyroid Gland.

Ectopic thyroid is a rare clinical disease, with the majority of the patient presented with hypo-functional thyroid tissue and absence of orthotopic thyroid gland. During embryogenesis, the thyroid gland descends from the foramen cecum to its normal position located below the larynx and hyoid bone, anterior to the 2nd, 3rd, and 4th tracheal cartilaginous rings. Any defect that occurs during this period will result in ectopic thyroid. Hence, ectopic thyroid is usually found along the course of the thyroglossal duct, laterally in submandibular glands and even in distant places such as mediastinum or very rarely in sub-diaphragmatic organs. However, the presence of an orthotoptic thyroid may lead some difficulties in the diagnosis of this disease; hence, fine-needle aspiration is recommended to avoid unnecessary operation provided the patient is asymptomatic.

Unenhanced multidetector computed tomography findings in acute central pulmonary embolism.

BACKGROUND: Computed tomography pulmonary angiography (CTPA) is the gold standard for the diagnosis of pulmonary embolism (PE). However, contrast is contraindicated in some patients. The purpose of this study was to determine the diagnostic accuracy of unenhanced multidetector CT (MDCT) for diagnosis of central PE using CTPA as the gold standard. METHODS: The records of patients with suspected PE seen between 2010 and 2013 were retrospectively reviewed. Inclusion criteria were an acute, central PE confirmed by CTPA and non-enhanced MDCT before contrast injection. Patients with a PE ruled out by CTPA served as a control group. MDCT findings studied were high-attenuation emboli in pulmonary artery (PA), main PA dilatation > 33.2 mm, and peripheral wedge-shaped consolidation. Receiver operating characteristic (ROC) analysis was used to determine the sensitivity and specificity of unenhanced MDCT to detect PE. Wells score of all patients were calculated using data extracted from medical records prior to imaging analysis. RESULTS: Thirty-two patients with a PE confirmed by CTPA and 32 with a PE ruled out by CTPA were included. Among the three main MDCT findings, high-attenuation emboli in the PA showed best diagnostic performance (Sensitivity 72.9%; Specificity 100%), followed by main PA dilatation > 33.2 mm (sensitivity 46.9%; specificity 90.6%), and peripheral wedge-shaped consolidation (sensitivity 43.8%; specificity 78.1%). Given any one or more positive findings on unenhanced MDCT, the sensitivity was 96.9% and specificity was 71.9% for a diagnosis of PE in patients. The area under the curve (AUC) of a composite measure of unenhanced MDCT findings (0.909) was significantly higher than that of the Wells score (0.688), indicating unenhanced MDCT was reliable for detecting PE than Wells score. CONCLUSIONS: Unenhanced MDCT is an alternative for the diagnosis of acute central PE when CTPA is not available.

Gadoxetic acid-enhanced magnetic resonance imaging can predict the pathologic stage of solitary hepatocellular carcinoma.

BACKGROUND: Although important for determining long-term outcome, pathologic stage of hepatocellular carcinoma (HCC) is difficult to predict before surgery. Current state-of-the-art magnetic resonance imaging (MRI) using gadoxetic acid provides many imaging features that could potentially be used to classify single HCC as pT1 or pT2. AIM: To determine which gadoxetic acid-enhanced MRI (EOB-MRI) findings predict pathologic stage T2 in patients with solitary HCC (cT1). METHODS: Pre-operative EOB-MRI findings were reviewed in a retrospective cohort of patients with solitary HCC. The following imaging features were examined: Hyperintensity in unenhanced T2-weighted images, hypointensity in unenhanced T1-weighted images, arterial enhancement, corona enhancement, washout appearance, capsular appearance, hypointensity in the tumor tissue during the hepatobiliary (HB) phase, peritumoral hypointensity in the HB phase, hypointense rim in the HB phase, intratumoral fat, hyperintensity on diffusion-weighted imaging, hypointensity on apparent diffusion coefficient map, mosaic appearance, nodule-in-nodule appearance, and the margin (smooth or irregular). Surgical pathology was used as the reference method for tumor staging. Univariate and multivariate analyses were performed to identify predictors of microvascular invasion or satellite nodules. RESULTS: There were 39 (34.2%; 39 of 114) and 75 (65.8%; 75 of 114) pathological stage T2 and T1 HCCs, respectively. Large tumor size (≥ 2.3 cm) and two MRI findings, i.e., corona enhancement [odds ratio = 2.67; 95% confidence interval: 1.101-6.480] and peritumoral hypointensity in HB phase images (odds ratio = 2.203; 95% confidence interval: 0.961-5.049) were associated with high risk of pT2 HCC. The positive likelihood ratio was 6.25 (95% confidence interval: 1.788-21.845), and sensitivity of EOB-MRI for detecting pT2 HCC was 86.2% when two or three of these MRI features were present. Small tumor size and hypointense rim in the HB phase were regarded as benign features. Small HCCs with hypointense rim but not associated with aggressive features were mostly pT1 lesions (specificity, 100%). CONCLUSION: Imaging features on EOB-MRI could potentially be used to predict the pathologic stage of solitary HCC (cT1) as pT1 or pT2.

A comparison of pyelography and various reconstructions of multidetector helical computed tomography urography images for diagnosing urinary obstruction.

Radiologists and urologists require practical and helpful image reconstructions for diagnosing urinary obstruction. We performed different types of imaging and reconstruction, then used a self-designed urinary obstruction-specific questionnaire to evaluate the diagnostic outcome of them. Our results suggested that two-dimensional (2D) axial computed tomography (CT) is clinically superior to retrograde pyelography or antegrade pyelography, and to other modes of image reconstruction that are often used for diagnosing urinary obstruction.

An unusual appearance of renal epithelioid angiomyolipoma.

Epithelioid angiomyolipoma is a recently described rare variant of renal angiomyolipoma. It can occur in patients with or without tuberous sclerosis. We report the imaging findings of a case of epithelioid angiomyolipoma that showed the presence of fatty tissue undifferentiated from the typical angiomyolipoma at the beginning. After partial nephrectomy, tumour recurrence occurred two years later, presenting as completely solid tumours with no adipose tissue, and with invasion into the psoas muscle and left adrenal gland. Differentiation of this tumour from renal cell carcinoma is difficult. Both the radiologist and surgeon should be aware of the existence of this tumour and its potentially malignant behaviour.

CT-guided transthoracic cutting needle biopsy of intrathoracic lesions: comparison between coaxial and single needle technique.

PURPOSE: To evaluate the complication rates and diagnostic accuracy of two different CT-guided transthoracic cutting needle biopsy techniques: coaxial method and single needle method. METHODS: This study involved 198 consecutive subjects with 198 intrathoracic lesions. The first 98 consecutive subjects received a single needle cutting technique and the next 100 consecutive subjects received a coaxial technique. Both groups were compared in relation the diagnostic accuracy and complication rates. RESULTS: No significant difference was found between the two groups concerning patient characteristics, lesions and procedure variables. There was a borderline statistical difference in the incidence of pneumothorax at within 24-h post biopsy between patients in the single needle group (5%) and the coaxial group (13%) (P=0.053). Little difference was found in the pneumothorax rate at immediately post biopsy between the two groups, which was 28% in the single needle group and 31% in the coaxial group. There was no significant difference in the hemoptysis rate between the two groups, which was 9.2% in the single needle group and 11% in the coaxial group. Both techniques yielded an overall diagnostic accuracy of 98% for malignant lesions with similar sensitivity (single needle: 96.9% vs. coaxial: 96.4%) and specificity (single needle: 100% vs. coaxial: 100%). CONCLUSION: There is little difference in the pneumothorax rates and bleeding complications between patients who either received a single needle or a coaxial transthoracic cutting biopsy. Both techniques produce an overall diagnostic accuracy of 98% for malignant lesions.

Computed tomography appearance of ovarian fibrothecomas with and without torsion.

BACKGROUND: Fibrothecomas are the most common solid ovarian tumors and may undergo torsion. Early diagnosis of these tumors is important in order to allow prompt surgical treatment. PURPOSE: To describe the features of ovarian fibrothecoma on computed tomography (CT) and to determine the possibility of detecting tumor torsion in this kind of tumor. MATERIAL AND METHODS: The CT images of 11 patients with ovarian fibrothecomas in the past 8 years at our hospital were retrospectively reviewed. The CT attenuation values of each tumor were measured in both non-enhanced and enhanced scans. The size and degree of enhancement were evaluated and correlated with tumor torsion. All cases were pathologically proven. RESULTS: Three kinds of tumor pattern were found: 1) homogeneous tumor with significant enhancement containing scattered, low-attenuated regions after contrast injection; 2) heterogeneous tumor with mild enhancement after contrast injection; and 3) low-attenuated soft-tissue mass with no obvious enhancement after contrast injection. CONCLUSION: Fibrothecomas usually appear as a homogeneous solid tumor with varying degrees of enhancement. Calcification may be present and, as these tumors enlarge, myxoid or cystic degeneration may occur, resulting in a heterogeneous pattern. The larger the tumor, the greater is the chance of torsion. Lack of tumor enhancement is the most reliable sign for detection of ovarian torsion and should facilitate prompt surgical intervention to remove damaged tissue.

Adjusting mammography--audit recommendations in a lower-incidence Taiwanese population.

RATIONALE AND OBJECTIVES: Medical auditing of screening mammography is crucial to improving the quality of breast cancer care. Audit methodology and recommendations are well documented in the ACR's Breast Imaging Reporting and Data System (BI-RADS). However, when screening a population with a lower incidence rate of breast cancer, performance recommendations should be adjusted for a better fit. MATERIALS AND METHODS: On the basis of known lower breast cancer incidence rates in Taiwan compared with the BI-RADS study populations, the authors investigated a proposed calculation method to adjust the recommendations accordingly. A medical audit of 8,249 consecutive digital mammographic screening examinations was completed. All examinations were done by a hospital-based breast imaging department in Taiwan. Imaging interpretation and medical auditing followed the BI-RADS standards. The results were then compared with those of previous studies as well as the proposed recommendations. RESULTS: Two of the BI-RADS medical auditing recommendations were adjusted for the Taiwanese population. They were the positive predictive value (PPV) of the initial screening mammographic examination (PPV1) (changed from 5%-10% to 1.7%-3.4%) and cancer detection rate (changed from 2-10 per 1,000 to 0.7-3.4 per 1,000). In the medical auditing results, there were 89 biopsies, with 22 breast malignancies detected. PPV1 was 3.1%, PPV2 was 16.2%, and PPV3 was 24.7%. The cancer detection rate was 2.7 per 1,000 screens, with minimal cancer of 50%, node negative cancer of 71.4%, and a recall rate of 8.5%. CONCLUSION: The medical auditing results of this study are consistent with the authors' proposed adjustments to the BI-RADS recommendations for the Taiwanese population. The calculation methods would be generally applicable to other countries or populations to generate their own recommendations for screening mammography.

Sonographic appearance of angiolymphoid hyperplasia with eosinophilia in the upper arm.

Angiolymphoid hyperplasia with eosinophilia is an uncommon benign condition characterized by cutaneous nodules involving primarily the head and neck regions of young adults. We report thecase of a 49-year-old woman with such a lesion in the arm. Sonographically, the lesion exhibited a hypoechoic rim and an echogenic central portion. On color Doppler imaging, the central portion was markedly vascular.

Clinical significance of poor CT enhancement of the thickened small-bowel wall in patients with acute abdominal pain.

OBJECTIVE: Our purpose was to compare clinical outcomes in patients with acute abdominal pain and inner-layer enhancement of a thickened small-bowel wall, as shown on CT, with outcomes in similar patients without such enhancement. MATERIALS AND METHODS: We retrospectively studied outcomes in 126 patients with acute abdominal pain and small-bowel wall thickening on CT: 84 with inner-layer enhancement and 42 without this enhancement. We compared the surgical, small-bowel resection, small-bowel necrosis, and mortality rates between the two groups using the chi-square test. RESULTS: Among the 42 patients without inner-layer enhancement, 32 (76%) underwent an operation, 27 (64%) received segmental small-bowel resection, 26 (62%) had small-bowel necrosis, and seven (17%) died. All of these proportions were significantly higher (p < 0.01) than the corresponding rates-34 (40%), nine (11%), five (6%), and two (2%), respectively-in the 84 patients with inner-layer enhancement. All 31 patients with necrotic small bowel had pathologic evidence of ischemic necrosis involving the mucosa. CONCLUSION: Among patients with acute abdominal pain, those whose CT scans did not show inner-layer enhancement of a thickened small-bowel wall were more prone to undergo surgery and small-bowel resection and were more likely to have small-bowel necrosis than those with such enhancement. Poor inner-layer enhancement on CT might be consistent with sloughed or necrotic mucosa, as observed on pathology.

Malignant mesothelioma of the tunica vaginalis testis: unusual sonographic appearance.

Malignant mesothelioma of the tunica vaginalis testis is a rare and aggressive neoplasm. It is similar to malignant mesothelioma of the peritoneum, usually associated with asbestos exposure. We present an unusual case in which the tumor was a mix of a hypoechoic solid nodule and a cystic component with low-level internal echoes.

Leiomyoma arising from the tunica albuginea of the testis: sonographic findings.

Leiomyomas are benign neoplasms that may arise from any structure or organ containing smooth muscle. The majority of genitourinary leimyomas are found in the renal capsule, but this tumor has also been reported in the epididymis, spermatic cord, and tunica albuginea. Sonography is the imaging modality of choice for evaluating intrascrotal pathology, but the sonographic appearance of leiomyomas arising from the tunica albuginea have rarely been reported. We report a case of such a leiomyoma that was diagnosed sonographically.

Prenatal diagnosis of congenital mesoblastic nephroma in mid-second trimester by sonography and magnetic resonance imaging.

Although congenital mesoblastic nephroma (CMN) is a rare benign congenital renal tumor, it is the most common solid renal tumor in the newborn period. The most common presentation of congenital mesoblastic nephroma is polyhydramnios, and only one case with prenatal fetal hydrops has been previously reported. Prenatal diagnosis of CMN has previously been made on the basis of the findings of sonography in the third trimester, and magnetic resonance imaging (MRI)-based diagnosis has been reported recently. Here we report a case of prenatally diagnosed classical type CMN diagnosed at 22 + 3 weeks of gestation based on the findings of sonography and magnetic resonance imaging. The characteristic imaging findings in this case were fetal hydrops and polyhydramnios. To our knowledge, this is the youngest reported gestational age for prenatal diagnosis of CMN and it is the second case of CMN associated with fetal hydrops detected prenatally.