Hwa Seon Shin

US-guided transthoracic biopsy of peripheral lung lesions: pleural contact length influences diagnostic yield

Background Transthoracic biopsy of peripheral lung lesions under ultrasonography (US) guidance is a useful diagnostic technique. However, factors affecting diagnostic yield of US-guided transthoracic biopsy of peripheral lung lesions are not well established. Purpose To determine the factors that influence diagnostic yield of US-guided transthoracic biopsy in peripheral lung lesions. Material and Methods A total of 100 consecutive patients underwent US-guided percutaneous cutting biopsy of peripheral lung lesions from October 2007 to March 2009. After seven unconfirmed cases were excluded, 97 procedures in 93 consecutive patients were included in this study. The accuracy of the lung biopsies was assessed by comparing the biopsy results with the final diagnoses. We divided the cases into a correct group (true-positive and true-negative) and an incorrect group (false-positive, false-negative, and non-diagnostic results) and analyzed the differences in the lesions, procedures, and patient variables between the two groups. Results According to the final diagnoses, 56 cases (57.7%) were malignant and 41 cases (42.3%) were benign. An overall diagnostic accuracy of 91.8% was obtained. The median size of the lesions was 46.0 mm (interquartile range [IQR], 30.0–69.5 mm), and the median lesion-pleura contact arc length (LPCAL) was 31.0 mm (IQR, 18.0–51.0 mm). Multivariate logistic regression analysis showed that only LPCAL (odds ratio, 1.16; 95% CI, 1.04–1.30) was a significant predictor of a correct diagnosis. When we divided the lesions into those with LPCAL values >30 mm and LPCAL values ≤30 mm, the sensitivity (96.6% vs. 74.1%; P = 0.02) and the accuracy (98% vs. 85.4%; P = 0.03) were significantly higher in the group with larger LPCAL. Conclusion In US-guided transthoracic biopsy of peripheral lung lesions, the LPCAL of the lesions is an important factor for a correct diagnosis.

Mass and Fat Infiltration of Intercostal Muscles Measured by CT Histogram Analysis and Their Correlations with COPD Severity

RATIONALE AND OBJECTIVES Chronic obstructive pulmonary disease (COPD) is characterized by progressive respiratory function impairment and respiratory muscle dysfunction. We hypothesized that the mass and fat infiltration of respiratory muscles correlates with COPD severity and emphysema extent. MATERIALS AND METHODS Ninety-eight male patients with COPD underwent chest computed tomography (CT) and spirometry. The mass and fat infiltrations of intercostal and latissimus muscles were quantified as the cross-sectional area (CSA) and attenuation of these muscles using CT histogram analysis. Intercostal index and latissimus index were defined as intercostal CSAs and latissimus CSAs divided by body mass index. The emphysema extent was measured as the ratio of the emphysematous lung volume to the total lung volume using a density-mask technique. Pearson correlation analyses were performed to evaluate the relationships between these parameters. Multiple regression analysis was performed using forced expiratory volume in 1 second (FEV1) as the dependent parameter and the clinical and CT data as the independent parameters. RESULTS FEV1 was significantly correlated with intercostal index (r = 0.57), latissimus index (r = 0.34), intercostal attenuation (r = 0.62), and latissimus attenuation (r = 0.38). Emphysema extent was significantly correlated with intercostal index (r = -0.36) and intercostal attenuation (r = -0.50). Multiple regression analysis showed that FEV1 was predicted by intercostal attenuation (B = 0.40), intercostal CSA (B = 0.23), emphysema extent (B = -0.23), and age (B = -0.21, R(2) = 0.64, P < .001). CONCLUSIONS A decrease in intercostal mass and an increase in intercostal fat are associated with worsening of COPD severity.

Fish bone foreign bodies in the pharynx and upper esophagus: evaluation with 64-slice MDCT

Background Fish bone (FB) is one of the common causes of foreign body impaction in the pharynx and esophagus. Purpose To investigate the efficacy of 64-slice multidetector computed tomography (MDCT) for the evaluation of pharynx and upper esophageal FB foreign bodies. Material and Methods Sixty-six patients with suspected FB foreign body ingestion were examined by plain radiography (n = 40) and unenhanced MDCT (n = 66). We analyzed the presence, location, size, shape, and lying position of the foreign bodies. Results On MDCT, 46 foreign bodies were detected. Among them, 45 were confirmed by endoscopy. The sensitivity of MDCT for the detection of foreign bodies was 100%, which was superior to that of the plain radiography (51.7%). The location of the foreign bodies was most common in the upper esophagus (n = 22, 47.8%), followed by pharyngoesophageal junction (n = 10, 21.7%), transjunctional (n = 7, 15.2%), hypopharynx (n = 5, 10.9%), and oropharynx (n = 2, 4.3%). Their longest length was 5.3–40.1 mm (mean, 21.3 mm). Thirty-three FBs (71.7%) were linear and 13 (28.3%) were flat in shape. They showed transverse (n = 23, 50.0%), parallel (n = 13, 28.3%), and oblique positions (n = 10, 21.7%) to the long axis of the pharynx and esophagus, respectively. Conclusion MDCT is useful for the evaluation of the pharynx and upper esophageal FB foreign bodies.

Bone subtraction 3D CT venography for the evaluation of cerebral veins and venous sinuses: imaging techniques, normal variations, and pathologic findings.

OBJECTIVE Varying anatomic characteristics and clinical and radiologic manifestations are diagnostic challenges in the evaluation of the cerebral vein and of venous sinus diseases. The purpose of this article is to introduce bone subtraction CT venography and review normal variations and diseases involving the cerebral veins and venous sinuses. CONCLUSION Knowledge of the normal variations and pathologic findings will be helpful for the accurate diagnosis of diseases involving the cerebral venous system. Bone subtraction CT venography offers complete 3D visualization of the cerebral venous system and can be useful for the evaluation of the cerebral vein and venous sinus diseases.

Ruptured extracranial carotid artery: Endovascular treatment with covered stent graft

BACKGROUND AND PURPOSE Rupture of the extracranial carotid artery is a rare, but potentially disastrous event. We aimed to review the clinical presentations and radiologic findings of this entity and to evaluate the efficacy of endovascular treatment with covered stent graft. MATERIALS AND METHODS Since January 2009, eight patients with extracranial carotid artery rupture received endovascular treatment with covered stent graft. We retrospectively reviewed their medical records and radiologic findings. RESULTS The ruptured sites were in the common carotid artery (n=5), cervical ICA (n=2) and petrous ICA (n=1), respectively. The causes of injury included spontaneous (n=2), carotid blowout syndrome (CBS) (n=2), iatrogenic (n=2) and traumatic (n=2). Technical success and immediate hemostasis were achieved in all cases. Procedure-related complications occurred in 3 patients (37.5%). In a patient, the ipsilateral angular branch of the MCA was occluded during the procedure and it was completely reopened via mechanical thrombectomy without any neurologic deficit. Minor cerebral infarction was developed in 2 patients (25%). During a mean follow-up of 334 days (range 3-2053 days), two patients died: one from recurrent CBS and the other from aspiration pneumonia. CONCLUSIONS The covered stent grafting is an effective method for the treatment of extracranial carotid artery rupture.

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.

Lower Extremity Arterial Calcification as a Predictor of Coronary Atherosclerosis in Patients with Peripheral Arterial Disease

Background Until now, there has been no study on the relationship between the calcification of the lower extremity arteries and significant coronary arterial disease (CAD). Objectives To evaluate whether lower extremity calcium scores (LECS) are associated with CAD and whether this can predict multivessel-CAD in patients with peripheral arterial disease (PAD). Patients and Methods We retrospectively enrolled 103 PAD patients without cardiac symptoms or known CAD. All patients underwent cardiac computed tomography (CT) and lower extremity CT within 1 month and were categorized as nonsignificant CAD, single-CAD, or multivessel-CAD. The coronary calcium scores (CCS) were quantitatively measured according to the Agatston method and LECS were semi-quantitatively measured according to the presence of lower extremity calcification in the segment. The extent of CAD was evaluated according to the presence of ≥ 50% luminal diameter stenosis in the segment of CAD. Results LECS in multivessel-CAD were significantly higher than those in nonsignificant CAD (10.0 ± 5.8 versus 4.0 ± 3.1, P < 0.001). LECS significantly correlated with CCS (r = 0.831, P < 0.001) and the extent of CAD (r = 0.631, P < 0.001). Multivariate regression analysis demonstrated LECS and log-transformed CCS were independent predictors for multivessel-CAD. In receiver operating characteristic curve analysis, the diagnostic performance of LECS was 0.807 (95% confidence interval = 0.724-0.891, P < 0.001) for predicting multivessel-CAD. Conclusion Peripheral arterial calcification is significantly correlated with CAD extent in patients with PAD. Peripheral arterial calcification can be a useful marker for predicting multivessel-CAD.

FSE T2-weighted two-point Dixon technique for fat suppression in the lumbar spine: comparison with SPAIR technique

PURPOSE Fat suppression magnetic resonance imaging (MRI) technique has been used to improve the diagnostic confidence in lumbar spine diseases. We aimed to compare T2-weighted water-fat separation technique (T2 Dixon) with spectral attenuated inversion recovery (SPAIR) image for fat suppression. METHODS Lumbar spine MRI examinations were performed in 79 patients by using a 3.0 T machine. We compared T2 Dixon water-only image and SPAIR image for the evaluation of fat suppression quality and lesion conspicuity. For qualitative evaluation, two radiologists scored the images from Dixon and SPAIR for fat suppression uniformity and lesion conspicuity. Quantitative assessment was also performed for 39 lesions in 26 patients who had lesions in their spine bodies. Contrast ratio (CR) and contrast-to-noise ratio (CNR) were calculated by signal intensity measurement of the lesions, adjacent bodies, and background noise. The Wilcoxons signed-rank test and paired sample t-test were used to assess the statistical significance of qualitative and quantitative data, respectively. RESULTS For qualitative assessment, T2 Dixon water-only image showed higher mean scores for fat suppression quality and lesion conspicuity than SPAIR (2.99±0.11 vs. 2.18±0.38 and 2.84±0.37 vs. 2.28±0.51, respectively). For quantitative measurement, the CR and CNR values of the lesions were higher on T2 Dixon than on SPAIR. Both qualitative and quantitative results showed statistically significant differences between T2 Dixon and SPAIR (P < 0.01 in all). CONCLUSION T2 Dixon sequence was superior to SPAIR for the quality of fat suppression and for the delineation of lumbar spine lesions.

The oblique occipital sinus: anatomical study using bone subtraction 3D CT venography

Background and purposeAn occipital sinus draining into the sigmoid sinus has been termed the oblique occipital sinus (OOS). The frequency, anatomical features, patterns, and relationship with the transverse sinus of the oblique occipital sinus were analyzed in this study.Materials and methodsThe study included 1805 patients who underwent brain CT angiography during a 3-year period from 2013 to 2015. CT examinations were performed using a 64-slice MDCT system.ResultsThe OOS was identified in 41 patients (2.3%). There were many anatomical variations in the oblique occipital sinuses. A hypoplastic or aplastic TS was seen in 31 (75.6%) of the 41 patients with OOS.ConclusionMany anatomical variations in the oblique occipital sinus can be seen on CT venography. Some OOSs function as the main drainage route of the intracranial veins instead of the TS. Thus, careful examination is essential for preoperative evaluation in posterior fossa lesions.