Jun Hyun Baik

The role of diffusion-weighted imaging and the apparent diffusion coefficient (ADC) values for breast tumors.

Objective We wanted to evaluate the role of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) for detecting breast tumors, as compared with the T1- and T2-weighted images. Materials and Methods Forty-one female patients underwent breast MRI, and this included the T1-, T2-, DWI and dynamic contrast-enhanced images. Sixty-five enhancing lesions were detected on the dynamic contrast-enhanced images and we used this as a reference image for detecting tumor. Fifty-six breast lesions were detected on DWI and the histological diagnoses were as follows: 43 invasive ductal carcinomas, one mucinous carcinoma, one mixed infiltrative and mucinous carcinoma, seven ductal carcinomas in situ (DCIS), and four benign tumors. First, we compared the detectability of breast lesions on DWI with that of the T1- and T2-weighted images. We then compared the ADCs of the malignant and benign breast lesions to the ADCs of the normal fibroglandular tissue. Results Fifty-six lesions were detected via DWI (detectability of 86.2%). The detectabilities of breast lesions on the T1- and T2-weighted imaging were 61.5% (40/65) and 75.4% (49/65), respectively. The mean ADCs of the invasive ductal carcinoma (0.89 ± 0.18 × 10-3mm2/second) and DCIS (1.17 ± 0.18 × 10-3mm2/second) are significantly lower than those of the benign lesions (1.41 ± 0.56 × 10-3mm2/second) and the normal fibroglandular tissue (1.51 ± 0.29 × 10-3mm2/second). Conclusion DWI has a high sensitivity for detecting breast tumors, and especially for detecting malignant breast tumors. DWI was an effective imaging technique for detecting breast lesions, as compared to using the T1- and T2-weighted images.

Typical and Atypical Manifestations of Intrathoracic Sarcoidosis

Sarcoidosis is a systemic disorder of unknown cause that is characterized by the presence of noncaseating granulomas. The radiological findings associated with sarcoidosis have been well described. The findings include symmetric, bilateral hilar and paratracheal lymphadenopathy, with or without concomitant parenchymal abnormalities (multiple small nodules in a peribronchovascular distribution along with irregular thickening of the interstitium). However, in 25% to 30% of cases, the radiological findings are atypical and unfamiliar to most radiologists, which cause difficulty for making a correct diagnosis. Many atypical forms of intrathoracic sarcoidosis have been described sporadically. We have collected cases with unusual radiological findings associated with pulmonary sarcoidosis (unilateral or asymmetric lymphadenopathy, necrosis or cavitation, large opacity, ground glass opacity, an airway abnormality and pleural involvement) and describe the typical forms of the disorder as well. The understanding of a wide range of the radiological manifestations of sarcoidosis will be very helpful for making a proper diagnosis.

High-resolution CT findings of re-expansion pulmonary edema.

Objective To describe the high-resolution CT (HRCT) findings of re-expansion pulmonary edema (REPE) following a thoracentesis for a spontaneous pneumothorax. Materials and Methods HRCT scans from 43 patients who developed REPE immediately after a thoracentesis for treatment of pneumothorax were retrospectively analyzed. The study group consisted of 41 men and two women with a mean age of 34 years. The average time interval between insertion of the drainage tube and HRCT was 8.5 hours (range, 1-24 hours). The patterns and distribution of the lung lesions were analyzed and were assigned one of the following classifications: consolidation, ground-glass opacity (GGO), intralobular interstitial thickening, interlobular septal thickening, thickening of bronchovascular bundles, and nodules. The presence of pleural effusion and contralateral lung involvement was also assessed. Results Patchy areas of GGO were observed in all 43 patients examined. Consolidation was noted in 22 patients (51%). The geographic distribution of GGO and consolidation was noted in 25 patients (58%). Interlobular septal thickening and intralobular interstitial thickening was noted in 28 patients (65%), respectively. Bronchovascular bundle thickening was seen in 13 patients (30%), whereas ill-defined centrilobular GGO nodules were observed in five patients (12%). The lesions were predominantly peripheral in 38 patients (88%). Of these lesions, gravity-dependent distribution was noted in 23 cases (53%). Bilateral lung involvement was noted in four patients (9%), and a small amount of pleural effusion was seen in seven patients (16%). Conclusion The HRCT findings of REPE were peripheral patchy areas of GGO that were frequently combined with consolidation as well as interlobular septal and intralobular interstitial thickening.

Colon Ischemia Associated with Buerger's Disease: Case Report and Review of the Literature

Buergers disease, or thromboangiitis obliterans, is a nonatherosclerotic inflammatory disease affecting the small- and medium-sized arteries and veins of the extremities (arms, hands, legs, and feet). It is most common in the Orient, Southeast Asia, India, and the Middle East, and usually affects men aged between 20 and 40 years, although it is becoming more common in women. It is well established that most such patients smoke heavily and experience an improvement in symptoms following smoking cessation. Mesenteric involvement in Buergers disease is extremely rare; however, we describe herein two cases of colon ischemia in patients who were previously diagnosed with lower-extremity Buergers disease. In one case, the patient developed colonic obstruction, and surgical resection was performed. Histopathologic findings were compatible with the chronic stage of Buergers disease. In the other case, angiography revealed abrupt occlusion of the inferior mesenteric artery with numerous collateral vessels, just like the corkscrew appearance found in the extremities. If patients with established Buergers disease of the extremities complain of gastrointestinal symptoms, early interventional diagnosis should be performed to prevent intestinal obstruction and gangrene.

Usefulness of assisted procedures for arteriovenous fistula maturation without compromising access patency.

Introduction: To increase the rate of arteriovenous fistula (AVF) use, assisted procedures for immature AVF have been strenuously performed. However, this is controversial in that an AVF matured by these assisted procedures may require more frequent intervention to maintain its patency, and have decreased long‐term patency.

Emergency Rescue Primary Stenting for Atherosclerotic Basilar Artery Occlusion with Acute Thrombosis A Case Report

We demonstrate endovascular stent deployment for the treatment of atherosclerotic basilar artery occlusion with acute thrombosis. Application of a microstent without previous balloon dilatation resulted in vessel reopening and good clinical improvement. Emergency primary stent application can be technically feasible and improve the outcome in acute basilar artery occlusion and clinical status.

Exchange over the guidewire from non-tunneled to tunneled hemodialysis catheters can be performed without patency loss:

Purpose: The exchange from a non-tunneled hemodialysis catheter to a tunneled one over a guidewire using a previous venotomy has been reported to be safe. However, some concerns that it may increase infection risk prevent its clinical application. This approach seems particularly useful for acute kidney injury patients requiring initial renal replacement therapy, in whom we frequently worry about the choice of non-tunneled versus tunneled catheters. Materials and methods: From March 2012 to February 2016, 88 cases to receive the over-the-guidewire exchange method from a non-tunneled to a tunneled catheter and 521 cases to receive de novo tunneled catheter placement from the hemodialysis vascular access cohort were compared retrospectively. Results: The immediate complication, later catheter dysfunction requiring replacement, and infection rates were comparable between the two groups. Newly placed tunneled catheter survival in the over-the-guidewire exchange group was comparable with survival in the de novo tunneled catheter group (p = 0.24). In addition, when we compared the same two methods among only intensive care unit patients; they remained similar (p = 0.19). Conclusion: An exchange with the over-the-guidewire method from a non-tunneled to a tunneled catheter was comparable to a de novo catheter placement technique. Therefore, this method should be viewed more favorably and should especially be considered for acute kidney injury patients.

Pitfalls in Radiographic Interpretation of Emphysema Patients

Emphysema commonly accompanies various complications such as pneumonia. Sometimes, these comorbidities look so strange on images, because destroyed airspaces could change the usual disease progression. So, we demonstrated various cases of common comorbidities with unusual radiographic findings in emphysema patients. Awareness of various findings of emphysema with commonly coexistent diseases may aid in the proper diagnosis and management of emphysema patients.

Conversion of Percutaneous Endoscopic Gastrostomy to Gastrojejunostomy Under Fluoroscopic Guidance for Treatment of Gastrocutaneous Fistula

Persistent enterocutaneous fistula after the removal of a gastrostomy tube is an unusual complication of percutaneous endoscopic gastrostomy (PEG). The following case report describes an 81-year-old man diagnosed with stroke and dysphagia in May 2008. The patient had been using a PEG since 2008, and PEG site infection occurred in June 2013. The PEG tube was removed and a new PEG tube was inserted. Thereafter, formation of gastrocutaneous fistula around the previous infected PEG site was observed. The fistula was refractory to medical management, accompanied by long duration of fasting and peripheral alimentation. Therefore, gastrojejunostomy tube insertion via the previously inserted PEG tube was performed, under fluoroscopic guidance; this mode of management was successful. For patients who have a gastrocutaneous fistula, gastrojejunostomy tube insertion via the pre-existing PEG tube is a safe and effective alternative management for enteral feeding.