Sang Hoon Cha

Computed tomographic differences of pyogenic liver abscesses caused by Klebsiella pneumoniae and non-Klebsiella pneumoniae.

Objective: To investigate the distinctive computed tomographic(CT) features of pyogenic liver abscess (PLA) caused by Klebsiella pneumoniae (KLA). Methods: 114 PLA patients (62 men, 52 women, age range 25-89 years, mean age 60.9 years) with positive yield of blood or pus cultures were divided into 2 groups; KLA group (n = 58) and non-KLA group (n = 56). We retrospectively reviewed the CT images. The independent-sample t-test, X2 test, or Fishers exact test were used with SPSS for windows version 11.0. Results: Gas formation showed no significant difference between two groups (P = 0.284), but air-fluid pattern was found only in KLA group (P = 0.027). The rim on dynamic CT was showed less frequently in KLA group than non-KLA group (P < 0.001), and smooth and regular rim was more common in non-KLA group (P < 0.001). The septation and septal breakage were more common in KLA group (P < 0.001). The turquoise sign was found significantly more in KLA group (P < 0.001). The hairball sign was detected only in KLA group (P < 0.001). The cluster sign was less frequent in KLA group (P < 0.001). Conclusion: KLA had a series of characteristic intra-abscess features; septal breakage, turquoise-like structure, hairball-like content, air-fluid level, and no enhanced rim. When turquoise/hairball sign or air-fluid level is present in abscess, KLA would be a probable diagnosis in the clinical field.

Maple syrup urine disease encephalopathy: a follow-up study in the acute stage using diffusion-weighted MRI.

Neonatal maple syrup urine disease (MSUD) is associated with diffuse oedema and characteristic MSUD oedema. We present a newborn infant with two coexisting different types of oedema. The myelinated white matter showed a marked decrease in the water apparent diffusion coefficient (ADC) compatible with cytotoxic oedema. The unmyelinated white matter showed an increase in ADC, consistent with vasogenic-interstitial oedema. On follow-up studies, the cytotoxic oedema showed improvement, but the vasogenic-interstitial oedema progressed into brain atrophy.

Contrast-enhanced power Doppler US: Is it useful in the differentiation of gallbladder disease? - Preliminary results

Thirteen patients with gallbladder disease underwent power Doppler ultrasound (PDUS) before and after microbubble contrast agent injection. Lesion and liver bed vascularity was evaluated. Pathological diagnoses in nine patients were two acute cholecystitis, four chronic inflammation, one adenoma and two adenocarcinoma. Two cases of cancer were included on clinical and radiological findings. Two cases were excluded because no pathologic diagnosis was available. Liver bed hyperemia was noted only in acute cholecystitis. Contrast-enhanced PDUS was superior to nonenhanced PDUS in the demonstration of vascularity of gallbladder diseases. However, contrast-enhanced PDUS has limited value in the differentiation.

Prediction of liver cirrhosis, using diagnostic imaging tools

Early diagnosis of liver cirrhosis is important. Ultrasound-guided liver biopsy is the gold standard for diagnosis of liver cirrhosis. However, its invasiveness and sampling bias limit the applicability of the method. Basic imaging for the diagnosis of liver cirrhosis has developed over the last few decades, enabling early detection of morphological changes of the liver by ultrasonography (US), computed tomography, and magnetic resonance imaging (MRI). They are also accurate diagnostic methods for advanced liver cirrhosis, for which early diagnosis is difficult. There are a number of ways to compensate for this difficulty, including texture analysis to more closely identify the homogeneity of hepatic parenchyma, elastography to measure the stiffness and elasticity of the liver, and perfusion studies to determine the blood flow volume, transit time, and velocity. Amongst these methods, elastography using US and MRI was found to be slightly easier, faster, and able to provide an accurate diagnosis. Early diagnosis of liver cirrhosis using MRI or US elastography is therefore a realistic alternative, but further research is still needed.

An Innovative Ultrasound Technique for Evaluation of Tumor Vascularity in Breast Cancers: Superb Micro-Vascular Imaging

Tumor vascularity is an important indicator for differential diagnosis, tumor growth, and prognosis. Superb micro-vascular imaging (SMI) is an innovative ultrasound technique for vascular examination that uses a multidimensional filter to eliminate clutter and preserve extremely low-velocity flows. Theoretically, SMI could depict more vessels and more detailed vascular morphology, due to the increased sensitivity of slow blood flow. Here, we report the early experience of using SMI in 21 breast cancer patients. We evaluated tumor vascular features in breast cancer and compared SMI and conventional color or power Doppler imaging. SMI was superior to color or power Doppler imaging in detecting tumor vessels, the details of vessel morphology, and both peripheral and central vascular distribution. In conclusion, SMI is a promising ultrasound technique for evaluating microvascular information of breast cancers.

Classification of Metastatic versus Non-Metastatic Axillary Nodes in Breast Cancer Patients: Value of Cortex-Hilum Area Ratio with Ultrasound.

Purpose To investigate the significance of the cortex-hilum (CH) area ratio and longitudinal-transverse (LT) axis ratio and the blood flow pattern for diagnosis of metastatic axillary lymph nodes by ultrasound in breast cancer patients. Methods From October 2005 to July 2006, we prospectively evaluated axillary nodes with ultrasound in 205 consecutive patients who had category 4B, 4C or 5 breast lesions according to the Breast Imaging Reporting and Data System-Ultrasound (BI-RADS-Ultrasound®). Among the 205, there were 24 patients who had pathologic verification of breast cancer and axillary lymph node status. For a total of 80 axillary nodes we measured the areas of the cortex and hilum of lymph nodes and calculated the area ratio. We also measured the length of the longitudinal and transverse axis of the lymph nodes and calculated the length ratio. We evaluated the blood flow pattern on power Doppler imaging and classified each lymph node into a central or peripheral pattern. Diagnostic performance was analyzed according to positive criteria for lymph node metastasis (CH area ratio >2, LT axis ratio <2, peripheral type on power Doppler imaging). Results The sensitivity of the CH area ratio was superior to that of the LT axis ratio (94.1% vs. 82.3%, p=0.031) and to that of the blood flow pattern (94.1% vs. 29.4%, p=0.009). For specificity, all three evaluating parameters had high values (89.1-95.6%) and no significant differences were found (p=0.121). The CH area ratio had a better positive predictive value than the LT axis ratio (94.1% vs. 80.0%, p=0.030) and power Doppler imaging (94.1% vs. 66.6%, p=0.028). For the negative predictive value, the CH area ratio was superior to the LT axis ratio (95.6% vs. 86.6%, p=0.035) and the blood flow pattern (95.6% vs. 63.0%, p=0.027). Conclusion We recommend the CH area ratio of an axillary lymph node on ultrasound as a quantitative indicator for the classification of lymph nodes. The CH area ratio can improve diagnostic performance when compared with the LT axis ratio or blood flow pattern.

Scrotal swelling caused by acute necrotizing pancreatitis: CT diagnosis

Scrotal involvement is a rare complication of acute pancreatitis. It presents as scrotal swelling and skin color change, which mimics the presentations of testicular torsion, epididymitis, and testicular tumor. Its differential diagnosis is important because scrotal involvement of acute pancreatitis can be treated conservatively. Abdominopelvic CT provides a useful means of diagnosing this complication. Here, the authors present a case of acute pancreatitis extending to the left scrotum, mimicking a testicular tumor. A CT scan helped avoid unnecessary orchiectomy.

Hepatic capsular retraction: unusual finding of cavernous hemangioma.

We report a case of hepatic giant hemangioma, which showed hepatic capsular retraction on CT and MRI. Pathologic examination revealed fibrosis combined with hemangioma, especially in a subcapsular location, which was responsible for the capsular retraction.

Single-session endovascular treatment for symptomatic lower extremity deep vein thrombosis: a feasibility study

Background: The risk of complications and discomfort in patients who undergo prolonged infusion of a thrombolytic agent is significant when conventional catheter-directed thrombolysis is used to treat lower extremity deep vein thrombosis (DVT). Purpose: To evaluate the feasibility and safety of single-session endovascular treatment for symptomatic lower extremity DVT. Material and Methods: Single-session endovascular treatment for lower extremity DVT was performed on 29 limbs in 26 patients diagnosed with acute DVT in our institution. Nine patients were male and 17 female, with a mean age of 64 years (range 28–82 years). At 5–10 min after the locoregional injection of the thrombolytic agent (urokinase) via a 5-Fr catheter to soften the thrombus, aspiration thrombectomy was performed with a large-bore sheath. In patients with an underlying anatomical stenosis or obstruction, combined angioplasty with or without stent placement was performed immediately after the complete removal of the thrombus. We then evaluated the technical and clinical outcomes of the procedure, along with any complications or recurrences of DVT. Results: Technical success was achieved in 24 procedures (82.8%) of single-session endovascular treatment for lower extremity DVT, and clinical success was achieved in 22 (75.9%) of these single-session procedures. Additional catheter-directed thrombolysis procedures were performed on five limbs after repeated aspiration thrombectomies failed to completely remove thrombi in those limbs. Stenotic or occlusive lesions were revealed in 24 limbs and percutaneous angioplasty procedures with or without stent placement were performed in these cases. No major complications resulted from the procedure. Conclusion: Single-session endovascular treatment is a feasible technique that provides acceptable technical and clinical success with excellent safety for treating symptomatic lower extremity DVT.

Biliary reflux detection in anomalous union of the pancreatico- biliary duct patients

AIMnTo demonstrate the imaging findings of biliopancreatic and pancreatico-biliary reflux in patients with anomalous union of the pancreatico-biliary duct (AUPBD) on gadoxetic acid-enhanced functional magnetic resonance cholangiography (fMRC).nnnMETHODSnThis study included six consecutive patients (two men and four women; mean age 47.5 years) with AUPBD. All subjects underwent endoscopic retrograde cholangiopancreatography (ERCP); one subject also underwent bile sampling of the common bile duct (CBD) to measure the amylase level because his gadoxetic acid-enhanced fMRC images showed evidence of pancreatico-biliary reflux of pancreatic secretions. Of the five patients with choledochal cysts, four underwent pylorus-preserving pancreaticoduodenectomy.nnnRESULTSnThe five cases of choledochal cysts were classified as Todani classificationu2005I. In three of the six patients with AUPBD, injected contrast media reached the distal CBD and pancreatic duct on delay images, suggesting biliopancreatic reflux. In two of these six patients, a band-like filling defect was noted in the CBD on pre-fatty meal images, which decreased in size on delayed post-fatty meal images, suggesting pancreatico-biliary reflux of pancreatic secretions, and the bile sampled from the CBD in one patient had an amylase level of 113,000 IU/L. In one of the six patients with AUPBD, contrast media did not reach the distal CBD due to multiple CBD stones.nnnCONCLUSIONnGadoxetic acid-enhanced fMRC successfully demonstrated biliopancreatic reflux of bile and pancreatico-biliary reflux of pancreatic secretions in patients with AUPBD with and without choledochal cysts.