Medical Devices of the Abdomen and Pelvis and Their Complications: A Radiologic Atlas

A variety of medical devices have evolved throughout the years. Commonly used devices have typical radiological appearances which are familiar to radiologists. However, some new devices, as well as devices that are not commonly used, may be missed or misinterpreted by radiologists. It is even more difficult to identify a certain medical device with limited clinical history. Therefore, accurate identification of medical devices is crucial to diagnose malposition and potential complications. In this article, we provide a pictorial review of medical devices of the abdomen and pelvis according to classifications that include gastrointestinal devices, hepatobiliary devices, genitourinary devices, and miscellaneous. We also comprehensively review the clinical and radiologic features of complications related to these medical devices.

Undifferentiated Carcinoma with Osteoclast-Like Giant Cells of the Pancreas Mimicking a Predominantly Calcified Mass: Case Report and Literature Review

Undifferentiated carcinoma with osteoclast-like giant cells (UCOGCs) of the pancreas is a rare neoplasm that contains osteoclast-like giant cells, which are morphologically identical to those seen in giant cell tumors of bones. Histopathologically, it is composed of round to spindle-shaped neoplastic cells and non-neoplastic histiocytic giant cells. Although only limited radiologic findings are available due to the rarity of this tumor, UCOGCs shows variable imaging features in the literature from an inhomogeneous solid mass to a multilocular cystic tumor. Herein, we report an unusual manifestation of UCOGCs of the pancreas mimicking a predominantly calcified mass with radiologic-pathologic correlation.

Toxocariasis Mimicking Lymphoma and Presenting as Multiple Lymphadenopathy: A Case Report

Toxocariasis, a parasitic infection, causes hyper eosinophilia resulting in radiological presentation of eosinophilic infiltrations in the involved organs. In the abdomen, toxocariasis has been reported to manifest as infiltrations in the liver or in the gastrointestinal tract, but it is known to be uncommon to manifest as multiple lymphadenopathy. There have been two case reports of toxocariasis presenting as generalized lymphadenopathy in the chest, neck and inguinal regions. To the best of our knowledge, generalized conglomerated lymphadenopathy occurring mostly in the abdomen from toxocariasis has not been published in the English literature. Herein, we report a rare case of toxocariasis presenting as multiple conglomerated lymphadenopathy mimicking lymphoma on CT.

Efficacy and Safety of Radiofrequency Ablation Performed by an Endocrinologist for Benign Thyroid Nodules

BACKGROUND AND OBJECTIVES: Radiofrequency ablation has recently been used for the treatment of benign thyroid nodules, with outstanding results. However, in most studies, the procedure was usually performed by a radiologist or surgeon. This study aimed to evaluate the efficacy and safety of radiofrequency ablation for nodules >2 cm performed by an endocrinologist with several years of experience performing fine-needle aspiration cytology. MATERIALS AND METHODS: This study was a cross-sectional analysis of 111 patients who received radiofrequency ablation between April 2010 and July 2013. A total of 73 patients with 75 nodules >2 cm in diameter with at least 6 months of follow-up examinations were included. RESULTS: The mean follow-up period was 11.5 months. The mean nodule volume decreased from 17.0+/-15.3 mL preoperatively to 6.0+/-8.5 mL postoperatively, with a mean volume reduction of 69.7%. There were no major complications, and only 1 patient (1.3%) presented with a minor complication (hemorrhaging of the thyroid parenchyma). CONCLUSION: Radiofrequency ablation is a safe method for reducing benign thyroid nodules, and is not associated with any major complications.

Correlation between Abdominal Fat Amount and Fatty Liver, using Liver to Kidney Echo Ratio on Ultrasound

PURPOSE: It has been generally recognized that fatty liver can often be seen in the obese population. This study was conducted in order to evaluate the association between fatty liver and abdominal fat volume. MATERIALS AND METHODS: A total of 105 patients who visited our obesity clinic in the recent three years underwent fat CT scans and abdominal US. Attenuation difference between liver and spleen on CT was considered as a reference standard for the diagnosis of fatty liver. On US, the echogenicity of the liver parenchyma was measured in three different regions of interest (ROI) close to the adjacent right kidney in the same slice, avoiding vessels, bile duct, and calcification. Similar measurements were performed in the right renal cortex. The mean values were calculated automatically on the histogram of the ROI using the PACS program. The hepatorenal echogenicity ratio (HER; mean hepatic echogenicity/mean renal echogenicity) was then calculated. Abdominal fat volume was measured using a 3 mm slice CT scan at the L4/5 level and was calculated automatically using a workstation. Abdominal fat was classified according to total fat (TF), visceral fat (VF), and subcutaneous fat (SF). We used Pearson's bivariate correlation method for assessment of the correlation between HER and TF, VF, and SF, respectively. RESULTS: Significant correlation was observed between HER and abdominal fat (TF, VF, and SF). HER showed significant correlation with VF and TF (r = 0.491 and 0.402, respectively; p = 0.000). The correlation between HER and SF (r = 0.255, p = 0.009) was less significant than for VF or TF. CONCLUSIONS: Fat measurement (HER) by hepatic ultrasound correlated well with the amount of abdominal fat. In particular, the VF was found to show a stronger association with fatty liver than SF.

A Case of Salmonella Typhi Complicating Acute Appendicitis Proven by Gene STY0312 Polymerase Chain Reaction (PCR) / 감염과화학요법

Typhoid fever frequently manifests as gastrointestinal complications, such as ileitis or colitis, but appendicitis is quite rare. A 37-year-old man was admitted due to abdominal pain, fever and diarrhea. Two weeks before admission, he underwent an appendectomy. The blood culture upon admission revealed Salmonella Typhi. A polymerase chain reaction(PCR) was performed on the tissue of the vermiform appendix and the STY0312 gene of S. Typhi was detected. This is the first case of acute appendicitis complicated with typhoid fever proven by PCR in Korea.

Cystic Lesions of the Gastrointestinal Tract: Multimodality Imaging with Pathologic Correlations

The cystic lesions of the gastrointestinal (GI) tract demonstrate the various pathologic findings. Some lesions may present a diagnostic challenge because of non-specific imaging features; however, other lesions are easily diagnosed using characteristic radiologic features and anatomic locations. Cystic masses from the GI tract can be divided into several categories: congenital lesions, neoplastic lesions (cystic neoplasms, cystic degeneration of solid neoplasms), and other miscellaneous lesions. In this pictorial review, we describe the pathologic findings of various cystic lesions of the GI tract as well as the radiologic features of GI cystic lesions from several imaging modalities including a barium study, transabdominal ultrasound (US), computed tomography (CT), and magnetic resonance (MR) imaging.

A Renal Perforating Artery Mistaken for Arterial Bleeding after Percutaneous Renal Biopsy: A Case Report

Perirenal hematoma after a renal biopsy is a common complication that usually resolves spontaneously, but this rarely requires transfusions or surgical/radiological intervention. We report here on a case of a renal perforating artery that was mistaken for renal arterial bleeding in a 53-year-old woman who was complicated with perirenal hematoma after undergoing a percutaneous renal biopsy. On the color and pulsed wave Doppler ultrasonography, linear blood flow was seen in the perirenal hematoma, which extended perpendicularly from the renal parenchyma into the perirenal space, and this linear blood flow exhibited an arterial pulse wave. On CT angiography, the renal perforating artery was demonstrated as a curvilinear vessel coursing tangentially to the renal margin and we decided that it was a pseudolesion caused by the renal perforating artery. A renal perforating artery may be mistaken for renal arterial bleeding after a percutaneous renal biopsy. A renal perforating artery and arterial bleeding can be differentiated by the location and shape seen on a color Doppler examination and the pulse waves characteristics.

Inflammatory Hepatic Nodules Associated with Urinary Tract Infection in Two Pediatric Patients

Inflammatory nodule in the liver associated with acute urinary infection is an uncommon presentation. We recently experienced two pediatric patients, admitted for urinary tract infection, in whom a solitary hyperechoic nodule or multiple low echoic nodules in the liver were incidentally discovered. All patients complained of fever, and urine culture results were positive for Klebsiella, Streptococcus, and Escherichia coli. After receiving treatment with antibiotics, the hepatic nodules gradually decreased in size and completely disappeared.

CT Findings of Primary Squamous Cell Carcinoma of the Stomach: A Case Report

Primary squamous cell carcinoma is a rare tumor of the stomach with an incidence ranging from 0.04% to 0.4% of all diagnosed gastric cancers. We report a case of squamous cell carcinoma in the stomach associated with hypertrophic gastropathy and observed as a huge mass and wall thickening on the greater curvature site by a multidetector CT.

Evaluation of Fibrosis in Liver Cirrhosis by Superparamagnetic Iron Oxide (SPIO)-Enhanced MR Imaging: Does the Radiological Non-Invasive Fibrosis Index Correlate with the Laboratory Non-Invasive Fibrosis Index?

PURPOSE: To evaluate the correlation between the radiological non-invasive hepatic fibrosis index (RNHFI), as determined by SPIO-enhanced MRI, and the laboratory non-invasive hepatic fibrosis index. MATERIALS AND METHODS: Patients (99 total: 61 men and 38 women; mean age: 58 years) who underwent SPIO-enhanced MRI (1.5T) during 5 years included. These patients were subdivided into a liver cirrhosis group (LCG) and a non-liver cirrhosis group (non-LCG). Using PACS view, we measured the RNHFI (mean standard deviation of hepatic signal intensity (SD), noise-corrected coefficient of variation (CV)) of three ROIs in the liver parenchyma by SPIO-enhanced MRI. The laboratory non-invasive hepatic fibrosis index (AST-platelet ratio index (APRI)) of all patients was calculated from the laboratory data. We compared the RNHFI and APRI of LCG with those of non-LC group using Student's t-test. A bivariate correlation was performed to investigate the relationship between the RNHFI and APRI in the LCG. RESULTS: For the LCG, mean values of SD and CV by SPIO-enhanced MRI were 10.3 +/-3.7 and 0.19+/-0.08, respectively. For the non-LCG, mean values of SD and CV were 6.5+/-1.6 and 0.08+/-0.05, respectively. The mean APRI of the LCG and the non-LCG were 2.04+/-1.7 and 0.32+/-0.32, respectively. The RNHFI and APRI were significantly different between both groups (p<05). For the LCG, the bivariate correlation between SD and APRI revealed a statistically significant positive correlation (r=0.5, p<0.001). In both groups, there was no statistically significant correlation between CV and APRI. CONCLUSION: A measurement of SD can be a simple and useful method for the evaluation of hepatic fibrosis.

Usefulness of High-Frequency Compound Spatial Sonography in the Assessment of Hepatitis B Virus Related Chronic Liver Disease

PURPOSE: To evaluate the liver parenchyma according to the echo patterns of CSS (compound spatial sonography), and to correlate them with the extent of hepatic fibrosis and the serum aminotransferase level. MATERIALS AND METHODS: The CSS images were classified into the following three echo patterns: type I, a normallooking echo; type II, hyperechoic or hypoechoic nodules scattered in a normal-looking echo; type III, a severely heterogeneous echogenic or hypoechoic honeycomb-like echo. The CSS findings were correlated with the histopathology findings in 63 patients with HBV. The serum aminotransferase levels and the occurrence of acute exacerbation in 168 patients with HBV, with and without a progressed parenchymal echo pattern, and who were followed up more than 1-year period, were compared. The interobserver agreement between the two radiologists for assessing the parenchymal echo pattern was scored. RESULTS: The correlation between the CSS pattern and hepatic fibrosis was statistically significant (correlation coefficient = 0.58, p < 0.05). The baseline serum aminotransferase level was not significantly different between the patients with and without a progressed parenchymal echo pattern. However, the rate of acute exacerbation was higher in patients with a progressed parenchymal echo pattern (p < 0.05). The interobserver agreement was good (k statistic = 0.63, 0.78). CONCLUSION: The liver parenchymal pattern based on the 5-12 MHz CSS is a useful and objective tool for diagnosing and monitoring HBV related chronic liver disease.

US Diagnosis of Sparganosis Within the Thigh: Case Report

Sparganosis is an uncommon infection caused by sparganum, a migrating plerocercoid larva. Currently, various imaging modalities have been actively used for the diagnosis of sparganosis before surgery. We present a case of sparganosis arising in the subcutaneous layer of the thigh that was diagnosed only by an ultrasound examination.

Tuberculous Spondylitis vs Pyogenic Spondylitis: Focusing on the Discriminative MR Findings for Differentiation

PURPOSE: The purpose of this study is to analyze the most discriminative MR findings for making the differential diagnosis of tuberculous and pyogenic spondylitis. MATERIALS AND METHODS: Sixty MR scans of 18 pyogenic spondylitis patients and 42 tuberculous spondylitis patients were retrospectively reviewed. The statistical analysis was performed using stepwise discriminant analysis and Student's T-test. RESULTS: The patients with tuberculous spondylitis had a significantly higher incidence of MRI findings as follows (p <0.05): smooth margin of a paraspinal mass/abscess in 67% [28/42] of the tuberculous spondylitis patients vs 6% [1/18] in the pyogenic spondylitis patients, mild endplate erosion in 52% [22/42] vs 38% [7/18], respectively, the presence of paraspinal mass/abscess in 100% [42/42] vs 6% [1/18], respectively, central dark signal intensity of the abscess in 86% [36/42] vs 39% [7/18]), respectively, subligamentous spread in 81% [34/42] vs 50% [9/18]), respectively, severe vertebral collapse in 20% [8/42] vs 11% [2/18]), respectively, and posterior extension in 62% [26/42] vs 33% [6/18]), respectively. Among of them, the significant discriminative MR findings were the margin of a paraspinal mass, the grade of endplate erosion and the presence or absence of a paraspinal mass in that order. CONCLUSION: In the differentiation of tuberculous and pyogenic spondylitis, the margin of the paraspinal mass, the grade of endplate erosion and the presence or absence of a paraspinal mass are the most three discriminating MR findings in that order.

Spontaneous Tilting after Placement of the Gunther-Tulip Inferior Vena Caval Filter: A Case Report

Tilting of a deployed filter in the inferior vena cava (IVC) is a particular kind of periprocedural complication and this can reduce the filter's clot-trapping ability and increase the occlusion of the IVC at a later period. The authors report here on a case of spontaneous tilting of an inferior vena caval filter that was associated with thrombosis in the IVC within 2 weeks of the initially successful placement of the filter without tilting.

Diagnostic Usefulness of Ultrasonographic Examination of Cubital Tunnel Syndrome: Analysis of Ulnar Nerve Cross-sectional Area

PURPOSE: To prospectively evaluate the accuracy of sonography for diagnosis of cubital tunnel syndrome (CUTS) confirmed by electrodiagnostic study. ATERIALS and METHODS: From February 2004 to March 2005, we prospectively analyzed 24 elbows in 19 patients (8 women, 11 men; mean age, 49.2 years; range 23-65 years) with cubital tunnel syndrome, including 5 bilateral cases. Diagnoses of CUTS were confirmed by both clinical symptom and electrodiagnostic study. Sonographic findings of 20 asymptomatic cases served as controls. In sonographic examination, the cross sectional area of the ulnar nerve was measured at the inlet (at the level of medial epicondyle) and outlet (at the level of convergence of flexor carpi ulnaris tendons) of the cubital tunnel. The shape and echogenicity of the ulnar nerve were also evaluated, as were possible causes of entrapment. The accuracy of using ultrasonographic cross sectional area to diagnose CUTS was evaluated with receiver operating characteristic (ROC) analysis. RESULTS: The cross sectional area of the ulnar nerve at the inlet and outlet levels in CUTS patients was increased much more than in the asymptomatic cases. Decreased echogenicity and distortion of normal parallel echotexture of the ulnar nerve were observed in all CUTS patients. At the inlet level, the area under the ROC curve (AUC) was 0.816, and the ideal cut-off value for CUTS diagnosis was 0.08 cm2 with a sensitivity of 58.3%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 66.7%. At the distal outlet level, the AUC was 0.785, and the cut-off value was 0.06 cm2 with a sensitivity of 79.2%, specificity of 70%, PPV of 76%, and NPV of 73.7%. When the summation value of inlet and outlet cross sectional areas was used, the AUC was 0.853, and cut-off value was 0.14 cm2 with a sensitivity of 70.8%, specificity of 85%, PPV of 85%, and NPV of 70.8%. CONCLUSION: Measurement of the cross sectional area of the ulnar nerve at the inlet and outlet of the cubital tunnel can aid in the sonographic diagnosis of cubital tunnel syndrome by more objectively determining the increase in cross sectional area.

CT and MR Imaging Findings of Subdural Dermoid Cyst Extending into the Right Foramen Ovale: A Case Report

Intracranial dermoid cyst is a rare congenital benign disease, representing less than 0.5% of primary brain tumors. Nevertheless, if ruptured spontaneously or during surgery, it has a poor prognosis due to chemical meningitis. Therefore, it is essential to perform accurate diagnosis and proper treatment. We report an intracranial subdural dermoid cyst that may be misdiagnosed as extracranial or epidural lesion because of extension into the right foramen ovale, and describe the CT and MR imaging findings.

Ectopic Varices in Colonic Stoma: MDCT Findings

Ectopic stomal varices are an unusual cause of gastrointestinal hemorrhage. The term "ectopic stomal varices" means abnormally dilated veins that have developed in the stomal mucosa. We describe the 2D reformatted and 3D volume rendered images by MDCT in a patient with an episode of acute bleeding from the colonic stoma. This case indicates that the 2D reformatted and 3D volume rendered images are useful to detect this rare complication of portal hypertension, and they help to tailor adequate treatment for the patients with bleeding from stomal varices.

Transmural Migration of Surgical Sponge Evacuated by Defecation: Mimicking an Intraperitoneal Gossypiboma

The spontaneous defecation of the surpical retained sponge is very rare. Here, we report a case of migrating surgical sponge that was retained in the colon and it was evacuated by defecation.

Extramedullary Plasmacytoma of the Pancreas: Imaging Findings: Case Report

Extramedullary plasmacytoma involves organs outside the bone marrow, but involvement of the pancreas is very rare. We present the imaging findings of extramedullary plasmacytoma of the pancreas in a patient with multiple myeloma. Mixed echogenecity was noted at US, and marked enhancement at CT and MR.