Jiyoung Hwang

Percutaneous radiofrequency ablation of small hepatocellular carcinoma invisible on both ultrasonography and unenhanced CT: a preliminary study of combined treatment with transarterial chemoembolisation

The purpose of this study was to assess the feasibility and efficacy of percutaneous radiofrequency ablation combined with transarterial chemoembolisation (TACE) for the treatment of hepatocellular carcinoma that are invisible on both ultrasound and unenhanced CT. 73 patients with a total of 101 nodular hepatocellular carcinomas were referred for possible radiofrequency (RF) ablation. Of these, 14 lesions (14%) in 14 patients were invisible on both ultrasound and unenhanced CT. The invisible nodules averaged 1.2 cm in diameter (range, 0.8-2.0 cm; median, 1.1 cm). After segmental TACE, percutaneous RF ablation was performed if the index tumour was visible on fluoroscopy, ultrasound or CT. All cases of combined treatment were evaluated for size of ablative zone, complications, rate of technical effectiveness at 1-month follow-up CT and local tumour progression. After TACE, percutaneous RF ablation was technically feasible in 10 (71%) of the 14 nodules. RF ablation was performed with the guidance of fluoroscopy (n = 6, 42%), ultrasound (n = 2, 14%) or CT (n = 2, 14%). The mean diameter of the ablative zone by percutaneous RF ablation combined with TACE was 4.8+/-0.7 cm and 3.4+/-0.6 cm in the long and short axis, respectively. No major complications were documented. The primary technical effectiveness rate for nodules treated by combined treatment was 100% (10/10) at 1-month follow-up CT. No local tumour progression was found during the follow-up period (median 15 months; range 4-20 months). Percutaneous RF ablation combined with TACE is a feasible and effective technique for treating small hepatocellular carcinomas that are not visible on ultrasound or unenhanced CT.

Mini-Gastric Bypass to Control Morbid Obesity and Diabetes Mellitus: What Radiologists Need to Know

Laparoscopic mini-gastric bypass surgery is a safe and simple surgical intervention for treating morbid obesity and diabetes mellitus and is now being performed more frequently. Radiologists must be critical in their postoperative evaluation of these patients. In this pictorial review, we explain and illustrate the surgical technique, normal postoperative anatomy, and associated complications as seen on imaging examinations, including fluoroscopy and computed tomography.

The Relationship Between Urinary Stone Components and Visceral Adipose Tissue Using Computed Tomography–based Fat Delineation

OBJECTIVE To determine the relationship between body mass index (BMI), visceral adipose tissue (VAT), and stone components. METHODS A cross-sectional study has been done for urinary stone cohort between 2010 and 2012. Data on patients age, gender, BMI, urinary pH, stone components, and VAT using computed tomography-based delineation were collected. Obesity was defined as BMI≥25 kg/m2 or as VAT≥100 cm2. To compare the differences between the types of stones, multinomial logistic regression analyses were conducted. RESULTS Of 203 cases, 49.3% patients were obese based on BMI, and 65.5% were obese using VAT criteria. Multinomial logistic regression analysis revealed that obesity defined by VAT was found to be associated with uric acid stones compared with calcium phosphate stones (odds ratio [OR] 6.544, 95% confidence interval [CI], P=.030) and mixed calcium oxalate phosphate stones (OR 5.582, 95% CI, P=.038). Similar results were observed in calcium oxalate stones over calcium phosphate stones (OR 2.984, 95% CI, P=.032) and calcium oxalate phosphate stones (OR 2.542, 95% CI, P=.041). On the contrary, obesity defined based on BMI has no correlation over all types of urinary stone components. CONCLUSION This result implies that VAT has a more important role in uric acid and calcium oxalate stone formation than total body fat, represented by BMI.

Cryptogenic multifocal ulcerous stenosing enteritis: Radiologic features and clinical behavior

AIM To investigate the characteristic radiologic findings of cryptogenic multifocal ulcerous stenosing enteritis (CMUSE) which can be differentiated from other similar bowel disease and to assess their clinical behavior. METHODS Twenty pathologically and clinically confirmed CMUSE patients (males:females = 8:12; mean age: 40.4 years) between March 2002 and August 2015 from seven academic centers in South Korea were retrospectively reviewed. We evaluated small bowel series (SBS; n = 25), computed tomography (CT) enterography (n = 21), magnetic resonance (MR) enterography (n = 2), and abdominopelvic CT (n = 18) images, focusing on enteric and perienteric manifestations. Any change in radiologic features during follow-up period was recorded. We evaluated clinical data including presenting symptoms, laboratory finding and presence of relapse from electronic medical records. Histopathologic findings were also evaluated. RESULTS The main symptoms were abdominal pain (n = 12) and anemia (n = 10). All patients showed small bowel strictures (n = 52, mean: 2.6 per patient) on initial CT/MR, located in the ileum (n = 47) or jejunum (n = 5). Strictures showed short-length (mean: 10.44 mm) and circumferential bowel wall thickening (mean: 5.56 mm) with layered enhancement (n = 48) that were also noted on initial SBS (n = 36) with shallow ulcers (n = 10). Some ulcerative lesions or wall thickening progressed into strictures on follow-up SBS/CT, and some strictures revealed recurrent ulceration on follow-up SBS. There were no penetrating disease features like fistula or abscess and no gastrointestinal tract involvement except the small bowel. Nine patients experienced disease recurrence (median relapse-free period: 32 mo) even post-operatively. Histopathologic features of surgically resected specimens were characterized as multiple superficial ulcerations confined to mucosa or submucosa and multiple strictures. CONCLUSION Under characteristic radiologic findings with multiple short-segmental strictures and/or shallow ulcers of the small intestine, CMUSE should be considered when assessing patients with recurrent abdominal pain and anemia.

Evaluation for fracture patterns around the wrist on three‐dimensional extremity computed tomography, especially focused on the triquetrum

To describe fracture patterns of triquetrum and analyse them according to fracture classifications, anatomy of intrinsic carpal ligaments and comparison with other wrist fractures.

Acute diverticulitis of the terminal ileum: ultrasonography and CT findings

We describe a rare case of terminal ileal diverticulitis in a 68-year-old female with a day of history Epub ahead of print of right lower quadrant pain and tenderness, mimicking acute appendicitis. Ultrasonography revealed small sac-like out-pouching lesions with increased echogenicity of surrounding fat in thickened terminal ileum, suggesting inflamed diverticula. We diagnosed terminal ileal diverticulitis primarily by ultrasonography. The diagnosis was confirmed by subsequent computed tomography.We describe a rare case of terminal ileal diverticulitis in a 68-year-old female with a day of history of right lower quadrant pain and tenderness, mimicking acute appendicitis. Ultrasonography revealed small sac-like out-pouching lesions with increased echogenicity of surrounding fat in thickened terminal ileum, suggesting inflamed diverticula. We diagnosed terminal ileal diverticulitis primarily by ultrasonography. The diagnosis was confirmed by subsequent computed tomography.

Capsule, septum, and T2 hyperintense foci for differentiation between large hepatocellular carcinoma (≥5 cm) and intrahepatic cholangiocarcinoma on gadoxetic acid MRI

ObjectiveTo determine the added value of capsule, septum, and T2 hyperintense foci for differentiating large hepatocellular carcinoma (HCC; ≥ 5 cm) from intrahepatic cholangiocarcinoma (ICC) using gadoxetic acid MRI.MethodsThe study included 116 patients (94 men, 22 women; mean age, 56.8 years) with surgically confirmed HCCs (n = 87, 5.0–18.0 cm) or ICCs (n = 29, 5.0–14.0 cm) who underwent gadoxetic acid MRI. Three observers independently reviewed MRIs in two sessions, examining enhancement patterns only and then adding capsule, septum, and T2 hyperintense foci. Reviewers used a five-point scale to score accuracy, sensitivity, and specificity.ResultsA significant increase was observed in accuracy when ancillary features (96.1–98.3%) were added compared to enhancement pattern only (83.6–88.4%; p ≤ 0.02). Sensitivity was significantly increased with combined reading (97.1–98.3%) compared to enhancement features only (81.6–88.5%; p ≤ 0.006) for two observers, with no difference in specificity (84.5–89.7% vs. 86.2–98.3%; p > 0.05). We found substantial to excellent interobserver agreement for ancillary features (0.598–0.976).ConclusionAdding capsule, septum, and T2 hyperintense foci to enhancement patterns for gadoxetic acid MRI increased diagnostic performance for characterizing large HCC by differentiating it from ICC.Key Points• Capsule, septum, and T2 hyperintense foci were useful for characterizing large HCC.• Adding ancillary features to enhancement pattern increased accuracy for diagnosing large HCC.• Interobserver agreement was substantial to excellent for ancillary features.

Gadoxetic acid-enhanced MRI for T-staging of gallbladder carcinoma: emphasis on liver invasion

OBJECTIVE To evaluate the diagnostic performance of gadoxetic acid-enhanced MRI with an emphasis on the usefulness of the hepatobiliary phase (HBP) in T-staging of gallbladder carcinoma. METHODS 66 patients with surgically confirmed gallbladder carcinoma underwent MRI. Two radiologists independently reviewed two sets of gadoxetic acid-enhanced MRI without and with the HBP. Local tumour spread was evaluated according to T-staging, and the results were compared with pathological findings. The diagnostic performance of two image sets to differentiate each T-stage was compared. RESULTS The sensitivities of MRI with the HBP to differentiate T1 vs ≥ T2 lesions, ≤ T2 vs ≥ T3 lesions and ≤ T3 vs T4 lesions were 96.3%, 85.7% and 100% for Observer 1 and 92.6%, 95.2% and 100% for Observer 2, respectively (p<0.0001). By adding the HBP, the sensitivities to differentiate ≤ T2 vs ≥ T3 lesions were increased from 66.7% to 85.7% for Observer 1 and from 81.0% to 95.2% for Observer 2, although there was no significant difference (p>0.05). The overall accuracies for T-staging were increased from 80.3% to 86.4% for Observer 1, a statistically significant degree (p=0.046), and from 83.8% to 87.9% for Observer 2 (p>0.05). The k-value for the two observers indicated excellent agreement. CONCLUSION Gadoxetic acid-enhanced MRI provided acceptable diagnostic performance for T-staging of gallbladder carcinoma. Addition of the HBP aids in the detection of liver invasion. ADVANCES IN KNOWLEDGE In the T-staging of gallbladder carcinoma, gadoxetic acid-enhanced MRI with the HBP may enhance detection of liver invasion.

Breast Lesions in Children and Adolescents: Diagnosis and Management

Pediatric breast disease is uncommon, and primary breast carcinoma in children is extremely rare. Therefore, the approach used to address breast lesions in pediatric patients differs from that in adults in many ways. Knowledge of the normal imaging features at various stages of development and the characteristics of breast disease in the pediatric population can help the radiologist to make confident diagnoses and manage patients appropriately. Most breast diseases in children are benign or associated with breast development, suggesting a need for conservative treatment. Interventional procedures might affect the developing breast and are only indicated in a limited number of cases. Histologic examination should be performed in pediatric patients, taking into account the size of the lesion and clinical history together with the imaging findings. A core needle biopsy is useful for accurate diagnosis and avoidance of irreparable damage in pediatric patients. Biopsy should be considered in the event of abnormal imaging findings, such as non-circumscribed margins, complex solid and cystic components, posterior acoustic shadowing, size above 3 cm, or an increase in mass size. A clinical history that includes a risk factor for malignancy, such as prior chest irradiation, known concurrent cancer not involving the breast, or family history of breast cancer, should prompt consideration of biopsy even if the lesion has a probably benign appearance on ultrasonography.

Visibility of bony structures around hip prostheses in dual‐energy CT: With or without metal artefact reduction software

The development of dual‐energy CT and metal artefact reduction software provides a further chance of reducing metal‐related artefacts. However, there have been only a few studies regarding whether MARs practically affect visibility of structures around a metallic hip prosthesis on post‐operative CT evaluation.