Levoatriocardinal Vein Combined with Pulmonary Venous Varix Mimicking Arteriovenous Malformations: A Case Report.

The levoatriocardinal vein is an uncommon pulmonary venous abnormality that connects the left atrium or pulmonary vein with the systemic vein. It is distinct from partial anomalous pulmonary venous return in that the former forms a connection with the left atrium through the normal pulmonary vein whereas the latter involves pulmonary venous drainage to the systemic vein. Herein, we describe a case of the levoatriocardinal vein initially misdiagnosed as a pulmonary arteriovenous malformation using chest radiography and chest CT. The levoatriocardinal vein combined with pulmonary venous varix was confirmed using pulmonary angiography. To the best of our knowledge, this unusual coexistence of the levoatriocardinal vein and pulmonary venous varix has not been reported in English literature.

Effect of Hybrid Kernel and Iterative Reconstruction on Objective and Subjective Analysis of Lung Nodule Calcification in Low-Dose Chest CT.

Objective: To evaluate the differences in subjective calcification detection rates and objective calcium volumes in lung nodules according to different reconstruction methods using hybrid kernel (FC13-H) and iterative reconstruction (IR). Materials and Methods: Overall, 35 patients with small (< 4 mm) calcified pulmonary nodules on chest CT were included. Raw data were reconstructed using filtered back projection (FBP) or IR algorithm (AIDR-3D; Canon Medical Systems Corporation), with three types of reconstruction kernel: conventional lung kernel (FC55), FC13-H and conventional soft tissue kernel (FC13). The calcium volumes of pulmonary nodules were quantified using the modified Agatston scoring method. Two radiologists independently interpreted the role of each nodule calcification on the six types of reconstructed images (FC55/FBP, FC55/AIDR-3D, FC13-H/FBP, FC13-H/AIDR-3D, FC13/FBP, and FC13/AIDR-3D). Results: Seventy-eight calcified nodules detected on FC55/FBP images were regarded as reference standards. The calcium detection rates of FC55/AIDR-3D, FC13-H/FBP, FC13-H/AIDR-3D, FC13/FBP, and FC13/AIDR-3D protocols were 80.7%, 15.4%, 6.4%, 52.6%, and 28.2%, respectively, and FC13-H/AIDR-3D showed the smallest calcium detection rate. The calcium volume varied significantly with reconstruction protocols and FC13/AIDR-3D showed the smallest calcium volume (0.04 ± 0.22 mm3), followed by FC13-H/AIDR-3D. Conclusion: Hybrid kernel and IR influence subjective detection and objective measurement of calcium in lung nodules, particularly when both techniques (FC13-H/AIDR-3D) are combined.

Spontaneous Regression of an Intracranial Aneurysm Following Remote Aneurysm Clipping: Evaluation with High-Resolution Vessel Wall MRI.

Spontaneous regression of an unruptured aneurysm is very rare. We present a case of a 64-year-old woman with an unruptured cerebral aneurysm in which spontaneous regression occurred after contralateral clipping. High-resolution magnetic resonance imaging showed that the aneurysm had decreased in size and there was no evidence of thrombus. Level of Evidence Case, Level IV.

Suprapapillary versus transpapillary stent placement for malignant biliary obstruction: which is better?

PURPOSE: To compare the complications, stent patency, and patient survival with self-expandable metal stents (SEMSs) placed above or across the sphincter of Oddi in malignant biliary obstruction. MATERIALS AND METHODS: From January 2008 to December 2012, 155 patients were treated with percutaneous transhepatic SEMS placement. Seventy-four patients underwent suprapapillary stent placement (group A), and 81 patients underwent transpapillary stent placement (group B). Complications rates, stent patency, and patient survival were evaluated and analyzed for potential predictors. RESULTS: In group A, 68 covered and 28 uncovered SEMSs were placed, and, in group B, 78 covered and 19 uncovered SEMSs were placed. Thirty-six stent-related early complications were observed in a total of 154 patients (23.4%): pancreatitis (n = 23), cholangitis (n = 12), and cholecystitis (n = 1). The early complication rates for groups A and B were 14.9% (11 of 74) and 31.3% (25 of 80), respectively (P = .016). Pancreatitis occurred in three patients (4.1%) in group A and 20 patients (25.0%) in group B (P = .001). Stent location was a single independent predictor of pancreatitis (P < .001). Stent occlusions by tumor growth was more frequently observed in group A than in group B (P = .007), whereas stent occlusion by sludge incrustation was more frequently found in group B than in group A (P = .007). There was no significant difference in cumulative stent patency (P = .401) or patient survival (P = .792) between groups. CONCLUSIONS: To decrease the incidence of pancreatitis, suprapapillary placement of SEMSs is recommended for malignant biliary obstruction, but not in the lower 2 cm of the common bile duct.

Usefulness of acoustic radiation force impulse elastography in the differential diagnosis of benign and malignant solid pancreatic lesions.

PURPOSE: The aim of this study was to evaluate the tissue stiffness of solid pancreatic lesions by using acoustic radiation force impulse (ARFI) elastography to differentiate benign from malignant pancreatic lesions. METHODS: ARFI elastography was performed in 26 patients who had 27 focal solid pancreatic lesions, including 8 benign lesions (mass-forming pancreatitis, 5; autoimmune pancreatitis, 3) and 19 malignant lesions (pancreatic adenocarcinoma, 16; metastasis from colorectal cancer, 2; malignant neuroendocrine tumor, 1). On the elastographic images of virtual touch tissue imaging (VTI), the echogenicity of the mass was categorized on a 5-grade scale. On the elastographic image of virtual touch tissue quantification (VTQ), the shear wave velocities (SWVs) of the lesion and surrounding parenchyma were measured. RESULTS: On the VTI images, the mean echogenicity score of the malignant lesions (3.7±1.0) was higher than that of the benign lesions (3.1±0.4; P=0.023). On the VTQ images, there were no statistical differences in the mean SWV between the benign (2.4±1.1 m/sec) and malignant (3.3±1.0 m/sec) lesions (P=0.101). However, the mean SWV difference values between the lesion and background parenchyma of the malignant lesions (1.5±0.8 m/sec) were higher than those of the benign lesions (0.4±0.3 m/sec; P=0.011). CONCLUSION: ARFI elastography can determine the relative stiffness between a lesion and the background pancreatic parenchyma using VTI and VTQ, which is helpful in the differentiation between benign and malignant solid pancreatic lesions.