Dual-Energy Computed Tomography Virtual Noncalcium Imaging of Intracranial Arteries in Acute Ischemic Stroke: Differentiation Between Acute Thrombus and Calcification.

OBJECTIVE: Hyperdense artery sign (HAS) on noncontrast brain computed tomography (CT) indicates an acute thrombus within the cerebral artery. It is a valuable imaging biomarker for diagnosing large-vessel occlusion; however, its identification may be challenging with the presence of vascular calcification. Dual-energy CT virtual noncalcium (VNCa) imaging using a 3-material decomposition algorithm is helpful for differentiating between calcification and hemorrhage. This study aimed to clarify the potential of VNCa imaging for differentiating HAS from vascular calcification. METHODS: Patients with acute ischemic stroke and large-vessel occlusion identified on MR angiography, who also underwent noncontrast dual-energy CT, were included. The 80 kV/Sn 140 kV mixed images, with a weighting factor of 0.4, were considered 120 kVp-equivalent images. Postprocessing using a 3-material decomposition algorithm to differentiate between calcium (Ca), cerebrospinal fluid, and hemorrhage was performed via a commercially available 3-dimensional workstation. A mixed image, VNCa image, color-coded Ca image, and color-coded Ca image with VNCa image overlay (color-coded Ca-overlay image) were obtained, and axial reconstruction with a 1-mm slice thickness was performed for each image type. Two experienced neuroradiologists conducted imaging evaluations in consensus. RESULTS: Thirty-four patients (mean age, 76.0 years; 21 male and 13 female patients) were included. The mixed and VNCa images revealed an HAS (indicating an acute clot) corresponding to the large-vessel occlusion site in 30 patients. Among them, the VNCa and color-coded Ca-overlay images enabled clear differentiation between the acute thrombus and adjacent vessel wall calcification in 5 patients. Among the other 4 patients, the VNCa, Ca-overlay, and Ca images identified calcified cerebral emboli in the M1 segment in 1 patient. For the other 3 patients, no high attenuation corresponding to magnetic resonance angiography findings was observed in any of the mixed, VNCa, Ca-overlay, or Ca images. CONCLUSIONS: VNCa and color-coded Ca-overlay images obtained via dual-energy brain CT enabled differentiation of acute thrombus from vessel wall calcification and calcified cerebral emboli in patients with acute ischemic stroke.

Non-contrast dual-energy CT using X-map for acute ischemic stroke: region-specific comparison with simulated 120-kVp CT and diffusion-weighted MR images.

PURPOSE: X-map is a non-contrast dual-energy CT (DECT) application to identify acute ischemic stroke (AIS). Our aim was to verify region-specific characteristics of early ischemic changes (EIC) on X-map compared with simulated 120-kVp mixed-CT image and DWI. METHODS: Fifty AIS patients who underwent DECT and DWI were enrolled (mean age, 76 years; 34 men, 16 women). All datasets including mixed-CT image, X-map, and DWI were transformed into a standard brain atlas with 11 × 2 ROIs based on the ASPECTS + W system. ROIs with EIC on DWI, mixed-CT image, and X-map were defined as DWI-positive, mixed-CT-positive, and X-map-positive, and those with normal finding were DWI-negative, mixed-CT-negative, and X-map-negative respectively, in visual assessment by two neuroradiologists in consensus. RESULTS: EIC on X-maps were visually relevant to those on the other images: of 221 ROIs with mixed-CT-positive and X-map-positive, 198 (89.6%) were DWI-positive. X-map revealed moderate diagnostic accuracy for AIS compared with DWI in ROC curve analysis (AUC = 0.732). X-map identified EIC in deep white matter more sensitively than mixed-CT image: of 15 ROIs with mixed-CT-negative and X-map-positive in W segments, 14 (93.3%) were DWI-positive. X-map often showed EIC in cortical regions that were not detected on the other images: of 67 ROIs with mixed-CT-negative and X-map-positive in I and M1-M6 segments, 47 (70.1%) were DWI-negative. CONCLUSIONS: X-map is useful to detect EIC, especially in deep white matter, and may also provide additional information in acute ischemic lesions where DWI cannot be detected.

Comparison of Radiofrequency and Cryoballoon Pulmonary Vein Ablation for the Early and Late Recurrence of Atrial Fibrillation.

Objective Early recurrence (ER) after pulmonary vein isolation (PVI) for atrial fibrillation (AF) is expected to resolve within the recommended 3-month blanking period, irrespective of the ablation device used. To compare the occurrence and relationship of AF within the blanking period and subsequent late recurrence (LR) with radiofrequency (RF) and cryoballoon (CB) ablation. Methods A retrospective analysis of 294 patients (mean age=62±9, 70.0% male) undergoing PVI for drug-refractory paroxysmal AF was done. After categorizing the patients into the RF group (n=152) and the CB group (n=142), a group-wise comparison was done to investigate the impact of ER on LR throughout a 2-year follow-up. Results The groups were similar regarding the occurrence of ER (RF=22.4%, CB=24.6%, p=0.62), while LR was significantly higher in the RF group (p=0.003). ER was associated with LR in the RF group (p<0.01) but not in the CB group (p=0.08), while a significant independent association with an increased LR risk was observed [hazard ratio (HR) 6.12; 95% confidence interval (CI) 3.56-10.51, p<0.01]. RF ablation also significantly increased the risk of LR (HR=2.93; 95% CI=1.64-5.23, p<0.01). Conclusion A recurrence of atrial arrhythmia is more frequent with RF-PVI than with CB-PVI for patients with paroxysmal AF. ER and RF-ablation are strong predictors for LR after the 3-month blanking period.

Appropriate iMAR presets for metal artifact reduction from surgical clips and titanium burr hole covers on postoperative non-contrast brain CT.

PURPOSE: To evaluate suitable iterative metal artifact reduction (iMAR) presets for titanium neurosurgical clips and burr hole covers (BHCs) on postoperative non-contrast computed tomography (NCCT). METHOD: Twenty-two patients who underwent NCCT after intracranial aneurysmal clipping were included. NCCT images were postprocessed using eight currently available iMAR presets. In each image, a circular region of interest (ROI) was placed around clip, BHC, and on parietal lobe as reference. Standard deviation (SD) and attenuation value (HU) were measured in each ROI to obtain artifact index (AI) and contrast-to-noise ratio (CNR). For each iMAR preset, SD, AI, HU, and CNR were compared with those without iMAR for clips and BHCs. Visual assessment around each clip and BHC was performed by two neuroradiologists using three-point visual score (VS) (1 = no apparent, 2 = minor, and 3 = severe artifacts). RESULTS: Among the presets, the neuro-coils preset (iMAR-NC) showed the lowest SD, AI, and VS for clips (P < 0.001). For BHCs, HU, CNR, and VS with iMAR-NC were significantly higher than those without iMAR (P < 0.001). SD, AI, and VS with the shoulder implants preset (iMAR-ShI) were significantly lower than those without iMAR for clips (P = 0.002, 0.002, and P <  0.001, respectively). For BHCs, VS with iMAR-ShI was lowest among the presets (P = 0.004). CONCLUSIONS: Although iMAR-NC reduces metal artifacts from clips, it strengthens artifacts from BHCs. For postoperative NCCT, iMAR-ShI most effectively reduces metal artifacts from both clips and BHCs in a single preset.

[Evaluating Eye Lens Dose of Neurovascular and Cardiac Electrophysiology Interventional Physician].

PURPOSE: The International Commission on Radiological Protection recommended that interventional radiologies (IRs) have high radiation doses and that staff may also be exposed to high doses. In the present study, we measured the radiation exposure dose [3 mm dose equivalent, Hp (3) ] in the eye using an appropriate dosimeter placed next to the physician' s eye during neurovascular intervention procedure (Neuro-IR) and interventional cardiac electrophysiology procedure (EP-IR). METHOD: Physicians wore a direct eye dosemeter just lateral to the left eye and an additional direct eye dosemeter outside the radiation protective glasses close to their left eye. Additionally, a neck badge [0.07 mm dose equivalent, Hp (0.07) ] was worn outside the protective apron to the left of the neck, to compare the direct eye dosimeter estimated doses. The occupational eye lens dose was evaluated over a period of 6-month. RESULTS: The maximum Hp (3) of the Neuro-IR physician was estimated 5.1 mSv without the radiation protective glasses and 1.6 mSv with the radiation protective glasses. On the other hand, the maximum Hp (3) of the EP-IR physician was estimated 29 mSv without the radiation protective glasses and 15 mSv with the radiation protective glasses. CONCLUSION: Physicians eye lens dose [Hp (3) ] tended to be overestimated by the neck badge measurements [Hp (0.07)]. A correct evaluation of the lens dose [Hp (3) ] using the direct eye dosimeter is recommended. Although we found a positive correlation between Hp (0.07) and Hp (3), the value of R2 in the regression equation is low, we recommended that the eye lens dose estimated carefully from Hp (0.07).

Evaluation of lumbar intervertebral disc degeneration using dual energy CT virtual non-calcium imaging.

PURPOSE: To clarify the utility of dual energy CT (DECT) virtual non-calcium (VNCa) imaging for investigating lumbar intervertebral disc degeneration. METHOD: Fifty-three patients who underwent both DECT and MR imaging were retrospectively reviewed. Midsagittal T2-weighted imaging findings of all discs were classified based on modified Pfirrmann grade (mPG). Quantitative evaluation of VNCa maps was achieved by setting volumes of interest on each disc. We compared VNCa CT values with mPG using Spearman's rank correlation and one-way ANOVA. VNCa imaging findings of each disc were classified by two neuroradiologists into one of three categories based on the attenuation of nucleus pulposus (NP) compared to that of annulus fibrosus (AF) or muscle. The relationship between the visual categories for each rater and mPGs was analyzed by chi-square test. Statistical significance was established at P < 0.05. RESULTS: Among the included 171 lumbar discs, significant positive correlation was found between VNCa CT values for NP and mPGs (R2 = 0.574, P < 0.05), whereas no significant correlation was found between those for AF and mPGs (R2= -0.015, P = 0.846). Mean VNCa CT values for NP were significantly different among each mPG (P < 0.05 for each), except between grades 3 and 4 (P = 0.111). Mean VNCa CT values for AF were not significantly different among each mPG (P = 0.160-1.000). Statistically significant difference was observed among the visual categories for VNCa maps and mPGs in each rater (P < 0.05 for both). CONCLUSIONS: VNCa imaging acquired by a single DECT scan and post-processing has potential as an imaging biomarker of lumbar intervertebral disc degeneration.

OCCUPATIONAL RADIATION EXPOSURE DOSE OF THE EYE IN DEPARTMENT OF CARDIAC ARRHYTHMIA PHYSICIAN.

Interventional radiology (IR) procedures tend to be complex, which delivers high radiation exposure to patient. In the present study, we measured the radiation exposure dose [Hp(3)] in the eye using a direct eye dosemeter placed next to the physician's eye during procedures. Physicians wore a direct eye dosemeter just lateral to eyes and an additional direct eye dosemeter outside the radiation protective eyeglasses close to their eyes. Additionally, a neck glass badge was worn at the neck. Although we found a positive correlation between the left neck glass badge dose [Hp(0.07)] and the left eye lens dose [Hp(3)], the value of R2 of the regression equation were 0.62 and 0.71 (outside and inside). We thought that the exact eye lens dose might not be estimated from the neck glass badge. In conclusion, a correct evaluation of the lens dose [Hp(3)] using the direct eye dosemeter is recommended for tachyarrhythmia physicians.

Malignant triton tumor of the duodenum: report of a case.

We report a case of malignant triton tumor of the duodenum, which is extremely rare. A submucosal malignant tumor was detected in the duodenum of a 49-year-old woman. The tumor was completely resected by performing pancreaticoduodenectomy. Pathological examination revealed that the lesion was a malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation, i.e., a malignant triton tumor. Long-term survival has been achieved with no recurrence at 8.5 years after surgery.

[Reduction method of patients' radiation dose considering the size of field of view with a digital cine X-ray system loading a flat-panel detector].

Angiographic equipment has tended toward using flat-panel detector (FPD). However, the radiation dose varies depending on the size of field of view (FOV) in the FPD. Although we were using 7 inch FOV in cardiac procedures, we examined a way to reduce the patients' radiation dose by using 8 inch FOV utilizing a digital zoom processing. We measured the absorbed dose rates at an interventional reference point (IRP) with 20 cm acrylic board to compare 8 inch FOV using a digital zoom processing with 7 inch FOV. Additionally we visually evaluated these phantom images. Result of comparison of absorbed dose rates at IRP, 8 inch FOV using a digital zoom processing was reduced more than 7 inch FOV (fluoroscopic 29.0% and digital cine 37.5%). These phantom images were of equivalent quality. The method to use 8 inch FOV utilizing a digital zoom processing technique in cardiac procedures is one of the effective radiation exposure reduction methods.

Outcome of hepatoblastomas treated using the Japanese Study Group for Pediatric Liver Tumor (JPLT) protocol-2: report from the JPLT.

BACKGROUND: In the recent years, surgical resection with pre- and/or postoperative chemotherapy has markedly improved the survival rate of hepatoblastoma patients. We herein report the results of patients treated with the current protocol of the Japanese Study Group for Pediatric Liver Tumor, JPLT-2. METHODS: A total of 279 patients with malignant liver tumor were enrolled in JPLT-2. Data from 212 hepatoblastoma cases were analyzed. PRETEXT I patients were treated with primary resection followed by low doses of cisplatin-pirarubicin (tetrahydropyranyl-adriamycin). Otherwise, patients received preoperative cisplatin-pirarubicin (CITA), followed by surgery and postoperative chemotherapy. Ifosfamide, pirarubicin, etoposide, and carboplatin (ITEC) were given as a salvage treatment. High-dose chemotherapy with hematopoietic stem cell transplantation (SCT) was reserved for patients with metastatic diseases. RESULTS: The 5-year overall survival rate (OS) in non-metastatic cases was 100% for PRETEXT I, 87.1% for PRETEXT II, 89.7% for PRETEXT III, and 78.3% for PRETEXT IV. The 5-year OS in metastatic cases was 43.9%. The outcome in non-metastatic PRETEXT IV cases was markedly improved, while the results of metastatic tumors remained poor. CONCLUSIONS: JPLT-2 protocol achieved satisfactory survival among children with non-metastatic hepatoblastoma. New approaches are needed for patients with metastatic diseases.

Menkes disease with gastroesophageal reflux disease and successful surgical treatment: a case report and literature review.

The complication of Menkes disease (MD) and gastroesophageal reflux disease (GERD) is extremely rare. This report describes the very rare case of a one-year-old boy with MD complicated with GERD, and the successful surgical treatment of GERD. We review the literature on this relationship between MD and GERD, and discuss the clinical features of this association. Furthermore, the possible cause of the onset of GERD complicated with MD is explored in this report.

Disorders of interstitial cells of Cajal in a neonate with segmental dilatation of the intestine.

Localized myopathy of the muscular layers may be an important factor contributing to segmental dilatation of the intestine (SDI). Only one report has described SDI of the jejunum in a neonate showing no abnormality of the interstitial cells of Cajal (ICC). The present report describes the very rare case of a neonatal girl with segmental dilatation of the distal duodenum and proximal jejunum with irregular arrangements of Auerbach's plexus and ICC and the successful surgical treatment of SDI. We review the literature on this type of relationship between abnormality of ICC and SDI and discuss the clinical features of this complication. Furthermore, the possible neuropathic cause of SDI complicated with disorders of ICC was explored in this report.

Genome-wide analysis of allelic imbalances reveals 4q deletions as a poor prognostic factor and MDM4 amplification at 1q32.1 in hepatoblastoma.

In a single-nucleotide polymorphism array-based analysis of 56 hepatoblastoma (HB) tumors, allelic imbalances were detected in 37 tumors (66%). Chromosome gains were found in 1q (28 tumors), 2q (24), 6p (8), 8q (8), 17q (6), and 20pq (10), and losses in 1p (6), 4q (9), and 16q (4). Fine mapping delineated the shortest overlapping region (SOR) of gains at 1q32.1 (1.3 Mb) and 2q24.2-q24.3 (4.8 Mb), and losses at 4q34.3-q35.2 (8.7 Mb) and 4q32.3 (1.6 Mb). Uniparental disomy of 11pter-11p15.4 (IGF2) and loss of 11pter-p14.1 were found in 11 and 2 tumors, respectively. Expression of HTATIP2 (11p15.1) was absent in 9 of 20 tumors. Amplification was identified in four tumors at 1q32.1, where the candidate oncogene MDM4 is located. In the 4q32.3-SRO, ANXA10S, a variant of the candidate tumor suppressor ANXA10, showed no expression in 19 of 24 tumors. Sequence analysis of ANXA10S identified a missense mutation (E36K, c.106G>A) in a HB cell line. Multivariate analysis revealed that both 4q deletion and RASSF1A methylation (relative risks: 4.21 and 7.55, respectively) are independent prognostic factors. Our results indicate that allelic imbalances and gene expression patterns provide possible diagnostic and prognostic markers, as well as therapeutic targets in a subset of HB.

Pediatric alveolar echinococcosis invading the diaphragm and spreading to the chest and abdominal wall.

Hepatic alveolar echinococcosis (AE) is an endemic disease in certain parts of the world and relatively rare in children. This report describes a 9-year-old girl with hepatic AE invading the diaphragm and directly spreading to the chest and abdominal wall. She was treated by surgical extirpation and albendazole therapy. In advanced hepatic AE, combined therapy of surgical and medical intervention is thought to improve the prognosis.

Alveolar echinococcosis of the liver in children.

BACKGROUND/PURPOSE: Alveolar echinococcosis of the liver (AEL) is a zoonosis that is distributed in cold regions of the northern hemisphere. The disease is mostly found in adults and rarely in pediatric patients because it tends to be slow growing. PATIENTS AND METHODS: Ten Japanese pediatric patients (under 15 years old) with AEL have been operated on in Hokkaido University Hospital from January 1936 to June 2008. We examined these children and revealed the characteristics of AEL. RESULTS: The patients included three males and seven females whose mean age was 10.9 years old, ranging from 7 to 15. The length of follow-up was from 3 months to 33 years (median 19 years). Six cases were picked up by mass screening; nine cases who underwent hepatectomy are still alive and one case whose tumors were unresectable died of liver failure. CONCLUSION: Our cases indicate that some AEL pediatric patients advanced rapidly, so early detection is imperative. Thus, screening examinations are essential for children in contaminated areas and, if a liver tumor is found on a screening examination and diagnosed as AEL, complete radical resection should be performed.

A 5-year-old boy with unicentric Castleman disease affecting the mesentery: utility of serum IL-6 level and (18)F-FDG PET for diagnosis.

Castleman disease (CD) is a rare lymphoproliferative disorder of unknown etiology. It is quite difficult to diagnose CD without typical localized signs or symptoms. We present a 5-year-old boy with unicentric plasma cell CD in the mesentery, which was too small to be detected by any conventional imaging. (18)F-fluorodeoxyglucose positron emission tomography image and a serum cytokine profile prompted us to perform a curative surgical excision, confirming his diagnosis. Our case also supported an important role of interleukin-6 in the pathophysiology of plasma cell CD.

Hyperplastic polyp of the gallbladder associated with pancreaticobiliary maljunction in a 9-year-old girl.

The association between hyperplastic polyp of the gallbladder with pancreaticobiliary maljunction (PBM) is extremely rare. This report describes the rare case of a 9-year-old girl with PBM complicated by hyperplastic polyp of the gallbladder, and the successful surgical treatment of PBM. We review the literature on this type of relationship between hyperplastic polyp of the gallbladder and PBM, and discuss the clinical features of this complication. Furthermore, the possible cause of the onset of hyperplastic polyp of the gallbladder complicated by PBM was explored in this report.

Idiopathic thrombocytopenic purpura complicated with biliary atresia: a rare occurrence and literature review.

The association of biliary atresia (BA) and idiopathic thrombocytopenic purpura (ITP) is extremely rare, with only 2 cases being reported in the literature. This report describes the very rare case of a 1-year-old boy with BA complicated with ITP after cholangitis and the successful steroid treatment of ITP. We review the literature on this type of relationship between BA and ITP and discuss the clinical features of this complication. Furthermore, the possible cause of the onset of ITP complicated with BA was explored in this report.

Chylous ascites after nephrectomy without lymphadenectomy for malignant rhabdoid tumor of the kidney: A rare occurrence and literature review.

Chylous ascites (CA) is an extremely rare complication of abdominal surgery in children. This report describes a 4-month-old girl with malignant rhabdoid tumor of the kidney (MRTK), who developed CA after left nephrectomy without lymphadenectomy, and who was successfully treated conservatively with enteral therapy. The literature on CA after nephrectomy without lymphadenectomy for MRTK is reviewed herein, and the clinical problems of postoperative CA are discussed.

Management and outcome in prenatally diagnosed sacrococcygeal teratomas.

BACKGROUND: The aim of the present study was to retrospectively determine the clinical factors affecting the outcome after birth in prenatally diagnosed sacrococcygeal teratomas (SCT). METHODS: Six cases of prenatal SCT were identified from January 1985 until August 2005. A retrospective review of case-notes and pathological reports was carried out. Clinical data during the perinatal period, operative findings, postoperative complications and follow up were evaluated in the patients with prenatally diagnosed SCT. RESULTS: SCT presented as type I in two neonates and type III in four between 22 and 33 weeks' gestation. Fetal intervention was not performed for any fetus. Five of six were delivered by cesarean section and the other was delivered vaginally due to small tumor size. Patients were born at between 29 and 39 weeks' gestation and weighed from 1840 to 3500 g. All patients with type III SCT presented with related diseases, including bilateral hydronephrosis, neurological deficit of the communicating peroneal nerve such as paralytic talipes equines, bladder or bowel dysfunction, high-output cardiac failure, or fetal hydrops in one of a set of fraternal twins. A baby with high-output cardiac failure and fetal hydrops underwent urgent cesarean section at 29 weeks' gestation and died 8 days after birth despite intensive care due to multi-organ failure. In five cases, surgery was successful with good outcomes maintained at follow-up of between 8 months and 14 years. CONCLUSIONS: Detailed ultrasound should be performed to rule out associated anomalies, and determine the presence or absence of hydrops in prenatally diagnosed SCT. Fetal hydrops, orthopedic impairment such as lower extremity weakness and swelling, and urinary incontinence are important clinical factors affecting the outcome after birth in prenatally diagnosed SCT. In particular, the present study indicated that the association of a fraternal twin and fetal hydrops makes it very difficult to treat SCT perinatally.