Accelerated Synthetic MRI with Deep Learning-Based Reconstruction for Pediatric Neuroimaging.

BACKGROUND AND PURPOSE: Synthetic MR imaging is a time-efficient technique. However, its rather long scan time can be challenging for children. This study aimed to evaluate the clinical feasibility of accelerated synthetic MR imaging with deep learning-based reconstruction in pediatric neuroimaging and to investigate the impact of deep learning-based reconstruction on image quality and quantitative values in synthetic MR imaging. MATERIALS AND METHODS: This study included 47 children 2.3-14.7 years of age who underwent both standard and accelerated synthetic MR imaging at 3T. The accelerated synthetic MR imaging was reconstructed using a deep learning pipeline. The image quality, lesion detectability, tissue values, and brain volumetry were compared among accelerated deep learning and accelerated and standard synthetic data sets. RESULTS: The use of deep learning-based reconstruction in the accelerated synthetic scans significantly improved image quality for all contrast weightings (P < .001), resulting in image quality comparable with or superior to that of standard scans. There was no significant difference in lesion detectability between the accelerated deep learning and standard scans (P > .05). The tissue values and brain tissue volumes obtained with accelerated deep learning and the other 2 scans showed excellent agreement and a strong linear relationship (all, R 2 > 0.9). The difference in quantitative values of accelerated scans versus accelerated deep learning scans was very small (tissue values, <0.5%; volumetry, -1.46%-0.83%). CONCLUSIONS: The use of deep learning-based reconstruction in synthetic MR imaging can reduce scan time by 42% while maintaining image quality and lesion detectability and providing consistent quantitative values. The accelerated deep learning synthetic MR imaging can replace standard synthetic MR imaging in both contrast-weighted and quantitative imaging.

Influence of arm position on catheter placement during real-time ultrasound-guided right infraclavicular proximal axillary venous catheterization.

BACKGROUND: Real-time ultrasound-guided infraclavicular proximal axillary venous catheterization is used in many clinical situations and provides the advantages of catheter stabilization, a reduced risk of catheter-related infection, and comfort for the patient without limitation of movement. However, unintended catheter tip dislocation and accidental arterial puncture occur occasionally. This study was designed to investigate the influence of arm position on catheter placement and complications. METHODS: Patients were randomized to either the neutral group (n=240) or the abduction group (n=241). In the neutral group, patients were positioned with the head and shoulders placed in an anatomically neutral position and the arms kept by the side during catheterization. In the abduction group, the right upper arm was abducted at 90° from the trunk during catheterization. After real-time ultrasound-guided catheterization was carried out in the right infraclavicular proximal axillary vein, misplacement of the catheter and all complications were evaluated with ultrasound and chest radiography. RESULTS: The success rate of complete catheterization before evaluating the placement of the catheter was high in both groups (97.1 vs 98.8%, P=not significant). The incidence of accidental arterial puncture was not different (1.7 vs 0%, P=not significant). The incidence of misplacement of the catheter was higher in the neutral group than in the abduction group (3.9 vs 0.4%, P=0.01). There were no complications, such as haemothorax, pneumothorax, or injury to the brachial plexus and phrenic nerve, in either group. CONCLUSIONS: Upper arm abduction may minimize the risk of misplacement of the catheter during real-time ultrasound-guided infraclavicular proximal axillary venous catheterization. CLINICAL TRIAL REGISTRATION: The trial was registered with the Clinical Trial Registry of Korea: https://cris.nih.go.kr/cris/index.jsp. Identifier: KCT0001417.

Short-term changes of intraocular pressure after cervical interlaminar epidural injection: a pilot study.

BACKGROUND: Cervical epidural injection (CEI) is widely performed on patients with intervertebral disc herniation. The aim of the present study was to investigate the short-term effects of CEI on non-invasive intraocular pressure (IOP) measurements in subjects with normal eyes. METHODS: This prospective study enrolled 15 patients who were undergoing CEI at the C5/6 level with an interlaminar approach in the left lateral decubitus position. IOP was measured in both eyes by a rebound tonometer (Icare-PRO, Icare Finland Oy, Helsinki, Finland). A total volume of 14 ml (4 ml non-ionic contrast, a mixture of 0.2% lidocaine 1 ml and normal saline 4 ml for irrigation and a mixture of normal saline 4.5 ml with non-particulate betamethasone 2 mg) was injected with 1.0 ml s(-1). IOP was measured 5 min after the lateral decubitus position (T0, baseline), immediately after CEI (T1), and 1 min intervals for 5 min (T2-T6). RESULTS: The values of left and right baseline IOP (T0) were 18.9 (2.0) and 15.6 (2.6) mm Hg, respectively. IOP of left and right eyes at T1 [26.6 (4.2) and 21.2 (2.5) mm Hg, respectively] and T2 [26.2 (4.5) and 21.0 (2.8) mm Hg, respectively] were significantly higher compared with T0. These values immediately decreased at T3 and returned to baseline levels within 5 min after CEI. CONCLUSIONS: CEI resulted in an elevation of IOP of both eyes. However, the effects were transient only lasting a few minutes.

Effectiveness of the Streamlined Liner of the Pharynx Airway (SLIPATM) in allowing positive pressure ventilation during gynaecological laparoscopic surgery.

The aim of this study was to assess whether the Streamlined Liner of the Pharynx Airway (SLIPA) performed as well as an endotracheal tube for positive pressure ventilation in gynaecological laparoscopic surgery in the Trendelenburg position. Forty patients (American Society of Anesthesiologists physical status I to III) were randomly divided into two groups: SLIPA (n = 20) or endotracheal tube group (n = 20). Lung mechanics and severity of postoperative sore throat were assessed in both groups. In the SLIPA group, the oropharyngeal leak pressure was also measured. There were no significant differences between groups in the lung mechanics. In the SLIPA group, oropharyngeal leak pressure and peak inspiratory pressure increased significantly after gas insufflation compared to 10 minutes after patient positioning in the lithotomy position (P < 0.05). The difference between oropharyngeal leak pressure and peak inspiratory pressure (approximately 10 cmH2O throughout the procedure) remained suitable for airway maintenance. The incidence of sore throat was similar in both groups but the severity was less in the SLIPA group 24 hours after surgery (P < 0.05). There were no other complications such as regurgitation noted in either group. In the study population, the SLIPA performed as well as an endotracheal tube in allowing positive pressure ventilation without gas leak during gynaecological laparoscopy. The way in which the SLIPA increases its resistance to gas leak as the inspiratory pressure rises may account for this.

Comparison of diamond-like carbon-coated nitinol stents with or without polyethylene glycol grafting and uncoated nitinol stents in a canine iliac artery model.

OBJECTIVE: Neointimal hyperplasia is a major complication of endovascular stent placement with consequent in-stent restenosis or occlusion. Improvements in the biocompatibility of stent designs could reduce stent-associated thrombosis and in-stent restenosis. We hypothesised that the use of a diamond-like carbon (DLC)-coated nitinol stent or a polyethylene glycol (PEG)-DLC-coated nitinol stent could reduce the formation of neointimal hyperplasia, thereby improving stent patency with improved biocompatibility. METHODS: A total of 24 stents were implanted, under general anaesthesia, into the iliac arteries of six dogs (four stents in each dog) using the carotid artery approach. The experimental study dogs were divided into three groups: the uncoated nitinol stent group (n = 8), the DLC-nitinol stent group (n = 8) and the PEG-DLC-nitinol stent group (n = 8). RESULTS: The mean percentage of neointimal hyperplasia was significantly less in the DLC-nitinol stent group (26.7±7.6%) than in the nitinol stent group (40.0±20.3%) (p = 0.021). However, the mean percentage of neointimal hyperplasia was significantly greater in the PEG-DLC-nitinol stent group (58.7±24.7%) than in the nitinol stent group (40.0±20.3%) (p = 0.01). CONCLUSION: Our findings indicate that DLC-coated nitinol stents might induce less neointimal hyperplasia than conventional nitinol stents following implantation in a canine iliac artery model; however, the DLC-coated nitinol stent surface when reformed with PEG induces more neointimal hyperplasia than either a conventional or DLC-coated nitinol stent.

Caudal epidural block in children: comparison of needle insertion parallel with caudal canal versus conventional two-step technique.

This study compared the technique of inserting the needle for caudal epidural blockade in a single pass parallel to the caudal canal versus the conventional technique of approaching the caudal canal with the needle at a steeper angle. Seventy-five patients, aged 0 to 72 months, scheduled for urological surgery were prospectively enrolled in this study. Patients were randomly divided into two groups: a conventional method group (caudal block performed with conventional needle insertion, n=40) and a new method group (needle inserted into the skin at an angle of 200 and into the caudal space without redirection, n=35). Two anaesthetists (A, B) performed the caudal blocks. For anaesthetist A, the mean time required (standard deviation) to perform needle insertion in the conventional method group was 2.2 (0.8) minutes and in the new method group 1.1 (0.7) minutes (P = 0.03). For anaesthetist B the mean time (standard deviation) to perform needle insertion in the conventional method group was 2.1 (1.1) minutes and in the new method group 1.3 (0.8) minutes (P = 0.04). Successful block was considered as first pass placement of the needle in the caudal canal confirmed (after placement) by ultrasound imaging, and the absence of a bloody tap. Subcutaneous placement of the needle after the first attempt occurred in two cases in the conventional method group and three cases in the new method group. Bloody tap occurred in four cases, all in the conventional method group and none in the new method group. When required, the second pass was successful in all cases.

The clinical course of respiratory tuberculosis in lung cancer patients.

OBJECTIVE: To determine the clinical features of lung cancer patients with respiratory tuberculosis (TB), thereby elucidating the clinical course. SETTING: A tertiary referral hospital in Korea, with intermediate TB prevalence. DESIGN: A retrospective case-control study involving lung cancer patients in whom respiratory TB was diagnosed concurrently or sequentially. RESULTS: Of 36 lung cancer patients, 10 (27.8%) were diagnosed with TB concurrently with the diagnosis of lung cancer, while 26 (72.2%) were diagnosed with TB after the diagnosis of lung cancer. The median time from the diagnosis of lung cancer to the diagnosis of TB was 4 months (range -1-47). Five lung cancer patients presented with incidental microbiological or pathological findings. Of the 36 lung cancer patients, eight (22%) had no remarkable changes on chest radiography, while all control group patients had identifiable abnormalities (P < 0.001). In both groups, most patients completed the initially prescribed anti-tuberculosis medications, with some modest modifications. The most common cause of death in the lung cancer group was progression of lung cancer (89.5%). CONCLUSION: The clinical course of respiratory TB in lung cancer patients does not differ from that in patients without malignancy, suggesting that respiratory TB may not influence the clinical course of lung cancer patients if properly treated.

Circulating interleukin 17 is increased in the acute stage of Kawasaki disease.

OBJECTIVES: During the acute phase, patients with Kawasaki disease (KD), an acute systemic vasculitis, demonstrate a drastic increase in serum interleukin-6 (IL-6), which parallels the duration of the fever. Recently, IL-17 has been reported to induce IL-6 production. The aim of this study was to elucidate the involvement of IL-17 in the pathogenesis of KD. METHODS: Serum samples were obtained from patients with KD (n=30) and normal controls (n=20), and the concentrations of IL-17 and IL-6 measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: Compared with the normal controls (2.08 +/- 2.14 pg/mL), serum IL-17 was markedly elevated in patients with acute KD (25.47 +/- 5.05 pg/mL): levels gradually decreased in the subacute phase (5.94 +/- 2.83 pg/mL). In the acute phase, levels of IL-6 were 83.52 +/- 19.12 pg/L, which correlated well with the serum levels of IL-17. CONCLUSION: These results suggest that IL-17 may be involved in the development of, or the effects of inflammation in KD.

Spontaneous regression of a herniated cervical disc in a patient with myelopathy. Case report.

The authors present a case of spontaneous regression of a herniated cervical nucleus pulposus in a patient with myelopathy. This 37-year-old woman developed sudden quadriparesis; she had reported no history of trauma. Magnetic resonance (MR) imaging revealed a large disc herniation and increased signal intensity of the cord at the C5-6 level. The extruded disc fragment was found to have resolved on follow-up MR imaging after 28 months, despite the fact that the patient had undergone no specific treatment. The patient's symptoms had subsided almost totally. This is the first case of MR-documented regression of a cervical disc herniation in a patient with myelopathy.

Intraspinal epidermoid cyst occurring 15 years after lipomyelomeningocele repair. Case report.

The authors report the case of a spinal epidermoid cyst that developed in a patient who had undergone surgery for lipomyelomeningocele repair 15 years earlier. The patient presented with symptoms of retethering. Magnetic resonance imaging revealed a cystic intraspinal mass that extended from L-2 to L-5. The mass proved to be an epidermoid cyst. Spinal epidermoid cysts can cause retethering after a repair of lipomyelomeningocele, and the risk of this development can be present for decades.

Surgical options of hypertensive intracerebral hematoma: stereotactic endoscopic removal versus stereotactic catheter drainage.

The authors analyzed the difference between two surgical procedures, stereotactic endoscopic removal (SER) and stereotactic catheter drainage (SCD), in 18 patients of ganglionic intracerebral hematoma (ICH). Ten patients underwent SCD and eight SER within 24 hours of insult. The mean age was 53.3 (33-81) years and male to female ratio was 11:7. The mean volume of hematoma was 34.4 (23-105) ml. All patients had major neurological deficits without signs of transtentorial herniation. Mean follow-up was 8 (6-10) months. Under local anesthesia, Otzuki's cannula was placed through a burr hole. ICH was removed with suction and forceps under endoscopic guidance. Hemostasis was performed with Nd-YAG laser. For SCD, we used silicone catheter and urokinase. The hematoma was drained in 3-5 days in SER, whereas 7-10 days in SCD. Postoperative rebleeding occurred in one case of SER. Mortality rate was 13% in SER, 10% in SCD. The patients who gained most from these treatments were those who had been admitted with an impaired level of consciousness. The whole procedure can be done under direct vision in SER, so SER might replace SCD with similar mortality.

Cine MR CSF flow study in hydrocephalus: what are the valuable parameters?

To evaluate the changes of intracranial cerebrospinal fluid (CSF) dynamics in hydrocephalus, we studied the various parameters of cine phase contrast (PC) magnetic resonance (MR) CSF flow images in cases of acutely progressive hydrocephalus, comparing them with those in normal CSF circulation. The MR images were obtained with 1.5 T unit using the 2 dimensional cine PC sequence with cardiac gating in 10 non-obstructive hydrocephalus (NOH), 3 obstructive hydrocephalus (OH), and 10 controls. The temporal velocity information from the anterior and posterior cervical pericord spaces, third and fourth ventricles, and aqueduct were plotted as wave form. The wave forms were analyzed for configurations, amplitude parameters (Smax, Smin, Sdif), and temporal parameters (R-S, R-SMV, R-D, R-DMV). The statistical significance of each parameter was examined with paired t-test. All patients with OH underwent endoscopic thrid ventriculostomy, whereas all NOH underwent shunting procedures. In 5 ROIs, distinct reproducible configuration features were obtained at aqueductal and cervical pericord spaces. Statistically significant differences between control and hydrocephalus only in temporal parameters were determined. In NOH, the graph showed R-DMV shortening (p < 0.01) at anterior cervical pericord space. In OH, there were R-DMV shortening (p < 0.05) at anterior cervical pericord space, R-SMV shortening (p < 0.02) at posterior cervical pericord space. Also the level of obstructions could be determined in all OHs. The analysis of MR CSF flow images may give us valuable information on the site of obstruction, explaining the cause of hydrocephalus, thus deciding the necessity of shunting procedures using in vivo images.

Preliminary results of a new covered biliary metal stent for malignant biliary obstruction.

BACKGROUND AND STUDY AIMS: The biliary stents in current use have a tendency to be blocked, so we designed a self-expandable metal stent covered with polyurethane to overcome the risk of tumor ingrowth of uncovered self-expandable metal stents. To evaluate the success and the effectiveness of the new membrane-covered self-expandable metal stent (covered modified Gianturco biliary stent), we studied patients with biliary obstruction caused by biliopancreatic carcinoma. PATIENTS AND METHODS: We retrospectively evaluated 47 patients with malignant biliary obstruction to receive either a newly developed self-expandable metal stent covered with polyurethane (21 cases) or an uncovered metal stent (Strecker stent or Wallstent, 26 cases) by the endoscopic transpapillary route. RESULTS: The success rate of stent insertion and drainage effect of stent showed no statistical difference in patients with a new membrane-covered self-expandable metal stent compared with those with an uncovered metal stent (90.4% vs. 88.5%, P > 0.05; and 100% vs. 95.6%, P > 0.05, respectively). The median patency of the stent was slightly prolonged in patients with a membrane-covered self-expandable metal stent, but there was no statistical difference between two groups (267 vs. 233 days, P > 0.05). The rate of early complication related to stent insertion showed no significant difference between the two groups. During the follow-up period, stent occlusion due to tumor ingrowth occurred in two patients (10.5%) in the membrane-covered, self-expandable stent group, compared with six patients (26.1%) in the uncovered metal stent group. The membrane-covered metal stent was removed successfully and a polyethylene stent was reinserted in one patient who had developed tumor overgrowth. CONCLUSIONS: A new, membrane-covered, self-expandable metal stent has a tendency towards better long-term patency than the uncovered metal stent, and it can effectively prevent tumor ingrowth into the stent. Also it is possible to remove an occluded membrane-covered stent. However, a case-controlled study, including a larger patient number, and long-term follow-up are needed.

Neurosurgical aspects of sedimentation levels in acute intracerebral haematoma.

We describe the neurosurgical aspects of sedimentation levels that are rarely found in acute intracerebral haematomas (ICH). We had four patients with acute ICH whose cerebral computed tomography revealed sedimentation levels. Two patients had received thrombolytic therapy for ischaemic heart disease and one for ischaemic stroke. Another patient, who was diagnosed later as having a coagulation disorder, did not have any medical history on admission. All patients had emergency ICH drainage under local anaesthesia. In the immediate postoperative period, we observed dramatic improvement in all the patients, without surgical complications. The sedimentation level in an ICH should be identified as a specific indicator of a coagulation defect and a thorough search for possible underlying coagulopathy is warranted. We believe that simple ICH drainage should be performed as the haematoma is in a liquid form.

A new trend in operative technique for intracerebral hemorrhage: a comparative study of stereotactic endoscopic removal and stereotactic catheter drainage.

The development of less invasive methods to evacuate intracerebral hematomas (ICHs) has improved outcome in patients with traumatic brain injury. Eighteen patients with ICHs underwent surgery via one of two methods: stereotactic endoscopic removal (SER) or stereotactic catheter drainage (SCD). The outcome results were then compared. The patient population was composed of 11 men and seven women with a mean age of 53.3 years (range 33-81 years), all suffering from ICH in the basal ganglia. The mean hematoma volume was 34.4 ml (range 23-105 ml). All patients had major neurological deficits, but showed no sign of transtentorial herniation. Ten patients underwent SCD and eight had SER. All procedures were performed within 24 hours of insult. After local anesthesia was induced in the patient, an intracranial pressure (ICP) monitoring catheter and an Otzuki cannula were placed through separate burr holes in the skull. Using the SER technique, the ICH was removed using suction and forceps through the side window of the cannula until the ICP had decreased significantly. Hemostasis was attained by lesioning with a Nd-YAG laser. In the SCD procedure, we placed a silicone catheter into the hematoma to drain it and then added urokinase. The hematoma was drained for 3 to 5 days in the SER method and 7 to 10 days in the SCD method. Rebleeding occurred in one of the early cases in which we used the SER procedure. At follow-up evaluation, the mortality rate was 13% in the SER group and 10% in the SCD group. The patients in whom outcome was most improved from these treatments were those who had been admitted with an impaired level of consciousness. Stereotactic catheter drainage is a precise, safe, and brief procedure with a very low rebleeding rate, but its outcome effect was more delayed than other procedures. Stereotactic endoscopic removal can easily replace SCD, with a similar mortality rate. Both procedures can be accomplished under direct visualization so as to eliminate any undesirable event or outcome.