Miniaturized Self-Resonant Micro Coil Array with A Floating Structure for Wireless Multi-Channel Transmission.

Micro size antennas have significant merits due to the small size effect, enabling new device concepts. However, the low-quality factor (Q-factor), the large size of impedance matching components, and the poor selectivity of the multi-array design remain challenging issues. To solve these issues, a floating coil structure stacked on a loop micro-antenna is suggested. Various floating coil designs are prepared with appropriate matching conditions at specific target frequencies, using an easy fabrication process without the need for additional space. A simple one-loop antenna design shows a higher Q-factor than other, more complicated designs. The micro-sized loop antenna with the 80 µm trace width design exhibits the highest Q-factor, around 31 within 7 GHz. The 8 different floating coil designs result in high-frequency selectivity from 1 to 7 GHz. The highest selectivity contrast and WPT efficiency are above 7 and around 1%, respectively. Considering the size of the antenna, the efficiency is not low, mainly due to the good matching effect with the high Q-factor of the floating coil and the loop antenna. This micro-antenna array concept with high integration density can be applied for advanced wireless neural stimulation or in wireless pixel array concepts in flexible displays.

Stress Release Effect of Micro-hole Arrays for Flexible Electrodes and Thin Film Transistors.

The effects of micro-hole arrays in the thin metal films were studied as a method to release bending stress in flexible electrodes and flexible thin film transistors (TFTs). Interest in flexible electronics is increasing, and many approaches have been suggested to solve the issue of the electrical failure of electrodes or electrical components such as TFTs after repeated bending. Here, we demonstrate a micro-hole array structure as a common solution to release bending stress. Although micro-size cracks were generated and propagated from the hole edges, the cracks stopped within a certain range when enough stress was released. Moreover, since the crack sites were predictable and controllable, a fatal electrical breakdown in a conductive layer such as a metal electrode or the semiconducting junction of a TFT can be prevented by specifically arranging the hole arrays. Thin film layers fabricated without holes suffered an electrical breakdown due to random crack propagation during bending tests. Aluminum thin film electrodes prepared with arrays of 3 µm diameter holes and 25% hole area showed excellent durability after 300,000 bending cycles. The change in resistance was below 3%. The electrical characteristics of an a-IGZO TFT with the micro-hole structure were almost equivalent to a standard a-IGZO TFT. After 10,000 bending cycles, ION and the ratio of ION/IOFF remained >107 A and ∼107, respectively. Since the effective hole diameter is micrometer in size, fabrication does not require additional process steps or expensive process equipment. Therefore, the approach can be an important way to enhance the reliability of various electrical devices in flexible and wearable applications.

Color-sensitive and spectrometer-free plasmonic sensor for biosensing applications.

A color-sensitive and spectrometer-free sensing method using plasmonic nanohole arrays and the color components, L* , a* , and b* , of the CIELAB defined by the international commission on illumination (CIE) is introduced for the analysis of optically transparent materials in the visible range. Spectral analysis based on plasmonic nanoparticles or nanostructures can be applied to real-time bio-detection, but complex optical instrumentations and low spatial resolution have limited the sensing ability. Therefore, we take an advantage of color image processing instead of spectral analysis which induces the distinctive color information of plasmonic nanohole arrays with different transparent materials. It guarantees high spatial resolution which is essential to bio-detection such as living cells. To establish our sensing platform, the color components, L* , a* , and b* , were extracted from photo images by an image sensor, statistically processed using a JAVA program, and finally utilized as three individual sensing factors. Additionally, our study on a correlation between the spacing of plasmonic sensors and the color sensitivity to the refractive index reveals geometrically optimal conditions of nanohole arrays. The weighted mean calculation with the three individual sensing factors offers an enhanced distinction of the optical difference for transparent materials. In this work, a color sensitivity of 156.94 RIU-1 and a minimum mean absolute error of 1.298×10-4 RIU were achieved. The difference in the refractive index can be recognized up to 10-4 level with the suggested sensing platform and the signal process. This unique color-sensitive sensing method enables a simple, easy-to-control, and highly accurate analysis without complicated measurement systems including a spectrometer. Therefore, our sensing platform can be applied as a very powerful tool to in-situ label-free bio-detection fields.

Enhancement of Interface Characteristics of Neural Probe Based on Graphene, ZnO Nanowires, and Conducting Polymer PEDOT.

In the growing field of brain-machine interface (BMI), the interface between electrodes and neural tissues plays an important role in the recording and stimulation of neural signals. To minimize tissue damage while retaining high sensitivity, a flexible and a smaller electrode with low impedance is required. However, it is a major challenge to reduce electrode size while retaining the conductive characteristics of the electrode. In addition, the mechanical mismatch between stiff electrodes and soft tissues creates damaging reactive tissue responses. Here, we demonstrate a neural probe structure based on graphene, ZnO nanowires, and conducting polymer that provides flexibility and low impedance performance. A hybrid Au and graphene structure was utilized to achieve both flexibility and good conductivity. Using ZnO nanowires to increase the effective surface area drastically decreased the impedance value and enhanced the signal-to-noise ratio (SNR). A poly[3,4-ethylenedioxythiophene] (PEDOT) coating on the neural probe improved the electrical characteristics of the electrode while providing better biocompatibility. In vivo neural signal recordings showed that our neural probe can detect clearer signals.

Comprehensive code stroke program to reduce reperfusion delay for in-hospital stroke patients.

BACKGROUND: Stroke may occur during hospital admission (in-hospital stroke). Although patients with in-hospital stroke are potentially good candidates for reperfusion therapy, they often do not receive treatment as rapidly as expected. AIMS: We investigated the effect of a code stroke program for in-hospital stroke, which included the use of computerized physician order entry, specific evaluation and treatment protocols for in-hospital stroke patients, and regular education of medical staffs. METHODS: We implemented the program in the cardiology and cardiovascular surgery departments/wards (target-ward group) in November 2008. We compared time intervals from symptom onset to evaluation and reperfusion treatment before and after program implementation between the target-ward and other departments/wards (other-ward group). RESULTS: Among 70 consecutive in-hospital stroke patients who received reperfusion therapy between July 2002 and February 2015, 28 and 42 were treated before and after program implementation, respectively. After program implementation, time intervals from symptom onset to neurology notification (50 min vs. 28 min; P = 0.033), symptom onset to brain imaging (91 min vs. 41 min; P < 0.001), and symptom recognition to notification (22 min vs. 9 min; P = 0.011) were reduced in the target-ward group. Finally, times from symptom onset to intravenous tissue plasminogen activator administration and to arterial puncture were reduced by 55 min (120 min vs. 65 min; P < 0.001) and 130 min (295 min vs. 165 min; P < 0.001), respectively. However, time reductions in the other-ward group were not significant. CONCLUSIONS: The comprehensive program for in-hospital stroke that included the use of computerized physician order entry was effective in reducing time intervals to evaluation and reperfusion therapy.

Anteroposterior translation of the glenohumeral joint in various pathologies: differences between shoulder MRI in the adducted neutral rotation and abducted externally rotated positions.

PURPOSE: The present study was performed to determine the translation of the glenohumeral joint in patients with and without shoulder lesions by comparing the magnetic resonance images obtained in the conventional adducted neutral rotation position with those obtained in the abducted externally rotated position. METHODS: Two hundred and eighty-five consecutive shoulders without rotator cuff tears that had been subjected to magnetic resonance imaging (MRI) without arthrography in the abducted externally rotated position were reviewed retrospectively. Among them, 50 shoulders without pathology were selected at random to be compared with three shoulder pathology groups, comprising shoulders with superior labrum, anterior-to-posterior (SLAP) lesions without range of motion (ROM) limitation (group I, 47 shoulders), with massive rotator cuff tears without ROM limitation (group II, 20 shoulders), and with full-thickness subscapularis tendon tears without ROM limitation (group III, 20 shoulders). Glenohumeral translation in the anterior-to-posterior direction relative to the glenoid face was evaluated using a method based on the glenohumeral contact point (CP) and humeral head centre (HHC) in the adducted neutral rotation and abducted externally rotated views, which were measured by three orthopaedic surgeons. For each shoulder, the differences in translation for the glenohumeral CP and HHC between the adducted neutral rotation and abducted externally rotated views were calculated as relative posterior translation in millimetres. RESULTS: The differences in ΔCP and ΔHHC between group I and the normal control group were not statistically significant. The differences in ΔCP (P = 0.001) and ΔHHC (P = 0.001) between group II and the normal control group were statistically significant. Additionally, the differences in ΔCP and ΔHHC between group III and the normal control group were not statistically significant. CONCLUSIONS: The MRI in abducted externally rotated view in patients with SLAP lesions or full-thickness subscapularis tendon tears diagnosed by conventional MRI alone showed no significant glenohumeral posterior translation relative to the adducted neutral rotation view in the present study. However, the abducted externally rotated view in patients with massive rotator cuff tears showed significant glenohumeral anterior translation relative to the adducted neutral rotation view.

Prevalence of renal dysfunction in patients with cirrhosis according to ADQI-IAC working party proposal.

BACKGROUND/AIMS: A revised classification system for renal dysfunction in patients with cirrhosis was proposed by the Acute Dialysis Quality Initiative and the International Ascites Club Working Group in 2011. The aim of this study was to determine the prevalence of renal dysfunction according to the criteria in this proposal. METHODS: The medical records of cirrhotic patients who were admitted to Konkuk University Hospital between 2006 and 2010 were reviewed retrospectively. The data obtained at first admission were collected. Acute kidney injury (AKI) and chronic kidney disease (CKD) were defined using the proposed diagnostic criteria of kidney dysfunction in cirrhosis. RESULTS: Six hundred and forty-three patients were admitted, of whom 190 (29.5%), 273 (42.5%), and 180 (28.0%) were Child-Pugh class A, B, and C, respectively. Eighty-three patients (12.9%) were diagnosed with AKI, the most common cause for which was dehydration (30 patients). Three patients had hepatorenal syndrome type 1 and 26 patients had prerenal-type AKI caused by volume deficiency after variceal bleeding. In addition, 22 patients (3.4%) were diagnosed with CKD, 1 patient with hepatorenal syndrome type 2, and 3 patients (0.5%) with AKI on CKD. CONCLUSIONS: Both AKI and CKD are common among hospitalized cirrhotic patients, and often occur simultaneously (16.8%). The most common type of renal dysfunction was AKI (12.9%). Diagnosis of type 2 hepatorenal syndrome remains difficult. A prospective cohort study is warranted to evaluate the clinical course in cirrhotic patients with renal dysfunction.

Recurrence of gastroesophageal reflux disease correlated with a short dinner-to-bedtime interval.

BACKGROUND AND AIM: Gastroesophageal reflux disease (GERD) can be classified into erosive reflux disease (ERD) and nonerosive gastroesophageal reflux disease (NERD). We aimed to compare the recurrence rates of ERD and NERD and determine the risk factors related to the recurrence. METHODS: This prospective study comprised 337 consecutive adults who completed questionnaires on their GERD symptoms, height, weight, sleeping position, dinner time, and bedtime. During upper gastrointestinal endoscopy, the presence of a hiatal hernia and mucosal breaks in the low esophagus, esophageal length (the distance between the Z-line and the incisors), and the esophageal length-to-height ratio were recorded. Recurrence was diagnosed when the patient required additional proton pump inhibitor medication after initial recovery with 4-8 weeks of treatment. RESULTS: Recurrence was experienced by 47 (26.0%) of 181 GERD patients. The recurrence rate did not differ between the 48 ERD (27.1%) and 133 NERD (25.6%) patients (P = 0.849). Of the various factors studied, recurrence was found to be correlated with a dinner-to-bedtime interval of less than 3 h (P = 0.002), globus sensation (P = 0.031), and old age (P = 0.047). Logistic regression analysis revealed that a short interval between dinner and bedtime was the only factor significantly related to the recurrence (P = 0.002). CONCLUSION: Both ERD and NERD patients who sleep within 3 h after eating have a higher risk of GERD recurrence. Our findings highlight the impact of a short dinner-to-bedtime interval on the recurrence of GERD (ClinicalTrials.gov ID: KCT0000134).

Beneficial effects of stroke-unit care in stroke patients with atrial fibrillation.

PURPOSE: Continuous cardiac monitoring in a stroke unit (SU) may improve detection of atrial fibrillation (AF), and SU care may improve the rate of anticoagulation by better adherence to a standardized treatment protocol in patients with AF. We investigated the effects of the SU on the detection of AF and the rate of warfarin therapy in patients with AF. MATERIALS AND METHODS: Acute stroke patients who had been admitted before or after the opening of the SU were included in our study. SU patients were monitored continuously with electrocardiography. Rates of AF and warfarin therapy were compared between patients admitted to the SU (SU group) and those admitted to the general ward (GW) prior to the opening of the SU (GW group). RESULTS: Total 951 patients had been admitted to the GW prior to the opening of the SU (from January 2000 to November 2002), and 2349 patients to the SU (from January 2003 to December 2008). AF was found in 149 patients (15.7%) in the GW group and in 487 (20.7%) in the SU group. Most of AF detected during admission was paroxysmal AF (84.8%). The frequency of newly detected AF was higher in the SU group than the GW group (2.5% vs. 0.7%, p=0.001). The rate of anticoagulation consideration was also higher in the SU group. CONCLUSION: SU care improved the detection of AF and the rate of anticoagulation consideration in acute stroke patients. Our findings support the benefits of continuous cardiac monitoring in the SU for stroke patients.

Predictive value of Refit Model for End-Stage Liver Disease, Refit Model for End-Stage Liver Disease-Na, and pre-existing scoring system for 3-month mortality in Korean patients with cirrhosis.

BACKGROUND AND AIM: The Model for End-Stage Liver Disease (MELD) has been widely used for predicting short-term mortality in patients with cirrhosis in the U.S. A modification of the MELD score was published in 2011. This was validated for Korean patients with cirrhosis. METHODS: The medical records of patients with cirrhosis who were admitted to Konkuk University Hospital from 2006 to 2010 were retrospectively reviewed. The predictive value for 3-month mortality was compared between the Refit MELD, Refit MELD-Na, MELD, MELD-Na, and Child-Pugh score. The comparison was performed by calculating the area under the receiver operating curve (AUROC). RESULTS: A total of 882 patients were enrolled and 77 (8.7%) died within 3 months. The most common etiology was alcohol (45.4%) followed by hepatitis B (34.2%). The AUROCs of the Refit MELD, Refit MELD-Na, MELD, MELD-Na, and Child-Pugh score were 0.842, 0.817, 0.844, 0.848, and 0.831, respectively. The Refit MELD-Na showed a lower value than MELD-Na (P = 0.0005), MELD (P = 0.0190), and the Refit MELD (P = 0.0174). When the patients with hepatitis B, C, and alcoholic cirrhosis were analyzed, the AUROCs were 0.960, 0.920, 0.953, 0.951, 0.896, 0.959, 0.956, 0.947, 0.956, 0.943, and 0.746, 0.707, 0.752, 0.747, 0.755. CONCLUSIONS: The improvement in predictive value for 3-month mortality was not definite. The Refit MELD-Na especially showed the lowest value. This result may have been due to differences in underlying etiology of cirrhosis between Korea and the U.S. Thus, a larger prospective study is warranted.

Gastric cancers with microsatellite instability exhibit high fluorodeoxyglucose uptake on positron emission tomography.

BACKGROUND: Gastric cancers exhibit various degrees of (18)F-fluorodeoxyglucose (FDG) uptakes on positron emission tomography/computed tomography (PET/CT) imaging. The aim of this study was to evaluate whether FDG uptake in gastric cancer varies according to the microsatellite instability (MSI) status. METHODS: Consecutive gastric cancer patients who underwent PET/CT imaging and MSI analysis were included in the study. The maximum standardized uptake value (SUVmax) of gastric cancer was assessed using PET/CT imaging. RESULTS: Of 131 gastric cancers, 16 exhibited a high incidence of MSI (MSI-H) and 3 exhibited a low incidence of MSI (MSI-L). In 29 subjects who showed no uptake on PET/CT imaging the gastric cancers were all microsatellite stable (MSS). Gastric cancers with MSI were related to age older than 60 years (p = 0.002), cancer volume larger than 10 cm(3) (p = 0.015), and the presence of FDG uptake on PET/CT imaging (p = 0.001). A higher SUVmax of gastric cancer was linked to the presence of MSI (p < 0.001). CONCLUSION: The presence of MSI is related to FDG uptake in gastric cancer. Care should be taken with MSS gastric cancers, because they show lower SUVmax on PET/CT imaging than MSI gastric cancers.

The frequency and risk of preclinical coronary artery disease detected using multichannel cardiac computed tomography in patients with ischemic stroke.

BACKGROUND: Atherosclerosis is a systemic disease. Many ischemic stroke patients may have concomitant coronary artery disease (CAD). Detection and treatment of preclinical CAD in stroke patients may improve long-term outcome and survival because CAD is a major cause of death during follow-up in stroke patients. However, association between coronary and cerebral artery atherosclerosis in stroke patients has not fully been investigated. This study aimed at examining the frequency and high-risk groups of CAD in ischemic stroke patients. METHODS: Consecutive patients who were admitted due to acute ischemic stroke between July 2006 and June 2010 were prospectively enrolled in this study. A total of 1,304 patients who underwent MSCT coronary angiography and cerebral angiography were included in this study. By using 64-multislice computed tomography coronary angiography, we investigated the frequency of CAD and association between coronary and cerebral artery atherosclerosis in terms of location and burden (severity and extent) in stroke patients. We also sought to identify high-risk groups for CAD among stroke patients. RESULTS: The frequency of significant (≥50%) CAD was 32.3% and the frequency of any degree of CAD was 70.1%. Diabetes mellitus, serum levels of total cholesterol, high-density lipoprotein cholesterol and triglyceride, and significant stenosis of the extracranial carotid, intracranial vertebral and basilar arteries were independently associated with CAD. However, no association was found between CAD and significant stenosis of the anterior, middle and posterior cerebral arteries. The association between CAD and cerebral atherosclerosis was stronger with increased severity and extent of cerebral atherosclerosis. When compared to patients with <2 risk factors and without significant cerebral atherosclerosis, those with multiple (≥2) risk factors and atherosclerosis in both the carotid and the vertebrobasilar arteries had very high risks of CAD [odds ratio (OR) 8.36; 95% confidence interval (CI) 4.15-16.87]. The risk was also high in patients with multiple risk factors and atherosclerosis in either the carotid or the vertebrobasilar artery (OR 4.13; 95% CI 2.62-6.51), and in those with <2 risk factors but atherosclerosis in both the carotid and the vertebrobasilar arteries (OR 3.40; 95% CI 1.22-9.47). CONCLUSIONS: A substantial portion of stroke patients had preclinical CAD, and there was a clear relationship between coronary and cerebral artery atherosclerosis in terms of location and burden. The risk of CAD was particularly high in stroke patients with multiple risk factors and atherosclerosis of the carotid and/or vertebrobasilar arteries.

Safety and outcome after thrombolytic treatment in ischemic stroke patients with high-risk cardioembolic sources and prior subtherapeutic warfarin use.

BACKGROUND: Hemorrhage is a major complication of thrombolytic treatment. Concerns have been raised about the risk of hemorrhage in patients having received warfarin. Therefore, different indications for thrombolytic treatment are in use for stroke patients on warfarin. However, it remains uncertain whether the prior warfarin use actually increases their risk of bleeding in patients treated with thrombolysis. METHODS: This study included 179 consecutive patients who had high-risk cardioembolic sources and received thrombolytic treatment. Patients were treated with intravenous thrombolytic agents, or underwent intraarterial thrombolysis if their international normalized ratio (INR) was ≤1.7. We compared the frequency of bleeding complications between patients with prior warfarin use and those without. We also investigated whether there were differences in functional outcome and recanalization rates between them. RESULTS: A prior warfarin use was present in 28 patients (15.6%). Although INR levels were higher in the prior warfarin group, the frequency of bleeding complications was not different between patients who received prior warfarin and those who did not. No differences were observed in patients with or without prior warfarin use, for successful recanalization rate (Thrombolysis in Myocardial Infarction grade 2 or 3), mortality, or modified Rankin score (≤2) at 3months. CONCLUSIONS: Thrombolytic therapy for patients who previously received warfarin and had an INR≤1.7 did not affect bleeding risk, clinical outcome, or recanalization rate. Our data suggest that patients with a history of prior warfarin use may be safely treated with thrombolytic agents when their INR levels are low.

Cortex-sparing infarctions in patients with occlusion of the middle cerebral artery.

BACKGROUND: In patients with a middle cerebral artery (MCA) occlusion, the involvement of the cortex may be affected by the presence of leptomeningeal anastomoses between the cerebral arteries. METHODS: The authors enrolled consecutive patients with acute infarctions in the MCA territory and MCA occlusion on angiographic studies. Infarct patterns were classified into three categories based on the extent of cortical surface involvement: total cortex (TC), partial cortex (PC) and no cortex (NC). The authors analysed the infarction patterns by stroke subtype, and investigated factors that resulted in cortex sparing. RESULTS: Out of 73 total patients, cortex-sparing infarctions were seen in 53 patients (72.6%, NC in 39 (53.5%) and PC in 14 (19.1%)). The extent of cortical involvement differed according to stroke subtype (p=0.036). TC was more frequent (42.9% vs 22.2%), and PC was less frequent (10.7% vs 27.9%, p=0.037) in cardioembolism than large-artery atherosclerosis. However, the proportion of patients with complete cortical sparing (NC) was similar between cardioembolism and large-artery atherosclerosis (46.4% vs 49.9%). In the upstream of leptomeningeal collateral arteries, the extent of cortical involvement was associated with significant stenosis of the ipsilateral anterior or posterior cerebral artery (p=0.011). CONCLUSION: This study suggests that pre-existing arteriolar connections, which may cover almost entire cortical surfaces of the MCA territory, exist in many patients. The findings also suggest that the extent of cortical involvement is different between stroke subtypes, and is critically affected by the status of upstream collateral arteries.

A case of Takotsubo cardiomyopathy in a patient with iatrogenic thyrotoxicosis.

Takotsubo cardiomyopathy is a condition caused by intense emotional or physical stress leading to rapid and severe reversible cardiac dysfunction. The etiology and mechanism of this disease are unknown. Thyroid hormone has many effects on the heart and vascular system. There were some reports of Takotsubo cardiomyopathy with hyperthyroidism, especially Grave's disease. We report a patient who presented chest pain and cardiac arrest, and finally diagnosed as Takotsubo cardiomyopathy caused by iatrogenic thyrotoxicosis.

Percutaneous temporal wiring method for minimally invasive plate osteosynthesis of a distal tibial fracture.

Reduction of distal tibial fractures-especially fractures that include an oblique or spiral fracture component-during operative treatment with minimally invasive plate osteosynthesis is not always easy. Unexpected and unacceptable displacement can sometimes be seen after plate fixation. We designed an effective fracture reduction method involving a percutaneous temporal wiring technique for the reduction of distal tibial fractures, including fractures that contain oblique or spiral fracture components, during the minimally invasive plate osteosynthesis procedure. Our method can consistently accomplish satisfactory reduction of these fractures and easily maintain reduced fractures, fix the plate, reduce the level of radiation exposure during the operation.

Classic risk factors for atherosclerosis are not major determinants for location of extracranial or intracranial cerebral atherosclerosis.

BACKGROUND: The prevalence of extracranial (EC) and intracranial (IC) atherosclerosis varies among races. Although several studies have sought to identify specific vascular risk factors that are associated with EC or IC atherosclerosis, the exact relationships are uncertain. This study aimed to determine if there are any specific risk factors for EC or IC atherosclerosis. METHODS: For this study, we considered 3,349 consecutive patients who had been entered into a stroke registry between January 1999 and June 2007. After the exclusion of patients who had not undergone angiography, patients with cardiac sources of embolism or other causes of stroke, and non-Koreans, we had a total of 2,169 patients of single ethnicity with an angiographic analysis. Patients with atherosclerosis in both the IC and EC arteries (856 patients) were excluded. Finally, we identified 1,313 patients who had EC atherosclerosis (EC group, n = 256), IC atherosclerosis (IC group, n = 566) or normal angiographic findings (no-lesion group, n = 488). The frequency of risk factors and the demographic parameters were compared among these groups. RESULTS: When compared to the normal group, the IC group was associated with older age and hypertension, and the EC group was associated with older age, higher initial blood sugar and low-density lipoprotein cholesterol levels. However, in a direct comparison between the IC and EC groups, we did not observe any significant risk factors or variables except for a higher frequency of males and higher total cholesterol levels in the EC group. CONCLUSIONS: Vascular risk factors may not be major determinants of location for atherosclerosis in the EC or IC arteries.

The patellar inferior pole: a new landmark of the anteromedial working portal for arthroscopic surgery of the posterior horn of the medial meniscus.

We assessed the patellar inferior pole (PIP) as a new landmark of the anteromedial (AM) instrumental portal for arthroscopic surgery of the posterior horn of the medial meniscus (PHMM). Fifty normal right knees in young adults (group 1) and 50 knees from adults of various ages undergoing arthroscopic surgery for relatively simple intra-articular pathologies or diagnosis (group 2) were included. In both groups, on 30 degrees flexion true lateral plain radiographs, the line passing through the PIP and the distalmost femoral condyle; (Kim's AM portal line) was drawn, then the length from the anterior end of the medial tibial plateau (MTP) to the meeting point of Kim's AM portal line with the MTP (length C) and the anteroposterior length of the MTP (length D) was measured. The length C was then taken as a percentage of length D (C-D percentage), and the distance between the PIP and the anterior joint line (length E) was measured. The average C-D percentages and lengths E were 110+/-33.6% and 14.8+/-3.8 mm in group 1, and 114+/-38.4% and 16.3+/-4.7 mm in group 2. There were no significant differences in the C-D percentages or the lengths E between the two groups. Also, in group 2, the AM portal was made at the PIP level, and we assessed the relative ease of instrument insertion to reach the PHMM and the body of the lateral meniscus (LM) using a scoring system of our own design. Fort-nine and 48 knees were classified as good for the PHMM and for the body of the LM, respectively. We concluded that the PIP can be used as a skin landmark for arthroscopic surgery of the PHMM.

Mechanism of infarction involving ipsilateral carotid and posterior cerebral artery territories.

BACKGROUND: We investigated the potential mechanism of infarction involving the territories of both the internal carotid artery (ICA) and the ipsilateral posterior cerebral artery (PCA). METHODS: Among consecutive patients with an ischemic stroke who had undergone both diffusion-weighted magnetic resonance imaging (DWI) and cerebral angiography, those who were found to have acute lesions in the ipsilateral ICA and PCA territories on DWI were selected for this study. The mechanism of infarction was sought by investigating angiographic findings and DWI lesion patterns. The frequency of patency between the ICA and PCA in the patient group was compared with that in the normal control group. RESULTS: Infarctions involving ipsilateral ICA and PCA territories were rare (21 of 1,388 patients, 1.5%). Sixteen of those 21 patients (76%) demonstrated steno-occlusive lesions of the relevant ICA. Cardioembolic sources were rarely found. All but 1 patient with fetal-type PCA (fPCA) or the posterior communicating artery demonstrated significant ICA stenosis. The fPCA was more frequently found in the ipsilateral hemisphere of patients with an infarction than in the control group (44.4 vs. 18.5%, p = 0.006). Ischemic lesions in the ICA territory were usually small but multiple, and those in the PCA territory were single and located in the cortex. CONCLUSIONS: Large artery atherosclerosis of the carotid artery was very common in patients with infarctions involving the ipsilateral ICA and PCA territories. Extracranial cervical artery evaluation is indispensable in those patients.

A new subtype classification of ischemic stroke based on treatment and etiologic mechanism.

A new subtype classification of ischemic stroke was developed to reflect recent therapeutic strategies as well as evolving concepts of stroke definitions and mechanisms. In 200 consecutive patients with acute ischemic stroke, the inter-rater reliability and proportion of subtypes of the new classification system were assessed and compared with those of the Trial of ORG 10172 in the Acute Stroke Treatment (TOAST) classification. The most frequent subtype of the new classification was atherothrombosis (n = 80, 40%), followed by stroke of undetermined etiology (n = 54, 27%), small artery disease (n = 33, 16.5%), cardioembolism (n = 26, 13%), and stroke of other determined etiology (n = 7, 3.5%). Three raters agreed to the stroke subtype diagnosis in 165 out of 200 cases and the overall kappa value was excellent (kappa = 0.82). The new classification system for brain infarction was easy to use and had high inter-rater reliability.