Gallbladder hemorrhage mimicking acute cholecystitis in a patient under antiplatelet therapy

Hemorrhage within the gallbladder is rare but potentially fatal. It can be easily overlooked and misdiagnosed because of its low incidence and presentation that is similar to other types of hepatobiliary disease. We present an unusual case of gallbladder hemorrhage in a 36-year-old male patient who was taking antiplatelet medication following cardiac surgery. The patient was misdiagnosed with acute primary cholecystitis and, in consideration of postoperative complications with cardiovascular comorbities, serial treatment with urgent percutaneous transhepatic gallbladder drainage and delayed laparoscopic cholecystectomy was prescribed. Unexpectedly, a gallbladder hemorrhage was intraoperatively confirmed as the gallbladder appeared filled with dark blood clot-like materials. The patient recovered well and was discharged on the 3rd postoperative day without complications. In patients who are on antiplatelet therapy, gallbladder hemorrhage should be considered in the differential diagnosis if they have symptoms typical of biliary colic. In addition, delayed surgery with prompt biliary diversion may represent a safe and effective treatment approach.

AKR1B10 is associated with smoking and smoking-related non-small-cell lung cancer

This prospective study explored the relationship between expression of AKR1B10 mRNA and various clinical parameters in non-small-cell lung cancer (NSCLC) in terms of its validation as a marker for NSCLC. Tumour tissue samples were collected from 229 patients with NSCLC. Tissue samples from adjacent non-malignant lung tissue (> 5 cm from the tumour) of 89 of these patients and samples from 20 patients with benign lung disease were used as controls. Quantitative reverse transcription- polymerase chain reaction showed significantly higher levels of AKR1B10 mRNA expression in NSCLC tumour tissue than in adjacent non-malignant lung tissue and benign lung tissue. Statistically significant factors for AKR1B10 mRNA over-expression were found to be male gender, smoking, squamous cell carcinoma and moderate or poor cell differentiation. It is concluded that AKR1B10 seems to have potential as a prognostic marker for NSCLC and warrants further investigation.

Nano-scaled Pt/Ag/Ni/Au contacts on p-type GaN for low contact resistance and high reflectivity

We synthesized the vertical-structured LED (VLED) using nano-scaled Pt between p-type GaN and Ag-based reflector. The metallization scheme on p-type GaN for high reflectance and low was the nano-scaled Pt/Ag/Ni/Au. Nano-scaled Pt (5 A) on Ag/Ni/Au exhibited reasonably high reflectance of 86.2% at the wavelength of 460 nm due to high transmittance of light through nano-scaled Pt (5 A) onto Ag layer. Ohmic behavior of contact metal, Pt/Ag/Ni/Au, to p-type GaN was achieved using surface treatments of p-type GaN prior to the deposition of contact metals and the specific contact resistance was observed with decreasing Pt thickness of 5 A, resulting in 1.5 x 10(-4) ohms cm2. Forward voltages of Pt (5 A)/Ag/Ni contact to p-type GaN showed 4.19 V with the current injection of 350 mA. Output voltages with various thickness of Pt showed the highest value at the smallest thickness of Pt due to its high transmittance of light onto Ag, leading to high reflectance. Our results propose that nano-scaled Pt/Ag/Ni could act as a promising contact metal to p-type GaN for improving the performance of VLEDs.

Prediction of acute pulmonary complications after resection of lung cancer in patients with preexisting interstitial lung disease

INTRODUCTION

Interstitial lung disease (ILD) is associated with a high morbidity from acute pulmonary complications, such as acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), after pulmonary resection. This study attempts to uncover the risk factors for postoperative ALI/ARDS in lung cancer patients with ILD.

MATERIALS AND METHODS

We retrospectively reviewed 100 patients with ILD who underwent curative lung resection for lung cancer, from January 2000 to December 2008.

RESULTS

Of the 100 patients, 91 were male, and 9 were female. The median age was 66 years. Fifty-eight patients underwent a preoperative carbon monoxide diffusing capacity test (DLCo). Twelve pneumonectomies and 88 lobectomies were performed. Acute pulmonary complications were observed in 28 patients (13 with ALI and 15 with ARDS). Operative mortality was 14%. Cause of death was due to respiratory failure from ALI/ARDS in all patients, except in one patient who died due to complications of acute renal failure. For all 100 patients, univariate analysis revealed that preexisting comorbidities, such as ischemic heart disease, renal failure, COPD, and neoadjuvant treatment for lung cancer, were risk factors for the development of postoperative ALI/ARDS. For the 58 patients who underwent preoperative DLCo testing, significant univariate risk factors included preexisting comorbidities and decreased DLCo. Multivariate analysis did not show any significant risk factors for ALI/ARDS.

CONCLUSIONS

Preexisting comorbidities and decreased preoperative DLCo were the most significant risk factors for the development of acute pulmonary complications after pulmonary resection in patients with lung cancer and ILD.

Comparing the effects of 5% albumin and 6% hydroxyethyl starch 130/0.4 on coagulation and inflammatory response when used as priming solutions for cardiopulmonary bypass

AIM

This prospective, randomized and controlled trial compares the use of human albumin (HA) and hydroxyethyl starch (HES) 130/0.4 in the priming solution for a non-biocompatible cardiopulmonary bypass (CPB) circuit. The effects of each substance on coagulation, postoperative blood loss and pro-inflammatory activities were examined.

METHODS

Thirty-six adult patients undergoing mitral valvular heart surgery were randomly assigned to either the HA or HES group; 500 mL of 5% HA or 6% HES 130/0.4 were added to the priming solution of the CPB circuit for each group, respectively. Coagulation variables were measured perioperatively; these variables included thromboelastographic (TEG) parameters and pro-inflammatory markers such as interleukin (IL)-6, IL-8 and tumor necrotic factor (TNF)-a. Postoperative blood loss and transfusion requirements were also assessed.

RESULTS

There were no significant intergroup differences in the coagulation variables (including TEG parameters), serum concentrations of IL-6, IL-8 and TNF-a, and blood loss or transfusion requirements. TEG parameters, which indicate the speed of solid clot formation and the strength of the fibrin clot, decreased up to 4 hours after CPB in both groups. Serum concentrations of IL-6, IL-8 and TNF-a were higher up to 12 hours after surgery compared to baseline values in both groups. Hemoglobin levels and platelet counts were lower up to 12 hours after surgery compared to baseline values in both groups.

CONCLUSION

HES 130/0.4 was comparable to albumin as a component of the priming solution for a non-biocompatible CPB circuit. The two substances showed similar effects on coagulation variables, blood loss and pro-inflammatory activities in adult patients undergoing mitral valvular heart surgery.

Silicon enhances natural enemy attraction and biological control through induced plant defences

Silicon (Si) is known to have a role in constitutive plant defence against arthropod pests, and recent work has illustrated involvement in induced plant defences. The present tri-trophic study tested the hypothesis that Si increases natural enemy attraction to pest-infested plants and improves biological control. Cucumber plants treated with potassium silicate (Si+) and untreated control plants (Si-) were maintained in separately vented glasshouse compartments. Y-tube olfactometer studies showed that adult Dicranolaius bellulus were significantly more attracted to Si+ plants upon which Helicoverpa armigera larvae had fed compared with Si-, pest-infested plants. Predators were not significantly more attracted to Si+ plants when comparing uninfested cucumbers. In a field experiment, we placed H. armigera-infested and uninfested Si+ and Si- cucumber plants in a lucerne stand. Removal rates of H. armigera egg baits showed predation was greater for Si+ infested plants than for other treatments. Results suggest that Si applied to plants with a subsequent pest infestation increases the plants' attractiveness to natural enemies; an effect that was reflected in elevated biological control in the field.

Comparison of mechanical rigidity between plate augmentation leaving the nail in situ and interlocking nail using cadaveric fracture model of the femur

Thirteen matched pairs of cadaveric femurs were placed into two groups. In each group, a transverse fracture was created at a point 70% distal between the lesser trochanter and the adductor tubercle. One femur out of each matched pair was then stabilised with an interlocking intramedullary nail (nail only group) and the other femur was stabilised with plate augmentation after interlocking intramedullary nailing (plate augmentation group). The bending load to promote 5-mm displacement showed statistically significant differences between the plate augmentation group (mean 843.36 ± 409.13 N) and the nail only group (mean 315.02 ± 219.80 N) (p = 0.001). Torsional torque at the angle of 15 degrees showed statistically significant differences between the two groups; a mean of 2.09 ± 0.53 N·m for the plate augmentation group and a mean of 0.63 ± 0.46 N·m for the nail only group (p = 0.0001). We found a 2.6-fold increase in bending stiffness and a 3.3-fold increase in torsional stiffness in plate augmentation leaving a nail in situ compared to interlocking nailing only in the distal third fracture of femur.

Inhibition of Orientia tsutsugamushi infection by a truncated recombinant 56-kDa outer membrane protein

AIMS

The objective of this study was to evaluate recombinant 56-kDa outer membrane protein as a potential inhibitor to infection from Orientia tsutsugamushi.

METHODS AND RESULTS

The 56-kDa protein was cloned and expressed in an Escherichia coli system, and the degree of target cell attachment to immobilized 56-kDa protein was measured in a cell adhesion assay. The results showed that the 56-kDa protein has an ability to attach HeLa cells. Furthermore, treatment of target cells with a truncated 56-kDa 1-418 (amino acid residues) protein inhibited target cell infection by O. tsutsugamushi, demonstrated with an indirect immunofluorescence antibody assay.

CONCLUSIONS

The truncated 56-kDa protein (a.a. 1-418) plays an important role in O. tsutsugamushi infection, and the 56-kDa protein could be useful and effective in the inhibition of O. tsutsugamushi attachment and infection.

SIGNIFICANCE AND IMPACT OF THE STUDY

The attachment of the 56-kDa protein to target cells was directly determined by in vitro adherence test, and the invasion of target cells by O. tsutsugamushi was inhibited by treating the target cells with a truncated 56-kDa protein.

Outcomes after repeated resection for recurrent pulmonary metastases from colorectal cancer

BACKGROUND

It remains controversial whether metastasectomy is still feasible in patients with pulmonary recurrence from colorectal cancer, after initial metastasectomy. The aim of this study was to evaluate outcomes of repeated metastasectomy in these patients.

MATERIALS AND METHODS

From 1995 to 2007, 202 patients had received a pulmonary metastasectomy from colorectal cancer at our institution. Over a median follow-up of 28.9 months, 48 patients received second metastasectomy (29 wedge resections, 5 segmentectomies, 13 lobectomies, and 1 completion pneumonectomy). The median disease-free interval was 9.6 months. Among these 48 patients, 28 showed pulmonary recurrence again and of those, 10 patients received third metastasectomy (two wedge resections, two segmentectomies, four lobectomies, and two completion pneumonectomies).

RESULTS

There was no postoperative mortality. Of the 48 patients who underwent second metastasectomy, overall and disease-free 5-year survivals were 79% and 49%, respectively, after second operation. Of the 10 patients who received third metastasectomy, overall survival was 78% at 5 years after last operation.

CONCLUSIONS

Repeated resection after initial metastasectomy can be carried out safely and provides long-term survival in patients with recurrent pulmonary metastasis from colorectal cancer. Our findings indicate that close follow-up for the early detection of recurrence and parenchyma-saving resection can improve the results after repeated resection.

Relationship between echocardiographic index of ventricular filling pressure and intraoperative haemodynamic changes during off-pump coronary bypass surgery

BACKGROUND

The ratio of mitral velocity to early-diastolic velocity of the mitral annulus (E/e') is an indicator of diastolic function representing acute loading conditions of the left ventricle. We tested the efficacy of E/e' as a predictor of haemodynamic derangement during off-pump coronary artery bypass surgery (OPCAB), when heart displacement causes loading changes.

METHODS AND RESULTS

Fifty patients with left ventricular (LV) ejection fraction >or= 50% were divided into two groups; E/e'<8 (normal LV filling pressure, n=25) and >15 (increased LV filling pressure, n=25). Haemodynamic measurements were recorded after induction of anaesthesia, during grafting, and after sternum closure. Patients' characteristics and operative data were similar between the groups. Cardiac index and mixed venous oxygen saturation were significantly lower during grafting and after sternum closure in the E/e'>15 group, compared with E/e'<8 group and with the baseline values. The E/e'>15 group required significantly longer ventilation time and length of stay in the intensive care unit.

CONCLUSIONS

Even in patients with preserved systolic LV function, patients with E/e'>15 were more prone to undergo a significant decrease in cardiac output during OPCAB, which did not return to baseline level after completion of grafting. Whether this finding is associated with increased morbidity and mortality should be validated.

Effect of low-dose ketamine on inflammatory response in off-pump coronary artery bypass graft surgery

BACKGROUND

Off-pump coronary artery bypass graft surgery (OPCAB) is still associated with a marked systemic inflammatory response. The aim of this study was to investigate whether pre-emptive, low dose of ketamine, which has been reported to have anti-inflammatory activity in on-pump coronary artery bypass surgery, could reduce inflammatory response in low-risk patients undergoing OPCAB.

METHODS

In this prospective randomized-controlled trial, 50 patients with stable angina and preserved myocardial function undergoing OPCAB were randomly assigned to receive either 0.5 mg kg(-1) of ketamine (Ketamine group, n=25) or normal saline (Control group, n=25) during induction of anaesthesia. Inflammatory markers including C-reactive protein (CRP), interleukin (IL)-6, tumour necrosis factor-alpha (TNF-alpha), and cardiac enzymes were measured previous to induction (T1), 4 h after surgery (T2), and the first and second days after the surgery (T3 and T4).

RESULTS

There were no significant intergroup differences in the serum concentrations of the CRP, IL-6, and TNF-alpha and cardiac enzymes. Pro-inflammatory markers and cardiac enzymes, except TNF-alpha, were all increased after the surgery compared with baseline values in both groups.

CONCLUSIONS

Low-dose ketamine administered during anaesthesia induction did not exert any evident anti-inflammatory effect in terms of reducing the serum concentrations of pro-inflammatory markers in low-risk patients undergoing OPCAB.

Heteropolymorphism of mitochondrial NADH dehydrogenase subunit 3 gene for the population analysis of chum salmon, Oncorhynchus keta

Mitochondrial DNAs (mtDNAs) has been frequently used as genetic markers for the population genetic studies. In this study we used chum salmon (Oncorhynchus keta) from Korea, Japan andAmerica, and compared their mitochondrial NADH dehydrogenase subunit 3 (ND3) genes by DNA sequence analysis. Sequence variation was studied in the ND3 among total 11 individuals from three populations. The ND3 gene was amplified by PCR targeting parts of cytochrome oxidase III gene (COIII) and NADH dehydrogenase subunit 4L gene (ND4L). ND3 gene sequence, encoded 752 bps, presented some genetic variation in the chum salmon populations. The observed nucleotide variations inferred the distinct genetic differentiation of American salmons from Korean and Japanese chum salmons. Six sites of single nucleotide polymorphism (SNP) were explored in the ND3 locus. Denaturing gradient gel electrophoresis analysis also showed a clear heterogenous band in American salmons compared to Asian salmons.

Effect of kimchi powder level and drying methods on quality characteristics of breakfast sausage

This study was conducted to determine the effect of the addition of kimchi powder on the quality characteristics of meat batter and breakfast sausage. Breakfast sausages were supplemented with freeze dried kimchi powder (FKP) or hot air dried kimchi powder (HKP) at levels of 1% (FKP-1 and HKP-1) or 2% (FKP-2 and HKP-2). The emulsion stability, cooking yield, and apparent viscosity in meat batters improved with increments of kimchi powder (p<0.05). Increased levels of kimchi powder in breakfast sausage decreased the L(∗) value, pH, and springiness, and increased the a(∗) value, b(∗) value, hardness, chewiness, and gumminess (p<0.05). Sensory evaluations indicated that a higher overall acceptability was attained when the kimchi powder was added to breakfast sausage at a level of 2%.

B cell lineage contributions to antiviral host responses

B cell responses are a major immune protective mechanism induced against a large variety of pathogens. Technical advances over the last decade, particularly in the isolation and characterization of B cell subsets by multicolor flow cytometry, have demonstrated the multifaceted nature of pathogen-induced B cell responses. In addition to participation by the major follicular B cell population, three B cell subsets are now recognized as key contributors to pathogen-induced host defenses: marginal zone (MZ) B cells, B-1a and B-1b cells. Each of these subsets seems to require unique activation signals and to react with distinct response patterns. Here we provide a brief review of the main developmental and functional features of these B cell subsets. Furthermore, we outline our current understanding of how each subset contributes to the humoral response to influenza virus infection and what regulates their differential responses. Understanding of the multilayered nature of the humoral responses to infectious agents and the complex innate immune signals that shape pathogen-specific humoral responses are likely at the heart of enhancing our ability to induce appropriate and long-lasting humoral responses for prophylaxis and therapy.

A single institutional experience of thymic epithelial tumours over 11 years: clinical features and outcome and implications for future management

Thymic epithelial tumours (TETs), the most common tumour of the anterior mediastinum, are epithelial neoplasms of the thymus with a wide spectrum of morphologic features. We retrospectively analysed clinical features of TET and the correlation of World Health Organisation (WHO) histologic classification and Masaoka staging system with different treatment modalities in 195 patients, from 1995 to 2005. According to the Masaoka's staging system, there were 78 (40.0 %) patients with stage I, 38 (19.5%) with stage II, 41 (21.0%) with stage III, 38 (19.5%) with stage IV. All patients were reclassified according to the WHO criteria as follows: Type A (n=9, 4.6%), AB (n=37, 18.9%), B1 (n=29, 14.8%), B2 (n=48, 24.6%), B3 (n=40, 20.5%), C (n=32, 16.4%). There was a fairly good correlation between Masaoka staging and WHO histotype (P<0.05). However, in multivariate analysis, the tumour stage and WHO histotype were two independent factors separately for predicting overall survival (P<0.001, P<0.001, respectively). Thus, both Masaoka stage and WHO histotype should be considered in risk stratification of therapy for TET patients. Patients with completely resected types B2, B3 and C and adjuvant radiotherapy (n=57) had more favourable disease-free and overall survival as compared with those without adjuvant treatment (n=20) (P=0.015, 0.015, respectively). Given that the predominant sites of recurrence after surgery was pleura/pericardium and lung, and the fact that complete resection was a significant influential factor for survival at log–rank test, an active investigation of newer treatment strategies such as neoadjuvant treatment to improve the resectability and development of optimal adjuvant treatment modality is a high priority especially for those with high-risk for recurrence or in patients with advanced stage disease.

Helicobacter pylori eradication for low-grade gastric mucosa-associated lymphoid tissue lymphoma is more successful in inducing remission in distal compared to proximal disease

A series of studies has shown that Helicobacter pylori eradication induces remission in most patients with low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma. However, there have been few reports about the effect of bacterial treatment on the gastric MALT lymphoma in Korea, a well-known H. pylori endemic area. A total of 111 H. pylori-infected patients were prospectively enrolled in Seoul National University Hospital and 99 among them were completely followed up according to our protocol. After H. pylori eradication, tumoural response was evaluated by endoscopy and histopathology every 2–3 months till complete remission (CR) and every 6 months after achieving CR. Median follow-up period was 41 months (range, 11–125 months). Helicobacter pylori was successfully eradicated in all 99 patients and CR was obtained in 84 (84.8%) of 99 patients. The median time to reach CR was 3 months and 94% of CR is in continuous complete remission. Five patients with CR relapsed after 10–22 months without the evidence of H. pylori reinfection. Cumulative recurrence rate was 2.3, 7.7 and 9.3% at 1, 2 and 3 years, respectively. Tumours were mainly located in distal stomach (67.7%) and tumours in distal stomach were associated with more favourable response than those in proximal stomach (P=0.001). Majority of patients with low-grade gastric MALT lymphoma treated by exclusive H. pylori eradication have a favourable long-term outcome, offering a real chance of cure. Tumour location could be a predictive factor for remission following H. pylori eradication.

Pulmonary cavitary mass containing a mural nodule: differential diagnosis between intracavitary aspergilloma and cavitating lung cancer on contrast-enhanced computed tomography

AIM

The objective of this study was to identify whether there were any significant differences in the computed tomography (CT) findings of an intracavitary aspergilloma and a cavitating lung cancer containing a mural nodule.

MATERIALS AND METHODS

The CT and histopathological findings of 12 patients (male:female ratio 3:9; aged 51-76 years) with cavitating lung cancer containing a mural nodule and 26 patients (male:female ratio 14:12; aged 29-72 years) with intracavitary aspergilloma were retrospectively reviewed.

RESULTS

The mural nodules within cavitating lung cancer were more enhanced (p<0.001) and showed a nondependent location more frequently (p=0.012) than those of intracavitary aspergillomas. The cavitary walls were thicker in cavitating lung cancer (mean 5.8mm thick) than those in intracavitary aspergillomas (mean 2.6mm thick; p=0.035). Adjacent bronchiectasis and volume decrease of the involved lobe were observed more frequently in intracavitary aspergillomas than in cavitating lung cancers (p<0.001 and p=0.008, respectively).

CONCLUSION

Whether a mural nodule within a cavitary lesion is contrast-enhanced or not is one of the most important features in making a differential diagnosis between an intracavitary aspergilloma and a cavitating lung cancer. Assessment of dependent location of a mural nodule within the cavity and wall thickness of the cavity itself can also be helpful for differentiation.

Phosphorus recovery by mesoporous structure material from wastewater

This study was designed to investigate the fundamental aspects of a possible removal of phosphorous from wastewater by using the mesoporous structure materials for wastewater reuse. The zirconium sulphate with mesoporous structure as a new type of ion exchangers was synthesised by hydrothermal reaction. From the results of X-ray diffraction and transmission electron microscope, it was discovered that the synthesised material had hexagonal mesoporous structure with a pore size of approximately 40-50A. Experimental results showed that the zirconium sulphate with mesoporous structure had very high sorption capacity for the phosphorus. The novel ion exchange occurred between PO4(3-) and SO4(2-), OH-. The amount of phosphate ions exchanged into the solid was as great as 3.4 mmol/g-ZS. Furthermore, it is possible to obtain a higher removal efficiency than other ion exchange media and adsorbents.

The prevalence and risk factors associated with isolated untreated systolic hypertension in Korea: the Korean National Health and Nutrition Survey 2001

Although isolated systolic hypertension (ISH) increases the risk of coronary heart disease and stroke, more than any other hypertension subtype, the prevalence and risk factors associated with ISH in the Korean population are not known. The 2001 Korean National Health and Nutrition Survey was a cross-sectional and nationally representative survey conducted in 2001. The prevalence of ISH by age and body mass index (BMI) was examined in 6601 Korean adults over 20 years of age. After adjusting for age, 4.32+/-0.32% of Korean adults had ISH, 5.28+/-0.37% had isolated diastolic hypertension and 5.82+/-0.36% had systolic/diastolic hypertension. The overall prevalence of ISH was found to increase directly with advancing age and increasing BMI. Although the ISH was found to be more common in men overall (4.81+/-0.50% in men, 4.12+/-0.37% in women), it was more common in women over 70 years of age. Independent variables associated with risk for ISH included advanced age, BMI, triglyceride (TG) levels, monthly income and alcohol intake. However, gender, fasting blood glucose, total cholesterol and high-density lipoprotein cholesterol levels, residential area, education level and smoking were found not to be significantly associated with ISH risk. The findings of the present study demonstrate that the prevalence of untreated ISH in Korea was lower than in Western countries. Age, BMI, TG levels, monthly income and alcohol intake were associated with ISH.

Impact of hemoglobin on survival of cervical carcinoma patients treated with concurrent chemoradiotherapy is dependent on lymph node metastasis findings by magnetic resonance imaging

The objective of this study was to confirm whether hemoglobin (Hb) levels during chemoradiotherapy are associated with survival in patients with locally advanced cervical carcinoma and to assess impact of the Hb level on survival according to lymph node (LN) metastasis. A retrospective review of 85 cervical carcinoma patients treated with concurrent chemoradiotherapy was conducted. The stage of disease ranged between FIGO stage IB and stage IVA. Disease-free and overall survivals were evaluated by univariate and multivariate analyses. After median follow-up of 35.7 months, 24 patients developed recurrence of disease and 14 patients died from their disease. Stage, LN metastasis, and squamous cell carcinoma antigen and Hb levels during chemoradiation were correlated significantly with survival (P < 0.05). Maintenance of Hb above 10.0 g/dL was associated with better survival (P < 0.05). However, no such benefits were observed in patients with LN metastasis by magnetic resonance imaging (MRI). Multivariate Cox regression hazard model showed that Hb levels during chemoradiation were an independent prognostic factor in patients without LN metastasis by MRI. Maintenance of Hb during chemoradiation is of benefit in cervical carcinoma patients without LN metastasis but not with LN metastasis by MRI.