Advances in Myocardial Perfusion MR Imaging: Physiological Implications,the Importance of Quantitative Analysis,and Impact on Patient Care in Coronary Artery Disease

Stress myocardial perfusion imaging (MPI) is the preferred test in patients with intermediate-to-high clinical likelihood of coronary artery disease (CAD) and can be used as a gatekeeper to avoid unnecessary revascularization. Cardiac magnetic resonance (CMR) has a number of favorable characteristics, including: (1) high spatial resolution that can delineate subendocardial ischemia; (2) comprehensive assessment of morphology, global and regional cardiac functions, tissue characterization, and coronary artery stenosis; and (3) no radiation exposure to patients. According to meta-analysis studies, the diagnostic accuracy of perfusion CMR is comparable to positron emission tomography (PET) and perfusion CT, and is better than single-photon emission CT (SPECT) when fractional flow reserve (FFR) is used as a reference standard. In addition, stress CMR has an excellent prognostic value. One meta-analysis study demonstrated the annual event rate of cardiovascular death or non-fatal myocardial infarction was 4.9% and 0.8%, respectively, in patients with positive and negative stress CMR. Quantitative assessment of perfusion CMR not only allows the objective evaluation of regional ischemia but also provides insights into the pathophysiology of microvascular disease and diffuse subclinical atherosclerosis. For accurate quantification of myocardial perfusion, saturation correction of arterial input function is important. There are two major approaches for saturation correction, one is a dual-bolus method and the other is a dual-sequence method. Absolute quantitative mapping with myocardial perfusion CMR has good accuracy in detecting coronary microvascular dysfunction. Flow measurement in the coronary sinus (CS) with phase contrast cine CMR is an alternative approach to quantify global coronary flow reserve (CFR). The measurement of global CFR by quantitative analysis of perfusion CMR or flow measurement in the CS permits assessment of microvascular disease and diffuse subclinical atherosclerosis, which may provide improved prediction of future event risk in patients with suspected or known CAD. Multi-institutional studies to validate the diagnostic and prognostic values of quantitative perfusion CMR approaches are required.     

A large negative magnetoresistance effect in semiconducting crystals composed of an octahedrally ligated phthalocyanine complex with high-spin manganese(iii)

A design for an octahedrally ligated phthalocyanine complex with high-spin manganese(iii) (S = 2) and Mn^III(Pc)Cl₂ (Pc = phthalocyanine) is presented. The presence of high-spin state Mn^III in the fabricated Ph₄P[Mn^III(Pc)Cl₂]₂ (Ph₄P = tetraphenylphosphonium) semiconducting molecular crystal is indicated by the Mn–Cl distance, which suggests an electronic configuration of (d_yz, d_zx)²(d_xy)¹(d_z²)¹. This was confirmed by the Curie constant (C = 5.69 emu K mol⁻¹), which was found to be significantly larger than that of the isostructural Ph₄P[Mn^III(Pc)(CN)₂]₂, where Mn^III adopts a low-spin state (S = 1). The magnetoresistance (MR) effects of Ph₄P[Mn^III(Pc)Cl₂]₂ at 26.5 K under 9 T static magnetic fields perpendicular and parallel to the c-axis were determined to be −30% and −20%, respectively, which are significantly larger values than those of Ph₄P[Mn^III(Pc)(CN)₂]₂. Furthermore, the negative MR effect is comparable to that of Ph₄P[Fe^III(Pc)(CN)₂]₂ (S = 1/2), which exhibits the largest negative MR effect reported for [M^III(Mc)L₂]-based systems (Mc = macrocyclic ligand, L = axial ligand). This suggests that the spin state of the metal ion is the key to tuning the MR effect.

A Ph4P[Mn^III(Pc)Cl2]2 molecular crystal where Mn^III adopts a high-spin state (S = 2) was designed. The large magnetoresistance effect of fabricated Ph4P[Mn^III(Pc)Cl2]2 suggests that the spin state of the metal ion is the key to tuning the MR effect.     

IgG4-Related Lung Disease Exhibiting the Invasion into the Diaphragm: A Case Report

Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition which involves various organs. This is a very rare case of IgG4-related lung disease (IgG4-RLD) with the invasion into diaphragm. The patient was a 71-year-old man with a long-term exposure to asbestos who had a mass shadow in the left lower lung lobe, which was suspected to invade the left diaphragm on computed tomography (CT). Positron emission tomography (PET)/CT also presented an avid intake of fluorodeoxyglucose in the mass, which suspected lung cancer. Although bronchoscopic biopsy could not lead to the definite diagnosis, we performed left lower lobectomy combined with the resection of left diaphragm. The specimen showed the features of IgG4-RLD on pathology: the vein stenosis and fibrosis around the vein, the infiltration of IgG4-positive cells, and IgG cells to IgG4 cells ratio of 40%. Furthermore, there were inflammatory cells infiltrating to the diaphragm.     

Atrial Fibrillation-triggered Ventricular Fibrillation in a Patient with Early Repolarization Syndrome

A 54-year-old man with early repolarization syndrome (ERS) implanted with an implantable cardioverter-defibrillator (ICD) developed persistent atrial fibrillation (AF) three years after the implantation. Similarly, the remote monitoring system begun frequently detecting ventricular fibrillation (VF) and polymorphic ventricular tachycardia (PVT). Longer RR intervals were repeatedly observed just before the initiation of PVT/VF. Catheter ablation for AF successfully diminished both the PVT and VF events.     

Chylous Ascites Due to Hyperthyroidism and Heart Failure

Chylous ascites (CA) is the accumulation of fluid with a high triglyceride content in the peritoneal cavity. Only two cases in the literature have reported CA with hyperthyroidism. A 28-year-old previously healthy woman presented with gradual-onset abdominal swelling, exertional dyspnea, and diarrhea. Hyperthyroidism and heart failure were diagnosed using laboratory investigation and echocardiography. Ultrasonography revealed a large amount of ascites. The ascitic fluid was milky with elevated triglyceride levels. Treatment with anti-thyroid therapy and diuretics improved all symptoms, and the free triiodothyronine (T3) level normalized after five days. Hyperthyroidism and heart failure should be considered as reversible causes of CA.     

Endoscopic ultrasound-guided transmural drainage for pancreatic fistula or pancreatic duct dilation after pancreatic surgery

Background

Endoscopic ultrasound (EUS)-guided drainage is widely used to manage pancreatic pseudocysts. Several studies have reported the use of EUS-guided drainage for pancreatic fistula and stasis of pancreatic juice caused by stricture of the pancreatic duct after pancreatic resection.

Methods

At the authors’ hospital, 262 patients underwent surgery involving pancreatic resection from April 2005 to March 2010. In 90 of these patients (34%), a grade B or C postoperative pancreatic fistula developed that required additional treatment. The authors performed EUS-guided transmural drainage (EUS-TD) for six patients (2.1%) with a pancreatic fistula or dilation of the main pancreatic duct visible by EUS. Percutaneous drainage was provided for 18 patients (6.8%). The success rates for EUS-TD and percutaneous drainage were compared in a retrospective analysis.

Results

In all six cases, EUS-TD was performed successfully without complications. Five of the six patients were successfully treated with only one trial of EUS-TD. The final technical success rate was 100% for both EUS-TD and percutaneous drainage. Both the short- and long-term clinical success rates for EUS-TD were 100% and those for percutaneous drainage were 61.1 and 83%, respectively. The differences in these rates were not significant (short-term success, P?=?0.091 vs. long-term success, P?=?0.403). However, the time to clinical success was significantly shorter with EUS-TD (5.8?days) than with percutaneous drainage (30.4?days; P?=?0.0013) in the current series.

Conclusions

The EUS-TD approach appears to be a safe and technically feasible alternative to percutaneous drainage and may be considered as first-line therapy for pancreatic fistulas visible by EUS.     

Placebo controlled evaluation of Xilei San,a herbal preparation in patients with intractable ulcerative proctitis

Background and Aim: Topical mesalamine or corticosteroid has shown efficacy in patients with ulcerative proctitis, but patients often become refractory to these interventions. Xilei San is a herbal preparation with evidence of anti‐inflammatory effects. We evaluated the efficacy of topical Xilei San in ulcerative proctitis patients. Methods: In a double blind setting, 30 patients with intractable ulcerative proctitis despite ≥ 4 weeks of topical mesalamine or corticosteroid were randomly assigned to True (n = 15) and placebo (n = 15). Patients in True received suppository Xilei San (0.1 g/dose per day of Xilei San), the other 15 received placebo suppository. The initial efficacy was evaluated on day 14. Primary endpoint of the trial was avoiding relapse during 180 days, relapse meant recurrence of active disease. Riley's index was applied for endoscopic and histological evaluations, while patients' quality of life was evaluated by an inflammatory bowel disease questionnaire. Results: On day 14, the number of patients who achieved remission, clinical activity index ≤ 4 in True was significantly higher versus placebo (P < 0.04). Likewise, at day 180, an 81.8% of patients in True were without relapse versus 16.7% in placebo (P < 0.001). Further, significant endoscopic (P < 0.01), histological (P < 0.02) and inflammatory bowel disease questionnaire (P < 0.04) improvements were observed in True, but not in placebo. Conclusions: This is the first controlled investigation showing significant clinical and endoscopic efficacy for Xilei San in patients with intractable ulcerative proctitis. Topical Xilei San was well tolerated, and was without safety concerns.     

Voxel‐wise quantification of myocardial perfusion by cardiac magnetic resonance. Feasibility and methods comparison

The purpose of this study is to enable high spatial resolution voxel‐wise quantitative analysis of myocardial perfusion in dynamic contrast‐enhanced cardiovascular MR, in particular by finding the most favorable quantification algorithm in this context. Four deconvolution algorithms—Fermi function modeling, deconvolution using B‐spline basis, deconvolution using exponential basis, and autoregressive moving average modeling —were tested to calculate voxel‐wise perfusion estimates. The algorithms were developed on synthetic data and validated against a true gold‐standard using a hardware perfusion phantom. The accuracy of each method was assessed for different levels of spatial averaging and perfusion rate. Finally, voxel‐wise analysis was used to generate high resolution perfusion maps on real data acquired from five patients with suspected coronary artery disease and two healthy volunteers. On both synthetic and perfusion phantom data, the B‐spline method had the highest error in estimation of myocardial blood flow. The autoregressive moving average modeling and exponential methods gave accurate estimates of myocardial blood flow. The Fermi model was the most robust method to noise. Both simulations and maps in the patients and hardware phantom showed that voxel‐wise quantification of myocardium perfusion is feasible and can be used to detect abnormal regions. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.     

A Mother Speaks

Eosinophilic pneumonia was confirmed by bronchoalveolar lavage fluid examination and transbronchial lung biopsy. Aspergillus niger was cultured from the patient's pharyngeal swab and bronchoalveolar lavage fluid. Inhalation bronchoprovocation test with A. niger antigen was positive. Although the patient's condition improved promptly with 10 mg/day prednisolone administration, dry cough recurred approximately 2 months after completion of this therapy. Severe coughing disappeared on oral cleansing with 300 mg/day amphotericin B, and he recovered completely on 100 mg/day amphotericin B administration. Oral cleansing with amphotericin B may be efficacious in preventing relapses of eosinophilic pneumonia caused by allergic reaction to fungal antigen.