Fast MR imaging in obstetrics.

Ultrasonography (US) is the initial imaging modality of choice for evaluation of patients in obstetrics. However, the results of US are not always sufficient. Magnetic resonance (MR) imaging, which uses no ionizing radiation, may be an ideal method for further evaluation. Although MR imaging is not recommended during the first trimester and use of contrast material is not recommended in pregnant patients, fast MR imaging is useful in various obstetric settings and can provide more specific information with excellent tissue contrast and multiplanar views. In pregnant patients with acute conditions, various diseases (eg, red degeneration of a uterine leiomyoma) may be diagnosed. MR imaging allows characterization of pelvic masses discovered during pregnancy and diagnosis of postpartum complications (eg, abscess, hematoma, ovarian vein thrombosis). In pregnant patients with hydronephrosis, MR urography can demonstrate the site of obstruction and the cause (eg, a ureteral stone). MR pelvimetry may be beneficial in cases of breech presentation. Contrast material-enhanced dynamic MR imaging allows one to evaluate the vascularity of a placental polyp, detect the viable component of a gestational trophoblastic tumor, and diagnose a uterine arteriovenous malformation. MR imaging enables diagnosis of rare forms of ectopic pregnancy and early diagnosis of ectopic pregnancy.     

A Young Patient with Microscopic Polyangiitis Requiring Hemodialysis with Complications of Repeated Episodes of Posterior Reversible Encephalopathy Syndrome Probably Due to Different Etiologies

A young woman with microscopic polyangiitis (MPA) requiring hemodialysis showed repeated posterior reversible encephalopathy syndrome (PRES) with spatiotemporal multiple lesions over a period of two months. The first PRES episode with confusion and the second PRES episode with vertigo and nausea were caused by MPA, hypertension and renal failure. These symptoms were improved by the reinforcement of MPA treatment and blood pressure management. The third PRES episode with nausea, headache, seizure and visual changes was induced by rituximab infusion and hypertension. The PRES was improved with blood pressure and convulsant management. These conditions are challenging to diagnose and treat.     

Acute Thrombosis in a Contralateral Kidney after Radical Nephrectomy: Successful Treatment by Thrombolytic Therapy Using a Tissue-Type Plasminogen Activator

A 67-year-old male became anuric immediately after a right radical nephrectomy tor renal cell carcinoma. The patient was diagnosed with an acute arterial thrombosis of the remaining kidney within 4 hours after surgery by both CT scan and angiography. Thrombolytic therapy was started by a transcatheteral infusion of tissue-type plasminogen activator (TPA) resulting in a complete recanalization. Hydration and systemic administration of heparin followed, and renal function recovered within 3 weeks. This is the first report of acute thrombosis in a contralateral renal artery immediately after a radical nephrectomy which was successfully treated with TPA. It is probable that compression of the contralateral renal artery by the retractor for an extended period of time during surgery led to this unfavorable condition.     

Modulation of extracellular glutamate concentration by nitric oxide synthase inhibitor in rat transient forebrain ischemia

The purpose of the present study was to clarify the effect of topical administration of a nitric oxide synthase inhibitor on extracellular glutamate concentration in transient forebrain ischemia. Two microdialysis probes were inserted into the bilateral striata of Wistar rats. N^G-Nitro-l-arginine (l-NNA) with or withoutl-arginine was topically administered into the unilateral striatum through one of the microdialysis probes, while Ringer's solution was perfused into the contralateral striatum as the control, and 14 minutes of forebrain ischemia was applied. The extracellular glutamate concentration during ischemia and subsequent reperfusion was statistically significantly higher on the 100 μMl-NNA-perfused side than on the control side, but 1 MMl-NNA was ineffective. When 100 μMl-NNA was perfused together with 500 μMl-arginine, the glutamate concentration did not differ from that on the control side. Moreover, administration of 500 μMl-arginine significantly suppressed the glutamate elevation after reperfusion. The fact that the lower dose ofl-NNA increased the accumulation of glutamate during ischemia and reperfusion without altering the blood flow may indicate that nitric oxide affords protection against ischemic neuronal damage. However, since the higher dose ofl-NNA did not affect the glutamate concentration, it appears that the effect of nitric oxide on extracellular glutamate concentration in forebrain ischemia differs, depending on the degree of the inhibition of NOS activity.     

Patient with innominate artery steal accompanied with cerebral infarction]

A 49-year-old man suddenly suffered left hemiplegia, and was brought to our hospital by ambulance at the beginning of August, 2006. He had a history of hypertension, and had received replacement of a synthetic graft in the ascending aorta and aortic arch with innominate artery for dissecting aneurysm in the aorta 2 years before. On diffusion-weighted magnetic resonance images obtained after admission, cerebral infarction was detected at the right corona radiata, and MR angiography (MRA) showed obstruction of the right middle cerebral artery. He was given intravenous tissue-plasminogen activator (t-PA) a few hours after arrival, and his hemiplegia was improved on the following day. At 11 days after onset, recanalization of the right middle cerebral artery was seen by MRA. On Doppler ultrasonographic examination, obstruction and thrombus in the innominate artery were observed. Retrograde flow of the right vertebral artery was demonstrated by both pulse-Doppler ultrasonography and velocity-coded color MRA. This patient is a rare example of innominate artery steal and ischemic cerebrovascular disease with obstruction of the innominate artery. Cerebral infarction in this patient might have developed via artery-to-artery embolism, with the thrombus in the innominate artery, rather than through a hemodynamic mechanism with innominate artery steal.     

Waist circumference correlates with hepatic fat accumulation in male Japanese patients with non-alcoholic fatty liver disease, but not in females

Background and Aim:  Abdominal obesity, a component of metabolic syndrome, is a major risk factor for non-alcoholic fatty liver disease (NAFLD). In recent worldwide definitions of metabolic syndrome, waist measurement has been proposed as a simple and useful estimate of abdominal obesity, taking into account gender differences in waist circumference. The present cross-sectional study investigated the correlation of hepatic fat accumulation and waist circumference in Japanese NAFLD patients to determine if there are gender differences in this relationship.
Methods:  Consecutive patients ( n  = 2111) who had at least one of two criteria for liver disease (alanine aminotransferase [ALT] level >30 IU/mL and aspartate aminotransferase [AST]/ALT ratio <1) underwent abdominal ultrasonography. Patients positive for hepatitis B virus, hepatitis C virus or autoimmune antibodies and whose alcohol intake was >20 g/day were excluded. Patients with NAFLD underwent abdominal computed tomography. Hepatic fat accumulation was estimated by liver/spleen attenuation ratio (L/S ratio) and visceral adipose accumulation was measured as visceral fat area (VFA) at the umbilical level.
Results:  Of the 221 NAFLD patients, 103 were females. In males, the relationship between L/S ratio and waist circumference was negative ( r  =−0.356, P  < 0.01), and there was no correlation in the female group. The relationship between L/S ratio and VFA was negative in both groups (males: r  = −0.269, P  < 0.01; females: r  = −0.319, P  < 0.01). Subcutaneous fat area/total fat area ratio at the umbilical level was larger in females than in males ( P  < 0.01).
Conclusions:  In NAFLD patients, waist measurement is more susceptible to gender differences than VFA.     

The Effectiveness of the Stereotactic Burr Hole Technique for Deep Brain Stimulation

Deep brain stimulation (DBS) is performed by burr hole surgery. In microelectrode recording by multi-channel parallel probe, because all microelectrodes do not always fit in the burr hole, additional drilling to enlarge the hole is occasionally required, which is time consuming and more invasive. We report a stereotactic burr hole technique to avoid additional drilling, and the efficacy of this novel technique compared with the conventional procedure. Ten patients (20 burr holes) that received DBS were retrospectively analyzed (5 in the conventional burr hole group and 5 in the stereotactic burr hole group). In the stereotactic burr hole technique, the combination of the instrument stop slide of a Leksell frame and the Midas Rex perforator with a 14-mm perforator bit was attached to the instrument carrier slide of the arc in order to trephine under stereoguidance. The efficacy of this technique was assessed by the number of additional drillings. Factors associated with additional drilling were investigated including the angle and skull thickness around the entry points. Four of the 10 burr holes required additional drilling in the conventional burr hole group, whereas no additional drilling was required in the stereotactic burr hole group (p = 0.043). The thicknesses in the additional drilling group were 10.9 ± 0.9 mm compared to 9.1 ± 1.2 mm (p = 0.029) in the non-additional drilling group. There were no differences in the angles between the two groups. The stereotactic burr hole technique contributes to safe and exact DBS, particularly in patients with thick skulls.