Simple visualization of the corticospinal pathway using tractography: one-ROI and two-ROI methods

Diffusion tensor imaging (DTI), a magnetic resonance (MR) technique to analyze diffusion anisotropy of the brain, is able to demonstrate subtle white matter anatomy. Tractography is expected to be a unique, non-invasive tool to provide more pertinent insights into brain structure and orientation not accessible by conventional MRI. In this report, preliminary experiences of visualization of the corticospinal tract using tractography are described. DTI of the brain was performed in 5 normal volunteers using single-shot echo-planar imaging, then tractography was generated by our original software. We determined that the two-region-of-interest (ROI) method is superior to the one-ROI method.     

Intense Ga-67 accumulation in pure primary mediastinal seminomas

The authors examined three patients with pure primary mediastinal seminomas, all of whom had marked Ga-67 uptake on scintigraphy. The unusual presentation of sclerotic bone metastases with remarkable extraosseous soft tissue involvement was observed in one patient. Another had a seminoma associated with a multiloculated thymic cyst, which is a rare lesion.     

MR imaging of ischemic penumbra

Cerebral ischemic stroke is one of the most fatal diseases despite current advances in medical science. Recent demonstration of efficacy using intravenous and intra-arterial thrombolysis demands therapeutic intervention tailored to the physiologic state of the individual tissue and stratification of patients according to the potential risks for therapies. In such an era, the role of the neuroimaging becomes increasingly important to evaluate the extent and location of tissues at risk of infarction (ischemic penumbra), to distinguish it from unsalvageable infarcted tissues or doomed hemorrhagic parenchyma. In this review, we present briefly the current role and limitation of computed tomography and conventional magnetic resonance imaging (MRI). We also present the possible applications of advanced MR techniques, such as diffusion and perfusion imaging, concentrating on the delineation or detection of ischemic penumbra.     

Inguinal herniation in two patients with continuous ambulatory peritoneal dialysis

We report two cases of subacute inguinal swelling in uremic patients on continuous ambulatory peritoneal dialysis (CAPD). Computed tomography, scintigraphy demonstrated a mass in the right groin. Surgical repair of an inguinal hernia resulted in complete resolution of the inguinal swelling. Both patients could restart continuous ambulatory peritoneal dialysis, without complication.     

A case report of a young patient with invasive bladder cancer

A 29-year-old male with bladder cancer was referred to our hospital. Histological examination of transurethral biopsy showed transitional cell carcinoma with invasion into prostate (T4aN0M0, grade 3). Nerve-sparing radical cystectomy with ileal neobladder reconstruction was performed after 3 courses of neoadjuvant chemotherapy with Methotrexate, Epirubicin and Cisplatin. Continence and erectile function were preserved and no recurrence has been observed for 18 months after the operation. This is the sixth case of an invasive bladder cancer in Japanese patients under 30 years old.     

A case report: renal arteriovenous malformation associated with horseshoe kidney detected by hemorrhage due to injury

A case report of a patient with renal arteriovenous malformation associated with horseshoe kidney detected by hemorrhage due to injury. A 71-year-old man was injured in a traffic accident and conveyed to our hospital. The computed tomographic scan showed renal injury of the horseshoe kidney with retroperitonial hemorrhage. We treated him conservatively, but he complained of abdominal fullness and went into hemorrhagic shock. So, we performed arterial angiography. It showed a right renal arteriovenous malformation from which leakage of contrast medium was detected. Hemostasis was possible by embolization of the abnormal artery. He has not had any recurrence of renal arteriovenous malformation. To our knowledge, this case is the third report of renal arteriovenous malformation associated with horseshoe kidney in Japan.     

Folic acid reduces risks of having fetus affected with neural tube defects: dietary food folate and plasma folate concentration

OBJECTIVES: Risk of having fetus affected with neural tube defects can be reduced by maternal periconceptional folic acid supplementation. The purpose of the present study is to investigate how folate is taken from diets and to measure plasma folate concentrations. SUBJECTS AND METHODS: A total of 222 women comprising 5 groups, i.e., healthy women, mothers of myelodysplastic patients, pregnant women, myelodysplastic patients, nurse students, participated in our study. Food frequency questionnaires kept 3 days were analyzed based on the 5th standard table of food composition in Japan. Plasma folate concentrations were measured by means of chemiluminescent immunoassay method. Changes in plasma folate concentrations and possible adverse effects following the folic acid supplementation for 16 weeks were also investigated. RESULTS: The dietary intake of folate, plasma folate concentration and energy intake averaged 293 micrograms/day, 8.1 ng/ml and 1,857 Kcal, respectively, among the subjects. Pregnant women took the largest amount of folate from diets and demonstrated the highest plasma folate concentration among the groups. The dietary folate in myelodysplastic patients and nurse students was significantly lower compared to that of healthy women. The Recommended Dietary Allowance of folate was not fulfilled in 22% of non-pregnant adult women and 72% of pregnant women. The dietary folate was mainly taken from the 3rd food group but the 4th group of food was consumed most. Mean folate intake was significantly correlated with circulating concentrations of serum folate (p = 0.012 r = 0.186). The consecutive administration of 400 micrograms supplements for 16 weeks increased a baseline plasma value of 8.7 ng/ml to 32.6 but fell down rapidly to 17.3 24 hours later without any adverse effects. CONCLUSIONS: The dietary folate and serum folate concentrations averaged 293 micrograms/day and 8.1 ng/ml, respectively. The former is the first report based on the 5th standard table of food composition in Japan. Majority of pregnant women took less dietary folate than what recommended by the government. Those who are capable of becoming pregnant are recommended to consume much of the 3rd food group and those who are planning to become pregnant are recommended to take 400 micrograms of folic acid supplements from 4 weeks before to 12 weeks after conception.     

Optimization of TI values in inversion-recovery MR sequences for the depiction of fine structures within gray and white matter: separation of globus pallidus interna and externa

RATIONALE AND OBJECTIVES: The authors' purpose was to search the inversion time (TI) values that enable the best differentiation of fine structures in gray matter (gray-gray differentiation). MATERIALS AND METHODS: Seven healthy adult volunteers with no history of neurologic disease or head trauma were recruited and gave their informed consent. The subjects consisted of two men and five women ranging in age from 25 to 38 years, with a mean age of 28 years +/- 5. The subjects were imaged with a turbo spin-echo inversion-recovery sequence. This sequence was performed in the axial plane at the level of the basal ganglia with the following parameters: repetition time, 3,200 msec; echo time, 15 msec; three signals acquired; echo train, seven; section thickness, 3 mm; matrix size, 256 x 256; and field of view, 180 mm. The tested values were TI = 100, 200, 300, 400, and 500 msec. Region-of interest measurements were performed at the following anatomic structures and represent gray-gray and white-white differentiations, respectively: globus pallidus externa versus globus pallidus interna, and optic radiation versus surrounding white matter. RESULTS: The maximum contrast index value occurred at TI = 400 msec for globus pallidus externa versus globus pallidus interna (P < .05) With the contrast-to-noise ratio, no significant difference in gray-gray differentiation was observed among the various TIs. The minimum signal-to-noise ratio of the gray matter occurred at TI = 400 msec (P < .05). A subjective evaluation revealed an overall superiority of gray-matter differentiation with TI = 400 msec. CONCLUSION: A TI of 400 msec was the most suitable for this purpose.     

The restriction of all minerals in the diet enhancing paraquat toxicity is regarded primarily as the shortage of Mg

This study compares the effect of the restriction of Mg with that of all-minerals in the diet on the toxicity of paraquat. To compare the severity of the toxicity, several biological values were examined; kininogen in plasma, thiobarbituric acid reactive substances in liver, Ca level in kidney, and Mg levels in liver and kidney. Osteogenic disorder Shionogi rats that cannot synthesize vitamin C like humans did not display paraquat symptoms after receiving minute amounts of paraquat dichloride, i.e. 125 ppm in the diet for 8 days, and those biological values remained the same as those of the control. Rats fed with Mg at half of the recommended amounts also did not show any changes in those levels. The dosage of 125 ppm paraquat under the restriction of Mg, however, induced paraquat intoxication and increased those levels greatly. This result arises a question whether the intoxication is due to the imbalance of Ca and Mg or due to the shortage of Mg itself, because imbalance of Ca and Mg sometimes induces more serious effects than the shortage of Mg itself. Therefore, we fed rats an all-mineral restricted diet where the balance of Ca and Mg was maintained. The dosage of paraquat under all-mineral restriction, however, induced much more serious intoxication than that under Mg restriction. In conclusion, the shortage of Mg itself seems to be responsible for the induction of paraquat intoxication.     

Groove pancreatic carcinomas: radiological and pathological findings

The aim of this study was to clarify the characteristics of pancreatic head carcinomas mainly invading the groove between the duodenum and the pancreatic head. Nine patients with pathologically proven pancreatic head carcinomas underwent thin-slice dynamic CT, MR imaging, duodenal endoscopy, and angiography (seven patients). Plate-like masses within the groove region were seen in all cases, which showed hypointensity on T1-weighted images and slight hyperintensity on T2-weighted MR images. The masses appeared hypovascular in the early phase and delayed enhancement in the late phase of dynamic CT and MR imaging. On MR cholangiopancreatography, stenosis of intrapancreatic common bile duct was seen in all patients, whereas stenosis of the main pancreatic duct was seen in only three cases. Endoscopy revealed luminal narrowing of the duodenum in all patients, and duodenal mucosal biopsy demonstrated adenocarcinoma in seven patients. Abdominal arteriography showed serrated encasement of peripancreatic arteries in seven patients who received angiographic examinations. The CT and MR imaging findings of groove pancreatic carcinomas resemble those of groove pancreatitis. Differential diagnosis may be achieved by the pathological diagnosis of a biopsy specimen of the duodenal mucosa and arterial encasement on arteriography.