Methemoglobin suppression in a 0.3 Tesla magnet: an in vitro and in vivo study.

RATIONALE AND OBJECTIVES: The aim of this study was to design a pulse sequence that suppresses methemoglobin and is applicable in a 0.3-T permanent magnet. MATERIALS AND METHODS: Blood samples were collected from six healthy volunteers. Magnetic resonance imaging was performed with a 0.3-T scanner until the typical signal intensities of methemoglobin were obtained. Each blood sample was then scanned using repetition times of 300, 600, 900, 1200, 1500, and 1800 ms and a constant echo time of 20 ms. All other parameters (field of view, slice thickness, matrix, and number of signal averages) were kept constant for all six sequences. Signal intensities and repetition time data were used to calculate the T1 relaxation time of extracellular methemoglobin. T1 was determined by ordinary least square regression according to the equation S =k(1 - e(-repetition time/T1)), where S is signal intensity and k is the proportional constant. A short tau inversion recovery sequence with an inversion time calculated from the T1 value of methemoglobin was used on fat, water, and methemoglobin blood samples and in 11 patients diagnosed with subacute brain hemorrhages. The inversion time was calculated as ln2 T1 (tissue), where T1 is the relaxation time of extracellular methemoglobin to be suppressed. RESULTS: The T1 relaxation time of extracellular methemoglobin was determined to be 231.24 +/- 9.068 ms, and inversion time was calculated to be 160 +/- 6.67 msec. Application of an inversion time of 160 ms showed complete suppression on extracellular methemoglobin blood samples and all of the 11 subjects. CONCLUSION: A methemoglobin suppression technique using an inversion time of 160 +/- 6.67 ms is applicable in a 0.3-T permanent magnet.

Trismus and trigeminal neuralgia in one patient with colon cancer.

A 64-year-old man got trismus and trigeminal neuralgia under the diagnosis of colon cancer with mandibular metastasis after emergency appendectomy and elective hemicolectomy. The patient chose to forgo further surgery and was given only palliative chemotherapy and radiotherapy. He died six months after diagnosis. Metastatic tumors to the oral cavity are relatively uncommon. They are found most commonly in the mandible, and 70% of cases are adenocarcinoma-most commonly from breast and lung, followed by adrenals, kidneys, prostate, thyroid and colon. Mandibular mass is usually the first sign, then soft-tissue swelling, pain and paresthesias. Tissue proof is needed to confirm the diagnosis. The treatment depends on the nature of the primary, the degree of dissemination and the precise location. However, the prognosis is grim, with the mean survival after diagnosis being only about 6-7 months.

Simultaneous Klebsiella pneumoniae and amoebic liver abscess in an immunocompetent patient.

Simultaneous Klebsiella pneumoniae and amoebic liver abscess is rarely reported in immunocompetent patients. A 47-year-old man was hospitalized with abdominal pain, fever, chills, and hypotension. Physical examination revealed right upper quadrant tenderness. Abdominal computed tomography showed an area of low attenuation with some liquefaction in the liver. Echo-guided aspiration revealed 30 mL of pus, which grew Klebsiella pneumoniae, and the same organism was isolated from the blood. Cytology examination of the pus showed scattered amoeba. The patient gradually improved over 1 month on treatment with cefmetazole and metronidazole, along with repeated drainage of the abscess. His amoebic indirect hemagglutination titer was 1:128, but no parasite ova or amoeba were found in the stool. He had no evidence of immunocompromise. Parasitic diseases may be a predisposing factor for bacterial infections, including pyogenic liver abscess. The possible coexistence of amoebae and bacteria in a liver abscess should not be discounted.

Emphysematous pyelonephritis.

OBJECTIVE: The mortality rate among patients with emphysematous pyelonephritis (EPN) is high and the best therapy has long been debated. MATERIAL AND METHODS: Between January 1993 and December 2004, 26 patients diagnosed with EPN were treated at our hospital. Historical, demographic and laboratory data were obtained from medical records for analysis. RESULTS: The mean age of the patients was 58.7+/-12.7 years. All patients had diabetes, and women outnumbered men (23:3). The clinical findings were non-specific. A plain abdominal X-ray was diagnostic in only 9/26 patients (36%), ultrasonography was accurate in 13 (50%) and CT was diagnostic in all cases. Eighteen patients survived, including all five treated with open drainage and three out of four treated with percutaneous drainage (although one of these later required nephrectomy), and eight died. Diabetic ketoacidosis or non-ketotic hyperosmolar syndrome, obesity and smoking were significant predictors of death. CONCLUSIONS: Early diagnosis by means of CT and CT-guided percutaneous drainage (which is better than ultrasonography-guided drainage) or open drainage, along with antibiotic treatment, may be a reasonable alternative to nephrectomy for this high morbidity condition.

Clinical features of human intestinal capillariasis in Taiwan.

Human intestinal capillariasis is a rare parasitosis that was first recognized in the Philippines in the 1960 s. Parasitosis is a life threatening disease and has been reported from Thailand, Japan, South of Taiwan (Kaoh-Siung), Korea, Iran, Egypt, Italy and Spain. Its clinical symptoms are characterized by chronic diarrhea, abdominal pain, borborygmus, marked weight loss, protein and electrolyte loss and cachexia. Capillariasis may be fatal if early treatment is not given. We reported 14 cases living in rural areas of Taiwan. Three cases had histories of travelling to Thailand. They might have been infected in Thailand while stayed there. Two cases had the diet of raw freshwater fish before. Three cases received emergency laparotomy due to peritonitis and two cases were found of enteritis cystica profunda. According to the route of transmission, freshwater and brackish-water fish may act as the intermediate host of the parasite. The most simple and convenient method of diagnosing capillariasis is stool examination. Two cases were diagnosed by histology. Mebendazole or albendezole 200 mg orally twice a day for 20-30 d is the treatment of choice. All the patients were cured, and relapses were not observed within 12 mo.

MR imaging of the musculoskeletal soft tissue mass: is heterogeneity a sign of malignancy?

BACKGROUND: Magnetic resonance (MR) is considered the imaging modality of choice to evaluate soft tissue lesions. Whether MR imaging can be used to differentiate benign from malignant soft tissue lesions is still controversial. To elucidate this controversy, MR images of 37 patients with soft tissue masses of the musculoskeletal system were reviewed at Christchurch Hospital, New Zealand. METHODS: There were 19 benign and 18 malignant lesions. MR images were evaluated with regard to lesion size, border definition, homogeneity, changes in pattern of homogeneity, signal characteristic (signal intensity on T1-weighted, T2-weighted), and demonstration of relation to neurovascular bundle and bone as well as edema in or around the lesion. RESULTS: Statistically significant imaging features favoring a diagnosis of malignancy included inhomogeneity at T2-weighted images (p = 0.002) and a change in pattern from homogeneity on T1-weighted images to inhomogeneity at T2-weighted images (p = 0.003). Malignant tumors also had neurovascular or bone involvement in 28% of cases, which was not seen in their benign counterparts. Size, border definition, and edema of surrounding tissues were generally not helpful in distinguishing benign from malignant soft tissue masses. CONCLUSIONS: The inhomogeneity of lesions on T2, the change from homogeneity on T1 to inhomogeneity on T2 sequence, and involvement of bone or neurovascular structures are features that may be helpful in differentiating benign from malignant soft tissue masses.