In order to remove the artifacts of peripheral digital subtraction angiography (DSA), an affine transformation-based automatic image registration algorithm is introduced here. The whole process is described as follows: First, rectangle feature templates are constructed with their centers of the extracted Harris corners in the mask, and motion vectors of the central feature points are estimated using template matching technology with the similarity measure of maximum histogram energy. And then the optimal parameters of the affine transformation are calculated with the matrix singular value decomposition (SVD) method. Finally, bilinear intensity interpolation is taken to the mask according to the specific affine transformation. More than 30 peripheral DSA registrations are performed with the presented algorithm, and as the result, moving artifacts of the images are removed with sub-pixel precision, and the time consumption is less enough to satisfy the clinical requirements. Experimental results show the efficiency and robustness of the algorithm.
Algorithms ; Angiography, Digital Subtraction ; methods ; Artifacts ; Automation ; methods ; Image Processing, Computer-Assisted ; methods

OBJECTIVEWernicke's encephalopathy (WE) is an acute neuropsychiatric syndrome resulting from thiamine deficiency, which is associated with significant morbidity and mortality. The disorder is still greatly underdiagnosed in children because of either a relatively non-specific clinical presentation in some cases or unrecognized clinical setting. The aim of this literature review was to provide knowledge of pediatric WE in an effort to assist in early diagnosis, thereby reducing the morbidity and mortality.

METHODSThe clinical manifestations, characteristic magnetic resonance imaging (MRI), diagnosis and treatment of one case and the other 35 cases reported in the last decade in children were summarized.

RESULTSThirty-six cases (22 boys and 14 girls, 2-month to 16-year-old) were analyzed. All the other 35 cases except for our case had underlying diseases: improper feeding in 25/35 cases, long-time vomiting in 5/35 cases, immunosuppressive therapy in 4/35 cases, long-time total parenteral nutrition without multivitamin preparations supplementation in 3/35 cases and anorexia nervosa in 1/35 case. The classic triad (mental-status changes, nystagmus and ophthalmoplegia, and ataxia) was seen in 6/36 cases. The other clinical manifestations included consciousness disturbance in 24/36 cases, infection in 22/36 cases, pathological reflex and muscular tension changes in 18/36 cases, convulsion in 17/36 cases, developmental delay in 4/36 cases and failure to thrive in 2/36 cases. Cerebrospinal fluid examination was performed in 31/36 cases, and a slightly raised protein concentration was seen in 7/31 cases. The cerebrospinal fluid lactate levels were detected in 4/36 cases (all increased), serum lactic acid levels in 7/36 cases (6/7 cases increased), serum pyruvate in 4/36 cases (all increased), thiamine pyrophosphate effect (TPPE) in 9/36 cases (all increased), and serum thiamine in 2/36 cases (increased in 1/2 cases). The brain computed tomography (CT) scan was conducted in 20/36 cases and 16/20 cases showed abnormal hypodensity in bilateral basal ganglia, one case revealed diffuse cortical atrophy. The brain MR scan was conducted in 13/36 cases and all the 13 cases revealed symmetrical abnormal signal in bilateral mamillary body and basal ganglia, and 7/13 cases showed abnormal signals in the tegmentum of midbrain, cerebral aqueduct and white matter around the third and fourth ventricles. The diagnosis of WE was confirmed by MR in 12 cases, triad combined with MR in 3 cases, autopsy in 1 case among the 13 cases who underwent MR scan. The diagnosis of WE was confirmed by the TPPE and/or lactate levels in 9/11 cases. The initial thiamine was given by intravenous or intramuscular infusion in 33/36 cases, unknown method in 1 case, orally in 1 case and no thiamine was used in 1 case. The dosage of thiamine was 100 mg daily in 29/35 cases, unknown in 3/35 cases, 50 mg daily in 2/35 cases, 600 mg daily in 1/35 case. 34/35 patients' clinical symptoms improved during 24 hours to 1 week after initial treatment, and 1 case died due to no response to thiamine. Nineteen patients were followed up for 2-2.5 months and 17 cases recovered completely.

CONCLUSIONWernicke's encephalopathy can be difficult to diagnose because of a relatively non-specific clinical presentation. The characteristic MRI findings and the dramatic response of neurological signs to parenteral thiamine will assist early clinical diagnosis. Early and timely thiamine supplementation could reverse the clinical features and improve the prognosis in most cases.

Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Sepsis ; complications ; Wernicke Encephalopathy ; complications ; diagnosis

Adult ; Aged ; Bacterial Infections ; diagnosis ; immunology ; Female ; Hepatitis B, Chronic ; diagnosis ; immunology ; microbiology ; Humans ; Male ; Middle Aged ; Prognosis ; T-Lymphocyte Subsets ; immunology ; Young Adult

OBJECTIVETo assess the value of three dimensional proton magnetic resonance spectroscopy (3D 1H-MRS) with body coil at 3T in the differential diagnosis of prostate cancer.

METHODSForty patients suspected of prostate cancer underwent MRI and MRS examinations, and then transrectal ultrasound guided prostate biopsy for pathological diagnosis. The MRI and MRS features of benign prostate hyperplasia, prostate cancer and prostatic intraepithelial neoplasia (PIN) were analyzed in comparison with the pathological reports, and the receiver operating characteristic curve was drawn for the diagnosis of cancer from peripheral zones.

RESULTSThe examinations were accomplished for all the patients. The mean ratios of (Cho + Cre)/Cit in the interstitial and glandular hyperplasia tissues, the cancer tissue of the central and peripheral glands, the healthy peripheral gland and PIN were 0.75 +/- 0.23, 0.59 +/- 0.14, 1.79 +/- 0.90, 1.18 +/- 0.95, 0.46 +/- 0.18, and 0.97 +/- 0.10, respectively, with statistically significant differences between the cancer and normal prostate tissues (P < 0.01). The optimum threshold for the diagnosis of prostate cancer in the peripheral zone was 0.68 with a sensitivity of 88.6% and a specificity of 88.7%.

CONCLUSIONThe 3D 1H-MRS with body coil at 3T has a high sensitivity and specificity in the differential diagnosis of prostate cancer, and can provide valuable information for the diagnosis of PIN.

Aged ; Aged, 80 and over ; Diagnosis, Differential ; Humans ; Imaging, Three-Dimensional ; Magnetic Resonance Spectroscopy ; methods ; Male ; Middle Aged ; Prostatic Neoplasms ; diagnosis ; Sensitivity and Specificity