Advanced diagnostic imaging of pancreatic cysts by multidetector computed tomography.

Nowadays, increasing use of cross sectional imaging especially multi-detector computed tomography causes greater detection of pancreatic cysts. The differentiation between pancreatic pseudocyst and cystic pancreatic neoplasm is essential in determining the proper treatment and prognosis. Typical imaging findings of benign pancreatic cystic lesion, especially in the asymptomatic patient, can be refined through imaging follow up. Fast scanning time and the thin slice of multidetector computed tomography provides a high resolution of image quality, less motion artifact and multi-planar reformation. It is a non invasive technique and entails few complications. However, in an atypical imaging pattern or if suggestive of malignant in nature, further investigation with endoscopic retrograde cholangiopancreatography (ERCP) with fine needle aspiration (FNA) for tissue diagnosis or cytology can aid in definite diagnosis.

Benign versus malignant compression fracture: a diagnostic accuracy of magnetic resonance imaging.

OBJECTIVE: To evaluate the accuracy, sensitivity, and specificity of various Magnetic Resonance Imaging (MRI) features in differentiating malignant from benign compression fracture of the spine. MATERIAL AND METHOD: Retrospective review of MRI spine of patients with vertebral compression fracture identified from the hospital database between June 2004 and February 2006 by two radiologists blinded to the clinical data. Various MRI features were evaluated for sensitivity, specificity, positive predictive value, and negative predictive value. An additional combination of two, three, four, and five MRI features that had statistically significant (P value less than 0.005) were also calculated for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: Fifty-eight spinal MRI were included from 35 patients with metastatic vertebral compression fractures and 23 patients with benign vertebral compression fractures. MR imaging features suggestive of malignant vertebral compression fracture were convex posterior border of the vertebral body, involvement of the pedicle or posterior element, epidural mass, paraspinal mass, and destruction of bony cortex. Among these, involvement of pedicle or posterior element was the most reliable finding (sensitivity 91.4% and specificity 82.6%) for diagnosis of malignant vertebral compression fracture. A combination of two or more MRI features gave very high specificity and PPV. CONCLUSION: Certain MR imaging characteristics can reliably distinguish malignant from benign compression fracture of the spine. Combination of several MRI features strongly affirmed the diagnosis of malignant compression fracture, especially in a patient where tissue biopsy is not justified.

Imaging findings and prevalence of central precocious puberty at Siriraj Hospital.

Central precocious puberty occurs as a result of premature pituitary stimulation and increased secretion of gonadotropins. The differential diagnosis of true precocious puberty includes cerebral and idiopathic categories. This differentiation, which cannot be made endocrinologically due to similarities in pituitary gonadotropin and sex steroid levels, may facilitatic by Magnetic Resonance Imaging (MRI) of the brain. Objective: To analyze MR imaging findings and incidence of each pathology in central precocious puberty, and to compare pituitary height in patients with central precocious puberty with patients in a control group. Materials and methods: A retrospective study of central precocious puberty in 22 patients was performed from March 2002 to July 2003. The control group consisted of 54 boys and 46 girls. Analyzed parameter included pituitary height, shape and posterior bright spot. The shape was assessed by a pituitary grading system which was based on the concavity of the upper pituitary surface (grade 1 = marked concavity, grade 2 = mild concavity, grade 3 = flat, grade 4 = mild convexity, grade 5 = marked convexity). Bone age, and pelvic ultrasonography were evaluated in the study group. Results: Twenty two children with central precocious puberty (4 boys and 18 girls) were divided into two subgroup according to MRI findings as follows : idiopathic 15 patients (68.18%) and noidiopathic 7 patients (3 patients had nodule at pituitary stalk, 2 had microadenoma, 1 had germ cell tumour at pinealgland, and 1 had hypothalamic harmatoma). The mean pituitary height in the study group was 5.59 mm (SD 1.7). The mean height of the control group was 5.25 mm. There was significant difference among the two groups (p < 0.005). Conclusion: The most common cause in central precocious puberty is idiopathic. However the MRI is necessary to necessary to excluding the surgical cause as tumor. Pituitary height of more than 5.25 mm may be a helpful variable for follow up the result of medical treatment in precocious children.