Diagnostic Performance of CT Colonography for the Detection of Colorectal Polyps

OBJECTIVE: To investigate the diagnostic value of CT colonography for the detection of colorectal polyps. MATERIALS AND METHODS: From December 2004 to December 2005, 399 patients underwent CT colonography and follow-up conventional colonoscopy. We excluded cases of advanced colorectal cancer. We retrospectively analyzed the CT colonography findings and follow-up conventional colonoscopy findings of 113 patients who had polyps more than 6 mm in diameter. Radiologists using 3D and 2D computer generated displays interpreted the CT colonography images. The colonoscopists were aware of the CT colonography findings before the procedure. RESULTS: CT colonography detected 132 polyps in 107 of the 113 patients and conventional colonoscopy detected 114 colorectal polyps more than 6 mm in diameter in 87 of the 113 patients. The sensitivity of CT colonography analyzed per polyp was 91% (41/45) for polyps more than 10 mm in diameter and 89% (101/114) for polyps more than 6 mm in diameter. Thirteen polyps were missed by CT colonography and were detected on follow-up conventional colonoscopy. CONCLUSION: CT colonography is a sensitive diagnostic tool for the detection of colorectal polyps and adequate bowel preparation, optimal bowel distention and clinical experience are needed to reduce the rate of missing appropriate lesions.

Prenatal Deaths and External Malformations Caused by X-Irradiation during the Preimplantation Period of ddy Mice / 대한방사선종양학회지

PURPOSE: To evaluate the effects of X-irradiation on prenatal deaths, i.e., preimplantation deaths, embryonic deaths, and fetal deaths, and on external malformations in precompacted preimplantation ddy mice. MATERIALS AND METHODS: Pregnant mice (n=85), obtained by limiting the mating time to from 6 to 9 A.M., were segregated into 11 groups. The first five groups (n=26) were irradiated with X-ray doses of 0.1, 0.5, 0.75, 1.5, and 3 Gy, respectively, at 24 h post conception (p.c.) of the preimplantation period. The second five (n=27) groups were irradiated at the same X-ray doses, respectively, but at 48 h p.c. of the preimplantation period. The last group (n=32) was the control group. The uterine contents were examined on the 18th day of gestation for prenatal deaths and external malformations. RESULTS: 1) A statistically significant increase in preimplantation deaths with increasing dose was observed in the experimental groups irradiated at 24 h p.c. and in the groups irradiated at 48 h p.c., as compared to the control group. The threshold dose was close to 0.05 Gy and 0.075 Gy for the irradiations at 24 h p.c. and 48 h p.c. respectively.2) A statistically significant increase in embryonic deaths with increasing dose was observed in all irradiation groups, except the group irradiated with a dose of 0.1 Gy at 48 h p.c..3) No fetal deaths were found in any experimental group.4) In the experimental groups irradiated at 24 h p.c., anomalies increased with statistical significance, as compared with the control group: 2 exencephalies, 2 open eyelids, 3 anophthalmias, 2 cleft palates, 2 gastroschisis, 1abdominal wall defect, 1 leg defect, and 2 short tail anomalies; the threshold dose for external malformations was close to 0.2 Gy at 24 h p.c.. In the groups irradiated at 48 h p.c., 1 open eyelid and 2 short tail anomalies were observed, but there was no statistical significance in those malformations. CONCLUSION: The results of this study reveal that X-irradiation of precompacted preimplantation ddy mice causes not only preimplantation deaths and embryonic deaths but also external malformations. In addition, external malformations were observed in our experiments at diagnostic doses, including 0.1 and 0.5 Gy. For this reason, we recommend that irradiation should be avoided during the preimplantation period by applying Rugh's 10-day rule.

A case of combined gastrojejunal and gastrocolic fistula secondary to gastric cancer

A rare case of gastric cancer associated with gastrojejunal and gastrocolic fistula is presented. A 56-year-old man who had been diagnosed with advanced gastric cancer(Borrmann's type III) 5 months previously was admitted due to watery diarrhea and frequent vomiting for 2 weeks. Fluoroscopic examination was visualized two abnormal passage of contrast medium from the stomach, one to the colon, and the other to the jejunum. Gastrofiberscopy revealed that the tumor on the great curvature of the body appeared to penetrate into the colon, while the other one on the antrum directly invaded into the jejunum. The patient was treated conservatively with total parenteral nutrition and pain control.

CT and MR Features of the Intracranial Schwannomas

PURPOSE: To evaluate CT and MR findings of the intracranial schwannomas arising from variable cranial nerves. MATERIALS AND METHODS: The authors retrospectively analyzed CT (n=21) and MR(n=15) findings of 24 cases in 23 patients(M : 7, F : 16) who had suffered from surgically-proven intracranial schwannomas over the previous fiveyears. RESULTS: Schwannomas arose from the acoustic nerve(n=18), the trigeminal nerve(n=2), the glossopha-ryngeal-vagal-accessory nerve complex (n=2), and the olfactory nerve(n=1). Intracranial schwannomas were welldefined, lobulated and inhomogeneously or homogeneously enhancing masses on CT and MR, and were located along the course of the specific cranial nerve. Acoustic schwannomas involved both the internal auditory canal(IAC) and the cerebellopontine angle(CPA) in 14 cases, the IAC in three, and the CPA in two. Two trigeminal schwannomas involved both middle and posterior cranial fossa and were in the shape of a dumbbell. One of the two schwannomas that invelved lower cranial nerve complex(9-11th) was located in the medullary cistern and jugular foramen ; the other was located in the central posterior cranial fossa. A case of olfactory schwannoma was located in the right cribriform plate. The precontrast CT scan showed low density in 13 cases(62%), isodensity in seven(33%) and highdensity in one(5%). On postcontrast CT scan, enhancement was seen in 20 cases(95%). Of the 15 cases with MR, 12had low signal intensity on T1 weighted image and 14 had high signal intensity on T2 weighted image. MR imaging after Gd-DTPA infusion showed enhancement in 14 cases. Enhancement was inhomogeneous in 14 cases on CT and in 13 on MR. Of 24 cases, intratumoral necrosis was seen in 19, ring enhancement in five and severe cystic change inone. Other findings were intratumoral calcification(21%), hemorrhage(8%), pressure bony erosion(70.8%), midline shift(58%), peritumoral edema(29%) and hydrocephalus(33%). On MR, there was in all 15 cases a peritumoral lowsignal intensity rim on T1- and T2-weighted images and on a T1 weighted image following gadolium infusion. A caseof olfactory groove schwannoma was associated with neurofibromatosis type I and a case of bilateral acoustic schwannoma with neurofibromatosis II. CONCLUSION: Schwannomas can be easily diagnosed when a well defined, lobulated and inhomogeneously enhancing mass with intratumoral necrosis, cystic change, calcification orhemorrhage is seen along the course of a cranial nerve. Peritumoral low signal intensity rim on MR may be helpful in differentiating intracranial schwannomas from other tumors.

CT and MRI Findings of 4th Ventricular Tumors

PURPOSE: The purpose of our study is to evaluate characteristic features of 4th ventricular tumors in CT and MRI. MATERIALS AND METHODS: Pathologically proved 9 patients with 4th ventricular tumor were examined by CT and/or MRI. 4th ventricular tumors were epedymoma(4 cases), medulloblastoma(2 cases), choroid plexus papilIoma(2 cases), and oligodendroglioma(1 case). Included in our study were only those mass lesions that were located at surgery predominently within 4th ventricle with or without ventricular expansion. RESULTS: The origin of 4th ventricular tumor was the roof (epedymoma 3 cases, medulloblastoma 2 cases), the floor (epedymoma 1 case), and the undetermined(remaining 3 cases). On MRI, all tumors were hypointense exept ependymoma(3 cases) showing isointensity on T1WI. All tumors were hyperintense on PDWI and T2WI. On Gd-DTPA enhanced T1WI, strong enhancement was seen in all but epedymoma(1 case) which showed mild enhancement. On CT, as compared with MR images, various density on precontrast and postcontrast images were seen. Calcification was seen in choroid plexus papilloma(1 case) and oligodendroglioma(1 case). Hydrocephalus is seen in all cases exept ependymoma(2 cases) and oligodendroglioma(1 case). Hemorrhage within tumor was present only in epedymoma(2 cases). Cystic change or necrosis of tumor was seen in ependymomma(3 cases), choroid plexus papilloma(1 case), and oligodendroglioma(1 case). Peritumoral edema was seen in medulloblastoma(1 case). Extension through the foramen Luschka and the Magendie was seen in ependymoma(2 cases), choroid plexus papilloma(2 cases), and medulloblastoma(1 case). Seeding along the CSF pathway was seen only in ependymoma(2 cases). CONCLUSION: The results of our study may suggest that specific diagnosis of 4th ventricular tumor can be suggested preoperatively by analysing the origin in 4th ventricle, difference of CT density or MRI signal inten. sity, presence of extension or seeding through cerebrospinal fluid of the lesion.

CT Findings of Spontaneous Subarachnoid Hemorrhage of Unknown Cause

PURPOSE: Spontaneous subarachnoid hemorrhage(S-SAH) is a relatively rare disease with good clinical course and prognosis. The purpose of this study is to evaluate the cisternal blood distribution on CT in patient with S-SAH. MATERIALS AND METHODS: Out of 406 patients with subarachnoid hemorrhage on brain CT scan, 11 patients confirmed to be S-SAH by angiography and clinical follow-up were examined. We analysed the CT findings of these 11 cases retrospectively. RESULTS: Five patients had only perimesencephalic distribution of hemorrhage:the prepontine, the interped- uncular, and the suprasellar cisterns were involved in 4 cases each, the basal sylvian cistern in 3 cases, and the ambient cistern in 2 cases. The quadrigeminal and a portion of the lateral sylvians were also involved in 1 case each. Six patients revealed cisternal hemorrhage extending beyond the perimesencephalic cistern into the ventricles, cortical sulci, and lateral sylvian fissure. Intraventricular hemorrhage was noted in 3 cases of these 6 patients. CONCLUSION: Our study suggests that uncomplicated clinical course and normal anglographic finding are more important than CT distribution of cisternal hemorrhage in diagnosing S-SAH.

Disseminated aspergillosis in malignant lymphoma: a case report

Aspergillosis is a rare disease of fungal infection produced by the genus Aspergillus in immunocompromised patients. It mainly involves the lung and may disseminate by invasion of biood vessels into the gastrointestinal tract. Brain and kidney. We report a case of the disseminated aspergillosis in malignant lymphoma affecting the lung. Brain and thyroid gland.

CT and MR findings of neuronal migration anomalies

No abstract available.