The Usefulness of In Vitro Proton Magnetic Resonance Spectroscopy for Differentiating Between Abdominal Body Fluids

PURPOSE: The purpose of this study was to determine whether in vitro proton (1H) magnetic resonance spectroscopy (MRS) is useful for distinguishing between abdominal types of fluids. MATERIALS AND METHODS: Thirty fluid samples that were obtained from patients who were undergoing diagnostic or therapeutic percutaneous drainage of abdominal fluids were examined in this study. According to their gross appearance and smell, each sample was classified as either purulent fluid (n=12) or non-purulent fluid (n=18). The non-purulent fluids were subdivided into hemorrhagic fluid (n=2), serosanguinous fluid with debris (n=2), and serosanguinous fluid without debris (n=14). In addition, according to the cytologic analysis, each sample was classified as either benign fluid (n=23) or malignant fluid (n=7). A set of humoral pathological examinations that included biochemical analysis and culture of the fluid were performed for all the fluid samples. In vitro 1H MRS was performed by using a 1.5T MR system and a birdcage head coil. MR spectra were obtained by using point-resolved spectroscopy (PRESS) (TR/TE=2000/30 msec) with water suppression. The MR spectra were analyzed on the basis of agreement between a radiologist and a physicist who worked in consensus. RESULTS: The MR spectra obtained from 30 samples could be classified into 8 different patterns, according to the presence of lipid (0.9/1.3 ppm), lactate (1.3 ppm), acetate (1.9 ppm), and succinate (2.4 ppm) peaks. The MR spectral patterns of the purulent fluids (n=12) were classified as follows: pattern-1 (n=7, 58%), pattern-2 (n=2, 17%), pattern-3 (n=1, 8%), pattern-6 (n=1, 8%) and pattern-8 (n=1, 8%). The MR spectral patterns of the non-purulent fluids (n=18) were classified as follows: pattern-4 (n=1, 6%), pattern-5 (n=5, 28%), pattern-6 (n=1, 6%), pattern-7 (n=3, 17%) and pattern-8 (n=8, 44%). The MR spectral patterns of the purulent fluids were significantly different from those of the non-purulent fluids (p < .05). The MR spectral patterns of benign fluids (n=23) were classified as follows: pattern-1 (n=7, 30%), pattern-2 (n=2, 9%), pattern-3 (n=1, 4%), pattern-4 (n=1, 4%), pattern-5 (n=3, 13%), pattern-6 (n=2, 9%), pattern-7 (n=1, 4%) and pattern-8 (n=6, 26%). The MR spectral patterns of malignant fluids (n=7) were classified as follows: pattern-5 (n=2, 29%), pattern-7 (n=2, 29%) and pattern-8 (n=3, 43%). No significant difference was found between the spectral patterns of the benign and malignant fluids (p= .300). CONCLUSION: In vitro 1H MRS could be useful for differentiating between purulent fluid and non-purulent fluid.

Transvenous Embolization in Patients with Dural Arteriovenous Fistula

PURPOSE: To evaluate the efficacy of transvenous embolization in patients with dural arteriovenous fistula (DAVF). MATERIALS AND METHODS: From October 2002 to July 2004, eight patients with angiographically confirmed DAVF underwent transvenous embolization of the affected dural sinuses. Concomitant transarterial embolization was performed in four patients. Patients included five men and three women aged 45-78 years (mean age, 55.4 years). The patient's medical records and angiographic features were retrospectively reviewed. Patients had follow-up periods ranging from 5 to 24 months (mean, 16.5 months). RESULTS: The locations of DAVF were transverse - sigmoid sinus in six patients and cavernous sinus in two patients. According to Cognard's classification, four of the DAVFs were Type I, two were type IIa, and two were Type IIb. Embolic materials used for the transvenous embolization were platinum detachable coils and fibered microcoils. After the transvenous embolization, there was complete obliteration of the DAVF in seven patients and significant flow reduction in one patient. All cases were clinically successful. There were no transient or permanent complications as a result of the endovascular procedures in any of the patients. One patient who had symptom recurrence 2 months after the initial treatment was successfully treated with repeated transvenous embolization. The remaining seven patients had no symptom recurrence during the follow-up period. CONCLUSION: Transvenous embolization is an effective and safe method in the treatment of patients with DAVF.

Assessment of Mesenteric Vascular Steno-occlusive Lesion in Acute Mesenteric Ischemia: Comparison between CT Angiography and Digital Subtraction Angiography

PURPOSE: Acute mesenteric ischemia (AMI) is one of the most dramatic abdominal emergencies. The most common cause of AMI is a thrombo-embolism of the mesenteric artery or vein. The aim of this study was to evaluate the feasibility of CT angiography for evaluating mesenteric vascular steno-occlusive lesion in AMI. MATERIALS AND METHODS: Fifteen patients with clinically and angiographically proven AMI underwent a two-phase CT. The CT angiographic images were reconstructed using a 3D rendering algorithm, such as the maximum intensity projection and volume-rendering. All the CT angiographic images were reviewed with respect to stenosis or occlusion of mesenteric vessel by the consensus of two radiologists, and were correlated with the findings of digital subtraction angiography. RESULTS:Digital subtraction angiography (DSA) visualized 60 mesenteric vessels including the superior mesenteric artery (n=15) and vein (n=15), and the inferior mesenteric artery (n=15) and vein (n=15). DSA showed steno-occlusive lesions in 16 mesenteric vessels (13 superior mesenteric arteries, two superior mesenteric veins, and one inferior mesenteric artery). CT angiography detected steno-occlusive lesions in 16 mesenteric vessels (12 superior mesenteric arteries, one superior mesenteric vein, and three inferior mesenteric arteries). The sensitivity, specificity, and accuracy of CT angiography for evaluating mesenteric vascular steno-occlusive lesion were 87.5%, 95.4%, and 93.3%, respectively. CONCLUSION: CT angiography is an useful adjunct to abdominal CT in an AMI setting on account of its ability to detect the causes of AMI such as a steno-occlusive lesion of the mesenteric vessel.

Hepatic Perfusion Disorders: A Pictorial Review of CT and MR Imaging

The liver has a unique dual blood supply through the portal vein and the hepatic artery. There are several communications between these two vessels under various conditions such as in hepatic tumors, trauma and liver cirrhosis, vascular compromise, among others. When vascular compromise occurs, this dual blood supply system can cause changes in the volume of blood flow in individual vessels or even in the direction of blood flow. With rapid image acquisition and increased resolution available in multislice CT and MR imaging, hepatic perfusion disorders are now more frequently encountered than in the past. Familiarity with imaging findings of these perfusion disorders will be helpful in characterizing focal hepatic lesions and will also help to avoid false positive diagnoses.

The Usefulness of 3T-TOF MR angiography in Patients with Cerebral Infarction

PURPOSE: This study was designed to evaluate the usefulness of 3T-TOF MR angiography (3T-TOF MRA) compared with transcranial Doppler sonography (TCD) and conventional angiography (CA) in patients with suspected cerebral infarction. MATERIALS AND METHODS: Fifty four patients with clinical symptoms of cerebral infarction were involved in this study, and had undergone 3T-TOF MRA and TCD, with CA in 11 patients. On the basis of divisions of the carotid artery, four groups were designated: group I, both vertebral arteries and basilar artery; group II, segment between 2 cm below bifurcation of common carotid artery and genu portion of internal carotid artery; group III, segment between petrous portion of internal carotid artery and bifurcation of anterior and middle cerebral artery; group IV, from bifurcation of anterior and middle cerebral artery to thier distal branches. Two radiologists retrospectively reviewed the vascular imaging and stenosis in 3T-TOF MRA, TCD, and CA. RESULTS: A total of 432 arteries, 108 in each group, were available. The assessment of vascular imaging quality in 3T-TOF MRA is scored 2.98, 2.96, 2.91, 2.88 in 4 groups, respectively. Agreement among 3TTOF MR angiography, TCD, and CA was high. CONCLUSION: 3T-TOF MR angiography may be useful method for the assessment of stenotic lesions of cranial vasculature in patients with cerebral infarction.

Usefulness of Apparent Diffusion Coefficient in Ovarian Cystic Tumors Using Diffusion-Weighted Magnetic Resonance Imaging

PURPOSE: To evaluate the usefulness of apparent diffusion coefficient (ADC) values using diffusion-weighted magnetic resonance imaging (DWI) in patients with ovarian cystic tumors. MATERIALS AND METHODS: During past 12 months, we studied 30 patients who were clinically suspected of having ovarian cystic tumors and who underwent DWI using a 1.5 T MR unit. Eight patients with small cystic ovarian lesions of less than 3 cm in diameter and insufficient DWI were excluded from the calculation of the ADC values. The remaining twenty-six cystic ovarian lesions in 22 patients were classified into four groups; ovarian cysts, cystadenomas, other benign tumors, and malignant tumors. DWI was obtained using single-shot spin echo planar imaging and two gradient steps (b values of 0, 800 sec/mm2). The ADC values were measured using regions-of-interest (ROI) in the cystic components of the DWI located in the same section as the T2-weighted image and away from the septation and solid components. RESULTS: The mean ADC values were 0.196+/-0.105x10(-3) mm2/sec in the ovarian cysts, 1.312+/-1.064x10(-3) mm2/sec in the cystadenomas, 0.274+/-0.124x10(-3) mm2/sec in the other benign tumors, and 1.011+/-0.080x10(-3) mm2/sec in the malignant tumors. The differences in the ADC values between the ovarian cysts and cystadenomas, the ovarian cysts and malignant tumors, the cystadenomas and other benign tumors, and the other benign tumors and malignant tumors were statistically significant (p 0.05). CONCLUSION: The calculated ADC values using DWI should be helpful in the differential diagnosis of cystic ovarian tumors.

Ovarian Involvement of Peripheral T-Cell Lymphoma as Initial Manifestation of Extranodal Disease

We report here on a case of peripheral T-cell lymphoma of the ovary as the initial manifestation of extranodal disease. A 45-year-old woman presented with an incidentally detected, ovarian mass. Contrast-enhanced CT scans showed a 6x5.3 cm diameter, heterogeneously enhancing mass in the right adnexa that invaded the adjacent uterus. An exploratory laparotomy revealed a solid mass in the right adnexa, which invaded the uterine cornus. Histological diagnosis was made as a peripheral T-cell lymphoma of the ovary.

Virtual Endoscopy Using Spiral CT in Patients with Carcinomas of the Hypopharynx and Larynx

PURPOSE: To compare the usefulness of virtual endoscopy using spiral CT with that of laryngoscopy in the detection and evaluation of laryngeal and pharyngeal carcinomas. MATERIALS AND METHODS: Twenty-four patients with pathologically proven laryngeal and pharyngeal carcinomas underwent laryngoscopy and virtual endoscopy using spiral CT. Eleven of the carcinomas were supraglottic, five were glottic, and eight were hypopharyngeal. Source images obtained by spiral CT were transmitted to an independent workstation and virtual endoscopic images were obtained using Navigator software. These were graded according to their quality (good, fair, bad), and were interpreted by two radiologists who were blinded to the conventional endoscopic findings. These latter were subsequently compared with the virtual endoscopic findings in terms of similarity to laryngoscopic examination and detectability of lesions. RESULTS: The overall image quality of virtual endoscopy was good in 16 cases (67%), fair in eight (33%), and bad in no case. Among the 11 supraglottic carcinomas, image quality was good in seven cases (64%), and fair in four (36%). In four of the five glottic carcinomas (80%) quality was good, and in one case (20%) it was fair, while among the eight hypopharyngeal carcinomas, quality was good in five cases (63%), and fair in three (37%). Overall, detection of the lesion was possible in 23 cases (96%). Due to the small size of the lesion, the CONCLUSION: Virtual endoscopy using spiral CT is a safe and noninvasive method, and also successfully detects laryngeal and pharygenal lesions, with good image quality. For the evaluation of laryngeal and hypopharyngeal carcinoma, its use may complement that of axial CT.

The Usefulness of Virtual Cystoscopy with Spiral CT in Evaluating Bladder Tumor

PURPOSE: To compare the role and clinical usefulness of virtual and convetional cys-t o s c o py in patientswith known bladder tumors. MATERIALS AND METHODS: S eventeen patients with a known bladder tumor underwentvirtual and conventional cystoscopy. As a result of conventional cystoscopy and s u r g e r y, 32 tumors weredetected. Prior to examination, each patient lay supine on the CT table, and the urinary bladder was catheterized,drained of all urine, and inflated with air. Spiral CT of the pelvis was then performed. CT data were transferredto a separate workstation and three-dimensional and virtual cystoscopic images were reconstructed. The latter wereinterpreted by two radiologists, who recorded the number, size, morphology, and exact location of the massesobserve d. The results of virtual CT cystoscopy were correlated with conventional cystoscopic findings. RESULTS:Twenty - two (69%) of 32 bladder tumors detected during conventional cystoscopy were visualized by virtualcystoscopy. Four (36%) of 11 tumors measured 0.5 cm or less, 15 (83%) of 18 measured 0.5 -3 cm and all (100%) oftumors measured 3 cm or more. With regard to tumor morphology, six (86%) of seven sessile tumors and 16 (64%) of25 which were pedunculated were detected. The procedure was well tol-erated by all patients, and no complicationswere reported. CONCLUSION: Due to its intrinsic weakness, virtual cystoscopy cannot replace itscon-ventional counterpart, though by developing data scan and acquisition techniques and software, and on thebasis of clinical experience, the latter can be used in the future for the diagnosis and follow up ofbladder tumors.

Virtual Gastroscopy Using Spiral CT in Gastric Lesions

PURPOSE: To compare virtual gastroscopy using spiral CT with conventional endoscopy for the detection andevaluation of gastric lesions. MATERIALS AND METHODS: During a previous six-month period, 30 patients withpathologically-proven gastric lesions underwent conventional endoscopy and virtual gastroscopy using spiral CT.There were 18 cases of advanced gastric carcinoma, eight benign ulcers, and four submucosal tumors(two leiomyomas,two lymphomas). Source images of virtual gastroscopy were three-dimensionally reconstructed within an AdvantageWindows Workstation and virtual gastroscopy images were obtained using Navigator Software. On analysis, imageswere graded according to their quality (excellent, good, poor). Virtual gastroscopy images were interpreted by tworadiologists blinded to conventional endoscopic findings, and were subsequently compared with endoscopic findingsin terms of detectability and findings. In the cases of advanced gastric carcinoma, lesions were classifiedaccording to Borrmann's system. RESULTS: For virtual gastroscopy, overall image quality was excellent in 21cases(70%), good in five(17%), and poor in four(13%). Lesions were detected in 25 cases(83%). Among the 18advanced gastric carcinomas, virtual gastroscopy image quality was excellent in 14 cases(78%), good in two(11%),and poor in two(11%). Lesions were detected in 16 cases(89%). Two Borrmann type IV cases were not detected. Amongthe eight benign ulcers, virtual gastroscopy image quality was excellent in three cases(38%), good in three(38%),and poor in two(25%). The detection of lesion was possible in five cases(63%). In all submucosal tumors, virtualgastroscopy image quality was excellent. Lesions were detected in all cases. CONCLUSION: Virtual gastroscopyusing spiral CT is safe and noninvasive, and for the evaluation of gastric lesions may be complementary to axialCT. It successfully detects gastric lesions, and in depicting the pattern of gastric folds its image quality isexcellent.