A Case of Splenic Hamartoma Diagnosed by Contrast-enhanced Ultrasonography and Magnetic Resonance Imaging / 대한소화기학회지

Splenic hamartoma is a very rare benign tumor, which is usually found incidentally after splenectomy or autopsy. Although percutaneous needle biopsy can be performed, it carries a high risk of bleeding after the procedure. Therefore, diagnosis is usually made by surgical resection. Herein, we report a case of splenic hamartoma diagnosed by magnetic resonance imaging and contrast-enhanced ultrasonography, which enables visualization of the unique signals of microbubbles in the vessels in real time. Relevant literature is also reviewed.

Acoustic Radiation Force Impulse Elastography for Focal Hepatic Tumors: Usefulness for Differentiating Hemangiomas from Malignant Tumors

OBJECTIVE: The purpose of this study is to investigate whether acoustic radiation force impulse (ARFI) elastography with ARFI quantification and ARFI 2-dimensional (2D) imaging is useful for differentiating hepatic hemangiomas from malignant hepatic tumors. MATERIALS AND METHODS: One-hundred-and-one tumors in 74 patients were included in this study: 28 hemangiomas, 26 hepatocellular carcinomas (HCCs), three cholangiocarcinomas (CCCs), 20 colon cancer metastases and 24 other metastases. B-mode ultrasound, ARFI 2D imaging, and ARFI quantification were performed in all tumors. Shear wave velocities (SWVs) of the tumors and the adjacent liver and their SWV differences were compared among the tumor groups. The ARFI 2D images were compared with B-mode images regarding the stiffness, conspicuity and size of the tumors. RESULTS: The mean SWV of the hemangiomas was significantly lower than the malignant hepatic tumor groups: hemangiomas, 1.80 +/- 0.57 m/sec; HCCs, 2.66 +/- 0.94 m/sec; CCCs, 3.27 +/- 0.64 m/sec; colon cancer metastases, 3.70 +/- 0.61 m/sec; and other metastases, 2.82 +/- 0.96 m/sec (p < 0.05). The area under the receiver operating characteristics curve of SWV for differentiating hemangiomas from malignant tumors was 0.86, with a sensitivity of 96.4% and a specificity of 65.8% at a cut-off value of 2.73 m/sec (p < 0.05). In the ARFI 2D images, the malignant tumors except HCCs were stiffer and more conspicuous as compared with the hemangiomas (p < 0.05). CONCLUSION: ARFI elastography with ARFI quantification and ARFI 2D imaging may be useful for differentiating hepatic hemangiomas from malignant hepatic tumors.

Parallel Wire Balloon Angioplsty for Undilatable Venous Stenosis in Hemodialysis Fistula

PURPOSE: The purpose of this study was to assess the value of the parallel wire balloon angioplasty technique for treating dysfunctional hemdialysis fistula with rigid stenosis, and this type of lesion was resistant to conventional angioplasty. MATERIALS AND METHODS: Between March 2002 and August 2003, we included 6 patients (mean age: 59, males: 2, females: 4) who were treated via parallel the wire balloon angioplasty technique and their hemodialysis fistula has stenoses that were resistant to conventional angioplasty. We performed conventional angioplasty in all patients, but we failed to achieve sufficient dilatation. In the cases of highly resistant stenosis, an additional 0.016 inch wire was inserted into the 7 F vascular sheath. During angioplasty, a 0.016 inch guide wire was inserted between the balloon and the stenosis and then it was pushed to and fro until the balloon indentation disappeared. After the procedure, we performed angiography to identify the residual stenosis and the procedure-related complications. RESULTS: The undilatable stenoses in 5 patients were successfully resolved without complications via the parallel wire angioplasty technique. In one patient, indentation of balloon was not resolved, but the residual stenosis was both minimal and hemodynamically insignificant. CONCLUSION: The parallel wire angioplasty technique seems to be a feasible and cost-effective method for treating a dysfunctional hemodialysis fistula with undilatable and rigid stenosis.

Retrograde Jejuno-gastric Intussusception

Retrograde jejuno-gastric intussusception is an unusual complication after gastroenterostomy. It is very difficult to diagnosis this illness before endoscopy or operation, so a high clinical suspicion is needed to make the diagnosis .There have been only 300 reported cases of this illness. There are four types of jejuno-gastric intussusception that are defined anatomically. Intussusception of the efferent limb of the jejunum is the most frequent type. Although the causative factors are not well known, this disease has a poor outcome unless it's treats promptly within 48 hours. We report here a case of hematemesis caused by intussusceptum from the efferent limb to the afferent limb of Braun anastomosis.

Bezoar Associated with Small Bowel Obstruction: Comparison of CT and US

PURPOSE: To compare the accuracy of computed tomography (CT) and ultrasound (US) in the diagnosis of bezoars in small bowel obstruction. MATERIALS AND METHODS: During a recent eight-year period, 23 patients underwent surgery due to small bowel obstruction caused by bezoars, and 14 who underwent both CT and US were included in this study. The scans obtained were retrospectively reviewed by two radiologists working independently, and the usefulness of each modality in terms of diagnostic capacity, determination of the level of obstruction and detection of additional bezoars was assessed. RESULTS: At surgery, a total of 22 bezoars were removed: 19 from the small intestine and three from the stomach; multiple bezoars were found in five of the 14 patients. The presence of bezoars was demonstrated by CT in all patients, and by US in ten (71%) (p=0.125). The level of obstruction was correctly predicted in 57% of cases at US and in 100% at CT (p=0.03). Overall sensitivity was 55% for US (12/22) and 96% for CT (21/22) (p<0.01). In three patients with associated gastric bezoars, US revealed only one, whereas all were demonstrated by CT. In five with multiple lesions, only five (39%) of 13 were apparent at US, but 12 (92%) were revealed by CT. CONCLUSION: Both US and CT were useful for the diagnosis of small bowel obstruction caused by bezoars. CT however, was more accurate in determining the level of obstruction and in revealing additional bezoars in the small bowel and stomach.

Hybrid Two-Dimensional Proton Spectroscopic Imaging of Pediatric Brain: Clinical Application

PURPOSE: To introduce and demonstrate the advantages of the new hybrid two-dimensional (2D) proton spectroscopic imaging (Sl) over the single voxel spectroscopy (SVS) and conventional 2D Sl in the clinical application of spectroscopy for pediatric cerebral disease. MATERIALS AND METHODS: Eighty-one hybrid 2D proton spectroscopic imaging was performed in 79 children (36 normal infants and children, 10 with hypoxic-ischemic injury, 20 with toxic metabolic encephalopathy, seven with brain tumor, three with meningoencephalitis, one with neurofibromatosis, one with Sturge-Weber syndrome and one with lissencephaly) ranging in age from the third day of life to 15 years. In adult volunteers (n = 5), all three techniques including hybrid 2D proton Sl, SVS using PRESS sequence, and conventional 2D proton Sl were performed. Both hybrid 2D proton Sl and SVS using PRESS sequence were performed in clinical cases(n= 12). All measurements were peformed with a 1.5-T scanner using standard head quadrature coil. The 16 x 16 phase encoding steps were set on variable field of view (FOV) depending on the size of the brain. The hybrid volume of interest inside FOV was set as 75 x 75 x 15 mm3 or smaller to get rid of unwanted fat signal. Point-resolved spectroscopy (TR/TE = 1,500 msec/135 or 270 msec) was employed with standard chemical shift selective saturation (CHESS) pulses for water suppression. The acquisition time and spectral quality of hybrid 2D proton Sl were compared with those of SVS and conventional 2D proton Sl. RESULTS: The hybrid 2D proton Sl was successfully conducted upon all patients. The 2D spectral data acquisition time was less than 6 minutes, while the data acquisition time of SVS was 4.3 minutes. This was short enough for pediatric application. The spectra acquired with hybrid 2D proton Sl showed nearly the same sensitivity and spectral resolution with SVS. The spectral quality of hybrid 2D proton Sl was, on the other hand, far better than that of conventional 2D proton Sl. The other advantage of hybrid 2D proton Sl was that the extent of metabolic abnormalities could be evaluated through the characteristics of the relative levels of the three metabolites, i.e., N-acetylaspartate, choline, and creatine. CONCLUSION: The hybrid 2D proton Sl can be successfully employed for the evaluation of the metabolic abnormalities in the various pathologic conditions of pediatric brain without penalty in acquisition time and spectral quality when compared to SVS. The extent of metabolic abnormalities, which cannot be obtained with SVS technique, also can be evaluated with hybrid 2D proton Sl.

(31)P MR Spectroscopic Measurement of Intracellular pH in Normal Human Hearts

PURPOSE: To assess the usefulness of intracellular pH (pHi), calculated by determining the shift of a high-energy metabolite such as inorganic phosphate (Pi) or gamma-ATP after performing MRS with ECG-gated two-dimensional 31P CSI (chemical shift imaging), as a parameter for the overall state of the intracellular milieu. MATERIALS AND METHODS: Proton decoupled 31P CSI was performed on a 1.5-T scanner using a (1)H-(31)P dual-tuned surface coil. Cardiac MRS data were obtained from eight normal volunteers aged 24-32 years with no history of heart disease. From the spectra obtained from several regions of the heart, peak position and peak area were estimated. The metabolic ratios of alpha-, beta-, gamma-ATP, PCr, Pi, phosphodiester and diphosphoglycerate were calculated, and pHi was estimated from the chemical shift of Pi and gamma-ATP resonance. We then compared the data for the anterior myocardium with those previously published. RESULTS: The major phosphorous metabolites identified in these human hearts were as follows: PCr, at -0.1 to +0.1 ppm; three phosphate peaks from ATP, with a chemical shift centered at about -2.7 ppm (gamma-ATP), -7.8 ppm (alpha-ATP), and -16.3 ppm (beta-ATP); and phosphodiester (PDE) at 2-3 ppm, inorganic phosphate (Pi) at 4.5-5.4 ppm, and diphosphoglycerate (DPG) at 5.4-6.3 ppm. The PCr/beta-ATP ratio was 2.20+/-0.17 and the PDE/beta-ATP ratio, 1.04+/-0.09. pHi readings were 7.31+/-0.23 (calculated by the shift of Pi) and 6.81+/-0.20 (calculated by the shift of gamma-ATP). Pi/PCR was 0.539, a ratio higher than that mentioned in previously published reports. CONCLUSION: The measurement of intracelluar metabolism was affected by various kinds of factors. We believe, however, that pHi readings indicate the overall state of the cardiac intracelluar milieu. An unexpected pHi readings, seen at MRS, may reflect errors in the MR procedure itself and, or in the alanytical method.

Imaging Features of Nontumorous Conditions Involving the Trachea and Main-stem Bronchi

A number of nontumorous diseases may affect the trachea and main-stem bronchi, and their nonspecific symptoms may include coughing, dyspnea, wheezing and stridor. The clinical course is often long-term and a misdiagnosis of bronchial asthma is common. The imaging findings of these nontumorous conditions are, however, relatively characteristic, and diagnosis either without or in conjunction with clinical information is often possible. For specific diagnosis, recognition of their imaging features is therefore of prime importance. In this pictorial essay, we illustrate the imaging features of various nontumorous conditions involving the trachea and main-stem bronchi.

Multi-Component Relaxation Study of Human Brain Using Relaxographic Analysis

PURPOSE: To demonstrate that the relaxographic method provides additional information such as the distribution of relaxation times and water content which are poentially applicable to clinical medicine. MATERIALS AND METHODS: First, the computer simulation was performed with the generated relaxation data to verify the accuracy and reliablility of the relaxographic method (CONTIN). Secondly, in order to see how well the CONTIN quantifies and resolves the two different T1 environments, we calculated the oil to water peak area ratios and identified peak positions of T1-distribution curve of the phantom solutions, which consist of four centrifugal tubes (10ml) filled with the compounds of 0, 10, 20, 30% of corn oil and distilled water, using CONTIN. Finally, inversion recovery MR images for a volunteer are acquired for each TI ranged from 40 to 1160 msec with TR/TE=2200/20 msec. From the 3 different ROIs (GM, WM, CSF), CONTIN analysis was performed to obtain the T1-distribution curves, which gave peak positions and peak area of each ROI location. RESULTS: The simulation result shows that the errors of peak positions were less in the higher peak (centered T1=600 msec) than in the lower peak (centered T1=150 msec) for all SNR but the errors of peak areas were larger in the higher peak than in the lower peak. The CONTIN analysis of the measured relaxation data of phantoms revealed two peaks between 20 and 60 msec and between 500 and 700 msec. The analysis gives the peak area ratio as oil 10%: oil 20%: oil 30%=1:1.3:1.9, which is different from the exact ratio, 1:2:3. For human brain, in ROI 3 (CSF), only one component of -distributions was observed whereas in ROI 1 (GM) and in ROI 2 (WM) we observed two components of T1-distribution. For the WM and CSF there was great agreement between the observed T1-relaxation times and the reported values. CONCLUSION: we demonstrated that the relaxographic method provided additional information such as the distribution of relaxation times and water content, which were not available in the routine relaxometry and T1/T2 mapping techniques. In addition, these additional information provided by relaxographic analysis may have clinical importance.

Percutaneous Insertion of Inferior Vena Cava Filter: Clinical Results of 8 patients

PURPOSE: To evaluate the efficacy and clinical results of percutaneous insertion of inferior vena cava(IVC) filter. MATERIALS AND METHODS: Over a two year period, eight IVC filters were placed in eight patients with pulmonary thromboembolism resulting from deep vein thrombosis of the legs. The indications for placement were contraindication to anticoagulation(3), and recurrent pulmonary embolism during anticoagulant therapy(5). Both femoral(7) and jugular(1) routes were used for percutaneous transvenous insertion. To delineate the caval anatomy and to ensure placement just caudal to the renal vein, a cavogram was obtained before filter placement. Bird's Nest (7) and Greenfield (1) filters were inserted. Follow-up information was obtained by means of duplex sonography, CT scan, abdominal radiograph, and perfusion scan of the lungs, followed by clinical evaluation. RESULTS: In all cases, procedures were technically successful. Placement complications occurred in three patients. In one, the filter was inadvertently placed above the iliac bifurcation; in the other two, prolapse of the Bird's Nest filter wire occurred. Occlusion of IVC occurred in two patients, and recurrent pulmonary embolism was suspected in one, who suffered from chest pain and shortness of breath. In the other patients, there was no clinical evidence of recurrence of the pulmonary embolism. CONCLUSION: Insertion of an inferior vena cava filteris a safe and effective method for the prevention of pulmonary embolism when anticoagulant therapy is either ineffective or contraindicated.

Phytobezoars in the Small Intestine: CT and US Appearances

PURPOSE: To describe CT and ultrasound(US) appearances of phytobezoar in the small intestine. MATERIALS AND METHODS: During the past two years, CT and US scans of six patients with phytobezoars of the small intestine were retrospectively reviewed. All patients presented symptoms of bowel obstruction, and four had a history of gastric surgery. Four phytobezoars were found in the jejunum and two in the ileum at surgery. We evaluated CT and US findings of phytobezoar and compared these with CT images of the removed phytobezoars. RESULTS: In three patients, US studies showed a curvilinear echogenic mass within the lumen of the dilated small bowel, with a clear posterior acoustic shadow. In six, CT scans revealed an intraluminal mass seen as having a thin soft tissue rim at the periphery and numerous aggregated low attenuation areas representing gas in the central portion. CT findings of the specimens were the same as those of phytobezoars in vivo. CONCLUSION: US and CT appearances of small intestinal phytobezoars are sufficiently distinctive to advocate the preoperative routine use of US and CT for diagnosing this entity.

A Case of Tracheopathia Osteoplastica / 결핵

Tracheopathia osteoplastica is a rare disease characterized by submucosal cartilaginous or bony projections into tracheobroncheal lumen with sparing of the posterior membranous portion of tracheobroncheal tree. The cause of this disorder is unknown. In the past, a majority of the cases were discovered incidentally at autopsy. But recently, antemortem diagnosis is increasingly reported after the introduction of computed tomography and bronchoscopy. We report a case of extensive tracheopathia osteoplastica diagnosed antemortem by computed tomography, bronchoscopic examination and biopsy.