Pancreaticobiliary maljunction in monozygotic twins--a case report

We experienced a case of pancreaticobiliary maljunction in monozygotic twins. While one of the twins suffered from gallbladder cancer with poor prognosis, the other was not associated with biliary malignancy. Ultrasonography, endoscopic ultrasonography, and magnetic resonance cholangiopancreatography are effective in diagnosis of this disorder before occurrence of biliary cancers. This case is not only of academic interest for familial occurrence, but also of clinical interest in the early detection of pancreaticobiliary maljunction.

Endoscopic diagnosis and staging of mucinous cystic neoplasms and intraductal papillary-mucinous tumors

BACKGROUND/PURPOSE

The number of patients with cystic neoplasms of the pancreas as detected using various types of imaging techniques has been steadily increasing. Among the cystic neoplasms, mucinous cystic neoplasms (MCNs) and intraductal papillary-mucinous tumors (IPMTs) were comparatively more frequently encountered. We used imaging techniques to focus on the differential diagnosis of MCNs and IPMTs, and tumor staging.

METHODS

Fifteen patients with MCNs with ovarian-like stroma and 109 patients with IPMTs were experienced. We examined the image findings for the differential diagnosis and stage diagnosis of these two types of cystic neoplasms.

RESULTS

Endoscopic ultrasonography could reveal detailed images of internal structure and was effective for the diagnosis of MCNs. Other endoscopic imaging modalities could not give specific findings for MCNs. Endoscopic retrograde cholangiopancreatography (ERCP; including duodenoscopic findings and pancreatogram) and pancreatoscopy showed the characteristic and specific findings of IPMTs. Also, endoscopic ultrasonography and intraductal ultrasonography were found to have high sensitivity and diagnostic accuracy for their differential diagnosis of neoplastic/nonneoplastic and invasive/noninvasive lesions in IPMTs.

CONCLUSIONS

Endoscopic imaging techniques are capable of revealing the detailed structure of pancreatic cystic lesions. They are effective for differential diagnosis, for assessing the degree of malignancy, and for deciding upon an appropriate treatment in patients with IPMTs.

Effect of a tyrosine kinase inhibitor STI571 in a patient with hepatic metastases from a duodenal gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors. The molecular etiology is the result of mutations in the c-Kit gene. The mutant c-Kit proteins, which are activated without a stem cell factor, contribute to the tumor development. STI571 selectively inhibits c-Kit, BCR-ABL, and PDGFR tyrosine kinases. Based on this potential to inhibit critical c-Kit function in GISTs, case studies have reported effective outcomes following treatment with STI571. This case report describes a highly effective use of STI571 in a 54-year-old woman with multiple liver metastases from a GIST originating in the duodenum.

A two-step method for marking polypectomy sites in the colon and rectum

BACKGROUND

Intraoperative localization of polypectomy sites is critical for laparoscopic and open surgery, but conventional methods of marking the colorectum are sometimes unreliable. A new two-step method for marking polypectomy sites for identification during laparoscopic and open operations is described.

METHODS

Eighteen patients with postpolypectomy lesions necessitating preoperative marking were enrolled in this study. A physiologic saline solution was endoscopically injected into the submucosa to produce an artificial submucosal elevation (pseudopolyp). A small volume of India ink was then injected into the submucosal elevation (pseudopolyp) with a separate needle.

RESULTS

The two-step method was easily applied for all lesions without complication. At surgery, all lesions were immediately visualized.

CONCLUSION

The two-step tattooing method proved to be easy, safe, and accurate for marking polypectomy sites.

Long-term effects of donepezil on P300 auditory event-related potentials in patients with Alzheimer's disease

The P300, one of the cognitive event-related potentials (ERPs) of the cerebral cortex, reflects the functioning of the neurochemical system involved in cognitive processes. We investigated clinical significance of the components of auditory P300 ERPs, in comparison with neuropsychologic tests including the Mini-Mental State Examination and the Japanese version of the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-J cog), for evaluating of the effect of donepezil (DPZ) (5 mg daily for 6 months), an acetylcholinesterase inhibitor, in patients with Alzheimer's disease (AD). Reduction of P300 latency associated with a parallel improvement of ADAS-J cog scores was observed after administration of 5 mg/day of DPZ in patients with AD. P300 latency gives very useful information on the progression of AD, especially in the longitudinal follow-up of patients with AD during treatment with DPZ acting on cholinergic pathways.

Efficacy of peroral pancreatoscopy in the diagnosis of pancreatic diseases

BACKGROUND

The aim of this study was to evaluate the usefulness of peroral pancreatoscopy in the diagnosis of pancreatic diseases.

METHODS

Both 3.7-mm (thin) and 0.8-mm (ultra-thin) diameter fiberoptic pancreatoscopes were used in 115 cases (pancreatic cancer, 35; benign ductal stenosis, 20; intraductal papillary-mucinous tumor, 60).

RESULTS

Observation rates for pancreatic cancer, benign ductal stenosis, and intraductal papillary-mucinous tumor were, respectively, 63%, 80%, and 95%. Tumor vessels and papillary tumor were observed when pancreatic cancer was smaller than 2 cm but not when the tumor was larger than 2 cm. Stenosis without significant mucosal changes was observed in 62% of cases of benign ductal stenosis. Coarse mucosa and friability were observed more frequently in association with pancreatic cancer than benign ductal stenosis. Granular mucosa or papillary tumor could be observed in 74% of cases of intraductal papillary-mucinous tumor. Papillary tumor was observed with increasing frequency in cases of intraductal papillary-mucinous tumor as the degree of malignancy increased.

CONCLUSIONS

Peroral pancreatoscopy with an ultra-thin fiberscope is useful in the diagnosis of minute pancreatic lesions. Peroral pancreatoscopy with a thin fiberscope can provide a definitive diagnosis of intraductal papillary-mucinous tumor including the degree of malignancy.

Three-dimensional image display without special eyeglasses: observation of magnetic resonance angiography using the stereoscopic liquid crystal display

The authors have developed a new stereoscopic liquid crystal display that provides real-time 3-dimensional image viewing without special eyeglasses. The device consists of 3 major parts: (1) an image display composed of a 10.4-inch color liquid crystal plate with a resolution of 640 x 480, (2) an automatic head tracking system, and (3) a special backlight unit for the right and left eyes. Eight radiologists interpreted 60 cases of magnetic resonance angiography (29 cases of cerebrovascular disease and 31 normal cases) to compare film display and the liquid crystal display (ie, pseudo 3-dimensional display and true 3-dimensional display). Using a continuously distributed scale ranging from 0% to 100%, the observers ranked their confidence levels in determining the presence or absence of steno-occlusive disease, aneurysm, and arteriovenous malformation (AVM) and their locations. For statistical evaluation, receiver operating characteristic (ROC) analysis and Brier score were used. For detecting AVM, film reading showed a significantly higher value in the area under the binormal ROC curve (Az) than did pseudo-3-dimensional display (P < .05). Excluding this, however, no significant difference existed in Az values among the 3 viewing methods. Also, there was no significant difference in Brier score between not only the stereoscopic view and nonstereoscopic view groups, but also the senior and junior groups. Subjective estimation of true 3-dimensional display showed that vessels were more distinguishable with less eye fatigue compared with stereoscopic film reading. The stereoscopic liquid crystal display provided almost equal efficacy to film reading; however, the short optimum distance for observation and the low resolution should be improved.

Role of ultrasonography in the detection of intraductal spread of breast cancer: correlation with pathologic findings, mammography and MR imaging

The purpose of this study was to assess the role of US in the detection of intraductal spread of breast cancer in comparison with mammography (MMG) and MRI. In 46 patients with breast cancer, US features of the intraductal component were classified as ductal type or distorted type. Histopathologically, 29 of 46 (63%) cases had intraductal components, and the sensitivity, specificity, and accuracy rates in detection of intraductal spread were 89, 76, and 85%, respectively. Each US pattern demonstrated good correspondence to the histologic components, and the distorted type correlated well with comedo-type carcinoma. Mammography was performed in all cases, and the sensitivity, specificity, and accuracy rates in detection of intraductal spread were 55, 100, and 72%, respectively. In comedo type, MMG could diagnose the extent of intraductal spread more accurately compared with US examination. Magnetic resonance imaging comparison was available in 25 cases. Magnetic resonance imaging depicted intraductal extension as an enhanced area during the early phase of a contrast enhancement study with a sensitivity of 93%. Ultrasound and MRI were closely related in terms of morphologic characteristics: the ductal type of US image correlated well with linear enhancement on MRI, whereas the distorted type correlated with regional or segmental enhancement. Current US examination is useful in depicting the intraductal spread of breast cancer; however, US has a tendency to underestimate intraductal component of comedo type compared with MMG and MRI.

Further reduction of radiation dose in helical CT for lung cancer screening using small tube current and a newly designed filter

A new aluminum filter, 5.8 mm thick at the center, was designed. The effective energy, exposure dose, absorbed dose, and noise were measured by using low-dose technique, very low-dose technique with a conventional filter, and very low-dose technique with a new filter on a chest phantom. Accuracy of very low-dose computed tomography (CT) with a new filter was compared against standard helical CT in 40 patients and against chest radiography in 35 patients. Effective energies were 42.6 keV and 51.6 keV at a conventional filter and the new filter, respectively. Compared against 20mA with a conventional filter, exposure dose was reduced by 17%, and absorbed dose was equivalent, at 30 mA with the new filter. Noise was improved by 9%. Compared with standard helical CT, the sensitivity, specificity, and accuracy of very-low-dose helical CT were 100%, 88%, and 95%, respectively. Very-low-dose helical CT was found to be significantly superior to chest radiography in the detection of lung cancers. Using a smaller tube current and an appropriate filter allows a further reduction in radiation dose in helical CT for lung cancer screening.

Breast ultrasonography: diagnostic efficacy of a computer-aided diagnostic system using fuzzy inference

We have developed a computer-aided diagnostic (CAD) system using fuzzy inference for breast sonography and have evaluated the performance of the system. Our CAD system is not an automated image processing method, but requires the observer's subjective "scoring." Seven radiologists interpreted 54 breast mass lesions (24 malignant, 30 benign). Six criteria (shape, border, halo, internal echoes, posterior echoes, and edge shadows) were scored using a five-point rating scale. The output was described as a real number from 0.0 to 1.0. For cancer diagnosis, the sensitivity of the radiologists, a six-criteria CAD version, and a four-criteria version (excluding posterior echoes and edge shadows) were 63.1%, 82.1%, and 78.0%, respectively. Specificity was 71.0%, 42.9%, and 51.0%, respectively, while accuracy was 67.5%, 60.3%, and 63.0%, respectively. No significant differences in the areas under ROC curve (Az) were found between the observers and CAD system. Several cases assessed as false-negative by observers were correctly diagnosed by the CAD system, and diagnostic efficacy could be improved, especially among novice sonographers. Although the system's high false-positive rate needs to be reduced, it will assist radiologists in generating a level of suspicion for malignancy.

Preoperative staging of thyroid papillary carcinoma with ultrasonography

OBJECTIVE

To evaluate the usefulness of ultrasonography including Doppler flow imaging for the preoperative staging of thyroid papillary carcinoma.

MATERIALS AND METHODS

In 77 patients with thyroid papillary carcinoma who underwent total thyroidectomy, the accuracy of ultrasonography in preoperative clinical staging was assessed with use of pathologic examination on the basis of TNM classification by the International Union Against Cancer (UICC).

RESULTS

In 63 (81.8%) cases, T categories were estimated accurately. The sensitivity in depicting tumor extension into the prethyroidal muscle and/or the sternocleidomastoid muscle was 77.8%, whereas the sensitivity for invasion into the trachea and the esophagus was 42.9 and 28.6%, respectively. In 37 (48.1%) cases, N categories were underestimated, and the sensitivity in the detection of regional lymph node metastasis was 36.7%. Doppler flow imaging was performed in 36 patients, and no correlation was found between flow patterns and the presence of local invasion or regional lymph node metastasis.

CONCLUSION

Ultrasonography was useful for preoperative investigation of thyroid papillary carcinoma, but several limitations existed, especially in evaluating extracapsular invasion to deep locations and regional lymph node metastasis.

Interobserver agreement in sonographic diagnosis of breast tumors

OBJECTIVE

To evaluate interobserver agreement in the interpretation of breast ultrasonography.

METHODS

55 breast masses (30 benign, 24 malignant) were interpreted by seven radiologists using a CRT viewing station. US criteria for differentiating between benign and malignant lesions included shape, border, boundary echoes, internal echoes, posterior echoes, and bilateral shadows. Each criterion and the observers' final impression was scored using the 5-point rating scales. For analyzing interobserver agreement, the kappa (kappa) values were employed.

RESULTS

The kappa values of shape and posterior echoes were significantly higher than those of the other four criteria (P<0.05). Agreement was intermediate in border and internal echoes, and was low in boundary echoes and bilateral shadows. Agreement in the senior group (four observers) was relatively higher than that in the junior group (three observers) for all criteria but for internal echoes. Easily-diagnosed cases showed significantly higher kappa values compared with more ambiguous cases (P<0.05).

CONCLUSION

Interobserver agreement in shape and posterior echoes was significantly higher than those of the other four criteria. Agreement was significantly dependent on case difficulty.

Eye-tracking device comparisons of three methods of magnetic resonance image series displays

This study evaluated the effectiveness of three kinds of display methods for magnetic resonance (MR) image interpretation using an eye-tracking device. Seven radiologists interpreted head MR studies by using a single monitor (17-inch, 1,024 X 1,280 bit) in the 4 images/screen display format. Three paging modes were compared: (A) rapid paging only, (B) multiple image series display at the same slice position with consecutive rapid paging, and (C) simultaneous display of multiple series with each image series being browsed independently. Using an eye-mark camera, the radiologist's point of fixation and the duration of fixation were recorded during actual image interpretation. In mode A, the duration of fixation was short, and the points of fixation were distributed randomly over the visual field. In mode B, the points of fixation were clustered chiefly on a specific image series. In mode C, the points of fixation were not clustered on a specified series, but the duration of viewing the T2 series was relatively long. The total tracing area in mode B and C was smaller than that in mode A. Multiple series display, in which selected key series of slices could be viewed effectively, was found to be suitable for MR image interpretation.