Diagnostic performance of bone scintigraphy analyzed by three artificial neural network systems.

OBJECTIVE: The accuracy of bone scintigraphy analyzed by computer-assisted diagnosis (CAD) software involving multiple artificial neural network (ANN) systems has not been well established. METHODS: We conducted a retrospective study to examine the accuracy of bone scintigraphy analyzed by CAD software, BONENAVI(®) version 2 (BN2; FUJIFILM RI Pharma Co., Ltd.), in patients with suspected bone metastases. In 399 patients, bone metastases were analyzed by means of the BN2 focused on balance of sensitivity and specificity ANN system (BN2-B), focused on specificity-ANN system (BN2-Sp), and focused on sensitivity-ANN system (BN2-Sen). The ANN presented an output between 0 and 1 for each patient. A cutoff value of 0.5 was chosen to provide BN2 with the binary classification of "bone metastasis" or "no bone metastasis". The area under the receiver operating characteristic curve (AUC) was used to evaluate diagnostic accuracy. RESULTS: A total of 18 % of male patients (36/196) and 12 % of female patients (24/203) had bone metastases. BN2-Sp and BN2-Sen were similar to BN2-B in the ability to identify patients who had bone metastases; the AUC values were 0.87 [95 % confidence interval (CI) 0.79-0.95], 0.92 (95 % CI 0.85-0.97), and 0.90 (95 % CI 0.83-0.97), respectively, in male patients. In female patients, the AUC values were 0.81 (95 % CI 0.71-0.91), 0.85 (95 % CI 0.78-0.93), and 0.81 (95 % CI 0.71-0.92), respectively. A total of 65.4 % of patients were classified as concordance of "bone metastases" (17.8 %) or "no bone metastases" (47.6 %), and 34.6 % were classified as mismatch. In the concordance group, BN2-B revealed an AUC of 0.94 (95 % CI 0.88-0.99), with a sensitivity of 94 % (95 % CI 79-98 %) and a specificity of 88 % (95 % CI 79-93 %) in 120 male patients and an AUC of 0.89 (95 % CI 0.78-1.00), with a sensitivity of 86 % (95 % CI 60-96 %) and a specificity of 85 % (95 % CI 78-90 %) in 141 female patients. CONCLUSIONS: Bone scintigraphy analyzed by BN2-B accurately identifies the presence of bone metastases in patients with concordance using three ANN systems, comprising 65 % of the patients we studied.

Insulin-derived amyloidosis and poor glycemic control: a case series.

OBJECTIVES: Insulin-derived amyloidosis is a rare skin-related complication of insulin therapy. The purpose of this study was to show the effects of insulin-derived amyloidosis on blood glucose levels, insulin dose requirements, and insulin absorption. METHODS: Seven patients were found to have insulin-derived amyloidosis at the Tokyo Medical University Ibaraki Medical Center. The clinical characteristics and insulin therapy of the 7 patients were investigated. Insulin absorption was studied by comparing the serum insulin levels after insulin injections into insulin-derived amyloidosis sites versus injections into normal sites in 4 patients. RESULTS: When the insulin-derived amyloidosis was discovered, the mean hemoglobin A1c level was 9.3%, and the mean daily insulin dose was 57 units. After changing the injection sites to avoid the insulin-derived amyloidosis, the blood glucose concentrations improved, and the mean daily insulin dose could be reduced to 27 units (P = .035; 53% reduction). The insulin absorption at insulin-derived amyloidosis sites was 34% of that at normal sites (P = .030). CONCLUSIONS: Insulin-derived amyloidosis caused poor glycemic control and increased insulin dose requirements because of impairments in insulin absorption.

Detection of hepatocellular carcinoma with ferucarbotran (resovist)-enhanced breath-hold MR imaging: feasibility of 10 minute-delayed images.

PURPOSE: We evaluated the optimal timing for breath-hold MR imaging with bolus-injectable superparamagnetic iron oxide (SPIO) for detecting hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty patients with 62 HCCs (52 hypervascular, 10 non-hypervascular) underwent MR imaging that included unenhanced and SPIO-enhanced T1-weighted gradient echo (GRE) and T2-weighted fast spin echo (FSE) sequences, perfusion study, and SPIO-enhanced T2*-weighted GRE sequences. We obtained SPIO-enhanced T2*-weighted sequences 10 and 30 min after injecting SPIO and made 2 image sets, comprising 10- or 30-min delayed T2*-weighted images. Three observers performed alternative free response receiver operating characteristic (AFROC) analysis, and quantitative evaluation was performed. RESULTS: Only Observers 2 and 3 recognized a significant difference in the area under the AFROC curve (Az) value in the 10-min delayed images; no significant difference was observed in the 30-min delayed images. There was no significant difference in the sensitivity of individual observers between 10- and 30-min delayed images. The contrast-to-noise (C/N) ratio of the 30-min delayed images was significantly higher than that of the 10-min delayed images. The C/N ratio of hypervascular HCCs in the 30-min delayed images was significantly higher than in the 10-min delayed images, but that of non-hypervascular HCCs showed no significant difference. CONCLUSION: In most cases, 10-min delayed SPIO-enhanced T2*-weighted images are sufficient to detect HCCs.

Image quality using dynamic MR imaging of the temporomandibular joint with true-FISP sequence.

We evaluated the quality of dynamic magnetic resonance (MR) imaging of the temporomandibular joint (TMJ) in 20 normal volunteers with 40 TMJs. To confirm TMJ, we obtained static proton density weighted images (PDWI) before performing dynamic MR imaging with true-fast imaging in a steady-state precession (true-FISP) sequence. Four sequences of the first 10 volunteers were examined to determine the optimal sequence. The 4 sequences included the integrated parallel acquisition technique (iPAT) and/or fat saturation technique. The optimal sequence was then determined and performed in all 20 volunteers. The quality of imaging was evaluated, especially with respect to the conspicuity of the articular disk, mandibular condyle, articular eminence and lateral pterygoid muscle. One of 3 confidence levels was assigned for this evaluation. Neither iPAT nor fat saturation obtained the best quality imaging. Detection rates in the 20 volunteers were 83% for the articular disk, 95% for the mandibular condyle, 96% for the articular eminence and 7.5% for the lateral pterygoid muscle. We recommend dynamic MR imaging of the TMJ with the true-FISP sequence using neither iPAT nor fat saturation. Nevertheless, dynamic MR imaging was inferior to static imaging in detecting the articular disk and still requires improvement.

The ratio of the maximum high attenuation area dimension to the maximum tumor dimension may be an index of the presence of lymph node metastasis in lung adenocarcinomas 3 cm or smaller on high-resolution computed tomography.

BACKGROUND: Limited resection of the lung can improve the postoperative quality of life if there is no lymph node metastasis. Small adenocarcinomas frequently appear on radiographs with areas of ground glass attenuation. We examined whether there is a correlation between the presence of lymph node metastasis and the ratio of the intratumor high-attenuation area (greatest dimension of high-attenuation area [H] to the maximum tumor dimension [T], H/T ratio) on high-resolution computed tomography (HRCT). METHODS: From January 1996 to June 2004, we studied 281 patients with lung adenocarcinomas of 3 cm or less in maximum dimension on preoperative HRCT. Each of the 281 patients had a lobectomy and lymph node dissection, and there was no case of limited resection. RESULTS: Lymph node metastasis was present in 11.4% (32 of 281 cases, N1 = 13 cases, N2 = 19 cases). None of the 94 cases with an H/T ratio of 60% or less had lymph node metastasis. Moreover, lymph node metastasis was noted even in a 6-mm tumor when the H/T ratio was 100%. Of the 187 cases with tumors having an H/T ratio greater than 60%, 32 had lymph node metastasis. CONCLUSIONS: The relationship between the H/T ratio and lymph node metastases was evaluated by HRCT in lung adenocarcinomas 3 cm or smaller in maximum dimension. The H/T ratio may provide useful information in deciding on limited resection for lung cancer in such cases.

Gd-EOB-DTPA enhanced MRI for hepatocellular carcinoma: quantitative evaluation of tumor enhancement in hepatobiliary phase.

OBJECTIVE: The purpose of this study was to evaluate the utility of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) for the quantitative evaluation of hepatocellular carcinoma (HCC) and dysplastic nodules in the hepatobiliary phase. MATERIAL AND METHODS: The subjects comprised 12 patients with 27 lesions (22 HCCs and 5 dysplastic nodules). Chemical-shift-selective fat-suppressed T1-weighted sequences were obtained before and 10, 20, and 40 min after the injection of Gd-EOB-DTPA. Quantitative analyses were performed with the enhancement ratio of the lesion and the contrast-to-noise (C/N) ratio. RESULTS: The enhancement ratios of the HCCs were 44.0+/-36.5, 44.7+/-46.8, and 47.7+/-52.8 (%) at 10, 20, and 40 min, respectively, after the injection of Gd-EOB-DTPA. The enhancement ratios of the dysplastic nodules were 36.2+/-34.3, 44.3+/-37.3, and 40.1+/-46.8 (%). The C/N ratios of the HCCs were 0.2+/-6.6 for the precontrast image, and -9.2+/-12.6, -9.9+/-14.8, and -12.7+/-15.7 at 10, 20, and 40 min, respectively, after the injection of Gd-EOB-DTPA. The C/N ratios of the dysplastic nodules were 1.4+/-8.0, -13.7+/-11.1, -13.3+/-7.6, and -13.1+/-10.4. No significant differences were found between the HCCs and the dysplastic nodules in the enhancement ratio and the C/N ratio. Only two HCCs showed a positive C/N ratio value, and these HCCs were pathologically confirmed to be a well differentiated and a moderately differentiated carcinoma, respectively. CONCLUSION: HCCs and some of the dysplastic nodules showed hypointensity in the hepatobiliary phase in Gd-EOB-DTPA-enhanced MRI. No specific enhancement was observed, regardless of tumor differentiation.

Perfusion study of hypervascular hepatocellular carcinoma with SPIO.

PURPOSE: We evaluated whether a perfusion study with Resovist is useful to assess blood flow in tumors in patients with hypervascular hepatocellular carcinoma (HCC). SUBJECTS AND METHODS: The subjects were 28 patients; the lesions consisted of 68 hypervascular HCC, 14 post-treatment nodules, and 7 hepatocellular hypovascular nodules. After rapid intravenous injection of Resovist, 7-phase imaging was performed using the single-shot echo-planar method. Diagnostic accuracy and tumor vascularity were evaluated by 3 radiologists using the alternative free response receiver operating characteristic method. Sensitivity, Az values, and positive predictive values were calculated. To assess interobserver variability, we evaluated the kappa static to measure the degree of agreement. RESULTS: The 3 observers indicated no significant difference in Az value related to the presence or absence of a perfusion study, and only one remarked a significant difference in sensitivity. However, kappa values were better in the presence than in the absence of a perfusion study. Blood flow assessment was poor in less than 1 cm. The 3 observers showed a positive predictive value of 90% or more. CONCLUSION: A perfusion study may facilitate the diagnosis of hypervascular HCC, improving the diagnostic accuracy.

Inflammatory pseudotumor of the liver in a patient with rectal cancer: a case report.

An inflammatory pseudotumor of the liver was discovered during a metastatic examination of a patient with rectal adenocarcinoma. Magnetic resonance imaging showed a three-component lesion that infiltrated a large portal vein, and CT arteriography and CT during arterial portography showed a portal obstruction. A histopathological examination proved that necrosis was present in the central zone; infiltration by proliferating connective tissue with chronic inflammatory cells was prominent in the middle zone; and fibrous changes, including pseudo-bile duct proliferation, were present in the peripheral zone. Magnetic resonance imaging revealed both portal infiltration and histopathological features including the above-noted three components. Magnetic resonance imaging is perhaps the most useful diagnostic modality.

[A case of orbital myositis complicated with optic neuropathy--analysis of the pathological mechanism of optic neuropathy from magnetic resonance imaging findings].

BACKGROUND: We observed a rare case of orbital myositis involving the optic nerve. CASE: A 52-year-old woman complained of visual disturbance, lid swelling, ocular pain, and conjunctival injection in her right eye. Her corrected vision was 0.15 in the right eye and 1.2 in the left eye. Relative afferent pupillary defect(RAPD) and central scotoma in visual field test were noted in the right eye. Ocular movement of her right eye was moderately disturbed in all directions. Although laboratory data showed elevation of erythrocyte sedimentation rate, other hematological data such as thyroid function, autoimmune antibodies, and viral infection antibodies were normal. Magnetic resonance imaging(MRI) findings showed compression of the optic nerve at the orbital apex by marked thickening of the right lateral rectus muscle and superior rectus muscle, and inflammation directly invading the optic nerve. Based on the above findings, we diagnosed the case as orbital myositis complicated with optic neuropathy, and started corticosteroid therapy. Her right corrected vision improved dramatically, and the RAPD, central scotoma, and lid swelling disappeared shortly after administration. Enlargement of the extraocular muscles was still present one month after corticosteroid therapy. CONCLUSION: MRI findings suggested that optic neuropathy in this case was induced not only by mechanical compression by the enlarged extraocular muscles at the orbital apex but also by direct inflammatory infiltration from the extraocular muscles.

Usefulness of dynamic renal scintigraphy in a patient with renal arteriovenous fistula treated by transcatheter embolization.

Tc-99m-DTPA renal scintigraphy was performed before and after transcatheter coil embolization in a patient with renal arteriovenous fistula (AVF). Before embolization, scintigraphy showed a characteristic accumulation pattern compatible with the hemodynamics of an aneurysmal type of AVF in the vascular phase. After embolization, the effects of treatment, such as a change in the split renal function on the treated-side and the disappearance of the shunt flow through the fistula were evident. It was concluded that dynamic renal scintigraphy was very useful for patients with an aneurysmal type of renal AVF scheduled for transcatheter embolization.

Dynamic MR cholangiography after fatty meal loading: cystic contractility and dynamic evaluation of biliary stasis.

PURPOSE: Dynamic MR cholangiography was conducted on patients with cholelithiasis or choledocholithiasis who had consumed a fatty test meal (Molyork) and the cystic contractility and dynamics of biliary stasis was evaluated. SUBJECTS AND METHOD: The subjects were 25 with intracystic cholelithiasis, 10 with choledocholithiasis and 10 normal controls. For an imaging sequence, the rapid acquisition with relaxation enhancement (RARE) method was employed and imaging was conducted for 40 min (every 30 s following Molyork administration) without breath-holding. The gallbladder contraction ratio was computed and the contractile ratio for the common bile duct was calculated. To determine the bile flow to the duodenum, the high-intensity signal, indicating the flow from the lower common bile duct, and perfusion of the duodenum were observed in dynamic mode on the monitor with the naked eye and interpreted as positive bile flow. The frequency of this flow was visually monitored. RESULTS: The gallbladder contractile ratio was significantly reduced in patients with cholelithiasis or choledocholithiasis compared with the controls. In a comparison with the normal controls, no sequential changes were noted in the mean contractile ratio of the common bile duct of the patients with cholelithiasis or choledocholithiasis. The mean frequency of bile flow observed for each 40 min period was 13+/-2.4, 6+/-2.2, and 4+/-1.3 times for the controls, those with intracystic cholelithiasis, and those with choledocholithiasis, respectively. Compared with the controls, the latter two patient groups showed evident reductions in the frequency of bile flow to the duodenum (p<0.001). CONCLUSION: Dynamic MRC combined with Molyork loading makes it possible to compute cystic contractile ratios and perform a dynamic examination of bile flow under non-invasive, near-physiological conditions.

Efficacy of dynamic MRI with superparamagnetic iron oxide (SH U 555 A): vascularity evaluation in hepatocellular carcinoma.

PURPOSE: A study was conducted to determine the possibility of evaluating the blood flow in cases of hypervascular hepatocellular carcinoma (HCC) by employing dynamic MRI with superparamagnetic iron oxide (SH U 555 A), which can be rapidly injected via an intravenous route. METHODS: Six patients with hypervascular HCC (23 nodules) served as the subjects. Dynamic MRI includes images obtained at precontrast and at 10 (perfusion phase), 60, 120, 180, 240, 300 and 600 s after the start of injection of SH U 555 A. CT hepatic arteriography (CTHA) and CT during arterial portography (CTAP) were used as the standards of reference, and these were performed in all patients three days after dynamic MRI. The signal changes were evaluated at each phase, especially at the perfusion phase from the viewpoints of a lesion-to-liver contrast-to-noise ratio (CNR) and visual examination. RESULTS: A total of 23 hypervascular HCC were detected on CTHA and CTAP. Of the 23 lesions, 17 were detected on SH U 555 A enhanced MRI. Incorrect timing during acquisition of the perfusion phase was considered in two cases with three lesions. Of 14 lesions, excluding two cases with incorrect timing, a reduction in the transient signal in the lesions at the perfusion phase was visually recognized in 10 lesions (71%). Significant differences were seen in tumor size between visible and non-visible tumors involving transient signal reduction (p< 0.05). CNR gradually increased after rapidly decreasing in the perfusion phase. CONCLUSION: SH U 555 A enhanced MRI is valuable in limited cases. Evaluation of tumor blood flow employing dynamic MRI with SH U 555 A is affected by tumor size and requires optimal timing of the perfusion phase.