High FDG Uptake in Pleomorphic Hyalinizing Angiectatic Tumor.

PHAT (pleomorphic hyalinizing angiectatic tumor) is a rare, locally aggressive, low-grade mesenchymal neoplasm of uncertain lineage with a predilection for the lower extremities. We report a 74-year-old woman with an enlarging mass on the right popliteal fossa undergoing FDG PET/CT to characterize its biological activity. Increased accumulation of FDG (SUVmax, 23.0) in the solid component of the tumor was seen. Diagnosis of PHAT was confirmed by examination of the surgical resection specimens. This case showed significant FDG accumulation relative to its pathological low-grade malignant nature.

Usefulness of proton magnetic resonance spectroscopy in predicting positive biopsy after high-intensity focused ultrasound for treatment of localized prostate cancer.

OBJECTIVES: To investigate the clinical effectiveness of proton magnetic resonance spectroscopy in predicting local recurrence or residual disease after high-intensity focused ultrasound for treatment of localized prostate cancer. METHODS: The present study included patients with localized prostate cancer who underwent high-intensity focused ultrasound of whole-gland ablation as primary therapy. Clinicopathological variables including proton magnetic resonance spectroscopy, T2-weighted magnetic resonance imaging, and prostate-specific antigen and its derivatives were analyzed to predict the positive prostate biopsy results using univariate and multivariate analyses. Furthermore, the presence of tumor in each of the 12 prostate sectors by T2-weighted magnetic resonance imaging and proton magnetic resonance spectroscopy were evaluated and compared with prostate biopsy results in each of the 12 prostate sectors in order to evaluate the local cancer distribution in the prostate after high-intensity focused ultrasound. RESULTS: Overall, we carried out 85 prostate biopsies in 52 patients. Multivariate logistic regression analysis showed that the positive finding of proton magnetic resonance spectroscopy was the only statistically significant prognostic parameter of pathological tumor progression in patients after high-intensity focused ultrasound. Prostate biopsy cores were obtained from 952 prostate sectors of 52 patients and 85 prostate biopsies. Compared with T2-weighted magnetic resonance imaging, proton magnetic resonance spectroscopy (sensitivity 52.8%, specificity 97.4%, positive predictive value 44.2% and negative predictive value 98.1%, P < 0.001) has higher values to predict local tumor progression in prostate sectors after high-intensity focused ultrasound. CONCLUSIONS: Proton magnetic resonance spectroscopy is a useful, non-invasive diagnostic modality that predicts local tumor progression in patients after high-intensity focused ultrasound, as well as local cancer distribution at each of the prostate sectors with pinpoint accuracy.

Feasibility of multiparametric prostate magnetic resonance imaging in the detection of cancer distribution: histopathological correlation with prostatectomy specimens.

PURPOSE: To prevent overtreatment, it is very important to diagnose the precise distribution and characteristics of all cancer lesions, including small daughter tumors. The purpose of this study was to evaluate the efficacy of T2-weighted magnetic resonance imaging (T2W), diffusion-weighted magnetic resonance imaging (DWI), magnetic resonance spectroscopy ((1)H-MRS), and prostate biopsy (PBx) in the detection of intraprostatic cancer distribution. METHODS: All patients underwent T2W, DWI, (1)H-MRS, and PBx followed by radical prostatectomy (RP). Individual prostates were divided into 12 segmental regions, each of which was examined for the presence or absence of malignancy on the basis of T2W, DWI, (1)H-MRS, and PBx, respectively. These results were compared with the histopathological findings for RP specimens. RESULTS: We included 54 consecutive patients with biopsy-proven prostate cancer (mean age, 62.7 years; median prostate-specific antigen level, 5.7 ng/mL) in this study. We could detect cancer in 247 of 540 evaluable lesions. The area under the receiver operator characteristic curve analysis yielded a higher value for DWI (0.68) than for T2W (0.65), (1)H-MRS (0.54), or PBx (0.56). In 180 cancerous regions of RP specimens with false-negative PBx results, T2W+DWI had the highest positive rate (53.3%) compared with that of each sequence alone, including T2W (45.6%), DWI (41.1%), and (1)H-MRS (30.0%). CONCLUSIONS: Multiparametric magnetic resonance imaging (T2W, (1)H-MRS, DWI) enables the detection of prostate cancer distribution with reasonable sensitivity and specificity. T2W+DWI was particularly effective in detecting cancer distribution with false-negative PBx results.

Clinical efficacy of proton magnetic resonance spectroscopy (1H-MRS) in the diagnosis of localized prostate cancer.

BACKGROUND: The objective of this study was to evaluate the efficacy of proton magnetic resonance spectroscopy (1H-MRS) in the detection of prostate cancer. MATERIALS AND METHODS: The experimental group consisted of 20 patients with localized prostate cancer who underwent radical prostatectomy. The sensitivity, positive predictive value and accuracy of the detection of prostate cancer in the 12 sections of the peripheral zone were calculated for prostate biopsy alone, 1H-MRS alone and the combination of these methods, respectively. RESULTS: The sensitivity, the positive predictive value, and the accuracy of the preoperative diagnosis of prostate cancer were 43.7%, 68.9% and 54.6%, respectively, with prostate biopsy alone; 60.6%, 87.8% and 71.4% with 1H-MRS alone; and 88.7%, 88.7% and 87.4% with the combination of biopsy and 1H-MRS, respectively. Combined use of biopsy and 1H-MRS significantly improved the sensitivity, positive predictive value and accuracy of the diagnosis. CONCLUSION: 1H-MRS together with biopsy might improve the diagnostic accuracy in prostate cancer.

Real-time MRI of orthotopic ileal neobladder voiding: preliminary findings.

OBJECTIVES: The purpose of this preliminary study was to analyze the dynamic changes in the configuration of the neobladder and naïve bladder during voiding using real-time MRI. METHODS: This study included 10 male patients who had a radical cystectomy and an ileal orthotopic neobladder due to organ-confined bladder cancer and had good urinary function, and 5 male control volunteers. With the subjects in the lateral decubitus position, real-time MRI was performed during micturition. A sagittal slice orientation was used to depict the bladder and the entire length of the urethra; individual movements along the X-axis and Y-axis of the bottom and top of the neobladder and the naïve bladder were recorded and analyzed. Urodynamic studies (UDS) and video voiding cystourethrography were performed in patients. RESULTS: Five of the 10 neobladder patients could void in the lateral decubitus position. In normal controls and patients who could void, the bladder outlet bladder moved ventrocranially during micturition. The ileal bladder outlet moved a significantly longer distance than the naïve bladder during micturition (X-axis, -13.4+/-1.5 vs. -3.6+/-4.3 cm, p=0.0014; Y-axis, -10.6+/-0.5 vs. -2.0+/-6.5 cm, p=0.0187). The distance that the bladder top moved between the naïve bladders and the neobladder did not differ. UDS did not show a difference between patients who could and could not void at lateral position. CONCLUSIONS: During micturition, the neobladder was found to rotate and move more dynamically than the naïve bladder. Real-time MRI is useful for assessing dynamic voiding function of orthotopic neobladders.

Impact of 16-slice computed tomography in percutaneous coronary intervention of chronic total occlusions.

The main reason for failure of percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) is because the calcified plaque prevents the guide wire crossing the occlusion. We aimed to identify the route, and characterize plaque components within CTO, using 16-slice computed tomography (MSCT). Twenty three angiographic CTO in 22 patients (mean age 69 +/- 5 years, 17 males) were included. All patients had undergone MSCT prior to PCI. Images were analyzed for lesion visibility and plaque characteristics of CTO. The presence and location of calcified plaque within the CTO were systematically assessed. Each lesion was classified as a noncalcified, moderately calcified, or exclusively calcified plaque. Procedural failure was defined as the inability to cross a guide wire through the occlusion. All coronary routes of CTO segment were visualized. MSCT revealed three markedly bent CTO segments (13.0%), which could not be identified by coronary angiography only. Calcified plaques were detected in 30 lesions of 19 CTO segments (82.6%), but were not detected in the other four. The majority of calcified plaque was located in the proximal lesion, or both proximal and distal lesions. Fifteen out of 30 calcified lesions (50.0%) were exclusively calcified plaques. Overall procedural success was obtained in 21 CTOs (91.3%). MSCT can accurately identify the route of the CTO segment and evaluate both distribution and amount of the calcified plaque within it. Even with the complicated and/or calcified lesions, PCI success rate was excellent under MSCT guidance. MSCT should become a useful tool in PCI of CTO.

[Cardiac rupture caused by myocardial infarction in the diagonal branch area: evaluation by cardiac multislice computed tomography: a case report].

A 75-year-old woman was admitted to the emergency room because of hypotension and loss of consciousness induced by cardiac tamponade. Electrocardiography revealed ST elevation and laboratory data showed elevation of serum creatine kinase and troponin I. The patient was referred to the cardiology department 5 days later. Cardiac catheterization revealed ventricular aneurysm in the anterior wall, significant stenosis (75%) in the left anterior descending coronary artery and subtotal stenosis (99%) in the diagonal branch. Cardiac multislice computed tomography suggested that the ventricular pseudoaneurysm was probably due to cardiac rupture caused by myocardial infarction in the diagonal area. Subsequently, aneurysmectomy and coronary artery bypass graft surgery were performed. Cardiac multislice computed tomography is useful for evaluating coronary artery and cardiac rupture.

Regional cerebral blood flow in a patient with Nasu-Hakola disease.

We report a functional neuroimaging study of a 43-year-old woman with Nasu-Hakola disease (NHD). Regional cerebral blood flow (rCBF) images were measured with technetium-99m ethyl cysteinate dimer single photon emission computed tomography (SPECT). rCBF was decreased in the bilateral frontal lobes and thalamus. This finding was consistent with the known underlying neuropathology in patients with NHD. Brain SPECT is useful for demonstrating the pathophysiologic brain region in patients with NHD.

Radiation-induced brain metabolic changes in the acute and early delayed phase detected with quantitative proton magnetic resonance spectroscopy.

OBJECTIVE: Quantitative proton magnetic resonance spectroscopy (MRS) was performed before and after radiation therapy to estimate its usefulness for evaluating radiation-induced metabolic brain changes. METHODS: Twenty patients with multiple brain metastases not having received any previous brain radiation were selected for the study. The total radiation dose varied from 40 (20 fractions) to 50 (25 fractions) Gy, with an opposition technique. MRS was performed just before irradiation, during the acute phase (n = 20, 8.5 +/- 4.6 days) and in the early delayed phase (n = 15, 3.6 +/- 0.5 months) after radiation. The concentration of N-acetyl-L-aspartate (NAA), choline-containing substance (Cho), and creatine/phosphocreatine (Cr) was quantified. RESULTS: The concentration of NAA decreased (P = 0.05 versus before radiation), and the concentration of Cho increased (P = 0.006 versus before radiation) during the early delayed phase. The concentration of Cr was not changed before or after radiation. CONCLUSIONS: Radiation-induced changes in brain metabolism were well detected with quantitative MRS in the early delayed phase. Quantitative MRS is a novel tool for estimating radiation-induced neurotoxicity.

Benign pleomorphic adenoma with extensive cystic degeneration: unusual MR findings in two cases.

Two cases of benign pleomorphic adenoma (PA) with extensive cystic degeneration are described. In both cases magnetic resonance (MR) imaging revealed entirely cystic tumors with an irregularity at the cyst wall. Some additional findings were observed: one case showed layering within the cyst contents caused by intratumoral hemorrhage, and the other had a small mural nodule at the cyst wall that showed very low intensity on both T1- and T2-weighted images and corresponded pathologically to the hyaline stroma. In both cases, preoperative diagnosis was difficult based on the MR findings alone. Benign PA should be included in the differential diagnosis of an entirely cystic parotid mass.

CT and MR findings of basal cell adenoma of the parotid gland.

We report a case of basal cell adenoma in the left parotid gland. A 34-year-old woman presented with a non-tender mass in the left parotid gland. She had first noted it 7- years previously, and it had been gradually increasing in size. The tumor was well-circumscribed with a smooth contour. On noncontrast-enhanced CT, the tumor showed homogeneous soft tissue attenuation. No cystic portion or calcification was seen. The tumor showed homogeneous moderate enhancement on contrast-enhanced CT. Capsule-like ring enhancement was demonstrated. On T1-weighted MR imaging, the tumor was homogeneously hypointense to the surrounding parotid tissue and isointense to muscle. On T2-weighted imaging the tumor was homogeneously hyperintense to muscle but slightly hypointense to the surrounding parotid tissue. On Gd-enhanced T1-weighted imaging, the tumor demonstrated homogeneous moderate enhancement. Capsule-like ring enhancement was also demonstrated. Salivary (technetium-99m-pertechnetate) scintigraphy did not show any uptake in the tumor.

Brown tumor of the sphenoid sinus in a patient with secondary hyperparathyroidism: CT and MR imaging findings.

We present a case of brown tumor of the sphenoid sinus in a patient with secondary hyperparathyroidism. CT showed an expansile soft-tissue attenuation mass centered in the sphenoid sinus. CT at bone window setting demonstrated expansile, lytic change and remodeling of the surrounding bone. On MR imaging, the lesion showed iso-intensity to gray matter on T1-weighted images and heterogeneous hyperintensity on T2-weighted images, and showed intense enhancement. The extent of the lesion and its relationship to the surrounding structures were best evaluated by CT and MR imaging.

Role of magnetic resonance imaging for evaluation of tumors in the cardiac region.

The aim of this study was to review the role of MRI in the assessment of heart neoplasm, 25 cases with heart neoplasm (10 myxoma, 6 rhabdomyoma, 5 angiosarcoma, 2 mesothelioma, 1 lymphoma, and 1 fibroma) were examined with MRI and echocardiography. Multislice T1- and T2-weighted spin-echo images and static gradient-echo images were taken in appropriate directions with electrocardiogram gating. Gadolinium enhancement was performed in 21 cases. Transthoracic echocardiography was performed in all cases. Except for the 5 patients with rhabdomyoma, the pathological diagnosis was obtained. MRI proved to be useful for tissue characterization of myxoma, angiosarcoma, mesothelioma, and fibroma in cases with tuberous sclerosis. MRI also proved to be useful for detection of the tumor, depiction of contour, relation with other cardiac structures, in cases with myxoma, angiosarcoma, mesothelioma, lymphoma, and fibroma. In the differential diagnosis, MRI provided important information in cases with myxoma, rhabdomyoma, angiosarcoma, and fibroma. In cases with tumors expanding into the mediastinum, such as mesothelioma and fibroma in this report, MRI was useful in determining the location and border. In cases with tumors adjacent to pericardium, MRI was useful in detecting pericardial invasion. Gadolinium enhancement added useful information in cases with myxoma, rhabdomyoma, angiosarcoma, and mesothelioma. The role of MRI with and without Gd enhancement differs somewhat in individual types of heart neoplasm, and adaptation must be considered in each kind of neoplasm. On the other hand, MRI is an essential examination in all cases with a cardiac mass, which has not been diagnosed, since it may provide useful information for the differential diagnosis.

Role of magnetic resonance imaging for evaluation of tumors in the cardiac region.

The aim of this study was to review the role of MRI in the assessment of heart neoplasm, 25 cases with heart neoplasm (10 myxoma, 6 rhabdomyoma, 5 angiosarcoma, 2 mesothelioma, 1 lymphoma, and 1 fibroma) were examined with MRI and echocardiography. Multislice T1- and T2-weighted spin-echo images and static gradient-echo images were taken in appropriate directions with electrocardiogram gating. Gadolinium enhancement was performed in 21 cases. Transthoracic echocardiography was performed in all cases. Except for the 5 patients with rhabdomyoma, the pathological diagnosis was obtained. MRI proved to be useful for tissue characterization of myxoma, angiosarcoma, mesothelioma, and fibroma in cases with tuberous sclerosis. MRI also proved to be useful for detection of the tumor, depiction of contour, relation with other cardiac structures, in cases with myxoma, angiosarcoma, mesothelioma, lymphoma, and fibroma. In the differential diagnosis, MRI provided important information in cases with myxoma, rhabdomyoma, angiosarcoma, and fibroma. In cases with tumors expanding into the mediastinum, such as mesothelioma and fibroma in this report, MRI was useful in determining the location and border. In cases with tumors adjacent to pericardium, MRI was useful in detecting pericardial invasion. Gadolinium enhancement added useful information in cases with myxoma, rhabdomyoma, angiosarcoma, and mesothelioma. The role of MRI with and without Gd enhancement differs somewhat in individual types of heart neoplasm, and adaptation must be considered in each kind of neoplasm. On the other hand, MRI is an essential examination in all cases with a cardiac mass, which has not been diagnosed, since it may provide useful information for the differential diagnosis.