Search

Isolated iliac vein injury caused by blunt pelvic trauma is a rare condition that is difficult to diagnose and often fatal. We report a case of a 52-year-old female who presented with life-threatening isolated iliac vein injury caused by blunt pelvic trauma that was successfully managed with endovascular uncovered stent placement. Although further studies are warranted to clarify the hemostatic mechanism, uncovered stent placement can be considered as an alternative treatment option to covered stent placement for life-threatening iliac vein injury when a covered stent is not rapidly available. [ABSTRACT FROM AUTHOR]

The purpose of this article is to review fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) and magnetic resonance imaging (MRI) findings in a variety of benign, malignant, and borderline malignant ovarian tumors. It is advantageous to become familiar with the wide variety of FDG-PET/CT findings of this entity. Benign ovarian tumors generally have faint uptake, whereas endometriomas, fibromas, and teratomas show mild to moderate uptake. Malignant ovarian tumors generally have intense uptake, whereas tumors with a small solid component often show minimal uptake. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate in vivo the influence of inversion pulse slice selectivity on oxygen-enhanced magnetic resonance imaging (MRI).Materials and Methods: Thirteen healthy volunteers were studied with a two-dimensional cardiac- and respiratory-gated adiabatic inversion-recovery half-Fourier single-shot turbo spin-echo (HASTE) sequence with either slice-selective or non-slice-selective inversion recovery (IR) pulse at inversion times increasing from 300 to 1400 ms. The signal-to-noise ratio (SNR) at every inversion time (TI), real signal difference (ΔSI), and relative enhancement ratio of lung parenchyma at TI ≥ 800 ms were statistically compared for oxygen-enhanced and non-oxygen-enhanced MR images with slice-selective or non-slice-selective IR pulses.Results: The SNRs of acquisitions with slice-selective IR pulses were significantly higher than those of non-slice-selective IR pulses (P < 0.05). At TI 800 ms, the ΔSI of lung parenchyma on IR-HASTE images with slice-selective inversion pulse type was significantly higher than on that with the non-slice-selective type (P < 0.05). Relative enhancement ratios of the slice-selective IR pulses were significantly lower than those of non-slice-selective IR pulses at TIs between 800 and 1400 ms (P < 0.05).Conclusion: Slice selectivity of inversion pulse type affects oxygen-enhanced MRI in vivo. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the study was to compare two analytical methods-maximum slope (MS) and the dualinput single-compartment model (CM)-in computed tomography (CT) measurements of hepatic perfusion and to assess the effects of extrahepatic systemic factors.Materials and Methods: A total of 109 patients underwent hepatic CT perfusion. The scans were conducted at the hepatic hilum 7-77 s after administration of contrast material. Hepatic arterial perfusion (HAP) and portal perfusion (HPP) (ml/min/100 ml) and the arterial perfusion fraction (APF, %) were calculated with the two methods, followed by correlation assessment. Partial correlation analysis was used to assess the effects on hepatic perfusion values by various factors, including age, sex, risk of cardiovascular disease, compensation for respiratory misregistration, arrival time of contrast material at the abdominal aorta, transit time from abdominal aorta to hepatic parenchyma, and liver dysfunction.Results: The mean HAPs, HPPs, and APFs were, respectively, 31.4, 104.2, and 23.9 for MS and 27.1, 141.3, and 22.1 for CM. HAP and APF showed significant (P<0.0001) and moderate correlation (γ=0.417 and 0.548) and HPP showed poor correlation (γ=0.172) between the two methods. While MS showed weak correlations (γ=-0.39 to 0.34; P<0.001 to <0.02) between multiple extrahepatic factors and perfusion values, CM showed weak correlation only between the patients' sex and HAP (γ=0.31, P=0.001).Conclusion: Hepatic perfusion values estimated by the two methods are not interchangeable. CM is less susceptible to extrahepatic systemic factors. [ABSTRACT FROM AUTHOR]

Purpose: Late gadolinium enhancement (LGE) during cardiac magnetic resonance imaging (MRI) can be seen in patients with myocardial fibrosis accompanied by myocardial infarction and cardiomyopathy. Some idiopathic dilated cardiomyopathy (DCM) patients have fibrosis in the myocardium and show LGE during cardiac MRI. The purpose of this study was to investigate the clinical significance of LGE in patients with DCM.Materials and Methods: We recruited 32 DCM patients who had a left ventricular ejection fraction (LVEF) of <40% by echocardiography and performed cardiac MRI. LGE images were obtained 15 min after injection of Gd-DTPA (0.1 mmol/kg) using an inversion recovery gradient echo sequence. We compared LGE(+) and LGE(-) groups in terms of their nonsustained ventricular tachycardia (NSVT) properties. We also compared LGE and the frequency of an implantable cardioverter defibrillator (ICD) implantation.Results: In total, 18 patients (56.3%) had LGE and a higher incidence of NSVT (P = 0.01). ICD implantation was more frequent in the LGE(+) group (P = 0.04).Conclusion: Because the LGE(+) patients showed a higher incidence of NSVT and ICD implantation, cardiac MRI could prove to be a useful tool in the management of DCM patients. [ABSTRACT FROM AUTHOR]

Purpose: Loeys-Dietz syndrome (LDS) is a connective tissue disease caused by mutations in the genes encoding the transforming growth factor-beta receptor (TGFBR). LDS is associated with aneurysms or dissections of the aorta similar to Marfan syndrome (MFS) as well as arterial tortuosity and aneurysms in the peripheral arteries. The purpose of this study was to evaluate the arterial diseases of LDS to differentiate it from MFS.Materials and Methods: A total of 10 LDS patients with an identified mutation in TGFBR (6 male, 4 female; mean age 36.3 years) and 20 MFS patients with an identified mutation in fibrilin-1 who were age- and sex-matched to the LDS subjects (12 male, 8 female; mean age 37.1 years) were reviewed. The prevalence of vertebral arterial tortuosity (VAT) and peripheral aneurysm (PAN) was studied using computed tomography angiography.Results: In all, 9 of the 10 LDS patients had VAT, and five PANs were observed in 3 patients. In contrast, 8 (40%) of the MFS patients had VAT, and 1 patient had a PAN. LDS had a higher prevalence of VAT (P = 0.017) by Fisher's exact test.Conclusion: The VAT was highly prevalent among LDS patients. Thus, the presence of VAT has the potential to differentiate LDS from MFS. [ABSTRACT FROM AUTHOR]

We report a case of hemangioma with an atypical vascular enhancement pattern. The hemangioma showed peripheral rim enhancement at the arterial phase during dynamic magnetic resonance imaging, and the peripheral enhanced zone was still apparent during the delayed phase, as shown on double-phase computed tomography hepatic arteriography. The rim enhancement pattern of this case, mimicking that of hepatocellular carcinoma, may be due to the surrounding liver parenchymal fibrotic change caused by an active hepatitis C viral infection. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the impact of three-dimensional (3D) T2-weighted turbo spin-echo imaging (TSE-T2WI) with tissue-specific variable refocusing flip angle (TS-VRFA) on image quality and prostate cancer (PCa) detection and extraprostatic extension (EPE) evaluation compared to 2D TSE-T2WI and conventional 3D TSE-T2WI with volume isotropic TSE acquisition (VISTA)., Materials and Methods: Image data sets of 40 patients who underwent 3-T MRI before prostatectomy, including multiplane 2D T2WI, 3D T2WI with TS-VRFA and VISTA, and diffusion-weighted images were independently evaluated by two radiologists. The detectability of PCa and EPE of each sequence was assessed using areas by the receiver operating characteristic curve (AUC) analysis. Image quality measures and contrast ratios (CR) between cancerous lesions and non-cancerous regions for each T2WI were also evaluated., Results: Overall image quality of TS-VRFA was better than that of VISTA and equivalent to 2D. The highest CR was obtained with TS-VRFA (P < 0.05). For both readers, no significances were observed in detectability for PCa detection between three sequences (P > 0.05). For both readers, there were no significant differences in AUC for EPE evaluation between three sequences (P > 0.05)., Conclusion: 3D T2 WI using TS-VRFA could potentially replace multiplane 2D T2 WI for prostate cancer diagnosis with better image quality than VISTA.

Purpose: Our aim was to investigate the diagnostic accuracy of fluorine-18-labeled fluorodeoxyglucose positron emission tomography computed tomography (FDG-PET/CT) relative to CT for detecting neck lymph node metastases in patients with squamous cell carcinoma (SCC) of the hypopharynx, oropharynx, and larynx., Methods: Thirty-four patients with SCC of the hypopharynx (n = 20), oropharynx (n = 5), and larynx (n = 9) who underwent neck dissection (29 bilateral, 5 unilateral; a total of 355 nodal levels) were assessed. Two observers determined the long-axis diameter and maximum standardized uptake value (SUVmax) of all visible neck nodes. Results of FDG-PET/CT were compared with those of corresponding histopathologic examinations according to the neck-level system., Results: Histopathology revealed metastases in 70 of 355 nodal levels. Using a best discriminative SUVmax cutoff of 3.65, sensitivity, specificity, and accuracy of FDG-PET/CT on a level-by-level basis were 72.9, 96.8, and 92.1 %; those for CT were 52.9, 98.6, and 89.6 %. Differences in sensitivity and accuracy were significant (p < 0.01). The best cutoff SUVmax on the ipsilateral side was 4.61, with corresponding figures of 81.6, 100, and 94.7 %; that on the contralateral side was 2.41, with figures of 60, 88.4, and 85.4 %., Conclusion: FDG-PET/CT with SUVmax is useful for preoperative evaluation of neck-node metastasis from SCC of the pharynx and larynx, especially on the ipsilateral side.

Integrated positron emission tomography/computed tomography (PET/CT) with 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG) is a useful technique for acquisition of both glucose metabolic and anatomic imaging data using a single device in a single diagnostic session, and has opened a new field in clinical oncologic imaging. FDG-PET/CT has been used successfully for the initial staging, restaging, monitoring of the response to therapy, and prognostication of head and neck carcinoma. The present review discusses the current role of FDG-PET/CT in the management of head and neck carcinoma, focusing on its usefulness and limitations for imaging in these patients.

Purpose: Separate assessment of changes in blood oxygenation and blood volume is required in blood oxygen level-dependent (BOLD) imaging. We developed a calculated echo time (TE) imaging technique designed to minimize effects of blood oxygenation and to evaluate blood volume specifically., Materials and Methods: Dynamic 3T multi-echo BOLD images of calf muscle were acquired from six healthy volunteers by use of a cuff-compression model. Calculated TE images at TE = 0 ms (cTE0) and T2* map (T2*) were calculated from acquired multi-echo images. The time courses of the mean value for the entire calf muscles in cTE0, in acquired BOLD images at TE = 45.2 ms (aTE45), and in T2* were obtained. The Euclidean distances between the two pairs of time courses were calculated: distance between aTE45 and T2* (D at), and that between cTE0 and T2* (D ct). The difference between D at and D ct was tested by use of the Wilcoxon signed rank test., Results: D at was significantly different from D ct (P = 0.031), indicating that the time course of cTE0 was significantly different from that of blood oxygenation-weighted images (T2* and aTE45)., Conclusion: The effect of blood oxygenation could be minimized using cTE0. Thus, signal intensity changes of cTE0 reflected changes in blood volume more specifically.

Purpose: To clarify the workload of certified radiologists and to estimate the current manpower shortages in Japan., Methods: We conducted a questionnaire survey for accredited training institutions. The contents included the radiologist employment pattern (full vs. part time), the number of computed tomography (CT) and magnetic resonance imaging (MRI) examinations and their radiology reports, the number of radiation therapy planning sessions, and the time per week spent for each work activity. We also used the hospital survey reports of Japan's Ministry of Health, Labor, and Welfare in our analyses., Results: The estimated numbers of CT and MRI interpretation reports and radiation treatment plans that one full-time radiologist could complete within 1 hospital day (8 h) were 19.9 and 1.22, respectively. To complete all CT and MRI reports, at least 2.09 times more full-time diagnostic radiologists are needed in Japan. For radiation therapy, at least 1.23 times more full-time radiation oncologists are necessary at large- and medium-scale hospitals, although the number of radiation oncologists needed in Japan is balanced to the current number., Conclusion: The number of full-time certified diagnostic radiologists for CT and MRI interpretation in Japan is insufficient. Centralized radiation therapy facilities may be more efficient for meeting the increasing demand.

Purpose: An MRI-based pre-test to determine the probability of pediatric leukemia prior to bone marrow aspiration would be useful to prevent unnecessary exposure to this invasive test. We aimed to evaluate the clivus-to-pons signal intensity ratio (CPR) and visual scoring (VS) on T1-weighted images (T1WI) and diffusion-weighted images (DWI) to distinguish pediatric leukemia patients from normal controls., Materials and Methods: We retrospectively reviewed 1.5-T brain MR images of 13 consecutive leukemia patients (3 girls, 10 boys; mean age, 8.23 years; range, 1-17 years) and 40 age- and gender-matched normal controls. We evaluated differences between leukemia patients and normal controls using Wilcoxon rank-sum and Mann-Whitney U tests with respect to the following parameters: (1) CPR on T1WI (CPRT1WI); (2) CPR on DWI (CPRDWI); (3) VS on T1WI (VST1WI); and (4) VS on DWI (VSDWI)., Results: The CPRT1WI values for leukemia patients and normal controls were 0.77 ± 0.12 and 1.39 ± 0.47, respectively (P < 0.001). The corresponding CPRDWI values were 1.03 ± 0.38 and 0.50 ± 0.17, respectively (P < 0.001). VST1WI and VSDWI were significantly different between the groups (P < 0.001 for both)., Conclusion: MRI-based quantitative and qualitative analyses of clival bone marrow on T1WI and DWI can distinguish pediatric leukemia patients from normal subjects.

Integrated positron emission tomography/computed tomography (PET/CT) with 2-[18F]fluoro-2-deoxy-D-glucose (FDG) is a useful technique for acquiring both glucose metabolic and anatomic imaging data using a single device in a single diagnostic session, and has opened up a new field of clinical oncologic imaging. FDG-PET/CT has been used successfully for the staging, treatment optimization, re-staging, therapy monitoring, and prognostication of uterine and ovarian cancers as well as various malignant tumors. The present review discusses the current role of FDG-PET/CT in the management of gynecologic malignancies, focusing on its usefulness and limitations for imaging such patients.

Insufficiency fracture of the clavicle is a rare complication that can occur in patients who have undergone neck dissection. The differential diagnoses of this entity include recurrent metastatic disease, post-radiation sarcoma, trauma, and infection. We reviewed the images of seven lesions in six patients who had undergone neck surgery and had stress fractures of the clavicle without tumor metastasis. All lesions involved clavicular fractures and had mass formation around the bone fracture. Two lesions mainly comprised sternoclavicular joint (SCJ) surface destruction, and six mainly comprised fractures of the proximal end of the clavicle. Five (71%) had increased clavicular bone density. Six lesions (86%) had fluid collection in the SCJ, and three of these lesions (in two patients) were complicated by infection. fluorodeoxyglucose-positron emission tomography (FDG-PET) showed relatively weak uptake (SUVmax 0.96-3.09).

A variety of different tumors can arise from any of the tissues present in the retroperitoneum, and they exhibit a wide range of pathologic types. Although computed tomography (CT) and magnetic resonance imaging (MRI) can demonstrate important characteristics of these tumors, diagnosis is often challenging for radiologists. The purpose of this pictorial essay is to review (18)F-fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) features of different kinds of benign and malignant retroperitoneal tumors in comparison with CT or MRI findings alone and to become familiar with the wide variety of imaging characteristics.

Objective: To compare the efficacy of computer-aided detection (CAD) for computed tomographic colonography (CTC) when employed as either primary-reader or second-reader paradigms in a low-prevalence screening population., Methods: Ninety screening patients underwent same-day CTC and colonoscopy. Four readers prospectively interpreted all CTC data sets using a second-reader paradigm (unassisted interpretation followed immediately by CAD assistance). Three months later, randomized anonymous data sets were re-interpreted by all readers using a primary-reader paradigm (only CAD prompts evaluated)., Results: Compared with the average per-patient sensitivity for unassisted interpretation (0.57), both CAD paradigms significantly increased sensitivity: 0.78 (p < 0.001) for the second-reader paradigm and 0.83 (p < 0.001) for the primary-reader paradigm. There was no significant difference between CAD paradigms (p = 0.25). The average per-patient specificity for polyps ≥6 mm was significantly higher using the primary-reader paradigm than the second-reader paradigm (0.90 vs. 0.83, respectively, p = 0.006), with ROC AUCs of 0.83 and 0.68, respectively. Reading time using CAD as a primary-reader paradigm (median 1.4 min) was significantly shorter than both unassisted (median 4.0 min, p < 0.001) and second-reader paradigms (median 5.5 min, p < 0.001)., Conclusion: CAD improves radiologist sensitivity in screening patients when used as either a second- or primary-reader paradigm, although the latter may improve specificity and efficiency more.