Imaging findings in inflammatory disease of the genital organs.

This review focuses on inflammatory diseases of female and male genital organs and discusses their epidemiology, pathogenesis, clinical presentation, and imaging findings. The female section covers pelvic inflammatory disease (PID) primarily caused by sexually transmitted infections (STIs) that affect the uterus, fallopian tubes, and ovaries. Unusual causes such as actinomycosis and tuberculosis have also been explored. The male section delves into infections affecting the vas deferens, epididymis, testes, prostate, and seminal vesicles. Uncommon causes such as tuberculosis, and Zinner syndrome have also been discussed. In addition, this review highlights other conditions that mimic male genital tract infections such as vasculitis, IgG4-related diseases, and sarcoidosis. Accurate diagnosis and appropriate management of these inflammatory diseases are essential for preventing serious complications and infertility. Imaging modalities such as ultrasound, magnetic resonance imaging, and computed tomography play a crucial role in diagnosis. Understanding the diverse etiologies and imaging findings is vital for the effective management of inflammatory diseases of the genital organs.

Triple modal treatment comprising with proton beam radiation, hyperthermia, and gemcitabine/nab-paclitaxel for locally advanced pancreatic cancer: a phase I/II study protocol (TT-LAP trial).

BACKGROUND: Locally advanced pancreatic ductal adenocarcinoma (PDAC), accounting for about 30% of PDAC patients, is difficult to cure by radical resection or systemic chemotherapy alone. A multidisciplinary strategy is required and our TT-LAP trial aims to evaluate whether triple-modal treatment with proton beam therapy (PBT), hyperthermia, and gemcitabine plus nab-paclitaxel is a safe and synergistically effective treatment for patients with locally advanced PDAC. METHODS: This trial is an interventional, open-label, non-randomized, single-center, single-arm phase I/II clinical trial organized and sponsored by the University of Tsukuba. Eligible patients who are diagnosed with locally advanced pancreatic cancer, including both borderline resectable (BR) and unresectable locally advanced (UR-LA) patients, and selected according to the inclusion and exclusion criteria will receive triple-modal treatment consisting of chemotherapy, hyperthermia, and proton beam radiation. Treatment induction will include 2 cycles of chemotherapy (gemcitabine plus nab-paclitaxel), proton beam therapy, and 6 total sessions of hyperthermia therapy. The initial 5 patients will move to phase II after adverse events are verified by a monitoring committee and safety is ensured. The primary endpoint is 2-year survival rate while secondary endpoints include adverse event rate, treatment completion rate, response rate, progression-free survival, overall survival, resection rate, pathologic response rate, and R0 (no pathologic cancer remnants) rate. The target sample size is set at 30 cases. DISCUSSION: The TT-LAP trial is the first to evaluate the safety and effectiveness (phases1/2) of triple-modal treatment comprised of proton beam therapy, hyperthermia, and gemcitabine/nab-paclitaxel for locally advanced pancreatic cancer. ETHICS AND DISSEMINATION: This protocol was approved by the Tsukuba University Clinical Research Review Board (reference number TCRB22-007). Results will be analyzed after study recruitment and follow-up are completed. Results will be presented at international meetings of interest in pancreatic cancer plus gastrointestinal, hepatobiliary, and pancreatic surgeries and published in peer-reviewed journals. TRIAL REGISTRATION: Japan Registry of Clinical Trials, jRCTs031220160. Registered 24 th June 2022, https://jrct.niph.go.jp/en-latest-detail/jRCTs031220160 .

Differentiation of silent corticotroph pituitary neuroendocrine tumors (PitNETs) from non-functioning PitNETs using kinetic analysis of dynamic MRI.

PURPOSE: Silent corticotroph pituitary adenomas (SCAs)/pituitary neuroendocrine tumors (PitNETs) are common non-functioning pituitary adenomas (NFAs)/PitNETs with a clinically aggressive course. This study aimed to investigate the ability of time-intensity analysis of dynamic magnetic resonance imaging (MRI) for distinguishing adrenocorticotropic hormone (ACTH)-positive SCAs and ACTH-negative SCAs from other NFAs. MATERIALS AND METHODS: We retrospectively evaluated the dynamic MRI findings of patients with NFAs. The initial slope of the kinetic curve (slopeini) obtained by dynamic MRI for each tumor was analyzed using a modified empirical mathematical model. The maximum slope of the kinetic curve (slopemax) was obtained by geometric calculation. RESULTS: A total of 106 patients with NFAs (11 ACTH-positive SCAs, 5 ACTH-negative SCAs, and 90 other NFAs) were evaluated. The kinetic curves of ACTH-positive SCAs had significantly lesser slopeini and slopemax compared with ACTH-negative SCAs (P = 0.040 and P = 0.001, respectively) and other NFAs (P = 0.018 and P = 0.035, respectively). Conversely, the slopeini and slopemax were significantly greater in ACTH-negative SCAs than in NFAs other than ACTH-negative SCAs (P = 0.033 and P = 0.044, respectively). In receiver operating characteristic analysis of ACTH-positive SCAs and other NFAs, the area under the curve (AUC) values for slopeini and slopemax were 0.762 and 0748, respectively. In predicting ACTH-negative SCAs, the AUC values for slopeini and slopemax were 0.784 and 0.846, respectively. CONCLUSIONS: Dynamic MRI can distinguish ACTH-positive SCAs and ACTH-negative SCAs from other NFAs.

Pulmonary arterial pseudoaneurysm as an unusual complication of pulmonary actinomycosis: Two case reports.

We report 2 cases of pulmonary actinomycosis complicated by a pseudoaneurysm. In Case 1, a 67-year-old man visited a hospital 7 months ago because of hemoptysis. CT revealed a suspected lung abscess in the left lingular segment; however, no diagnosis was confirmed by bronchoscopy. A CT scan taken after heavy hemoptysis showed a pseudoaneurysm within the consolidation of the same segment. On the same day, embolization of the left bronchial and intercostal arteries was performed. Left lingulectomy was performed 5 days later, and pulmonary actinomycosis was diagnosed histologically. Case 2 was a 51-year-old man with a 2-year history of cough and intermittent hemoptysis. CT showed a lesion with a cavity suggesting an abscess 3 months previously, and antibiotic treatment was started. After the appearance of massive hemoptysis, embolization was performed for a pseudoaneurysm seen on bronchial arteriography. Four days later, a left lower lobectomy was performed, and pulmonary actinomycosis was histologically diagnosed. Pseudoaneurysms are commonly associated with tuberculosis; however, only one report of pseudoaneurysms has been associated with pulmonary actinomycosis. Appropriate treatment should be selected according to the type of pseudoaneurysm and the risk of recurrent hemoptysis. Angiography and embolization are essential tools in diagnosing and treating pulmonary arterial pseudoaneurysms; however, surgical intervention may also be an option in some cases to ensure a good long-term outcome.

Differentiation of carcinosarcoma from endometrial carcinoma on magnetic resonance imaging using deep learning.

Purpose: To verify whether deep learning can be used to differentiate between carcinosarcomas (CSs) and endometrial carcinomas (ECs) using several magnetic resonance imaging (MRI) sequences. Material and methods: This retrospective study included 52 patients with CS and 279 patients with EC. A deep-learning model that uses convolutional neural networks (CNN) was trained with 572 T2-weighted images (T2WI) from 42 patients, 488 apparent diffusion coefficient of water maps from 33 patients, and 539 fat-saturated contrast-enhanced T1-weighted images from 40 patients with CS, as well as 1612 images from 223 patients with EC for each sequence. These were tested with 9-10 images of 9-10 patients with CS and 56 images of 56 patients with EC for each sequence, respectively. Three experienced radiologists independently interpreted these test images. The sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) for each sequence were compared between the CNN models and the radiologists. Results: The CNN model of each sequence had sensitivity 0.89-0.93, specificity 0.44-0.70, accuracy 0.83-0.89, and AUC 0.80-0.94. It also showed an equivalent or better diagnostic performance than the 3 readers (sensitivity 0.43-0.91, specificity 0.30-0.78, accuracy 0.45-0.88, and AUC 0.49-0.92). The CNN model displayed the highest diagnostic performance on T2WI (sensitivity 0.93, specificity 0.70, accuracy 0.89, and AUC 0.94). Conclusions: Deep learning provided diagnostic performance comparable to or better than experienced radiologists when distinguishing between CS and EC on MRI.

Treatment of ruptured rectal artery aneurysm in a patient with neurofibromatosis.

BACKGROUND: Superior rectal artery (SRA) aneurysms are rare. Although melena is the most common symptom, it has not been observed in cases of aneurysms located in the SRA trunk. Here, we report a case of a ruptured SRA trunk aneurysm successfully treated with coil embolization. Including our case, three of the four reported cases of SRA trunk aneurysms were related to neurofibromatosis type 1 (NF1). CASE PRESENTATION: A 52-year-old woman with NF1 was referred to our hospital for the investigation of an abdominal mass with back pain. She had previously undergone a blood transfusion at another hospital for anemia without melena. Computed tomography angiography revealed a ruptured SRA trunk aneurysm measuring 3 cm in diameter and surrounded by a retroperitoneal hematoma. The aneurysm was isolated by embolizing the SRA trunk distally and proximally. Distal embolization was performed retrogradely from the internal iliac artery (IIA) via the middle rectal artery (MRA)-SRA anastomosis because the antegrade approach from the inferior mesenteric artery (IMA) failed. To our knowledge, this is the first case of successful coil embolization of an IMA branch through the IIA. CONCLUSION: SRA trunk aneurysms are rare; however, they are frequently associated with NF1. Antegrade distal embolization beyond the aneurysm is sometimes difficult to achieve. In such cases, a retrograde approach via MRA-SRA anastomosis can be the choice for isolating SRA trunk aneurysms.

Effectiveness of temporal subtraction computed tomography images using deep learning in detecting vertebral bone metastases.

PURPOSE: To assess the clinical effectiveness of temporal subtraction computed tomography (TS CT) using deep learning to improve vertebral bone metastasis detection. METHOD: This retrospective study used TS CT comprising bony landmark detection, bone segmentation with a multi-atlas-based method, and spatial registration of two images by a log-domain diffeomorphic Demons algorithm. Paired current and past CT images of 50 patients without vertebral metastasis, recorded during June 2011-September 2016, were included as training data. A deep learning-based method estimated registration errors and suppressed false positives. Thereafter, paired CT images of 40 cancer patients with newly developed vertebral metastases and 40 control patients without vertebral metastases were evaluated. Six board-certified radiologists and five radiology residents independently interpreted 80 paired CT images with and without TS CT. RESULTS: Records of 40 patients in the metastasis group (median age: 64.5 years; 20 males) and 40 patients in the control group (median age: 64.0 years; 20 males) were evaluated. With TS CT, the overall figure of merit (FOM) of the board-certified radiologist and resident groups improved from 0.848 to 0.876 (p = 0.01) and from 0.752 to 0.799 (p = 0.02), respectively. The sub-analysis focusing on attenuation changes in lesions revealed that the FOM of osteoblastic lesions significantly improved in both the board-certified radiologist and resident groups using TS CT. The sub-analysis focusing on lesion location showed that the FOM of the resident group significantly improved in the vertebral arch (p = 0.04). CONCLUSIONS: TS CT was effective in detecting bone metastasis by both board-certified radiologists and radiology residents.

Diagnosing Ovarian Cancer on MRI: A Preliminary Study Comparing Deep Learning and Radiologist Assessments.

BACKGROUND: This study aimed to compare deep learning with radiologists' assessments for diagnosing ovarian carcinoma using MRI. METHODS: This retrospective study included 194 patients with pathologically confirmed ovarian carcinomas or borderline tumors and 271 patients with non-malignant lesions who underwent MRI between January 2015 and December 2020. T2WI, DWI, ADC map, and fat-saturated contrast-enhanced T1WI were used for the analysis. A deep learning model based on a convolutional neural network (CNN) was trained using 1798 images from 146 patients with malignant tumors and 1865 images from 219 patients with non-malignant lesions for each sequence, and we tested with 48 and 52 images of patients with malignant and non-malignant lesions, respectively. The sensitivity, specificity, accuracy, and AUC were compared between the CNN and interpretations of three experienced radiologists. RESULTS: The CNN of each sequence had a sensitivity of 0.77-0.85, specificity of 0.77-0.92, accuracy of 0.81-0.87, and an AUC of 0.83-0.89, and it achieved a diagnostic performance equivalent to the radiologists. The CNN showed the highest diagnostic performance on the ADC map among all sequences (specificity = 0.85; sensitivity = 0.77; accuracy = 0.81; AUC = 0.89). CONCLUSION: The CNNs provided a diagnostic performance that was non-inferior to the radiologists for diagnosing ovarian carcinomas on MRI.

A Transarterial Chemoembolization of Balloon-Occluded Alternate Infusions of Cisplatin and Gelatin Particles for Hepatocellular Carcinoma: A Phase I/II Multicenter Prospective Study of Safety and Efficacy.

PURPOSE: To evaluate the safety and efficacy of a newly developed technique of balloon-occluded alternate infusions of cisplatin and gelatin particles in transarterial chemoembolization in hepatocellular carcinoma (HCC) and to evaluate the liver damage following the procedure. MATERIALS AND METHODS: Forty-three patients with HCC from 4 medical centers were enrolled in this multicenter prospective study. Of these, 41 patients were observed for 6 months following balloon-occluded alternate infusion transarterial chemoembolization. The primary endpoint was the safety of the procedure, and the secondary endpoint was the objective response rate (ORR) of the HCCs at 2 months following treatment. RESULTS: Three patients experienced adverse events, including 1 patient with facial swelling and skin rash, dissection of the celiac artery, and bland portal vein thrombus. No major adverse events were identified. Two (5.3%) patients regressed from a Child-Pugh classification of A to B. The balloon-occluded alternate infusion transarterial chemoembolization treatment achieved a 22.0% complete response (CR) rate and a 73.2% ORR (95% confidence interval [CI], 57.9%-84.4%). In a retrospective analysis of 23 patients with HCCs above the up-to-7 criteria, the CR rate and ORR of the balloon-occluded alternate infusion transarterial chemoembolization were 21.7% and 82.6% (95% CI, 62.3%-93.6%), respectively. CONCLUSIONS: Balloon-occluded alternate infusion transarterial chemoembolization is safe and effective for achieving a high ORR while preserving liver function.

Hypofractionated Proton Beam Therapy for cT1-2N0M0 Non-small Cell Lung Cancer Patients With Interstitial Lung Disease.

BACKGROUND/AIM: To evaluate the outcomes of proton beam therapy (PBT) for early-stage non-small cell lung cancer (NSCLC) in patients with interstitial lung disease (ILD). PATIENTS AND METHODS: Between 2002 and 2017, 110 patients receiving hypofractionated PBT for cT1-2N0M0 NSCLC were reviewed. RESULTS: Of the 110 patients, 17 were diagnosed with ILD. The median follow-up period was 37.8 months. No significant difference in the 1-year cumulative rate of grade ≥2 pneumonitis was observed between patients with and those without ILD (17.6% vs. 14.1%, p=0.708). The lung doses were significantly lower in patients with than in those without ILD among patients without grade ≥2 pneumonitis. There were no significant differences in overall survival or local recurrence-free rates according to the presence of ILD. CONCLUSION: PBT appears to be a feasible and effective treatment for cT1-2N0M0 NSCLC in patients with ILD, but the lung dose should be strictly reduced.

The utility of dynamic MRI in differentiating the hormone-producing ability of pituitary adenomas.

PURPOSE: To investigate the relationship between dynamic magnetic resonance imaging (MRI) findings and hormonal activity in pituitary adenomas. METHODS: We retrospectively evaluated the dynamic MRI findings in 244 patients with pathologically confirmed pituitary adenomas and a diagnosis of clinically active prolactin (PRL)-producing adenomas. Among the 244 pituitary adenomas, 55, 16, 6, and 4 produced growth hormone (GH), PRL, adrenocorticotropic hormone, and thyroid-stimulating hormone, respectively, while 163 were non-functioning (NF) adenomas. For each adenoma, we calculated the washout rate (WR) and early (EER) and delayed (DER) tumour-to-normal-tissue enhancement ratios. RESULTS: The respective mean values of the WR, EER, and DER were 9.4%, 75.2%, and 64.5% for GH-producing adenomas; 6.2%, 117.1%, and 106.2% for PRL-producing adenomas; and 5.4%, 116.7%, and 108.7% for NF adenomas. GH-producing adenomas had significantly lower EER and DER values than PRL-producing (P < 0.001) and NF adenomas (P < 0.001). In ROC analysis of GH-producing and non-GH-producing adenomas, the areas under the curves of WR, EER, and DER were 0.593, 0.825, and 0.857, respectively. CONCLUSION: There are differences in dynamic MRI features between GH-producing and non-GH-producing adenomas, which suggests that EER and DER may be useful for diagnosing GH-producing adenomas.

Ovarian and non-ovarian teratomas: a wide spectrum of features.

Teratoma is a germ cell tumor (GCT) derived from stem cells of the early embryo and the germ line. Teratoma is the most common neoplasm of the ovaries and is usually diagnosed easily using imagings by detecting fat components. However, there are various histopathological types and the imaging findings differ according to the type. Teratoma usually occurs in the gonads or in the midline due to migration of primordial germ cells during development. The clinical course of teratomas depends on the age of the patient, histological type, and anatomical site. Sometimes teratomas show unusual manifestations, such as mature teratoma without demonstrable fat components, torsion, rupture, growing teratoma syndrome, anti-N-methyl-D-aspartate receptor encephalitis, and autoimmune hemolytic anemia. For all of these reasons, teratomas demonstrate a wide spectrum of imaging features and radiologists should be familiar with these variabilities. The present article aims to introduce a model encompassing types of GCTs based on their developmental potential, and to review several histopathological types in various anatomical sites and unusual manifestations of teratomas, with representative imaging findings.

Chemoembolization of a hepatocellular carcinoma supplied by a caudate artery forming a common trunk with the supraduodenal artery: A case report.

The supraduodenal artery might arise from the hepatic, gastroduodenal, or right gastric arteries, but only a few studies have addressed the branching pattern of this artery. We herein describe a case of an 80-year-old man with hepatocellular carcinoma located in segment I. Selective arteriography and CT angiography showed that the supraduodenal artery formed a common trunk with the caudate artery to feed the tumor. The patient was successfully treated with superselective transarterial chemoembolization without gastrointestinal complications. To avoid nontargeting chemoembolization of the duodenum, interventional radiologists should be aware of this branching pattern. In suspected cases, selective CT arteriography plays a crucial role.

Atypical femoral hernia called Laugier's hernia: clinical features, radiological findings, and management at a single center.

PURPOSE: Laugier's hernia is a rare clinical entity compared with a typical femoral hernia. Therefore, the clinical features, radiological findings, and appropriate treatment strategies remain largely unclear. In this study, we present 15 Laugier's hernia cases. Additionally, we review the relevant literature and discuss the clinical features, radiological findings, and appropriate treatment strategies pertaining to Laugier's hernia compared with a typical femoral hernia. METHODS: Among 1260 hernia patients, we retrospectively enrolled 15 Laugier's hernia patients (1.19%) and 89 femoral hernia patients (7.06%) who underwent herniorrhaphy and compared the demographic characteristics and radiological findings between the two groups. RESULTS: Regarding the patient characteristics, a significant difference was observed in the presence of pain (p < 0.001) and ileus symptoms (p = 0.001). Regarding the hernia characteristics, significant differences were observed in the size of the hernial sac (p = 0.001), contents of the hernial sac (p = 0.003), repositioning of the hernial sac (p < 0.001), and repair with polypropylene mesh (p < 0.001). The characteristic multi-detector computed tomography (MDCT) findings enabled the preoperative diagnosis of Laugier's hernia versus conventional femoral hernia. CONCLUSION: Surgeons should be alert to the possibility of atypical femoral hernias while examining femoral hernia or inguinal hernia patients. If Laugier's hernia is suspected, preoperative MDCT is recommended.

Detection of the artery of Adamkiewicz using multidetector row computed tomography in patients with spinal arteriovenous shunt disease.

PURPOSE: To plan a treatment strategy for a spinal arteriovenous shunt (SAVS), identifying the artery of Adamkiewicz (AKA) and its origin is indispensable. However, detecting the AKA is very difficult in patients with an SAVS when using computed tomography angiography (CTA) by the usual method to find the hairpin curved artery because dilated drainage veins nearly always coexist with the hairpin curved AKA. We designed a method to identify the AKA by focusing on the diameter and pathway of the anterior radiculomedullary arteries (RMAs). MATERIAL AND METHODS: Seven consecutive patients with an SAVS were surveyed. They underwent contrast-enhanced CTA and conventional angiography from January 2009 to December 2012. Two readers evaluated the CTA images and assumed that the AKA was the artery that ran through the anterior portion of the neural foramen and continued to pass on the ventral side of the spinal cord. RESULTS: Among the seven patients, nine AKAs were detected with conventional angiography. When using our method, seven AKAs and six AKAs were identified on CTA by Reader 1 and Reader 2, respectively. The average sensitivity was 72.3%, and the specificity, accuracy, positive predictive value, and negative predictive value were sufficiently high (i.e. > 85%) for both readers. The kappa value for detecting the AKA was 0.98. CONCLUSIONS: Detecting the origin of the AKA with CTA is challenging in patients with an SAVS. However, focusing on the diameter and pathway of the RMAs may allow successful identification.

High prevalence of intrapelvic parasitic arteries in patients with placenta accreta spectrum: A case-control study using unenhanced magnetic resonance angiography.

PURPOSE: To compare the prevalence of enlarged ovarian and intrapelvic parasitic arteries to the gravid uterus between cases of placenta accreta spectrum (PAS) and those with normal placentation using unenhanced magnetic resonance (MR) angiography. METHODS: Unenhanced time-of-flight MR angiography was performed in 12 consecutive women with PAS (mean age, 34 years; range, 23-42 years) and 24 women with normal placentation (mean age, 31 years; range, 24-42 years) in their third trimester and reviewed by two independent observers. The consensus reading served as the reference standard. Findings of pelvic arteriography performed at cesarean hysterectomy were reviewed in all cases of PAS. The prevalence of enlarged ovarian and intrapelvic parasitic arteries was compared using Fisher's exact test. The interobserver agreement was assessed with Kappa statistics. RESULTS: The prevalence of enlarged ovarian arteries was not significantly different between cases of PAS and normal placentation (17% [4/24 pelvic sides] vs. 4% [2/48 pelvic sides], P = .091). The prevalence of intrapelvic parasitic arteries was significantly higher in cases of PAS than in those with normal placentation (67% [16/24 pelvic sides] vs. 0% [0/48 pelvic sides], P < .0001). On a patient-by-patient basis, the intrapelvic parasitic artery was frequently present in women with PAS (92% [11/12 patients]). The Kappa values were 0.915 and 0.852 for detecting enlarged ovarian and intrapelvic parasitic arteries, respectively, indicating excellent interobserver agreement. CONCLUSIONS: The development of intrapelvic parasitic arteries was an anomalous phenomenon observed on unenhanced MR angiography in the majority of women with PAS but was not observed in those with normal placentation.

Mass-forming hepatic cryptococcosis: a mimicker of metastatic tumors.

This report provides the first imaging report of isolated intrahepatic cryptococcosis. An 83-year-old man was incidentally pointed out of hepatic nodules. CT revealed four well-defined nodules of 21 mm, 15 mm, 7 mm, and 5 mm in diameter without contrast enhancement. Two nodules displayed central hyperattenuation and the others were totally hyperattenuating. MRI showed that the nodules were hypointense relative to normal liver parenchyma on T1- and T2-weighted images. 18F-FDG PET imaging revealed no obvious increased uptake of nuclear species into the liver nodules. Partial resection of the three largest hepatic nodules was performed based on a preoperative diagnosis of hepatic metastasis from known sigmoid colon cancer. All three resected nodules were composed mainly of necrotic tissue with peripheral histiocytic aggregates and numerous yeast-like cells. The final diagnosis was hepatic cryptococcosis.

Clinical usefulness of temporal subtraction CT in detecting vertebral bone metastases.

PURPOSE: The purpose of this study was to determine whether temporal subtraction (TS) computed tomography (CT) contributes to the detection of vertebral bone metastases. METHOD: The calculation of TS CT was composed of bony landmark detection, bone segmentation with a multiatlas-based method, and spatial registration. Temporal increase and decrease of the CT values were visualized in blue and red, respectively. Paired CT images of 20 patients with cancer and newly-developed vertebral metastases were analyzed. Control CT examinations of 20 different patients were also included. The presence of vertebral metastases on the TS CT was evaluated by two board-certified radiologists. Five additional board-certified radiologists and five radiology residents independently interpreted the 40 paired CT images with and without TS CT. RESULTS: In the lesion conspicuity evaluation, 96% of vertebral metastases were scored as excellent or good. In the image interpretation examination, according to free-response receiver operating characteristics analysis, the overall figure of merit (FOM) of the board-certified radiologist group was 0.892 and 0.898 with and without TS CT, respectively. The FOM of the resident group improved from 0.849 to 0.902 with viewing TS CT. In the sub-analysis focusing on the location of the lesion, the FOM of the resident group significantly improved from 0.75 to 0.92 in vertebral arch lesions (p = 0.001). CONCLUSIONS: The TS CT may be useful to detect vertebral metastases because almost all the vertebral metastases were shown to be favorable visualization. The TS CT was proven to be especially helpful for radiology residents in detecting vertebral arch metastases.

Development of a small car-mounted magnetic resonance imaging system for human elbows using a 0.2 T permanent magnet.

Portable magnetic resonance imaging (MRI) scanners can provide opportunities for mobile operation in many environments including disease screening and primary care suites. Here, we develop a new, compact transportable MRI system for imaging small joints of the extremities using a 0.2 T, 200 kg permanent magnet. The whole system, including the magnet, gradient coils, RF probes, and MRI consoles (80 kg in weight) was installed in a standard-size minivan-style vehicle. The use of the open-geometry magnet enables easy patient positioning within the limited space of the vehicle. We show that our portable MRI system provides clinically relevant images of screening for elbow injuries induced by overuse of overhand throwing. This transportable system is deployable during sport events or in environments with poor access to MRI systems, and could be applicable for mass screening, early diagnosis, and case finding.