Utility of accelerated T2-weighted turbo spin-echo imaging with deep learning reconstruction in female pelvic MRI: a multi-reader study.

OBJECTIVES: To determine the clinical feasibility of T2-weighted turbo spin-echo (T2-TSE) imaging with deep learning reconstruction (DLR) in female pelvic MRI compared with conventional T2 TSE in terms of image quality and scan time. METHODS: Between May 2021 and September 2021, 52 women (mean age, 44 years ± 12) who underwent 3-T pelvic MRI with additional T2-TSE using a DLR algorithm were included in this single-center prospective study with patient's informed consents. Conventional, DLR, and DLR T2-TSE images with reduced scan times were independently assessed and compared by four radiologists. The overall image quality, differentiation of anatomic details, lesion conspicuity, and artifacts were evaluated using a 5-point scale. Inter-observer agreement of the qualitative scores was compared and reader protocol preferences were then evaluated. RESULTS: In the qualitative analysis of all readers, fast DLR T2-TSE showed significantly better overall image quality, differentiation of anatomic regions, lesion conspicuity, and lesser artifacts than conventional T2-TSE and DLR T2-TSE, despite approximately 50% reduction in scan time (all p < 0.05). The inter-reader agreement for the qualitative analysis was moderate to good. All readers preferred DLR over conventional T2-TSE regardless of scan time and preferred fast DLR T2-TSE (57.7-78.8%), except for one who preferred DLR over fast DLR T2-TSE (53.8% vs. 46.1%). CONCLUSION: In female pelvic MRI, image quality and accelerated image acquisition for T2-TSE can be significantly improved by using DLR compared to conventional T2-TSE. Fast DLR T2-TSE was non-inferior to DLR T2-TSE in terms of reader preference and image quality. CLINICAL RELEVANCE STATEMENT: DLR of T2-TSE in female pelvic MRI enables fast imaging along with maintaining optimal image quality compared with parallel imaging-based conventional T2-TSE. KEY POINTS: • Conventional T2 turbo spin-echo based on parallel imaging has limitations for accelerated image acquisition while maintaining good image quality. • Deep learning image reconstruction showed better image quality in both images obtained using the same or accelerated image acquisition parameters compared with conventional T2 turbo spin-echo in female pelvic MRI. • Deep learning image reconstruction enables accelerated image acquisition while maintaining good image quality in the T2-TSE of female pelvic MRI.

[Radiologic Evaluation of Uterine Lesions Using a Pattern Recognition Approach]. / 패턴 인식 ì ‘ê·¼ë²•ì„ 기반으로 한 자궁병변의 ì˜ìƒì˜í•™ì  평가.

It is important to distinguish uterine lesions from other lesions occurring in the pelvic cavity for the proper management. The primary radiological evaluation of uterine lesions is performed using transvaginal ultrasonography, and if the lesion is too large or shows atypical benign imaging findings, magnetic resonance imaging should be performed. Analyzing radiological findings of uterine lesions through a pattern recognition approach can help establish the accurate diagnosis and treatment plan. In this pictorial assay, we describe imaging characteristics of various lesions arising from the uterus and evaluate them based on the pattern recognition approach.

Primary Colonic Epithelioid Angiosarcoma with Hepatic Metastasis: A Case Report.

Colonic angiosarcoma is an extremely rare and aggressive malignant tumor with poor prognosis. We report a case of colonic epithelioid angiosarcoma with colonic obstruction and rapidly progressive hepatic metastasis in a 44-year-old female. Abdominal CT revealed a heterogeneously enhancing irregular mass in the ascending colon, causing proximal bowel distension. The patient underwent surgery, and histopathological examination revealed a poorly differentiated carcinoma. A follow-up liver dynamic MRI after 4 months revealed newly developed diffusely scattered numerous small nodules in both hepatic lobes with peripheral and nodular marked arterial hyperenhancement, raising the suspicion of hepatic angiosarcoma. A pathologic second opinion was obtained, and additional immunohistochemistry revealed colonic epithelioid angiosarcoma. The patient showed progressive hepatic metastasis on follow-up abdominal CT after 6 months and died 8 months after initial diagnosis. We describe an educational case of colonic angiosarcoma, a rare malignant tumor, with rapidly progressive hepatic metastasis that showed radiologic findings suggestive of angiosarcoma and enabled a re-diagnosis for proper treatment and prognosis prediction.

Clinical feasibility of accelerated diffusion weighted imaging of the abdomen with deep learning reconstruction: Comparison with conventional diffusion weighted imaging.

PURPOSE: To assess the clinical feasibility of accelerated deep learning-reconstructed diffusion weighted imaging (DWI) and to compare its image quality and acquisition time with those of conventional DWI. METHODS: Seventy-four consecutive patients who underwent 3 T abdominal magnetic resonance imaging (MRI) were retrospectively enrolled. DWI were acquired using both conventional DWI and DWI with deep-learning reconstruction (DL DWI). Image quality (overall image quality, anatomic sharpness and details, artifacts, noise, and lesion conspicuity) was scored by two radiologists and compared between two DWI sequences. The apparent diffusion coefficient (ADC) was measured in six locations of the liver parenchyma and focal lesions and compared between two DWI sequences. RESULTS: The mean acquisition time for the DL DWI (216.87 ± 49.23 sec) was significantly shorter (P < 0.001) than for conventional DWI (358.69 ± 105.93 sec). DL DWI achieved higher scores than conventional DWI for all qualitative image quality parameters (P < 0.001). DL DWI had a more homogeneous distribution of ADC values throughout the liver, except for the left superior section, compared with conventional DWI. The standard deviations of the ADC values for all hepatic areas were significantly lower in DL DWI than in conventional DWI (all, P < 0.001). The ADC values for the liver parenchyma and focal hepatic lesions were lower in DL DWI than in conventional DWI. CONCLUSIONS: DL DWI is a feasible acquisition technique in clinical routines and provides improved image quality and simultaneously significant reduction in scan time compared with conventional DWI.

Clinical Feasibility of Shear Wave Dispersion Slope for Noninvasive Diagnosis of Nonalcoholic Steatohepatitis in Patients With Morbid Obesity: Preliminary Results Using US Shear Wave Elastography.

ABSTRACT: We aimed to investigate the clinical feasibility of shear wave dispersion slope for assessing nonalcoholic steatohepatitis (NASH) in patients with morbid obesity before bariatric surgery.This prospective study collected data from 25 participants who received liver biopsy during bariatric surgery between February 2019 and December 2020. All participants underwent ultrasonography shear wave elastography before surgery and shear wave speed and shear wave dispersion slope were measured. Liver specimens were evaluated by 1 pathologist scored histologically for nonalcoholic fatty liver disease (NAFLD). Ultrasonography measurements were compared according to histopathologic findings. Diagnostic performance in differentiating NASH from NAFLD was evaluated using the area under the receiver operating characteristic curve (AUC). Median shear wave speed (1.48 vs 1.62 m/s, P = 0.014) and dispersion slope (8.40 vs 11.80 [m/s]/kHz, P = 0.004) were higher in NASH group than in NAFLD group. Shear wave dispersion slope tended to increase step by step as the severity of activity grade (P = 0.032) and hepatic fibrosis (P = 0.015) increased. The AUC of shear wave dispersion slope for differentiating NASH from NAFLD (AUC, 0.83; 95% confidence intervals, 0.66-1.00) was higher than that of shear wave speed (AUC, 0.78; 95% CI, 0.60-0.97), although it did not reach statistical significance (P = 0.729). Shear wave dispersion slope could be a feasible tool for assessing NASH in patients with morbid obesity.

Acute Ectopic Pancreatitis Mimicking Peptic Ulcer Disease: A Case Report.

BACKGROUND: The ectopic pancreas is an anatomically separate pancreatic tissue from normal glands with its own vascular and ductal system; it is most commonly found in the upper gastrointestinal tract. The ectopic pancreas is usually asymptomatic, but it can present with symptoms associated with complications, including bleeding, inflammation, and neoplasm without abnormalities in the normal pancreas. CASE PRESENTATION: We report a 31-year-old female with acute ectopic pancreatitis involving gastric antrum and proximal duodenum mimicking peptic ulcer disease, without pancreatitis in the normal pancreas. CONCLUSION: Ectopic pancreatitis is a rare condition and can mimic more common diseases depending on the anatomical location.

Clinical Feasibility of High-Resolution Contrast-Enhanced Dynamic T1-Weighted Magnetic Resonance Imaging of the Upper Abdomen Using Compressed Sensing.

OBJECTIVE: The objective of this study was to evaluate the clinical feasibility of high-resolution contrast-enhanced dynamic T1-weighted imaging (T1WI) using compressed sensing (CS) in magnetic resonance imaging. METHODS: This study retrospectively included 35 patients who underwent dynamic T1WI using volumetric interpolated breath-hold examination (VIBE) with CS reconstruction (CS-VIBE) and 35 patients with conventional VIBE for comparison. Two observers assessed the liver and pancreas edges, hepatic artery, motion artifacts, and overall image quality. Quantitative analysis was performed by measuring signal intensity and image noise. RESULTS: The results showed that CS-VIBE achieved significantly better anatomic delineation of the liver and pancreas edges and hepatic artery clarity than VIBE (P < 0.001). There were no significant differences in motion artifacts in dynamic phases and overall image quality. The signal intensities and INs of CS-VIBE were higher than VIBE. CONCLUSIONS: High-resolution dynamic T1WI using CS provides better anatomic delineation with comparable or better overall image quality than conventional VIBE.

Modified Reduced Field-of-View Diffusion-Weighted Magnetic Resonance Imaging of the Prostate: Comparison With Reduced Field-of-View Imaging and Single Shot Echo-Planar Imaging.

OBJECTIVE: The objective of this study was to compare the image quality and apparent diffusion coefficient (ADC) of diffusion-weighted imaging (DWI) with modified reduced field of view (FOV) based on 2-dimensional (2D)-selective radiofrequency excitations by tilting the excitation plane in prostate with reduced FOV using parallel-transmit-accelerated 2D-selective radiofrequency excitation and single-shot echo planar imaging (ssEPI). METHODS: Fifty patients who underwent multiparametric magnetic resonance imaging including 3 DWIs were included. Two observers independently performed qualitative image analyses using 5-point scale. Apparent diffusion coefficient measurements were performed for quantitative analysis. RESULTS: Modified reduced FOV provided the highest qualitative scores for all categories compared with reduced FOV and ssEPI (P < 0.000). Both reduced FOV DWIs showed higher ADC values compared with ssEPI (P < 0.001); however, the ADC ratios between the lesion and peripheral zone were not significantly different (all P > 0.05). CONCLUSIONS: The modified reduced FOV DWI showed better overall image quality, differentiability of anatomic regions, and lesion conspicuity with fewer artifacts compared with DWI with reduced FOV and ssEPI.

Reproducibility and diagnostic performance of the vascular index of superb microvascular imaging in real-time breast ultrasonography for evaluating breast masses.

PURPOSE: This study aimed to evaluate the reproducibility and diagnostic performance of a quantitative parameter of superb microvascular imaging (SMI) in real-time breast ultrasonography (US) for differentiating benign from malignant breast masses. METHODS: Eighty-seven breast masses in 75 patients who underwent both B-mode US and SMI before US-guided core needle biopsy were included in this study. Two radiologists performed B-mode US and measured the vascular index (VI) of SMI respectively for each lesion in real time. Intraobserver and interobserver agreements were analyzed for the VI of SMI. The diagnostic performance of B-mode US using the Breast Imaging Reporting and Database System lexicon and combined use with the VI of SMI was evaluated compared to pathology. RESULTS: The median VI of malignant masses (n=32) was significantly higher than that of benign masses (n=55) (7.6% and 2.6%, respectively; P<0.001). The intraobserver agreement for VI was excellent regardless of the pathology, size, or depth of the lesion. The interobserver agreement for VI was excellent regardless of the presence of a measurement interval. The interobserver agreement for the final diagnostic decision was improved by combining B-mode US and VI (κ=0.883) in comparison with B-mode US only (κ=0.617). Adding VI led to significant improvements in the specificity (87.2% vs. 52.7%, 83.6% vs. 49.0%), accuracy (89.7% vs. 69.3%, 84.0% vs. 65.9%) and positive predictive value (81.5% vs. 55.1%, 75.6% vs. 52.6%) of B-mode US for both observers compared with B-mode US alone (all, P=0.001). CONCLUSION: The VI of SMI for real-time breast US is highly reproducible and leads to improved diagnostic performance for differentiating between benign and malignant breast lesions in combination with B-mode US.

A pancreatic hemorrhagic pseudocyst with pseudoaneurysm and the role of doppler ultrasonography: a case report.

Hemorrhagic pseudocysts with pseudoaneurysms are a rare and fatal complication of chronic pancreatitis due to the erosion of pancreatic to peripancreatic arteries. The timing of the rupture cannot be accurately predicted, but prompt diagnosis and management are essential to prevent further bleeding. We describe the case of a 68-year-old man who presented acute epigastric pain and anemia and had a history of chronic pancreatitis with a pseudocyst. A biliary and pancreas MRI showed an enlarged size of a known pancreatic pseudocyst with internal high signal intensity material. Color-Doppler ultrasonography showed pulsating signals in the pseudocyst, and our final diagnosis was a pseudoaneurysm in the pancreatic hemorrhagic pseudocyst. The pseudoaneurysm was successfully treated with coil embolization of the feeding artery. We report this case of a rare complication of chronic pancreatitis to show that color-Doppler ultrasound is a non-invasive and effective diagnostic tool for pseudoaneurysm, which enables early detection and prompt treatment without the need for invasive diagnostic modalities.

Differentiation between stercoral perforation and colorectal cancer perforation.

OBJECTIVE: To determine the computed tomography (CT) signs associated with stercoral perforation and colorectal cancer perforation. MATERIALS AND METHODS: From May 2003 to Feb. 2015, all surgically and pathologically confirmed patients with stercoral perforation (n=8, mean age 68.3 years) or colon cancer perforation (n=11, mean age 66.3 years) were retrospectively reviewed by two board-certified radiologists blinded to the proven diagnosis. The following CT findings were evaluated and recorded for each patient: wall thickness of the distal colon adjacent to perforation site, pattern of the colon wall thickening and enhancement, length of the thickened bowel wall, presence of fecaloma, degree of proximal colon dilatation, and pericolonic inflammation or presence of pericolonic abscess, and number of enlarged pericolonic lymph nodes. These findings were correlated with the pathologic diagnosis. RESULTS: The mean thickness of the distal colonic wall adjacent to the perforation site was 13.6 mm in patients with colorectal cancer perforation and 5.1 mm with stercoral perforation, which was statistically different. There was a significant correlation between colorectal cancer perforation and eccentric wall thickening (p<0.01). CT findings of layered enhancing wall thickening (p<0.01) and the presence of fecaloma in the proximal colon (p<0.01) were significant findings for stercoral perforation. Patients with colorectal cancer displayed more pericolonic lymph nodes (mean 2.27, p<0.05). CONCLUSION: Fecaloma in the proximal colon and layered enhancing wall thickening adjacent to perforation site are likely due to stercoral perforation. Eccentric bowel wall thickening at the distal portion of the perforation site with many enlarged pericolonic lymph nodes is most likely due to colorectal cancer perforation.

A pancreatic hemorrhagic pseudocyst with pseudoaneurysm and the role of doppler ultrasonography: a case report

SUMMARY Hemorrhagic pseudocysts with pseudoaneurysms are a rare and fatal complication of chronic pancreatitis due to the erosion of pancreatic to peripancreatic arteries. The timing of the rupture cannot be accurately predicted, but prompt diagnosis and management are essential to prevent further bleeding. We describe the case of a 68-year-old man who presented acute epigastric pain and anemia and had a history of chronic pancreatitis with a pseudocyst. A biliary and pancreas MRI showed an enlarged size of a known pancreatic pseudocyst with internal high signal intensity material. Color-Doppler ultrasonography showed pulsating signals in the pseudocyst, and our final diagnosis was a pseudoaneurysm in the pancreatic hemorrhagic pseudocyst. The pseudoaneurysm was successfully treated with coil embolization of the feeding artery. We report this case of a rare complication of chronic pancreatitis to show that color-Doppler ultrasound is a non-invasive and effective diagnostic tool for pseudoaneurysm, which enables early detection and prompt treatment without the need for invasive diagnostic modalities.

Differentiation between stercoral perforation and colorectal cancer perforation

SUMMARY OBJECTIVE: To determine the computed tomography (CT) signs associated with stercoral perforation and colorectal cancer perforation. MATERIALS AND METHODS: From May 2003 to Feb. 2015, all surgically and pathologically confirmed patients with stercoral perforation (n=8, mean age 68.3 years) or colon cancer perforation (n=11, mean age 66.3 years) were retrospectively reviewed by two board-certified radiologists blinded to the proven diagnosis. The following CT findings were evaluated and recorded for each patient: wall thickness of the distal colon adjacent to perforation site, pattern of the colon wall thickening and enhancement, length of the thickened bowel wall, presence of fecaloma, degree of proximal colon dilatation, and pericolonic inflammation or presence of pericolonic abscess, and number of enlarged pericolonic lymph nodes. These findings were correlated with the pathologic diagnosis. RESULTS: The mean thickness of the distal colonic wall adjacent to the perforation site was 13.6 mm in patients with colorectal cancer perforation and 5.1 mm with stercoral perforation, which was statistically different. There was a significant correlation between colorectal cancer perforation and eccentric wall thickening (p<0.01). CT findings of layered enhancing wall thickening (p<0.01) and the presence of fecaloma in the proximal colon (p<0.01) were significant findings for stercoral perforation. Patients with colorectal cancer displayed more pericolonic lymph nodes (mean 2.27, p<0.05). CONCLUSION: Fecaloma in the proximal colon and layered enhancing wall thickening adjacent to perforation site are likely due to stercoral perforation. Eccentric bowel wall thickening at the distal portion of the perforation site with many enlarged pericolonic lymph nodes is most likely due to colorectal cancer perforation.

RESUMO OBJETIVO: Determinar os sinais de CT associados à perfuração estercoral e perfuração do câncer colorretal. MÉTODOS: De maio de 2003 a fevereiro de 2015, todos os pacientes cirurgicamente e patologicamente confirmados com perfuração estercoral (n = 8, idade média de 68,3 anos) ou perfuração de câncer de cólon (n = 11, idade média de 66,3 anos) foram revisados retrospectivamente por dois radiologistas certificados por placa cegados ao diagnóstico comprovado. Os seguintes achados CT foram avaliados e gravados para cada paciente: espessura da parede do cólon distal adjacente ao local da perfuração, padrão de espessamento e realce da parede do cólon, comprimento da parede intestinal espessada, presença de fecaloma, grau de dilatação do cólon proximal e inflamação pericolônica ou presença de abscesso pericolônico e número de linfonodos pericolônicos aumentados. Esses achados foram correlacionados com o diagnóstico patológico. RESULTADOS: A espessura média da parede colônica distal adjacente ao local de perfuração foi de 13,6 mm em pacientes com perfuração de câncer colorretal e 5,1 mm com perfuração estercoral, que foi estatisticamente diferente. Houve uma correlação significativa entre a perfuração do câncer colorretal e o espessamento da parede excêntrica (p < 0,01). Os achados de CT de espessamento de parede aprimorada em camadas (p < 0,01) e presença de fecaloma no cólon proximal (p < 0,01) foram achados significativos para perfuração estercoral. Os pacientes com câncer colorretal apresentaram mais linfonodos pericolônicos (média 2,27, p < 0,05). CONCLUSÃO: O fecaloma no cólon proximal e o espessamento da parede que aumenta a camada adjacente ao local da perfuração são provavelmente devidos à perfuração estereocálica. O espessamento da parede intestinal excêntrica na porção distal do local da perfuração com muitos gânglios linfáticos pericolônicos aumentados é provavelmente a perfuração do câncer colorretal.

Low-Tube-Voltage CT Urography Using Low-Concentration-Iodine Contrast Media and Iterative Reconstruction: A Multi-Institutional Randomized Controlled Trial for Comparison with Conventional CT Urography.

Objective: To compare the image quality of low-tube-voltage and low-iodine-concentration-contrast-medium (LVLC) computed tomography urography (CTU) with iterative reconstruction (IR) with that of conventional CTU. Materials and Methods: This prospective, multi-institutional, randomized controlled trial was performed at 16 hospitals using CT scanners from various vendors. Patients were randomly assigned to the following groups: 1) the LVLC-CTU (80 kVp and 240 mgI/mL) with IR group and 2) the conventional CTU (120 kVp and 350 mgI/mL) with filtered-back projection group. The overall diagnostic acceptability, sharpness, and noise were assessed. Additionally, the mean attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) in the urinary tract were evaluated. Results: The study included 299 patients (LVLC-CTU group: 150 patients; conventional CTU group: 149 patients). The LVLC-CTU group had a significantly lower effective radiation dose (5.73 ± 4.04 vs. 8.43 ± 4.38 mSv) compared to the conventional CTU group. LVLC-CTU showed at least standard diagnostic acceptability (score ≥ 3), but it was non-inferior when compared to conventional CTU. The mean attenuation value, mean SNR, CNR, and FOM in all pre-defined segments of the urinary tract were significantly higher in the LVLC-CTU group than in the conventional CTU group. Conclusion: The diagnostic acceptability and quantitative image quality of LVLC-CTU with IR are not inferior to those of conventional CTU. Additionally, LVLC-CTU with IR is beneficial because both radiation exposure and total iodine load are reduced.

Tuberculous peritonitis following intestinal perforation in malignancy.

Tuberculous peritonitis is one of the most common causes of exudative ascites, especially in the young, and is an important cause of extra-pulmonary disease. However, tuberculous peritonitis is challenging to diagnose because there are no pathognomonic clinical features or imaging findings. Therefore, it is commonly misdiagnosed as another type of peritoneal disease, especially so in elderly patients with malignant disease. In this report, we described two cases of tuberculous peritonitis that were observed after intestinal perforation in elderly patients with malignancies. These diagnoses were established by laparoscopic peritoneal biopsy or AFB cultures of the ascitic fluid. Both patients were treated with anti-TB medications.

Benign versus life-threatening causes of pneumatosis intestinalis: differentiating CT features.

OBJECTIVE: To assess the diagnostic performance of CT findings in differentiating causes of pneumatosis intestinalis (PI), including benign and life-threatening causes. METHODS: All CT reports containing the word "pneumatosis" were queried from June 1st, 2006 to May 31st, 2015. A total of 42 patients with PI were enrolled (mean age, 63.4 years; 23 males and 19 females) and divided into two groups on based on electronic medical records: a benign group (n=24) and a life-threatening group (n=18). Two radiologists reviewed CT images and evaluated CT findings including bowel distension, the pattern of bowel wall enhancement, bowel wall defect, portal venous gas (PVG), mesenteric venous gas (MVG), extraluminal free air, and ascites. RESULTS: CT findings including bowel distension, decreased bowel wall enhancement, PVG, and ascites were more commonly identified in the life-threatening group (all p<0.05). All cases with PVG were included in the life-threatening group (8/18 patients, 44.4%). Bowel wall defect, extraluminal free air, and mesenteric venous gas showed no statistical significance between both groups. CONCLUSION: PI and concurrent PVG, bowel distension, decreased bowel wall enhancement, or ascites were significantly associated with life-threatening causes and unfavorable prognosis. Thus, evaluating ancillary CT features when we encountered PI would help us characterize the causes of PI and determine the appropriate treatment option.

Breast Lesions in Children and Adolescents: Diagnosis and Management.

Pediatric breast disease is uncommon, and primary breast carcinoma in children is extremely rare. Therefore, the approach used to address breast lesions in pediatric patients differs from that in adults in many ways. Knowledge of the normal imaging features at various stages of development and the characteristics of breast disease in the pediatric population can help the radiologist to make confident diagnoses and manage patients appropriately. Most breast diseases in children are benign or associated with breast development, suggesting a need for conservative treatment. Interventional procedures might affect the developing breast and are only indicated in a limited number of cases. Histologic examination should be performed in pediatric patients, taking into account the size of the lesion and clinical history together with the imaging findings. A core needle biopsy is useful for accurate diagnosis and avoidance of irreparable damage in pediatric patients. Biopsy should be considered in the event of abnormal imaging findings, such as non-circumscribed margins, complex solid and cystic components, posterior acoustic shadowing, size above 3 cm, or an increase in mass size. A clinical history that includes a risk factor for malignancy, such as prior chest irradiation, known concurrent cancer not involving the breast, or family history of breast cancer, should prompt consideration of biopsy even if the lesion has a probably benign appearance on ultrasonography.

Benign versus life-threatening causes of pneumatosis intestinalis: differentiating CT features

SUMMARY OBJECTIVE: To assess the diagnostic performance of CT findings in differentiating causes of pneumatosis intestinalis (PI), including benign and life-threatening causes. METHODS: All CT reports containing the word "pneumatosis" were queried from June 1st, 2006 to May 31st, 2015. A total of 42 patients with PI were enrolled (mean age, 63.4 years; 23 males and 19 females) and divided into two groups on based on electronic medical records: a benign group (n=24) and a life-threatening group (n=18). Two radiologists reviewed CT images and evaluated CT findings including bowel distension, the pattern of bowel wall enhancement, bowel wall defect, portal venous gas (PVG), mesenteric venous gas (MVG), extraluminal free air, and ascites. RESULTS: CT findings including bowel distension, decreased bowel wall enhancement, PVG, and ascites were more commonly identified in the life-threatening group (all p<0.05). All cases with PVG were included in the life-threatening group (8/18 patients, 44.4%). Bowel wall defect, extraluminal free air, and mesenteric venous gas showed no statistical significance between both groups. CONCLUSION: PI and concurrent PVG, bowel distension, decreased bowel wall enhancement, or ascites were significantly associated with life-threatening causes and unfavorable prognosis. Thus, evaluating ancillary CT features when we encountered PI would help us characterize the causes of PI and determine the appropriate treatment option.

RESUMO OBJETIVO: Avaliar o desempenho diagnóstico dos achados CT em causas diferenciadoras da pneumatose intestinal (PI), incluindo causas benignas e que ameaçam a vida. MÉTODOS: Todos os relatórios CT contendo a palavra "pneumatose" foram questionados de 10 de junho de 2006 a 31 de maio de 2015. Um total de 42 pacientes com PI foi matriculado (idade média 63,4 anos, 23 do sexo masculino e 19 do sexo feminino) e divididos em dois grupos na base de registros médicos elétricos: grupo benigno, n = 24 e grupo com risco de vida, n = 18. Dois radiologistas analisaram as imagens da CT e avaliaram seus achados, incluindo distensão intestinal, padrão de realce da parede intestinal, defeito da parede intestinal, gás venoso portal (PVG), gás venoso mesentérico (MVG), ar extraluminal e ascite. RESULTADOS: Achados CT, incluindo distensão intestinal, diminuição do realce da parede intestinal. PVG e ascite foram mais comumente identificados em grupo com risco de vida (todos p < 0,05, respectivamente). Todos os casos com PVG foram incluídos em grupo com risco de vida (8/18 pacientes, 44,4%). Defeito da parede do intestino, ar livre extraluminal e gás venoso mesentérico não mostraram significância estatística entre dois grupos. CONCLUSÃO: PI e PVG concorrente, distensão intestinal, diminuição do aumento da parede do intestino ou ascites foram significativamente associados com causas que ameaçaram a vida e prognóstico desfavorável. Portanto, avaliar os recursos de CT auxiliares quando encontramos PI nos ajudaria a caracterizar as causas de PI e determinar a opção de tratamento apropriada.

Visibility of bony structures around hip prostheses in dual-energy CT: With or without metal artefact reduction software.

INTRODUCTION: The development of dual-energy CT and metal artefact reduction software provides a further chance of reducing metal-related artefacts. However, there have been only a few studies regarding whether MARs practically affect visibility of structures around a metallic hip prosthesis on post-operative CT evaluation. METHODS: Twenty-seven patients with 42 metallic hip prostheses underwent DECT. The datasets were reconstructed with 70, 90 and 110 keV with and without MARs. The areas were classified into 10 zones according to the reference zone. All the images were reviewed in terms of the severity of the beam-hardening artefacts, differentiation of the bony cortex and trabeculae and visualization of trabecular patterns with a three-point scale. The metallic screw diameter was measured in the acetabulum with 110 keV images. RESULTS: The scores were the worst on 70 keV images without MARs [mean scores:1.84-4.22 (p < 0.001-1.000)]. The structures in zone II were best visualized on 110 keV (p < 0.001-0.011, mean scores: 2.86-5.22). In other zones, there is general similarity in mean scores whether applying MARs or not (p < 0.001-0.920). The mean diameter of the screw was 5.85 mm without MARs and 3.44 mm with MARs (mean reference diameter: 6.48 mm). CONCLUSION: The 110 keV images without MARs are best for evaluating acetabular zone II. The visibility of the bony structures around the hip prosthesis is similar in the other zones with or without MARs regardless of keV. MARS may not be needed for the evaluation of the metallic hip prosthesis itself at sufficient high-energy levels; however, MARS still has a role in the evaluation of other soft tissues around the prosthesis.

Tuberculous peritonitis following intestinal perforation in malignancy

SUMMARY Tuberculous peritonitis is one of the most common causes of exudative ascites, especially in the young, and is an important cause of extra-pulmonary disease. However, tuberculous peritonitis is challenging to diagnose because there are no pathognomonic clinical features or imaging findings. Therefore, it is commonly misdiagnosed as another type of peritoneal disease, especially so in elderly patients with malignant disease. In this report, we described two cases of tuberculous peritonitis that were observed after intestinal perforation in elderly patients with malignancies. These diagnoses were established by laparoscopic peritoneal biopsy or AFB cultures of the ascitic fluid. Both patients were treated with anti-TB medications.