Rustu Turkay

Role of Diffusion-weighted MR Imaging in the Differentiation of Benign Retroperitoneal Fibrosis from Malignant Neoplasm: Preliminary Study

PURPOSE To evaluate diffusion-weighted imaging (DWI) features and signal intensity values at T2-weighted magnetic resonance (MR) imaging for differential diagnosis of benign retroperitoneal fibrosis (RPF) and plaque-like retroperitoneal malignant neoplasms. MATERIALS AND METHODS Institutional review board approval and informed consent were obtained for this retrospective study. Fifty-one patients with plaque-like confluent retroperitoneal soft-tissue masses were divided into three groups: group I, 25 patients with malignant RPF and retroperitoneal malignant neoplasm; group II, 16 patients with chronic RPF; and group III, 10 patients with active RPF. On T1-weighted (unenhanced and contrast material-enhanced), T2-weighted, and DWI (b = 1000 sec/mm(2)) images, apparent diffusion coefficient (ADC) values and quotients of postcontrast signal intensities between lesions and psoas muscle were evaluated. The χ(2) test was used to compare categorical values; one-way analysis of variance and Kruskal-Wallis tests were used to compare groups. RESULTS Overall sensitivity, specificity, and positive and negative predictive values of DWI findings were 92% (23 of 25 patients), 62% (16 of 26 patients), 70% (23 of 33 patients), and 89% (16 of 18 patients), respectively. Mean ADC values were 0.79 ± 0.19 in group I, 1.43 ± 0.16 in group II, and 0.91 ± 0.14 in group III. When comparing values, differences between groups I and II (ADC values, P < .0001; DWI quotients, P < .0001; postcontrast quotients, P = .001) and groups II and III (ADC values, P < .0001; DWI quotients, P = .016; postcontrast quotients, P = .04) were significant. There was no significant difference between groups I and III or between the three groups when T2-weighted values were compared. CONCLUSION ADC of chronic RPF was higher than that for active RPF or malignant RPF and retroperitoneal malignant neoplasm. DWI can contribute to differential diagnosis of chronic RPF and malignant neoplasms with RPF morphology. Lesions in the malignant group and active RPF group had similar enhancement patterns, while those in the chronic RPF group demonstrated less enhancement. Signal intensity values on T2-weighted images were not useful for differentiating these conditions.

Semantic Description of Liver CT Images: An Ontological Approach

Radiologists inspect CT scans and record their observations in reports to communicate with physicians. These reports may suffer from ambiguous language and inconsistencies resulting from subjective reporting styles, which present challenges in interpretation. Standardization efforts, such as the lexicon RadLex for radiology terms, aim to address this issue by developing standard vocabularies. While such vocabularies handle consistent annotation, they fall short in sufficiently processing reports for intelligent applications. To support such applications, the semantics of the concepts as well as their relationships must be modeled, for which, ontologies are effective. They enable the software to make inferences beyond what is present in the reports. This paper presents the open-source ontology ONLIRA (Ontology of the Liver for Radiology), which is developed to support such intelligent applications, such as identifying and ranking similar liver patient cases. ONLIRA is introduced in terms of its concepts, properties, and relations. Examples of real liver patient cases are provided for illustration purposes. The ontology is evaluated in terms of its ability to express real liver patient cases and address semantic queries.

Clinical experience sharing by similar case retrieval

Clinical experience sharing (CES) is a useful concept for both medical treatment and medical education purposes. One way of implementing CES is through the use of content based case retrieval (CBCR), where database of medical cases is browsed for case instances that are similar to the input query case. In this study, we introduce a new project called case retrieval in radiology (CaReRa), which aims at implementing CES for liver cases. We particularly focus on 3D liver images acquired by computed tomography (CT) and lay the foundations of a conceptual system outputting a ranked list of results for a given query case, formulated in this work as a liver lesion. A list of CT image features serves as computer generated descriptors together with user expressed annotations collected using a novel ontology of liver for radiology (ONLIRA). A two stage approach is proposed to utilize these two types of descriptors in cascade, namely semantic framing and similarity ranking. Initial retrieval performance results confirm the importance of ontology based descriptors, while also highlights the foci of future work needed to overcome the weaknesses.

Shear wave elastography: Can it be a new radiologic approach for the diagnosis of erectile dysfunction?

Introduction Erectile dysfunction (ED) is a common health problem among males, and radiology has limited use in its diagnosis and treatment. Shear wave elastography (SWE) is a new sonographic technique. In this study, we examined the significance of SWE in the diagnosis of ED. Methods The study included a total number of 70 participants. The mean age of the participants was 54.14 ± 8.03 years (range: 39 and 71 years old). We composed two groups. Group 1 had 35 patients who presented to the urology clinic in our hospital complaining of ED, and had a score of 17 or lower from the International Index of Erectile Function (IIEF) questionnaire. Group 2 consisted of 35 healthy volunteers who did not have ED. SWE measurements were performed from corpus cavernosum penis in both groups, and the results were noted. Differences between the groups were evaluated statistically. Results The difference between the mean SWE measurements of two groups (Group 1: 20.94 ± 6.23 kPa and group 2: 24.63 ± 7.58 kPa) was found to be statistically significant (p = 0.027; p < 0.05). For a cut-off value of 17.1 kPa, the SWE method has specificity, sensitivity, positive predictive value, and negative predictive value regarding diagnosis of ED as 94.29%, 34.29%, 85.71%, and 58.93%, respectively. The mean age of the groups did not show a statistically significant difference (p = 0.287; p > 0.05). Conclusions Due to its high specificity and positive predictive value, SWE can offer useful data in the radiologic evaluation of ED cases.

Evaluation of Liver, Kidney, and Spleen Elasticity in Healthy Newborns and Infants Using Shear Wave Elastography

Elasticity measurements of tissues can be valuable in the diagnosis and management of various diseases. The aim of this study was to determine the elasticity values for normal liver, kidney, and spleen of healthy newborns and infants using shear wave elastography (SWE) imaging.

Shear wave elastography findings of de Quervain tenosynovitis

OBJECTIVE Our aim was to evaluate the feasibility of using shear wave elastography (SWE) to assess first extensor compartment tendons rigidity and its alterations with tenosynovitis. MATERIALS AND METHODS We performed B-mode ultrasound and SWE to total number of 80 participants. All participants were evaluated clinically to call the diagnosis of de Quervain tenosynovitis or to rule out the diagnosis. We composed 2 groups. Group 1 included 40 healthy volunteers (33 females and 7 male participants with ages ranging from 24 to 60 years, median age was 37.5 years) and group 2 had 40 de Quervain patients (32 females and 8 male patients with ages ranging from 25 to 51 years, median age was 34 years). SWE measurements were repeated 3 times and arithmetic average was used for the final SWE value. RESULTS The median SWE value of healthy group (group 1) was 72kPa and the de Quervain patient group (group 2) was 29kPa. Two groups demonstrated statistically significant difference (p<0.001). The ROC curve analysis was performed and the SWE value of 40.5kPA was calculated as a cut-off value for the diagnosis of de Quervain tenosynovitis with 95% specificity and 85% sensitivity. CONCLUSION SWE modality can provide useful data regarding de Quervain tenosynovitis.

A rare case of epidermoid cyst of perineum: Diffusion-weighted MRI and ultrasonography findings

In the differential diagnosis of perineal cystic lesions, a wide range of lesions can be considered, but perineal epidermoid cyst is rare. We present a case of perineal epidermoid cyst, a man with a complaint of painless perianal mass who appeared at the general surgery clinic. Ultrasonographic and conventional magnetic resonance imaging (MRI) findings are noted along with the diffusion-weighted MRI findings. To our knowledge, there has been no specific study in the literature up to now focusing on the value of diffusion-weighted MRI findings in the differential diagnosis of perineal cystic lesions; this technique may be useful.

Vanishing ovarian mass: Sarcoidosis.

A woman was referred to our hospital with the working diagnosis of ovarian malignancy. While she was undergoing both clinical and radiological evaluation and monitoring, a decrease in the size of the ovarian mass was noted. After further evaluation via laboratory findings and tissue biopsy, we arrived at a final diagnosis of sarcoidosis, which is very unusual in the ovaries. Our case places emphasis on the importance of considering rare entities, such as ovarian sarcoidosis, and the importance of radiologic changes in solid ovarian mass dimensions over time.

Multi-ray medical ultrasound simulation without explicit speckle modelling

PurposeTo develop a medical ultrasound (US) simulation method using T1-weighted magnetic resonance images (MRI) as the input that offers a compromise between low-cost ray-based and high-cost realistic wave-based simulations.MethodsThe proposed method uses a novel multi-ray image formation approach with a virtual phased array transducer probe. A domain model is built from input MR images. Multiple virtual acoustic rays are emerged from each element of the linear transducer array. Reflected and transmitted acoustic energy at discrete points along each ray is computed independently. Simulated US images are computed by fusion of the reflected energy along multiple rays from multiple transducers, while phase delays due to differences in distances to transducers are taken into account. A preliminary implementation using GPUs is presented.ResultsPreliminary results show that the multi-ray approach is capable of generating view point-dependent realistic US images with an inherent Rician distributed speckle pattern automatically. The proposed simulator can reproduce the shadowing artefacts and demonstrates frequency dependence apt for practical training purposes. We also have presented preliminary results towards the utilization of the method for real-time simulations.ConclusionsThe proposed method offers a low-cost near-real-time wave-like simulation of realistic US images from input MR data. It can further be improved to cover the pathological findings using an improved domain model, without any algorithmic updates. Such a domain model would require lesion segmentation or manual embedding of virtual pathologies for training purposes.

Shear Wave Elastographic Alterations in the Kidney After Extracorporeal Shock Wave Lithotripsy: Shear Wave Elastographic Alterations in the Kidney After ESWL

Extracorporeal shock wave lithotripsy (ESWL) is a method used frequently for the treatment of renal stone disease. Although its safety is proven, there are still concerns about its unwanted effects on kidneys. In this prospective study, we aimed to evaluate renal tissue alterations with shear wave elastography (SWE) after ESWL. We also studied the correlation between SWE and resistive index (RI) changes.