Current Medical Imaging - Volume 17, Issue 2, 2021

Fluid-fluid levels result from the separation of two fluids of differing densities within a cavernous space with the boundary between the two layers running in a horizontal plane at 90 degrees to the direction of gravity. Magnetic resonance imaging is the most sensitive imaging modality to identify fluid-fluid levels. Although the most common bone lesions containing fluid-fluid levels are aneurysmal bone cyst and telangiectatic osteosarcoma, fluid-fluid levels can be observed in a wide variety of bone and soft tissue lesions. Therefore, fluid-fluid levels cannot be considered diagnostic of any particular type of tumor and the diagnosis should be made on the basis of other clinical, radiological and pathological findings. This article summarizes the pathophysiology and imaging characteristics of fluid-fluid levels and discusses the differential diagnosis of tumors with this imaging sign.

Background: This article represents a review of the use of image-guided cryotherapy in the treatment of musculoskeletal tumor lesions. Cryotherapy is able to induce a lethal effect on cancer cells through direct and indirect mechanisms. In this manuscript, we combined our experience with that of other authors who have published on this topic in order to provide indications on when to use cryotherapy in musculoskeletal oncology. Discussion: Image-Guided percutaneous cryotherapy is a therapeutic method now widely accepted in the treatment of patients with musculoskeletal tumors. It can be used both for palliative treatments of metastatic bone lesions and for the curative treatment of benign bone tumors, such as osteoid osteoma or osteoblastoma. In the treatment of bone metastases, cryotherapy plays a major role in alleviating or resolving disease-related pain, but it has also been demonstrated that it can have a role in local disease control. In recent years, the use of cryotherapy has also expanded for the treatment of both benign and malignant soft tissue tumors. Conclusion: Percutaneous cryotherapy can be considered a safe and effective technique in the treatment of benign and malignant musculoskeletal tumors. Cryotherapy can be considered the first option in benign tumor lesions, such as osteoid osteoma, and a valid alternative to radiofrequency ablation. In the treatment of painful bone metastases, it must be considered secondarily to other standard treatments (radiotherapy, bisphosphonate therapy, and chemotherapy) when they are no longer effective in controlling the disease or when they cannot be repeated (for example, radiotherapy).

Musculoskeletal tumors of the hand are a rare entity and are divided into skeletal and soft tissue tumors. Either category comprises benign and malignant or even intermediate tumors. Basic radiology allows an optimal resolution of bone and related soft tissue areas, ultrasound and more sophisticated radiologic tools such as scintigraphy, CT and MRI allow a more accurate evaluation of tumor extent. Enchondroma is the most common benign tumor affecting bone, whereas chondrosarcoma is the most commonly represented malignant neoplasm localized to hand bones. In the soft tissues, ganglions are the most common benign tumors and epithelioid sarcoma is the most frequently represented malignant tumor targeting hand soft tissues. The knowledge regarding diagnostic and therapeutic management of these tumors is often deriving from small case series, retrospective studies or even case reports. Evidences from prospective studies or controlled trials are limited and for this lack of clear and supported evidences, data from the medical literature on the topic are controversial, in terms of demographics, clinical presentation, diagnosis, prognosis and therapy. The correct recognition of the specific subtype and extension of the tumor through first line and second line radiology is essential for the surgeon, in order to effectively direct the therapeutic decisions.

Differentiation of malignant from benign soft tissue tumors is challenging with imaging alone, including that by magnetic resonance imaging and computed tomography. However, the accuracy of this differentiation has increased owing to the development of novel imaging technology. Detailed patient history and physical examination remain essential for differentiation between benign and malignant soft tissue tumors. Moreover, measurement only of tumor size based on Response Evaluation Criteria In Solid Tumors criteria is insufficient for the evaluation of response to chemotherapy or radiotherapy. Change in metabolic activity measured by ¹⁸F-fluorodeoxyglucose positron emission tomography or dynamic contrast enhanced-derived quantitative endpoints can more accurately evaluate treatment response compared to change in tumor size. Magnetic resonance imaging can accurately evaluate essential factors in surgical planning such as vascular or bone invasion and “tail sign”. Thus, imaging plays a critical role in the diagnosis and treatment of soft tissue tumors.

Myxofibrosarcoma is one of the most common soft tissue sarcomas in the elderly. It is characterized by an extremely high rate of local recurrence, higher than other soft tissue tumors, and a relatively low risk of distant metastases.Magnetic resonance imaging (MRI) is the imaging modality of choice for the assessment of myxofibrosarcoma, which plays a key role in the preoperative setting of these patients. MRI features associated with the high risk of local recurrence are: high myxoid matrix content (water-like appearance of the lesions), high grade of contrast enhancement and presence of an infiltrative pattern (“tail sign”). On the other hand, MRI features associated with worse sarcoma specific survival are: large size of the lesion, deep location, high grade of contrast enhancement. Recognizing the above-mentioned imaging features of myxofibrosarcoma may be helpful in stratifying the risk for local recurrence and disease-specific survival. Moreover, the surgical planning should be adjusted according to the MRI features.

Osteosarcoma of the jaws (OSJ) is a relatively rare disease, accounting for between 2% and 10% of all cases of osteosarcoma. It is morphologically and radiologically identical to the trunk and extremity variant, but distinct in several crucial aspects. The lesion is characterized by sarcomatous cells which produce a variable amount of osteoid bone. It arises centrally within the bone and can be subdivided into osteoblastic, chondroblastic and fibroblastic subtype, depending on the predominant cell type. Radiographically, these tumors display a spectrum of bone changes from well-demarcated borders to lytic bone destruction with indefinite margins and variable cortical bone erosion or, in some cases, images of sclerotic bone. Therapeutic options for OSJ include surgery, chemotherapy and radiotherapy, which are employed according to age of the patient, histological classification and localization of the tumor. Today, there is no general consensus in the treatment guidelines for the OSJ though surgery represents the key to the treatment. The main prognostic factor deeply influencing the patient’s prognosis remains the complete tumor resection with negative surgical margins. The aim of the present review is to describe state of the art regarding diagnostic and surgical treatment aspects of the primary osteosarcoma of the jaws.

In children and adolescents affected by musculoskeletal sarcomas (both soft tissue and bone sarcomas), the presence of lung metastases is a frequent complication, that should be known since the patient’s prognosis, as management, and treatment depend on it. During the staging phase, the detection of lung metastases should be sensitive and specific, and it should be carried out by minimizing the radiation exposure. To deal with this problem, imaging has reached important goals in recent years, thanks to the development of cone-beam CT or low-dose computed tomography, with some new iterative reconstruction methods, such as Veo and ASIR. Imaging is also fundamental for the possibility to perform lung biopsies under CT guidance, with less morbidity, less time-consumption, and shorter recovery time, compared to surgical biopsies.Moreover, important results have also been demonstrated in the treatment of lung metastases, due to the improvement of new mini-invasive image-guided percutaneous thermal ablation procedures, which proved to be safe and effective also in young patients.

Tumor-like lesions of the upper limb are more frequent than malignant neoplastic lesions and they represent a wide and heterogeneous group of disorders. The combination of clinical evaluation and imaging is the first pivotal step to attempt a distinction between benign and malignant masses, since there are important implications for further management, such as the requirement for conservative or interventional treatment. The classification of these pseudo tumoral lumps remains arbitrary and is still a matter of debate, currently based on a conjunct clinico-radiologic approach. In this article, we review various types of tumor-like lesions of the upper limb in terms of imaging approach and related clinic features, proponing a descriptive classification, useful in clinical practice to recognize these disorders, and to avoid unnecessary or potentially harmful procedures.

Background: Radio-frequency ablation (RFA) and Stereotactic Body Radiation Therapy (SBRT) are two emerging therapies for lung metastases. Introduction: Aliterature review was performed to evaluate the outcomes and complications of these procedures in patients with lung metastases from soft tissue sarcoma (STS). Methods: After selection, seven studies were included for each treatment encompassing a total of 424 patients: 218 in the SBRT group and 206 in the RFA group. Results: The mean age ranged from 47.9 to 64 years in the SBRT group and from 48 to 62.7 years in the RFA group. The most common histologic subtype was, in both groups, leiomyosarcoma. In the SBRT group, median overall survival ranged from 25.2 to 69 months and median disease- free interval was from 8.4 to 45 months. Two out of seven studies reported G3 and one G3 toxicity, respectively. In RFA patients, overall survival ranged from 15 to 50 months. The most frequent complication was pneumothorax. Local control showed a high percentage for both procedures. Conclusion: SBRT is recommended in patients unsuitable to surgery, in synchronous bilateral pulmonary metastases, in case of deep lesions and patients receiving high-risk systemic therapies. RFA is indicated in case of a long disease-free interval, in oligometastatic disease, when only the lung is involved, in small size lesions far from large vessels. Further large randomized studies are necessary to establish whether these treatments may also represent a reliable alternative to surgery.

Aim: FIR filter is the most widely used device in DSP applications, which is also applicable to integrate with image processing approaches. The ALU based FIR structure is applicable for various devices to increase the performance. The ALU design operation includes accumulation, subtraction, shifting, multiplication and filtering. Existing methods are designed with various multipliers like Wallace tree multiplier, DADDA multiplier, Vedic multiplier and adders like carry select adder, and carry look-ahead adder. Objective: The main objective is to reduce the area, delay and power factors since optimum VLSI circuit is employed in this paper. By these adders and multipliers, operations are independently enabling main operations in DSP. The FIR filter is designed using a MAC unit with clock regenerative comparators. Introduction: In the field of the VLSI industry, the low power, reduced time, and area-efficient designs are mostly preferred for various applications. Adders and multipliers play a vital role in VLSI circuit designs. The recent electronics industry uses a digital filter for various real-time applications. This utilizes Finite Impulse Response (FIR) and Infinite Impulse Response (IIR) filters, here the FIR filter is most stable than IIR filter. This FIR filter indicates the impulse signal into finite form and it is used mainly in DSP processors for getting high-speed. In these two ALU and FIR circuits, the adders and multiplier block’s usage is increased, it consumes much power. Methods: The proposed research work uses the clock-gating technique for reducing power consumption. Here the latch-based clock gating technique provides an efficient result. XOR-based logic circuit reduces the design complexity and utilizes the less area. Carry save accumulator is a digital adder used for addition. It provides the two set of output, which is partial sum and carry output. The ripple carry adder uses a full adder circuit for its operation. It propagates the carry value in the last bit. In addition, the combination of CSA and RCA utilizes less area, high speed and provides the better throughput. In multiplier block, the booth multiplier algorithm is used with XOR-based logic. Here this proposed FIR filter is designed for performing image filtration of retina image. This process improves the better visualization approach inthe medical field. Results: Thus, the proposed ALU based FIR filter with a latch-based clock gating technique is designed and analyzed with various parameters. Here the modified adders and multipliers are proposed for the efficiency of the system. The modified carry save adder is proposed with combining ripple carry adder logic for improving the adders’ performance. The enhanced booth multiplier is designed using add and shift method for reducing the numberof stages to calculate the result. This process is applied to perform image processing of the retina image. After designing the ALU based FIR filter structure in the VLSI environment, the image is loaded on the MATLAB as the .png format, then it is converted into a hex file, which is read from the Xilinx to perform filtering the process. Then the ‘dataout’ is converted into a binary file to obtain the result of the filtering process. The enhanced booth multiplier reduces the delay by reducing the number of stages to calculate the result. Here the clock gating technique is proposed with the latch-based design for reducing the dynamic and clock power consumption. The number of adder’s circuit in both ALU and FIR circuits is less since it improves the overall efficiency of the system. Conclusion: Thus, the proposed methodology concluded that the design and analysis of ALU based FIR filter for medical image processing give the efficient result on the way of achieving the factors such as power (Static & amp; Dynamic), Delay (Path delay) area utilization, MSE and PSNR. Here the image processing of FIR results to MSE and PSNR values, which obtained a better result than the existing VLSI based image processing works. The latch-based clock gating circuit is connected with the proposed circuit, based on the gated clock signal, it optimizes the gated circuit of the whole design since it also reduces the error and provides the efficient power report. This proposed VLSI model is simulated using Xilinx ISE 14.5 and Modelsim synthesizes it; here with the help of MATLAB, with the adaptation of the 2018a tool, the image filtering was done.

Background: Osteoporosis is a term used to represent the reduced bone density, which is caused by insufficient bone tissue production to balance the old bone tissue removal. Medical Imaging procedures such as X-Ray, Dual X-Ray and Computed Tomography (CT) scans are used widely in osteoporosis diagnosis. There are several existing procedures in practice to assist osteoporosis diagnosis, which can operate using a single imaging method. Objective: The purpose of this proposed work is to introduce a framework to assist the diagnosis of osteoporosis based on consenting all these X-Ray, Dual X-Ray and CT scan imaging techniques. The proposed work named “Aggregation of Region-based and Boundary-based Knowledge biased Segmentation for Osteoporosis Detection from X-Ray, Dual X-Ray and CT images” (ARBKSOD) is the integration of three functional modules. Methods: Fuzzy Histogram Medical Image Classifier (FHMIC), Log-Gabor Transform based ANN Training for osteoporosis detection (LGTAT) and Knowledge biased Osteoporosis Analyzer (KOA). Results: Together, all these three modules make the proposed method ARBKSOD scored the maximum accuracy of 93.11%, the highest precision value of 93.91% while processing the 6th image batch, the highest sensitivity of 92.93%, the highest specificity of 93.79% is observed during the experiment by ARBKSOD while processing the 6th image batch. The best average processing time of 10244 mS is achieved by ARBKSOD while processing the 7th image batch. Conclusion: Together, all these three modules make the proposed method ARBKSOD to produce a better result.

Introduction: The purpose of the present work was to evaluate the imaging characteristics of ⁸⁹Zr-PET in comparison with those obtained using fluorine-18 Fluorodeoxyglucose (18FFDG) PET (a gold standard tracer in PET imaging) using a small-animal NanoScan PET/CT scanner. Methods: The system’s spatial resolution, sensitivity, uniformity, and image quality were measured on a Nano Scan small-animal PET/CT scanner according to the NEMA NU4-2008 protocols. For reconstruction images, we used 2D and 3D reconstruction algorithms. The reconstruction methods included filter back projection (FBP), the ordered subsets expectation maximization (OSEM) algorithm, and the 3D Tera-Tomo algorithm, which are developed for the NanoScan small-animal PET/CT scanner. Results: The results obtained showed a significant difference in the spatial resolution for ⁸⁹Zr as compared to 22Na and 18F when using a 2D reconstruction algorithm. The spatial resolution values were much enhanced by using the 3D Tera-Tomo reconstruction for each isotope, the Full width at half maximum (FWHM) values was less than 1 for all isotopes at the center of the field of view (FOV). This difference in spatial resolution is dependent on the positron range, energy, and the reconstruction method. Conclusion: The long half-life of ⁸⁹Zr makes it an ideal positron emitter for performing immuno- PET, which is matched with the biological half-life of intact mAbs.⁸⁹Zr can also give several advantages over other long half-life positron emitters in relation to the overall imaging performance because of its relatively short positron range and simpler decay scheme. The values of ⁸⁹Zr sensitivity that were obtained in the present study were less than those of previous studies.

Aim: In this study, we aimed to find the percentage of random pathologies and abdominopelvic region anomalies that are not related to trauma in pediatric patients. Background: An abdominal assessment of an injured child usually involves computed tomography imaging of the abdomen and pelvis (CTAP) to determine the presence and size of injuries. Imaging may accidentally reveal irrelevant findings. Objective: Although the literature in adults has reviewed the frequency of discovering these random findings, few studies have been identified in the pediatric population. Methods: Data on 142 (38 female, 104 male) patients who underwent CTAP during their trauma evaluation between January 2019 and January 2020 were obtained from our level 3 pediatric trauma center records. The records and CTAP images were examined retrospectively for extra traumatic pathologies and anomalies. Results: 67 patients (47%) had 81 incidental findings. There were 17 clinically significant random findings. No potential tumors were found in this population. Conclusion: Pediatric trauma CTAP reveals random findings. For further evaluation, incidental findings should be indicated in the discharge summaries.

Background: Silent pituitary adenomas are clinically non-functional (i.e., without clinically evident pituitary hormone production). Introduction: The aim of this study was to investigate subjects with silent pituitary adenomas for possible variations in their clinical status. Methods: A total of 102 patients who had undergone surgery for pituitary adenoma and had been diagnosed with silent pituitary adenoma was included in the study. The patients’ preoperative and postoperative hormonal parameters and magnetic resonance imaging (MRI) features were collected, and pathological specimens were re-evaluated. Results: Immunohistochemistry results of the 102 patients were as follows: hormone-negative adenomas (n=35) 35.5%; FSH+LH-positivity (n=32) 31.3%; ACTH-positivity (n=11) 10.7%; α-subunit- positivity (n= 9) 8.8%; prolactin-positivity (n=8) 7.8%; GH-positivity (n=6) 5.4%; and plurihormonal adenoma (n=1). The mean sizes of SGA, SGHA, and SCA were 28.0±12.7, 30.0±16.0, and 27.7±8.9mm (p>0.05), respectively. With the exception of silent gonadotroph adenomas (SGAs), female gender dominance was shown in patients with silent growth hormone adenoma (SGHA) and silent corticotroph adenoma (SCA). Although no clinical relevance was observed in relation to hormonal excess, preoperative GH (4.21±4.6, vs. 0.27±0.36 p=0.00) was slightly more elevated in SGHA than in GH-negative adenomas. Additionally, preoperative basal ACTH values (47.3±28.7 vs. 23.9±14.4, p=0.003) were also higher in SCA compared to the other types. Our findings revealed SCAs to be of more aggressive behaviour than SGHAs and SGAs due to invasiveness in radiological imaging, their elevated re-operation, and postoperative ACTH values. Conclusion: Silent pituitary adenomas represent a challenging diagnostic tumour group. Careful initial evaluation of patients with pituitary adenomas should consider any mild signs and symptoms of functionality, particularly in cases of GH- and ACTH-secreting adenomas.