Universal Liver Extraction Algorithm: An Improved Chan–Vese Model

2018 ◽  
Vol 29 (1) ◽  
pp. 237-250 ◽  
Author(s):  
Sangeeta K. Siri ◽  
Mrityunjaya V. Latte

Abstract Liver segmentation is important to speed up liver disease diagnosis. It is also useful for detection, recognition, and measurement of objects in liver images. Sufficient work has been carried out until now, but common methodology for segmenting liver image from CT scan, MRI scan, PET scan, etc., is not available. The proposed methodology is an effort toward developing a general algorithm to segment liver image from abdominal computerized tomography (CT) scan and magnetic resonance imaging (MRI) scan images. In the proposed algorithm, pixel intensity range of the liver portion is obtained by cropping a random section of the liver. Using its histogram, threshold values are calculated. Further, threshold-based segmentation is performed, which separates liver from abdominal CT scan image/abdominal MRI scan image. Noise in the liver image is reduced using median filter, and the quality of the image is improved by sigmoidal function. The image is then converted into binary image. The Chan–Vese (C–V) model demands an initial contour, which evolves outward. A novel algorithm is proposed to identify the initial contour inside the liver without user intervention. This initial contour propagates outward and continues until the boundary of the liver is identified accurately. This process terminates by itself when the entire boundary of the liver is detected. The method has been validated on CT images and MRI images. Results on the variety of images are compared with existing algorithms, which reveal its robustness, effectiveness, and efficiency.

Author(s):  
Sangeeta K. Siri ◽  
S. Pramod Kumar ◽  
Mrityunjaya V. Latte

The liver is an important organ in human body with certain variations in its edges, color, shape and pixel intensity distribution. These uncertainties may be because of various liver pathologies, hereditary or both. Along with it, liver has close proximity to its nearby organs. Hence, identifying liver in scanned images is a challenging step in image processing. This task becomes more imprecise when liver diseases are present at the edges. The liver segmentation is prerequisite for liver volumetry, computer-based surgery planning, liver surgery modelling, surgery training, 3D view generation, etc. The proposed hybrid segmentation method overcomes the problems and identifies liver boundary in Computed-Tomography (CT) scan images accurately. In this paper, the first step is to study statistics of pixel intensity distribution within liver image, and novel methodology is designed to obtain thresholds. Then, threshold-based segmentation is applied which separates the liver from abdominal CT scan images. In the second step, liver edge is corrected using improved chain code and Bresenham pixel interconnection methods. This provides a precise liver image. The initial points are located inside the liver region without user interventions. These initial points evolve outwardly using Fast Marching Method (FMM), identifying the liver boundary accurately in CT abdominal scan images.


Neurosurgery ◽  
1991 ◽  
Vol 29 (2) ◽  
pp. 223-226 ◽  
Author(s):  
Erik Van de Kelft ◽  
Michel Van Vyve

Abstract Chronic perineal pain is an often encountered problem that is difficult to evaluate. Based on a series of 17 patients in whom urological, gynecological, and anorectal pathology was excluded, the authors compared magnetic resonance imaging (MRI) with computed tomographic (CT) scan with myelography in the investigation of chronic perineal pain. After a clinical neurological examination, patients underwent radiodiagnostic imaging of both techniques. Thirteen patients (76%) had one or more sacral meningeal cysts (MC) on MRI scan, whereas CT scan with myelography of the lumbar and sacral region revealed 7 patients (41%) with sacral MC. Sacral MC may be the etiology of chronic perineal pain in many instances, and MRI scan appears to be superior to CT scan with myelography in demonstrating sacral MC. Ten patients with sacral MC were operated on with moderate to excellent results 6 months after operation. Early postoperative results are encouraging, but further follow-up and larger series are required.


2021 ◽  
Vol 28 (1) ◽  
pp. 390-395
Author(s):  
Aneesh Dhar ◽  
Elysia Donovan ◽  
Darryl Leong ◽  
Sebastien J. Hotte ◽  
Anand Swaminath

Metastatic lesions of the heart are rare but have the potential to cause significant morbidity. We describe the case of a patient with renal cell carcinoma who presented with shortness of breath and palpitations and was found to have a metastatic myocardial lesion causing arrythmia. He received stereotactic body radiation therapy (SBRT) to alleviate symptoms and provide local control. SBRT planning was executed using a four-dimensional computed tomography (4DCT) scan to account for respiratory and cardiac motion. Images from a planning magnetic resonance imaging (MRI) scan and a gated diagnostic MRI scan of the heart were fused with the 4DCT to assist with delineating the tumour. A dose of 30 Gy in five fractions was delivered without incident. The patient’s cardiac MRI at two months post-treatment showed stability of his cardiac lesion. He subsequently died of distant disease progression, without any recurrence of his cardiac symptoms. SBRT may be considered for patients who present with a symptomatic metastatic cardiac lesion.


2021 ◽  
pp. 001857872098713
Author(s):  
Janna Afanasjeva ◽  
Michael Gabay ◽  
Thomas Poznanski ◽  
Stefanie Kerns

This is an update to the 2010 article published in Hospital Pharmacy on safety concerns involving transdermal patches and magnetic resonance imaging (MRI). Since publication of the original article, new brand and generic transdermal medications have become available and notable changes regarding the presence or absence of metallic content among existing transdermal formulations occurred. To update the tables within the article, Food and Drug Administration (FDA)-approved transdermal medications through October 2020 were researched in order to determine metallic content and procedures for reapplication after MRI, if applicable. Readers should consult the prescribing information or manufacturer for the most current information on use of transdermal medications in the MRI setting. Of note, manufacturers have not evaluated the use of transdermal products while patients undergo a MRI scan.


2016 ◽  
Vol 38 (01) ◽  
pp. 056-059
Author(s):  
Carlos Pereira

AbstractThe Kernohan-Woltman notch phenomenon is a paradoxical neurological manifestation consisting of a motor deficit ipsilateral to a primary brain injury. It has been observed in patients with brain tumors and with supratentorial hematomas. It is considered a false localizing neurological sign. Magnetic resonance imaging (MRI) scan has been the test of choice. The recognition of this phenomenon is important to prevent a surgical procedure on the opposite side of the lesion. The present case report describes a case of chronic subdural hematoma with a probable finding of the Kernohan-Woltman phenomenon, and it discusses its pathophysiology, imaging findings, treatment, and prognosis.


2013 ◽  
Vol 12 (3) ◽  
pp. 23-26 ◽  
Author(s):  
Md Abdullah Al Farooq ◽  
MA Mushfiqur Rahman ◽  
Tania Tajreen ◽  
Eqramur Rahman ◽  
Md Minhajuddin Sajid ◽  
...  

Background: Carcinoma pancreas is being diagnosed increasingly with the help of conventional imaging like ultrasonography (USG), computerized tomography (CT) scan and magnetic resonance imaging (MRI).Imaging also gives the opportunity to assess resectability. In our country MRI and CT scan are not widely available and most of the pancreatic carcinoma is too advanced for curative surgical resection when diagnosed. These are unresectable carcinoma pancreas (UCP). Objectives: To evaluate the efficacy of imaging in diagnosing carcinoma pancreas and to assess resectability after comparing them with peroperative findings. Methods: This retrospective study was carried out in the department of Hepato-Biliary-Pancreatic Surgery in Bangladesh Institute for Research and Rehabilitation in Diabetic Endocrine and Metabolic disorders (BIRDEM) hospital, Dhaka, Bangladesh from July 2004 to June 2006 (2 years). After laparotomy findings and histopathological confirmation 50 patients were labeled as UCP. Among 50 patients male were 28 & female patients were 22. Imaging modalities used before surgery was assessed and compared with per operative findings. USG were done in all patients and CTscan in 45 patients. MRI was done in 08 patients suspected clinically as pancreatic carcinoma where USG /CT scan had failed to reach a conclusion. Findings of the various imaging studies regarding diagnosis and unresectability were compared with per operative findings. Results: USG was able to diagnose 42 (84%) pancreatic carcinoma patients with unresectibility in 29 (69%). Forty five patients (90%) were diagnosed by CT scan and could label 38 (84.44%) as unresectable. MRI was 100% accurate to diagnose and label the entire 08 patient as unresectable carcinoma pancreas. Cumulative multimodal preoperative imaging was 91.33% accurate in diagnosing carcinoma pancreas and could tell the features of unresectibility in 73.59% patients. Conclusion: CT scan should be the primary imaging modality for diagnosing pancreatic carcinoma and its resectability. MRI is very promising for diagnosing and assessing UCP. Multimodal imaging is better than single imaging. Chattagram Maa-O-Shishu Hospital Medical College Journal Volume 12, Issue 3, September 2013: 23-26


2015 ◽  
Vol 7 (3) ◽  
Author(s):  
Roslind Karolina Hackenberg ◽  
Arnd Von den Driesch ◽  
Dietmar Pierre König

We report the case of a 62-year-old patient with lower back pain radiating into the right leg accompanied by numbness. The pain had an acute onset and was resistant to conservative pain treatment. A magnetic resonance imaging (MRI) scan of the lumbar spine showed no degenerative discovertebral lesions, but a swelling of the nerve root supplying the affected dermatome. For pain treatment the patient received lumbar epidural infiltrations. During this treatment the patient suddenly developed a skin rash with grouped vesicular blisters on an erythematous ground. After the diagnosis of a lumbar herpes zoster and an acyclovir treatment, the patient could be discharged in an ameliorated condition. This case demonstrates the importance to consider rare causes of lumbosciatic pain and disorders and to acknowledge unspecific changes in a MRI scan.


2019 ◽  
Vol 28 (4) ◽  
pp. 517-532 ◽  
Author(s):  
Sangeeta K. Siri ◽  
Mrityunjaya V. Latte

Abstract Liver segmentation from abdominal computed tomography (CT) scan images is a complicated and challenging task. Due to the haziness in the liver pixel range, the neighboring organs of the liver have the same intensity level and existence of noise. Segmentation is necessary in the detection, identification, analysis, and measurement of objects in CT scan images. A novel approach is proposed to meet the challenges in extracting liver images from abdominal CT scan images. The proposed approach consists of three phases: (1) preprocessing, (2) CT scan image transformation to neutrosophic set, and (3) postprocessing. In preprocessing, noise in the CT scan is reduced by median filter. A “new structure” is introduced to transform a CT scan image into a neutrosophic domain, which is expressed using three membership subsets: true subset (T), false subset (F), and indeterminacy subset (I). This transform approximately extracts the liver structure. In the postprocessing phase, morphological operation is performed on the indeterminacy subset (I). A novel algorithm is designed to identify the start points within the liver section automatically. The fast marching method is applied at start points that grow outwardly to detect the accurate liver boundary. The evaluation of the proposed segmentation algorithm is concluded using area- and distance-based metrics.


2013 ◽  
pp. 60-5
Author(s):  
Sony Hilal Wicaksono ◽  
Fachmi Ahmad Muslim ◽  
Vienna Rossimarina

Seorang pasien dapat didiagnosis penyakit jantung koroner (PJK) melalui empat cara: kematian jantung mendadak, sindrom koroner akut, angina pektoris stabil paska revaskularisasi, dan hasil diagnostik noninvasif (Computed Tomography scan/CT scan koroner, Single Photon Emission Computed Tomography Myocardial Perfusion Imaging/SPECT MPI nuklir atau Magnetic Resonance Imaging/MRI)1. Pemeriksaan noninvasif memegang peranan penting, yaitu sebagai satu-satunya cara mendiagnosis PJK asimtomatik. Oleh sebab itu, pemahaman mengenai interpretasi hasil pemeriksaan noninvasif seperti CT scan koroner, SPECT MPI nuklir atau MRI kardiak dimasukkan dalam kompetensi dasar program pendidikan spesialis jantung dan pembuluh darah menurut Kolegium PERKI.


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