Ultrasound is an important and low cost imaging modality used to study the internal organs of human body and blood flow through blood vessels. It uses high frequency sound waves to acquire images of internal organs. It is used to screen normal, benign and malignant tissues of various organs. Healthy and malignant tissues generate different echoes for ultrasound. Hence, it provides useful information about the potential tumor tissues that can be analyzed for diagnostic purposes before therapeutic procedures. Ultrasound images are affected with speckle noise due to an air gap between the transducer probe and the body. The challenge is to design and develop robust image preprocessing, segmentation and feature extraction algorithms to locate the tumor region and to extract subtle information from isolated tumor region for diagnosis. This information can be revealed using a scale space technique such as the Discrete Wavelet Transform (DWT). It decomposes an image into images at different scales using low pass and high pass filters. These filters help to identify the detail or sudden changes in intensity in the image. These changes are reflected in the wavelet coefficients. Various texture, statistical and image based features can be extracted from these coefficients. The extracted features are subjected to statistical analysis to identify the significant features to discriminate normal and malignant ultrasound images using supervised classifiers. This paper presents a review of wavelet techniques used for preprocessing, segmentation and feature extraction of breast, thyroid, ovarian and prostate cancer using ultrasound images.
Ultrasound examinations were done to evaluate clinically palpable abdominal masses in 125 children. The examinations were normal in 21 patients. In 15 patients, the clinically palpable masses were actually anterior abdominal wall abscesses or hematomas. Final diagnosis was available in 87 of 89 patients with intraabdominal masses detected on ultrasound. The majority (71%) were retroperitoneal masses where two-thirds were of renal origin. Ultrasound diagnosis was correct in 68 patients (78%). All cases of hydronephrosis were correctly diagnosed based on characteristic ultrasound appearances. Correct diagnoses of all cases of adrenal hematoma, psoas abscess, liver hematoma, liver abscess and one case of liver metastases were achieved with correlation of relevant clinical information.
Primary hyperparathyroidism due to ectopic parathyroid adenomas can pose diagnostic and management challenges, especially when imaging studies have localised the lesions to different sites. We report a case of symptomatic hypercalcaemia due to a mediastinal parathyroid adenoma. Ultrasonography identified a nodule posterior to the right thyroid gland. However, computed tomography and technetium-99m sestamibi scintigraphy revealed an ectopic parathyroid adenoma located in the anterior mediastinum. The adenoma was successfully removed through a median sternotomy. However, postoperatively, the patient developed prolonged symptomatic hypocalcaemia, possibly due to suppression of the normal parathyroid gland function, although the presence of concomitant hungry bone syndrome was possible. The histopathology of the mediastinal mass was consistent with a parathyroid adenoma.
Atrial myxoma is rarely seen in practice. We report a 67-year-old female who presented with acute cardiac insufficiency and pulmonary edema. Cardiac murmur was not detected on precordial examination. Urgent echocardiography, however, revealed atrial myxoma causing mitral valve obstruction. We point out that a normal cardiac examination does not exclude atrial myxoma. The diagnosis may be delayed until significant myocardial dysfunction occurs, as reported here. The clinical presentation of cardiac myxoma is discussed, along with appropriate investigations and treatment.
Primary corneal myxoma is extremely rare. It has only been reported on 2 previous occasions. Secondary corneal myxomas are more common, arising from corneal diseases such as infective keratitis, keratoconus, and bullous keratopathy. Myxomas occur commonly in other soft tissues such as the heart, paranasal sinuses, and muscles but can rarely present in periocular structures including the conjunctiva, orbit, and eyelid. Ours is only the third case of primary corneal myxoma reported in the literature and illustrates several unusual features. These include an inferonasal location between the corneal epithelium and Bowman layer and with no relationship to the corneal stroma, rapid tumor growth over a 3-month period, and no previous ocular trauma or conjunctival pathology. The histology of this lesion has an important part to play in the management of this condition as it determines the cellular origin, establishes a benign or malignant state, and helps with treatment and prognosis. One reported case of primary corneal myxoma recurred within 2 months after local resection. This was treated with bandage soft contact lens, and no recurrence had been reported since. Our case is now 12 months post op and has had no recurrence.
Breast cancer is the most common form of cancer among women worldwide. Early detection of breast cancer can increase treatment options and patients' survivability. Mammography is the gold standard for breast imaging and cancer detection. However, due to some limitations of this modality such as low sensitivity especially in dense breasts, other modalities like ultrasound and magnetic resonance imaging are often suggested to achieve additional information. Recently, computer-aided detection or diagnosis (CAD) systems have been developed to help radiologists in order to increase diagnosis accuracy. Generally, a CAD system consists of four stages: (a) preprocessing, (b) segmentation of regions of interest, (c) feature extraction and selection, and finally (d) classification. This paper presents the approaches which are applied to develop CAD systems on mammography and ultrasound images. The performance evaluation metrics of CAD systems are also reviewed.
Matched MeSH terms: Breast Neoplasms/ultrasonography*
The aim of the study was: to obtain the profile of patients (with regards to age and family history of breast cancer) with a palpable breast mass. To determine the validity of ultrasound in the assessment of the palpable breast mass by determining the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ultrasound in distinguishing a malignant mass. To determine the most discriminating ultrasound characteristics for differentiating benign and malignant masses. Seventy patients who had fine needle aspiration cytology of a palpable breast mass were subjected to an ultrasound assessment of the mass. The ultrasound findings were classified as benign, indeterminate or malignant. These findings were then compared with either the cytology or histology results in cases that eventually had surgical excision. The age of the patients ranged from 15 to 66 years old The majority was in the third and fourth decades with an average age of 25 years. The 8 patients with a proven malignant breast mass were aged between 39 and 66 years old. They did not have any family history of breast cancer. Only 4 patients had a family history of breast carcinoma and all proved to have a benign breast lesion. Ultrasound had a sensitivity of 100%, specificity of 85.7%, positive predictive value of 50%, negative predictive value of 100% and accuracy of 87.5% for distinguishing a malignant mass. For benign masses: 93.7% had well-defined margins, 81.3% had homogenous internal echoes, 91.7% had depth-width ratio of less than 1.0 and 89% were compressible. For malignant masses: 87.5% had either ill-defined or irregular margins, 87.5% had inhomogenous internal echoes and mixed posterior echoes, and 100% were incompressible. The majority of patients with a palpable breast mass were aged below 40 years old. Most of the patients with a malignant breast mass were aged 40 years and older. Neither a positive nor a negative family history of breast cancer had any significance on outcome. Ultrasound had high sensitivity, specificity and accuracy in distinguishing a malignant mass. The most discriminating benign ultrasound characteristic was compressibility. The most discriminating malignant ultrasound characteristic was ill-defined and irregular margins.
Matched MeSH terms: Breast Neoplasms/ultrasonography*
A 6-year-old Malay boy presented with fever and abdominal pain for 2 months. Computerised tomography showed a nodular mass in the left lobe of the liver. There was also portal vein thrombosis on the left side. Serum alpha-fetoprotein was not elevated and Hepatitis B antigen was negative. Biopsy of the liver mass led to a histological diagnosis of fibrolamellar hepatocellular carcinoma. In view of extensive tumour involvement, he could not be operated on but was treated with chemotherapy. However, the tumour did not respond. While this is expected for fibrolamellar hepatocellular carcinoma, the possibility of the tumour having a component of ordinary hepatocellular carcinoma could not be excluded as the tumour was not resected. Fibrolamellar hepatocellular carcinoma is a rare histological subtype of hepatocellular carcinoma, associated with a better prognosis. It affects the younger age group and has no association with cirrhosis, hepatitis B virus infection or exposure to oral contraceptives, all of which are implicated in ordinary hepatocellular carcinoma. Serum alpha-fetoprotein level is usually within normal limits and other laboratory values are not contributory to the diagnosis. The diagnosis is usually suggested by radiographic studies viz. CT scan of the abdomen, which would show an irregular non-homogenous mass in the liver, and confirmed by histological examination. The most characteristic microscopical feature is fibrosis arranged in a lamellar fashion around polygonal and deeply eosinophilic neoplastic hepatocytes.
The sonographic and CT appearances of 9 large cavernous hemangiomas of the liver were studied. On sonography, 6 masses (67%) exhibit heterogenous echo pattern; where in 2 patients the echotexture was a mixture of hypoechoic and isoechoic areas and in 4 patients there are varying amounts of bright hyperreflective areas similar to the texture typical of small hemangiomas. The masses were predominantly hypoechoic in the remaining 3 patients (33%). Incremental bolus or bolus-infusion dynamic CT showed peripheral contrast enhancement of varying intensities and thickness in all patients. The lesions were incorrectly diagnosed as hepatomas in 4 patients, suspected as hemangiomas with a differential diagnosis of hepatomas in 4 patients and an early liver abscess in 1 patient. It is concluded that large cavernous hemangiomas of the liver do not exhibit the typical homogenous hyperreflective echotexture as exhibited by small lesions and they mimic primary and secondary hepatic neoplasms. However, the diagnosis of hemangioma should be entertained when such a mass contains bright hyperechoic areas within its heterogenous echo pattern and exhibit peripheral enhancement on contrast enhanced CT. In addition to correlation with appropriate clinical information, confirmation of diagnosis include delayed scanning during a routine incremental bolus dynamic CT, single-slice dynamic contrast enhanced CT, angiography or isotope scintigraphy and magnetic resonance imaging depending on the availability of facility.
Realtime ultrasonography with general purpose sector transducer was used to guide 87 percutaneous biopsies on 82 patients with lesions suspected to be mediastinal masses on plain chest radiographs. In seven patients who had dyspnea the biopsies were done in erect or semi-erect sitting positions. Definitive diagnosis was obtained from 66 lesions (80.5%) where 46 (70.0%) were mediastinal and the remaining 20 lesions (30.0%) arising from the lung. Of the 46 mediastinal lesions where specific diagnosis were made, 42 (91.0%) were anterior and four (0.9%) posterior mediastinal lesions. The majority of these anterior mediastinal masses were lymphomatous nodes followed by germ cell tumours whereas all four posterior mediastinal masses were neurogenic. Of the lung lesions, 19 were primary malignancies. The remaining lung lesion which was located posteriorly was cryptococcus infection. One patient developed massive hemothorax, but subsequently recovered. No significant complications were encountered in the remaining patients. Surgery was carried on 11 patients. There is correlation between definitive diagnosis from percutaneous biopsy and final diagnosis after surgery in 80% of patients. It is proposed that all percutaneous biopsies for thoracic masses which abut the chest wall and cause mediastinal widening on a plain chest radiograph be guided by ultrasound. It can be effectively accomplished with ease and safety even without the use of dedicated biopsy ultrasound probes or biopsy attachments, and on patients in erect or semi-erect positions.
This study evaluates the usefulness of measuring gastric antral thickness on conventional ultrasonography as a means of suggesting gastric antral pathology. Normal and abnormal appearances of the gastric antrum are reviewed.
The purpose of this study was to develop a risk prediction score for distinguishing benign ovarian mass from malignant tumors using CA-125, human epididymis protein 4 (HE4), ultrasound findings, and menopausal status. The risk prediction score was compared to the risk of malignancy index and risk of ovarian malignancy algorithm (ROMA).
Secondary involvement of the urinary bladder in non-Hodgkin's lymphoma is relatively common; however, primary malignant lymphoma of this organ is extremely rare. The most common type of primary bladder lymphoma is a low-grade B-cell mucosa-associated lymphoid tissue (MALT) lymphoma. We report here on the imaging findings of a primary bladder lymphoma with bone marrow infiltration.
Three children aged 3-11 years had ultrasonography of the urinary tract for the investigation of dysuria and haematuria. A bladder mass was seen in these 3 children. One child had computed tomography scan, cystoscopy and bladder biopsy because rhabdomyosarcoma was considered. The biopsy revealed an inflammatory process. The urine culture of the other 2 children revealed E. coli. On ultrasonography, the inflammatory mass may appear homogeneously hypoechoic or may contain moderate level echoes. The mucosal surface of the mass may be smooth or lobulated. It is important to consider an infective cause for a bladder mass in children because computed tomography, cystoscopy and biopsy may be avoided.
Three children with cardiac tumors are described: a 12-year-old female child who had left atrial myxoma, and two males having rhabdomyoma of the right ventricle associated with tuberous sclerosis. The child with left atrial myxoma was symptomatic and the tumour was subsequently excised. The other two children with rhabdomyoma were managed conservatively.
Fine-needle aspiration (FNA) cytology of the thyroid is usually performed on an outpatient basis. The results of FNA are operator dependent and may be affected by the lesion characteristics and the aspiration technique. In current practice ultrasound (US) is widely used to guide the needle for aspiration of nondominant nodules. Our study aimed to compare the free-hand FNA with US-guided FNA in the evaluation of thyroid nodules. A total of 91 cases of thyroid lesions were studied at the Department of Pathology, Karnataka Institute of Medical Sciences, Hubli, India. All the cases underwent free-hand and US-guided FNA. The cytological samples from both procedures were analyzed for adequacy, cytological features, and possible diagnosis. The results were correlated with histopathological diagnosis whenever possible. Of 91 aspirates, 89 were satisfactory and 2 were unsatisfactory on US-guided FNA, whereas 85 were satisfactory and 6 were unsatisfactory in free-hand FNA. Of 91 cases 68 (74.7%) were nonneoplastic lesions and 21 (23.1%) were neoplastic lesions in US-guided FNA, whereas 67 cases (73.6%) were nonneoplastic and 18 cases (19.8%) were neoplastic in free-hand FNA. Histopathological study was possible in 25 patients, among whom 15 lesions were nonneoplastic and 10 were neoplastic. Sensitivity and specificity of US-guided FNA to detect neoplastic lesions were 81.81% and 92.85%, respectively, compared with free-hand FNA, for which the sensitivity and specificity were 54.54% and 92.85%, respectively. The diagnostic accuracy of guided FNA was 88% against the 76% accuracy rate of free-hand FNA. US-guided FNA provides a better representative sample and has a higher diagnostic rate in the evaluation of thyroid lesions.
Retinoblastoma, the most common primary intraocular malignancy of childhood, usually presents in the first three years of life. Atypical presentation of retinoblastoma can masquerade as virtually any ocular or orbital pathology, which may lead to diagnostic dilemmas especially in the presence of other systemic diseases. We report a 20-month-old boy who was diagnosed with coronary aneurysm as a complication of Kawasaki disease, and presented with sudden left eye redness. His mother noticed the presence of white pupillary reflex three months earlier. Atypical acute ocular presentation secondary to Kawasaki disease was initially suspected, but the presence of multiple calcification and mild proptosis on imaging suggested characteristics of advanced retinoblastoma. Histopathological examination of the enucleated eye, which revealed a classical rosette pattern appearance, confirmed the diagnosis. Atypical presentations of retinoblastoma are usually associated with advanced disease. The presence of other systemic conditions further complicates the diagnosis. Early diagnosis is important to reduce the mortality and morbidity.
The purpose of this study was to evaluate the diagnostic value of qualitative and semi-quantitative assessment of ultrasound elastography in differentiating between benign and malignant breast lesions. This prospective study was conducted in two tertiary medical centers. Consecutive B-mode ultrasound and real-time elastographic images were obtained for 67 malignant and 101 benign breast lesions in 168 women. Four experienced radiologists analyzed B-mode ultrasound alone and B-mode ultrasound combined with elastography independently. Conventional ultrasound findings were classified according to the American College of Radiology Breast Imaging Reporting and Data System classification. The elastographic assessment was based on qualitative and semi-quantitative parameters (i.e., strain pattern, width ratio, strain ratio). The sensitivity and specificity of combined elastography and conventional ultrasound were significantly higher than that of conventional ultrasound alone. The sensitivity, specificity, positive predictive value and negative predictive value was 97%, 61.4%, 62.5% and 96.8%, respectively, for conventional ultrasound and 100%, 93%, 99% and 90%, respectively, for combined technique. The semi-quantitative assessment with strain ratio and width ratio in elastography were the most useful parameters in differentiating between benign and malignant breast lesions. Cut-off point values for width ratio of more than 1.1 and strain ratio of more than 5.6 showed a high predictive value of malignancy with specificities of 84% and 76%, respectively (p
Matched MeSH terms: Breast Neoplasms/ultrasonography*
Papillary fibroelastoma is a rare primary tumor of the heart valves. This lesion can occur on any of the valves or endothelial surface of the heart and has been detected by echocardiography, by cardiac catheterization, during open heart operations for other conditions, and at autopsy. Because of the potential for comorbidities, this tumor should be removed. We present the case of an elderly man with a diagnosis of severe mitral valve regurgitation and moderate tricuspid valve regurgitation who was suspected to have a tricuspid valve vegetation. Mitral valve replacement, tricuspid valve repair, and excision of the lesion were performed successfully. A histologic examination of the vegetation confirmed it to be a papillary fibroelastoma. We present this case to emphasize the rarity of this tumor and the importance of a correct diagnosis to avoid delaying its prompt and definitive management.