The clinical application of percutaneous transthoracic needle biopsy (PTNB) has been established ... more The clinical application of percutaneous transthoracic needle biopsy (PTNB) has been established recently owing to improved imaging capabilities, biopsy techniques and cytopathologic diagnosis. Several authors have demonstrated its extremely high accuracy for the diagnosis of malignancy. We reviewed 134 patients who had sufficient medical records and biopsy results from TCVGH and RMH. The sensitivity of PTNB in detecting malignant neoplasm in this study was 90% and the specificity was 97.7%. The overall accuracy was 91.8%. The site or size of the lesions did not exert any influence on the outcome of PTNB. The most common complications during the procedure was pneumothorax, which occurred in 20% of the patients, but only 7 needed further management. We conclude that PTNB is a relatively simple and safe procedure that can provide high diagnostic accuracy in patients with pulmonary, hilar or mediastinal masses.
A 39-year-old male patient had adenoid cystic carcinoma arising from the minor salivary gland at ... more A 39-year-old male patient had adenoid cystic carcinoma arising from the minor salivary gland at the right side of the soft palate. The tumor caused a local bony destruction of the pterygoid plate, invaded the pterygopalatine fossa and infratemporal fossa, and then spread upward into the middle cranial fossa via the foramen ovale and foramen rotundum. The primary tumor was silent and located at submucosa. The patient instead presented symptoms of intracranial tumor, such as severe headache and impairment of the 2nd and 3rd divisions of the trigeminal nerve. The anatomy of the skull base and the spreading routes of the oral tumor are discussed.
From a functional point of view, the temporomandibular joint(TMJ) is one of the most important jo... more From a functional point of view, the temporomandibular joint(TMJ) is one of the most important joints in the body. Optimal radiographic visualization is becoming increasingly important to medical and dental specialists as abnormal TMJ derangements are becoming better understood. Because the most common TMJ arthropathy is the internal derangement of TMJ, arthrography of the temporomandibular joint is widely performed in clinical practice. From January 1986 to December 1990, twenty temporomandibular joint arthrographies were performed in patients with symptoms of pain, clicking and dysfunction. We report our findings on these twenty patients who were examined by arthrography, which was conducted due to internal derangements related to meniscal dysfunction.
Nasopharyngeal carcinoma (NPC) frequently invades the skull base and spreads intracranially. Whil... more Nasopharyngeal carcinoma (NPC) frequently invades the skull base and spreads intracranially. While we used CT scans to identify NPC with skull base invasion and intracranial spread, the routes of tumor infiltration were also studied. Of the one hundred and three patients retrospectively studied, fifty-two patients had skull base bony erosion, and forty had combined intracranial spread. Fifty-one patients had no evidence of skull base bony destruction, but one of them had cavernous sinus involvement. While sphenoid sinus, foramen lacerum and clivus were the most common sites of skull base invasion, intracranial spread occured most frequently in cavernous sinus, middle cranial fossa and posterior cranial fossa. The most common route of cavernous sinus spread was through the foramen lacerum, followed by sphenoid sinus destruction. CT scan with axial and coronal sections can help us to clearly define the routes of tumor infiltration.
Aneurysmal bone cysts are benign, expansile, osteolytic lesions of the bone. All the aneurysmal b... more Aneurysmal bone cysts are benign, expansile, osteolytic lesions of the bone. All the aneurysmal bone cysts studied in this case report were observed during the 2 year period, 1989 to 1991. The patients involved had received radiographic examination: plain and magnetic resonance (MR) image; one of the patients also received a computed tomography (CT). The plain radiograph generally showed a well-defined, expansile, osteolytic lesion associated with a pathologic fracture; the CT and MR images showed a fluid-fluid level within the lesion. This paper will report the findings of fluid-fluid levels, using radiographic images, in aneurysmal bone cysts.
The benign cystic treatoma is the most common ovarian neoplasm. Its complications include torsion... more The benign cystic treatoma is the most common ovarian neoplasm. Its complications include torsion of pedicle, rupture, and malignant change. Other complications are rare. Here we presented a case of benign ovarian teratoma with direct urinary bladder invasion and hematuria occurrence which was rare reported in the literature.
Ultrasound (US), computed tomography (CT) and magnetic resonance (MR) imaging are good imaging mo... more Ultrasound (US), computed tomography (CT) and magnetic resonance (MR) imaging are good imaging modalities in detecting primary and secondary focal hepatic tumors. Fatty tissue usually produces characteristic features on these images that it can be accurately diagnosed. An echogenic reflection is usually found on sonogram and low attenuation area is presented on CT. MR image is more specific for tissue characterization. The short Ti relaxation time enables Ti weighted image to have higher signal intensity. Though T2 weighted image is sensitive in detecting focal hepatic lesion, it is not specific for differentiating fatty component. A well-encapsulated hepatoma with fatty metamorphosis was originally diagnosed as focal nodular hyperplasia after US, CT and angiographic studies. After four-year follow-up in out-patient department, an operation was done because the tumor mass was getting bigger. The pathology revealed hepatocellular carcinoma (HCC) with fatty metamorphosis and fat vacuo...
Aneurysmal bone cyst is benign, expansile, osteolytic lesion of the bone. Recently, we observed o... more Aneurysmal bone cyst is benign, expansile, osteolytic lesion of the bone. Recently, we observed one case of aneurysmal bone cyst. The patient received the radiography examinations including plain radiograph showed a well-defined, expansile, osteolytic lesion; and CT and MR images showed a fluid-fluid level within the lesion. This paper is to present some interested findings of the fluid-fluid level in the CT and MRI imagings.
Cerebral venous angioma as a rare vascular malformation has been found only 212 cases over the pa... more Cerebral venous angioma as a rare vascular malformation has been found only 212 cases over the past 30 years. We recently obeserved 16 patients with 19 cerebral venous angiomas. The majority of them were documented with angiogaphically characteristic findings of ”caput Medusae” in the venous phase except one case because of previous venous thrombosis. In our study, infratentorial venous angiomas were more common than supratentorial ones, which is different most previous Western reports. In addition, patients were predominantly female.
Lymphangioma of the spleen is an extremely rare pathological entity. We present two cases with pa... more Lymphangioma of the spleen is an extremely rare pathological entity. We present two cases with pathological proof of splenic lymphangioma and report the clinical, radiologic and sonographic findings. The first case is of a 40-year-old woman, clinically presented with asymptomatic splenomegaly. Echogram demonstrated multiloculated cystic lesions in the spleen. Computerized Tomographic scan revealed an irregular margin, low attenuation lesion with internal fine septa. The gross and microscopic findings of the excised spleen were lymphangioma, but it is difficult to classify it as cavernous or cystic type, because the pathological examination revealed, nixed cavernous and cystic type components. The second case is of a 42-year-old asymptomatic woman, multi/ocular cystic lesion of spleen was disclosed incidentally when she was receiving exploratory laparotomy because of perforation of peptic ulcer. The pathological findings of the excised spleen were characteristic of cystic lymphangiom...
Current Medical Imaging Formerly Current Medical Imaging Reviews, 2020
Background: According to the Standards for Reporting Vascular Changes on Neuroimaging, White Matt... more Background: According to the Standards for Reporting Vascular Changes on Neuroimaging, White Matter Hyperintensities (WMHs) are cerebral white matter lesions that are characterized by abnormal tissues of variable sizes and appear hyperintense in T2-weighted Magnetic Resonance (MR) measurements without cavitation (i.e., their tissue signals differ from those of Cerebrospinal Fluid or CSF). Such abnormal tissue regions are typically observed in the MR images of brains of healthy older adults and are associated with a number of geriatric neurodegenerative diseases. Explanations of the exact causes and mechanisms of these diseases remain inconclusive. Moreover, WMHs are typically identified by visual assessment and manual examination, both of which require considerable time. This brings up a need of developing a method for detecting WMHs more objectively and enabling patients to be treated early. As a consequence, damages on nerve cells can be limited and the severity of patients’ condi...
Journal of the Chinese Institute of Engineers, 2015
This study develops a volume sphering analysis (VSA) approach to tissue classification and volume... more This study develops a volume sphering analysis (VSA) approach to tissue classification and volume calculation of multispectral magnetic resonance (MR) brain images. It processes all multispectral MR image slices as an image cube while using only one set of training samples obtained from a single multispectral image slice to perform tissue classification as well as to calculate tissue volumes. In order to make a one slice set of training samples fit for all MR image slices a novel multispectral signature-specified extrapolation algorithm is particularly designed for this purpose so that the selected set of training samples can be extrapolated to create new data samples that are also applicable to other MR image slices. As a consequence, it significantly reduces the tremendous burden on radiologists for selection of training samples as well as computational cost. To further resolve instability and inconsistency issues which may be caused by training sample extrapolation, the proposed VSA also includes a support vector machine to refine training samples and develops an iterative Fisher’s linear discriminant analysis (IFLDA) to make VSA robust and insensitive to new generated training samples so as to improve the traditional slice-by-slice MR image classification. Experimental results demonstrate that VSA in conjunction with IFLDA not only performs comparably to approaches using training samples from individual image slices, but also saves significant time in selecting training samples and computational cost.
Journal of the Chinese Medical Association : JCMA, 2004
Nasopharyngeal cancer (NPC) is one of the most common cancers in Taiwan. It can spread anteriorly... more Nasopharyngeal cancer (NPC) is one of the most common cancers in Taiwan. It can spread anteriorly, laterally, posteriorly, superiorly and inferiorly. Skull base invasion is the common presentation, in up to one-third of cases. We report a rare spreading pathway of NPC, via the eustachian tube. A 44-year-old male suffered from NPC and got radiotherapy about 2 years ago. He suffered from middle ear effusion and facial nerve palsy on the right side recently. The computed tomography and magnetic resonance image could clearly depict the infiltrating tumor over the mastoid region and tympanic cavity on the right side, spreading along the eustachian tube. It could result in eustachian tube dysfunction and middle ear effusion. The nature of the right facial palsy was most likely due to tumor infiltration.
Journal of the Chinese Medical Association : JCMA, 2003
To retrospectively evaluate the efficacy and safety of emergent and prophylactic arterial emboliz... more To retrospectively evaluate the efficacy and safety of emergent and prophylactic arterial embolization for obstetric hemorrhage within the past 4 years. We retrospectively collected 21 obstetric patients with treatment of selective arterial embolization between 1999 and 2002. Two groups of patients were identified. The first group consisted of 15 patients who experienced postpartum hemorrhage and underwent emergent embolization. The second group was made up of 6 patients who underwent prophylactic embolization with risk factors of severe obstetric bleeding. They had abnormal placentation antepartum diagnosed and accepted termination of pregnancy followed by hysterectomy. In the first group, 12 of 15 cases had a favorable outcome treated by single embolization session. One patient expired 4 days after embolization due to severe disseminated intravascular coagulopathy and multiple organ failure. One retained placenta with recurrent bleeding was controlled by repeated selective arteria...
In this paper, we present an automatic beam-vector (Doppler) angle and flow velocity measurement ... more In this paper, we present an automatic beam-vector (Doppler) angle and flow velocity measurement method and implement it in pulsatile flow measurements using a clinical Doppler ultrasound system. In current clinical Doppler ultrasound flow velocity measurements, the axis of the blood vessel needs to be set manually on the B-scan image to enable the estimation of the beam-vector angle and the beam-vector angle corrected flow velocity (the actual flow velocity). In this study, an annular array transducer was used to generate a conical-shaped and symmetrically focused ultrasound beam to measure the flow velocity vectors parallel and perpendicular to the ultrasound beam axis. The beam-vector angle and flow velocity is calculated from the mode frequency (f(d)) and the maximum Doppler frequency (f(max)) of the Doppler spectrum. We develop a spectrum normalization algorithm to enable the Doppler spectrum averaging using the spectra obtained within a single cardiac cycle. The Doppler spectrum averaging process reduces the noise level in the Doppler spectrum and also enables the calculation of the beam-vector angle and flow velocity for pulsatile flows to be measured. We have verified the measurement method in vivo over a wide range of angles, from 52 degrees to 80 degrees, and the standard deviations of the measured beam-vector angles and flow velocities in the carotid artery are lower than 2.2 degrees and 12 cm/s (about 13.3%), respectively.
The clinical application of percutaneous transthoracic needle biopsy (PTNB) has been established ... more The clinical application of percutaneous transthoracic needle biopsy (PTNB) has been established recently owing to improved imaging capabilities, biopsy techniques and cytopathologic diagnosis. Several authors have demonstrated its extremely high accuracy for the diagnosis of malignancy. We reviewed 134 patients who had sufficient medical records and biopsy results from TCVGH and RMH. The sensitivity of PTNB in detecting malignant neoplasm in this study was 90% and the specificity was 97.7%. The overall accuracy was 91.8%. The site or size of the lesions did not exert any influence on the outcome of PTNB. The most common complications during the procedure was pneumothorax, which occurred in 20% of the patients, but only 7 needed further management. We conclude that PTNB is a relatively simple and safe procedure that can provide high diagnostic accuracy in patients with pulmonary, hilar or mediastinal masses.
A 39-year-old male patient had adenoid cystic carcinoma arising from the minor salivary gland at ... more A 39-year-old male patient had adenoid cystic carcinoma arising from the minor salivary gland at the right side of the soft palate. The tumor caused a local bony destruction of the pterygoid plate, invaded the pterygopalatine fossa and infratemporal fossa, and then spread upward into the middle cranial fossa via the foramen ovale and foramen rotundum. The primary tumor was silent and located at submucosa. The patient instead presented symptoms of intracranial tumor, such as severe headache and impairment of the 2nd and 3rd divisions of the trigeminal nerve. The anatomy of the skull base and the spreading routes of the oral tumor are discussed.
From a functional point of view, the temporomandibular joint(TMJ) is one of the most important jo... more From a functional point of view, the temporomandibular joint(TMJ) is one of the most important joints in the body. Optimal radiographic visualization is becoming increasingly important to medical and dental specialists as abnormal TMJ derangements are becoming better understood. Because the most common TMJ arthropathy is the internal derangement of TMJ, arthrography of the temporomandibular joint is widely performed in clinical practice. From January 1986 to December 1990, twenty temporomandibular joint arthrographies were performed in patients with symptoms of pain, clicking and dysfunction. We report our findings on these twenty patients who were examined by arthrography, which was conducted due to internal derangements related to meniscal dysfunction.
Nasopharyngeal carcinoma (NPC) frequently invades the skull base and spreads intracranially. Whil... more Nasopharyngeal carcinoma (NPC) frequently invades the skull base and spreads intracranially. While we used CT scans to identify NPC with skull base invasion and intracranial spread, the routes of tumor infiltration were also studied. Of the one hundred and three patients retrospectively studied, fifty-two patients had skull base bony erosion, and forty had combined intracranial spread. Fifty-one patients had no evidence of skull base bony destruction, but one of them had cavernous sinus involvement. While sphenoid sinus, foramen lacerum and clivus were the most common sites of skull base invasion, intracranial spread occured most frequently in cavernous sinus, middle cranial fossa and posterior cranial fossa. The most common route of cavernous sinus spread was through the foramen lacerum, followed by sphenoid sinus destruction. CT scan with axial and coronal sections can help us to clearly define the routes of tumor infiltration.
Aneurysmal bone cysts are benign, expansile, osteolytic lesions of the bone. All the aneurysmal b... more Aneurysmal bone cysts are benign, expansile, osteolytic lesions of the bone. All the aneurysmal bone cysts studied in this case report were observed during the 2 year period, 1989 to 1991. The patients involved had received radiographic examination: plain and magnetic resonance (MR) image; one of the patients also received a computed tomography (CT). The plain radiograph generally showed a well-defined, expansile, osteolytic lesion associated with a pathologic fracture; the CT and MR images showed a fluid-fluid level within the lesion. This paper will report the findings of fluid-fluid levels, using radiographic images, in aneurysmal bone cysts.
The benign cystic treatoma is the most common ovarian neoplasm. Its complications include torsion... more The benign cystic treatoma is the most common ovarian neoplasm. Its complications include torsion of pedicle, rupture, and malignant change. Other complications are rare. Here we presented a case of benign ovarian teratoma with direct urinary bladder invasion and hematuria occurrence which was rare reported in the literature.
Ultrasound (US), computed tomography (CT) and magnetic resonance (MR) imaging are good imaging mo... more Ultrasound (US), computed tomography (CT) and magnetic resonance (MR) imaging are good imaging modalities in detecting primary and secondary focal hepatic tumors. Fatty tissue usually produces characteristic features on these images that it can be accurately diagnosed. An echogenic reflection is usually found on sonogram and low attenuation area is presented on CT. MR image is more specific for tissue characterization. The short Ti relaxation time enables Ti weighted image to have higher signal intensity. Though T2 weighted image is sensitive in detecting focal hepatic lesion, it is not specific for differentiating fatty component. A well-encapsulated hepatoma with fatty metamorphosis was originally diagnosed as focal nodular hyperplasia after US, CT and angiographic studies. After four-year follow-up in out-patient department, an operation was done because the tumor mass was getting bigger. The pathology revealed hepatocellular carcinoma (HCC) with fatty metamorphosis and fat vacuo...
Aneurysmal bone cyst is benign, expansile, osteolytic lesion of the bone. Recently, we observed o... more Aneurysmal bone cyst is benign, expansile, osteolytic lesion of the bone. Recently, we observed one case of aneurysmal bone cyst. The patient received the radiography examinations including plain radiograph showed a well-defined, expansile, osteolytic lesion; and CT and MR images showed a fluid-fluid level within the lesion. This paper is to present some interested findings of the fluid-fluid level in the CT and MRI imagings.
Cerebral venous angioma as a rare vascular malformation has been found only 212 cases over the pa... more Cerebral venous angioma as a rare vascular malformation has been found only 212 cases over the past 30 years. We recently obeserved 16 patients with 19 cerebral venous angiomas. The majority of them were documented with angiogaphically characteristic findings of ”caput Medusae” in the venous phase except one case because of previous venous thrombosis. In our study, infratentorial venous angiomas were more common than supratentorial ones, which is different most previous Western reports. In addition, patients were predominantly female.
Lymphangioma of the spleen is an extremely rare pathological entity. We present two cases with pa... more Lymphangioma of the spleen is an extremely rare pathological entity. We present two cases with pathological proof of splenic lymphangioma and report the clinical, radiologic and sonographic findings. The first case is of a 40-year-old woman, clinically presented with asymptomatic splenomegaly. Echogram demonstrated multiloculated cystic lesions in the spleen. Computerized Tomographic scan revealed an irregular margin, low attenuation lesion with internal fine septa. The gross and microscopic findings of the excised spleen were lymphangioma, but it is difficult to classify it as cavernous or cystic type, because the pathological examination revealed, nixed cavernous and cystic type components. The second case is of a 42-year-old asymptomatic woman, multi/ocular cystic lesion of spleen was disclosed incidentally when she was receiving exploratory laparotomy because of perforation of peptic ulcer. The pathological findings of the excised spleen were characteristic of cystic lymphangiom...
Current Medical Imaging Formerly Current Medical Imaging Reviews, 2020
Background: According to the Standards for Reporting Vascular Changes on Neuroimaging, White Matt... more Background: According to the Standards for Reporting Vascular Changes on Neuroimaging, White Matter Hyperintensities (WMHs) are cerebral white matter lesions that are characterized by abnormal tissues of variable sizes and appear hyperintense in T2-weighted Magnetic Resonance (MR) measurements without cavitation (i.e., their tissue signals differ from those of Cerebrospinal Fluid or CSF). Such abnormal tissue regions are typically observed in the MR images of brains of healthy older adults and are associated with a number of geriatric neurodegenerative diseases. Explanations of the exact causes and mechanisms of these diseases remain inconclusive. Moreover, WMHs are typically identified by visual assessment and manual examination, both of which require considerable time. This brings up a need of developing a method for detecting WMHs more objectively and enabling patients to be treated early. As a consequence, damages on nerve cells can be limited and the severity of patients’ condi...
Journal of the Chinese Institute of Engineers, 2015
This study develops a volume sphering analysis (VSA) approach to tissue classification and volume... more This study develops a volume sphering analysis (VSA) approach to tissue classification and volume calculation of multispectral magnetic resonance (MR) brain images. It processes all multispectral MR image slices as an image cube while using only one set of training samples obtained from a single multispectral image slice to perform tissue classification as well as to calculate tissue volumes. In order to make a one slice set of training samples fit for all MR image slices a novel multispectral signature-specified extrapolation algorithm is particularly designed for this purpose so that the selected set of training samples can be extrapolated to create new data samples that are also applicable to other MR image slices. As a consequence, it significantly reduces the tremendous burden on radiologists for selection of training samples as well as computational cost. To further resolve instability and inconsistency issues which may be caused by training sample extrapolation, the proposed VSA also includes a support vector machine to refine training samples and develops an iterative Fisher’s linear discriminant analysis (IFLDA) to make VSA robust and insensitive to new generated training samples so as to improve the traditional slice-by-slice MR image classification. Experimental results demonstrate that VSA in conjunction with IFLDA not only performs comparably to approaches using training samples from individual image slices, but also saves significant time in selecting training samples and computational cost.
Journal of the Chinese Medical Association : JCMA, 2004
Nasopharyngeal cancer (NPC) is one of the most common cancers in Taiwan. It can spread anteriorly... more Nasopharyngeal cancer (NPC) is one of the most common cancers in Taiwan. It can spread anteriorly, laterally, posteriorly, superiorly and inferiorly. Skull base invasion is the common presentation, in up to one-third of cases. We report a rare spreading pathway of NPC, via the eustachian tube. A 44-year-old male suffered from NPC and got radiotherapy about 2 years ago. He suffered from middle ear effusion and facial nerve palsy on the right side recently. The computed tomography and magnetic resonance image could clearly depict the infiltrating tumor over the mastoid region and tympanic cavity on the right side, spreading along the eustachian tube. It could result in eustachian tube dysfunction and middle ear effusion. The nature of the right facial palsy was most likely due to tumor infiltration.
Journal of the Chinese Medical Association : JCMA, 2003
To retrospectively evaluate the efficacy and safety of emergent and prophylactic arterial emboliz... more To retrospectively evaluate the efficacy and safety of emergent and prophylactic arterial embolization for obstetric hemorrhage within the past 4 years. We retrospectively collected 21 obstetric patients with treatment of selective arterial embolization between 1999 and 2002. Two groups of patients were identified. The first group consisted of 15 patients who experienced postpartum hemorrhage and underwent emergent embolization. The second group was made up of 6 patients who underwent prophylactic embolization with risk factors of severe obstetric bleeding. They had abnormal placentation antepartum diagnosed and accepted termination of pregnancy followed by hysterectomy. In the first group, 12 of 15 cases had a favorable outcome treated by single embolization session. One patient expired 4 days after embolization due to severe disseminated intravascular coagulopathy and multiple organ failure. One retained placenta with recurrent bleeding was controlled by repeated selective arteria...
In this paper, we present an automatic beam-vector (Doppler) angle and flow velocity measurement ... more In this paper, we present an automatic beam-vector (Doppler) angle and flow velocity measurement method and implement it in pulsatile flow measurements using a clinical Doppler ultrasound system. In current clinical Doppler ultrasound flow velocity measurements, the axis of the blood vessel needs to be set manually on the B-scan image to enable the estimation of the beam-vector angle and the beam-vector angle corrected flow velocity (the actual flow velocity). In this study, an annular array transducer was used to generate a conical-shaped and symmetrically focused ultrasound beam to measure the flow velocity vectors parallel and perpendicular to the ultrasound beam axis. The beam-vector angle and flow velocity is calculated from the mode frequency (f(d)) and the maximum Doppler frequency (f(max)) of the Doppler spectrum. We develop a spectrum normalization algorithm to enable the Doppler spectrum averaging using the spectra obtained within a single cardiac cycle. The Doppler spectrum averaging process reduces the noise level in the Doppler spectrum and also enables the calculation of the beam-vector angle and flow velocity for pulsatile flows to be measured. We have verified the measurement method in vivo over a wide range of angles, from 52 degrees to 80 degrees, and the standard deviations of the measured beam-vector angles and flow velocities in the carotid artery are lower than 2.2 degrees and 12 cm/s (about 13.3%), respectively.
Uploads
Papers by San-Kan Lee