Mike McBiles | University of California, San Francisco (original) (raw)

Papers by Mike McBiles

Journal of Nuclear Medicine, Jun 1, 1998

Seminars in Nuclear Medicine, Jul 31, 1995

Clinical Nuclear Medicine, 1996

Seminars in Nuclear Medicine, 1994

Seminars in Nuclear Medicine, 1994

Annals of Vascular Surgery, 1990

Lymphoscintigraphy has been very useful in determination of lymphatic abnormalities. However, the... more Lymphoscintigraphy has been very useful in determination of lymphatic abnormalities. However, the radioactive isotopes used have been investigational and difficult to obtain. The purpose of this study was to examine patients with extremity edema by lymphoscintigraphy using a radioactive colloid readily available in our nuclear pharmacy, Technetium 99m sulfur minicolloid. Forty limbs in 20 patients were evaluated using Technetium 99m sulfur minicoiloid iymphoscintigraphy. All patients had lower extremity edema initially attributed to a venous or lymphatic etiology. There were 12 patients with normal bilateral studies. Seven patients exhibited unilateral obstruction to lymphatic flow, and one had unilateral enhanced flow of lymph. Those with normal studies included five patients with nonspecific edema, four with varicosities, and one patient each with acute deep vein thrombosis, chylous ascites, and excision of the greater saphenous vein for arterial bypass grafting. Five patients with obstructed patterns had previous arterial bypass procedures, one had trauma to the extremity, and one had lymphedema tarda. The one enhanced lymphoscintigraphic pattern was seen in a patient with acute cellulitis. All patients had Doppler venous examinations and other studies included strain gauge phlethysmography, venograms, computed tomography, magnetic resonance imaging, and ultrasound. As with other scintigraphic imaging agents used to study lymphatic flow, Technetium 99m provides clinically useful information in evaluating the swollen extremity noninvasively. (Ann Vasc Surg 1990;4:255-259).

Seminars in Nuclear Medicine, 1995

Since the introduction of technetium-99m (99mTc) sestamibi (hexakis-2-methoxyisobutyl isonitrile)... more Since the introduction of technetium-99m (99mTc) sestamibi (hexakis-2-methoxyisobutyl isonitrile) as a parathyroid imaging agent in 1989, many investigators using several different imaging protocols have reported uniformly excellent results for localization of parathyroid adenomas. Exact localization of hyperplastic parathyroid glands has not met with as much success. However, the results of multiple comparative studies suggest that the diagnostic utility of sestamibi protocols equals or exceeds other noninvasive, nonscintigraphic imaging strategies, including high-resolution ultrasound, computed tomography, and magnetic resonance imaging. Two different, but not necessarily mutually exclusive imaging strategies have been used: subtraction imaging using iodine-123 (123I) or 99mTc sodium pertechnetate as the thyroid agent, and sestamibi dual-phase imaging, which takes advantage of differential washout of sestamibi from thyroid and parathyroid tissue. Sestamibi subtraction imaging has been shown to have greater sensitivity for abnormal parathyroid glands compared with thallium-201 subtraction imaging using pooled data, 87% versus 71%, respectively. Dual-phase sestamibi imaging protocols are much more variable in their conduct and have a much greater variability in sensitivity, 43% to 91%, but with a pooled sensitivity of 73%. Data suggest that dual phase techniques are at least as sensitive, and in optimized protocols, superior to, thallium-201 subtraction techniques. This superiority is attributed to the favorable washout kinetics of sestamibi and the superior imaging characteristics of the 99mTc label. Specificity and positive predictive value for both sestamibi techniques are very high, typically greater than 90% and at least equal to thallium-subtraction protocols, although specificity may be slightly lower for sestamibi subtraction techniques. Therefore, sestamibi protocols are the scintigraphic procedure of choice for parathyroid imaging. Dual-phase sestamibi protocols are more robust and lend themselves to single photon emission computer tomography (SPECT) imaging, and may be followed sequentially by subtraction techniques if results are inconclusive. Despite the excellent results of sestamibi parathyroid imaging, it is unclear whether this accuracy can compete with the even better success of an experienced surgeon in initial surgeries for hyperparathyroidism, and routine preoperative imaging before initial surgery is still controversial. However, sestamibi parathyroid imaging is an excellent addition to a correlative imaging approach in reoperations for persistent and recurrent hyperparathyroidism.

Journal of Vascular Surgery, 1997

This study was conducted to investigate and illustrate the use of Indium In-111 pentetreotide sci... more This study was conducted to investigate and illustrate the use of Indium In-111 pentetreotide scintigraphy as it applies to carotid body tumors (CBT). Localization has relied primarily on ultrasonography, computed tomography, and magnetic resonance imaging with angiographic confirmation. These methods only assess the cervical bifurcation without providing an evaluation of metastasis in patients without symptoms or recurrence in patients after surgery. Indium In-111 pentetreotide scintigraphy was used in five patients with a diagnosis of CBT. Four patients were evaluated after surgical excision for evidence of tumor recurrence. One patient was evaluated before excision for diagnostic confirmation. No evidence of tumor recurrence was demonstrated in the four patients who had undergone previous CBT excision. One of these patients had increased activity in the pituitary, later confirmed as an enlarged pituitary without evidence of an adenoma with computed tomography. The diagnosis of CBT was confirmed in the patient evaluated before surgery. This patient also had increased activity in the occipital region, confirmed as the site of previous ischemia on computed tomography. Indium In-111 pentetreotide scintigraphy is a new innovative method for viewing neuroendocrine tumors. Its potential lies not only in tumor localization but also in identification of recurrent tumor at the operative site and metastatic disease.

Journal of Digital Imaging, 1997

Radiographic correlation is essential for many of the examinations performed in nuclear medicine.... more Radiographic correlation is essential for many of the examinations performed in nuclear medicine. The purpose of this study was to evaluate the impact of a picture archiving and communications system (PACS) on the function and efficiency of a nuclear medicine department at a tertiary care institution. We evaluated 250 consecutive noncardiac nuclear medicine imaging examinations and asked the interpreting physician the following questions: (1) Was PACS used in the interpretation of the study? (2) Did the use of PACS expedite examination completion or aid in study interpretation? And (3) Did the use of PACS permit a definitive diagnosis to be made? PACS was accessed for correlative radiographic images in 155 of the 250 (62%) nuclear medicine examinations. Images available on PACS for review aided in study interpretation in 74% (115 of 155) of cases. The use of PACS was thought to expedite examination completion in 55% (86 of 155) of cases. The system was accessed but not operational in only 1% of cases (2 of 155). PACS provides reliable, rapid access to multimodality correlative radiographic images that aid in the interpretation of nuclear medicine examinations. Such systems also increase the efficiency of a nuclear medicine service by allowing timely and conclusive interpretations to be made.

Clinical Nuclear Medicine, 1996

Journal of Digital Imaging, 2000

As radiology departments become increasingly reliant on picture archiving and communication syste... more As radiology departments become increasingly reliant on picture archiving and communication systems, they become more vulnerable to computer downtime that can paralyze a smoothly running department. The experiences and strategies developed during various types of picture archiving and communication system (PACS) downtime in a large radiology department that has completely converted to soft copy interpretation in all modalities except mammography are presented. Because these failures can be minimized but not eliminated, careful planning is necessary to minimize their impact.

Journal of Nuclear Medicine, Jun 1, 1998

Seminars in Nuclear Medicine, Jul 31, 1995

Clinical Nuclear Medicine, 1996

Seminars in Nuclear Medicine, 1994

Seminars in Nuclear Medicine, 1994

Annals of Vascular Surgery, 1990

Lymphoscintigraphy has been very useful in determination of lymphatic abnormalities. However, the... more Lymphoscintigraphy has been very useful in determination of lymphatic abnormalities. However, the radioactive isotopes used have been investigational and difficult to obtain. The purpose of this study was to examine patients with extremity edema by lymphoscintigraphy using a radioactive colloid readily available in our nuclear pharmacy, Technetium 99m sulfur minicolloid. Forty limbs in 20 patients were evaluated using Technetium 99m sulfur minicoiloid iymphoscintigraphy. All patients had lower extremity edema initially attributed to a venous or lymphatic etiology. There were 12 patients with normal bilateral studies. Seven patients exhibited unilateral obstruction to lymphatic flow, and one had unilateral enhanced flow of lymph. Those with normal studies included five patients with nonspecific edema, four with varicosities, and one patient each with acute deep vein thrombosis, chylous ascites, and excision of the greater saphenous vein for arterial bypass grafting. Five patients with obstructed patterns had previous arterial bypass procedures, one had trauma to the extremity, and one had lymphedema tarda. The one enhanced lymphoscintigraphic pattern was seen in a patient with acute cellulitis. All patients had Doppler venous examinations and other studies included strain gauge phlethysmography, venograms, computed tomography, magnetic resonance imaging, and ultrasound. As with other scintigraphic imaging agents used to study lymphatic flow, Technetium 99m provides clinically useful information in evaluating the swollen extremity noninvasively. (Ann Vasc Surg 1990;4:255-259).

Seminars in Nuclear Medicine, 1995

Since the introduction of technetium-99m (99mTc) sestamibi (hexakis-2-methoxyisobutyl isonitrile)... more Since the introduction of technetium-99m (99mTc) sestamibi (hexakis-2-methoxyisobutyl isonitrile) as a parathyroid imaging agent in 1989, many investigators using several different imaging protocols have reported uniformly excellent results for localization of parathyroid adenomas. Exact localization of hyperplastic parathyroid glands has not met with as much success. However, the results of multiple comparative studies suggest that the diagnostic utility of sestamibi protocols equals or exceeds other noninvasive, nonscintigraphic imaging strategies, including high-resolution ultrasound, computed tomography, and magnetic resonance imaging. Two different, but not necessarily mutually exclusive imaging strategies have been used: subtraction imaging using iodine-123 (123I) or 99mTc sodium pertechnetate as the thyroid agent, and sestamibi dual-phase imaging, which takes advantage of differential washout of sestamibi from thyroid and parathyroid tissue. Sestamibi subtraction imaging has been shown to have greater sensitivity for abnormal parathyroid glands compared with thallium-201 subtraction imaging using pooled data, 87% versus 71%, respectively. Dual-phase sestamibi imaging protocols are much more variable in their conduct and have a much greater variability in sensitivity, 43% to 91%, but with a pooled sensitivity of 73%. Data suggest that dual phase techniques are at least as sensitive, and in optimized protocols, superior to, thallium-201 subtraction techniques. This superiority is attributed to the favorable washout kinetics of sestamibi and the superior imaging characteristics of the 99mTc label. Specificity and positive predictive value for both sestamibi techniques are very high, typically greater than 90% and at least equal to thallium-subtraction protocols, although specificity may be slightly lower for sestamibi subtraction techniques. Therefore, sestamibi protocols are the scintigraphic procedure of choice for parathyroid imaging. Dual-phase sestamibi protocols are more robust and lend themselves to single photon emission computer tomography (SPECT) imaging, and may be followed sequentially by subtraction techniques if results are inconclusive. Despite the excellent results of sestamibi parathyroid imaging, it is unclear whether this accuracy can compete with the even better success of an experienced surgeon in initial surgeries for hyperparathyroidism, and routine preoperative imaging before initial surgery is still controversial. However, sestamibi parathyroid imaging is an excellent addition to a correlative imaging approach in reoperations for persistent and recurrent hyperparathyroidism.

Journal of Vascular Surgery, 1997

This study was conducted to investigate and illustrate the use of Indium In-111 pentetreotide sci... more This study was conducted to investigate and illustrate the use of Indium In-111 pentetreotide scintigraphy as it applies to carotid body tumors (CBT). Localization has relied primarily on ultrasonography, computed tomography, and magnetic resonance imaging with angiographic confirmation. These methods only assess the cervical bifurcation without providing an evaluation of metastasis in patients without symptoms or recurrence in patients after surgery. Indium In-111 pentetreotide scintigraphy was used in five patients with a diagnosis of CBT. Four patients were evaluated after surgical excision for evidence of tumor recurrence. One patient was evaluated before excision for diagnostic confirmation. No evidence of tumor recurrence was demonstrated in the four patients who had undergone previous CBT excision. One of these patients had increased activity in the pituitary, later confirmed as an enlarged pituitary without evidence of an adenoma with computed tomography. The diagnosis of CBT was confirmed in the patient evaluated before surgery. This patient also had increased activity in the occipital region, confirmed as the site of previous ischemia on computed tomography. Indium In-111 pentetreotide scintigraphy is a new innovative method for viewing neuroendocrine tumors. Its potential lies not only in tumor localization but also in identification of recurrent tumor at the operative site and metastatic disease.

Journal of Digital Imaging, 1997

Radiographic correlation is essential for many of the examinations performed in nuclear medicine.... more Radiographic correlation is essential for many of the examinations performed in nuclear medicine. The purpose of this study was to evaluate the impact of a picture archiving and communications system (PACS) on the function and efficiency of a nuclear medicine department at a tertiary care institution. We evaluated 250 consecutive noncardiac nuclear medicine imaging examinations and asked the interpreting physician the following questions: (1) Was PACS used in the interpretation of the study? (2) Did the use of PACS expedite examination completion or aid in study interpretation? And (3) Did the use of PACS permit a definitive diagnosis to be made? PACS was accessed for correlative radiographic images in 155 of the 250 (62%) nuclear medicine examinations. Images available on PACS for review aided in study interpretation in 74% (115 of 155) of cases. The use of PACS was thought to expedite examination completion in 55% (86 of 155) of cases. The system was accessed but not operational in only 1% of cases (2 of 155). PACS provides reliable, rapid access to multimodality correlative radiographic images that aid in the interpretation of nuclear medicine examinations. Such systems also increase the efficiency of a nuclear medicine service by allowing timely and conclusive interpretations to be made.

Clinical Nuclear Medicine, 1996

Journal of Digital Imaging, 2000

As radiology departments become increasingly reliant on picture archiving and communication syste... more As radiology departments become increasingly reliant on picture archiving and communication systems, they become more vulnerable to computer downtime that can paralyze a smoothly running department. The experiences and strategies developed during various types of picture archiving and communication system (PACS) downtime in a large radiology department that has completely converted to soft copy interpretation in all modalities except mammography are presented. Because these failures can be minimized but not eliminated, careful planning is necessary to minimize their impact.