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Papers by Sarah Oh

Journal of Clinical Imaging Science, 2011

Orthotopic liver transplantation is an important treatment option for patients with end-stage liv... more Orthotopic liver transplantation is an important treatment option for patients with end-stage liver disease. Advances in surgical technique, along with improvements in organ preservation and immunosuppression have improved patient outcomes. Postoperative complications, however, can limit this success. Ultrasound is the primary imaging modality for evaluation of hepatic transplants, providing real-time information about vascular flow in the graft. Graft vascular complications are not uncommon, and their prompt recognition is crucial to allow for timely graft salvage. A multimodality approach including CT angiography, MRI, or conventional angiography may be necessary in cases of complex transplant vascular anatomy or when sonography and Doppler are inconclusive to diagnose the etiologies of these complications. The purpose of this article is to familiarize radiologists with the normal post-transplant vascular anatomy and the imaging appearances of the major vascular complications that may occur within the hepatic artery, portal vein, and venous outflow tract, with an emphasis on ultrasound.

ABSTRACT PURPOSE/AIM The purpose of this educational exhibit is to review the sonographic appeara... more ABSTRACT PURPOSE/AIM The purpose of this educational exhibit is to review the sonographic appearance of common and uncommon types of ectopic pregnancies and discuss surgical and medical management. Specific tips will be provided to differentiate ectopic pregnancies from its mimickers. CONTENT ORGANIZATION 1) Introduction to ectopic pregnancy and risk factors. 2) The following locations with imaging examples will be provided: a) Tubal b) Cornual c) Cervical d) Abdominal e) C-Section f) Ovarian g) Heterotopic 3) Discussion of the following pitfalls: a) Corpus luteum vs. Tubal Ectopic b) Abortion in Progress vs. Cervical Ectopic c) Gestational sac vs. Pseudosac 4) Discussion of medical and surgical management. SUMMARY Knowledge of the full imaging spectrum of ectopic pregnancies, their mimickers and technical and interpretative pearls is essential to achieve diagnostic accuracy.

Clinical Imaging, 2016

Acute hollow organ ischemia commonly presents with acute pain prompting radiologic evaluation and... more Acute hollow organ ischemia commonly presents with acute pain prompting radiologic evaluation and almost always requires urgent treatment. Despite different risk factors and anatomic differences, ischemia is commonly due to low flow states but can also be due to arterial and venous occlusion. Radiologic diagnosis is critical as many present with nonspecific symptoms. Contrast-enhanced computed tomography (CT) is the modality of choice. Magnetic resonance imaging (MRI) is preferred in suspected appendicitis in pregnant patients and is superior in biliary necrosis. This article provides a pictorial review of the CT/MRI features of hollow abdominal organ ischemia while highlighting key clinical features, pathogenesis, and management.

Clinical Imaging, 2016

Solid organ abdominal ischemia commonly presents with acute pain prompting radiologic evaluation ... more Solid organ abdominal ischemia commonly presents with acute pain prompting radiologic evaluation and often requires urgent treatment. Despite different risk factors and anatomic differences, most solid organ ischemia is due to arterial or venous occlusion and, less frequently, a low-flow state. Radiologic diagnosis is critical, as clinical presentations are often nonspecific. Contrast-enhanced computed tomography (CT) is the modality of choice (except in adnexal torsion) with magnetic resonance imaging (MRI) useful in equivocal cases or follow-up of ischemic disease. This article will provide a pictorial review of the CT and MRI features of solid abdominal organ ischemia while highlighting key clinical features, etiology, and management.

PURPOSE/AIM The purpose of this educational exhibit is to review the sonographic appearance of co... more PURPOSE/AIM The purpose of this educational exhibit is to review the sonographic appearance of common and uncommon types of ectopic pregnancies and discuss surgical and medical management. Specific tips will be provided to differentiate ectopic pregnancies from its mimickers. CONTENT ORGANIZATION 1) Introduction to ectopic pregnancy and risk factors. 2) The following locations with imaging examples will be provided: a) Tubal b) Cornual c) Cervical d) Abdominal e) C-Section f) Ovarian g) Heterotopic 3) Discussion of the following pitfalls: a) Corpus luteum vs. Tubal Ectopic b) Abortion in Progress vs. Cervical Ectopic c) Gestational sac vs. Pseudosac 4) Discussion of medical and surgical management. SUMMARY Knowledge of the full imaging spectrum of ectopic pregnancies, their mimickers and technical and interpretative pearls is essential to achieve diagnostic accuracy.

PURPOSE/AIM Ovarian cysts can be mimicked on ultrasound by less common gynecologic and non-gyneco... more PURPOSE/AIM Ovarian cysts can be mimicked on ultrasound by less common gynecologic and non-gynecologic conditions. We will discuss specific sonographic technical and interpretative pearls to differentiate these entities. Correlation with CT and MRI will be provided when necessary. CONTENT ORGANIZATION Simple/ hemorrhagic ovarian cysts Ovarian Mimics • Endometrioma • Cystic ovarian neoplasm Tubal Mimics • Hydrosalpinx/pyosalpinx/tuboovarian abscess • Ectopic pregnancy Extra-ovarian/Extra-tubal Pelvic Mimics • Peritoneal Inclusion Cyst • Paratubal/Paraovarian Cyst Non-gynecologic Mimics • Mesenteric Cyst • Urachal Cyst • Abscess, Seroma, Lymphocele • Varix • Lymph Nodes • Bladder Diverticulum • Fluid Filled Bowel SUMMARY Several less common cystic or hypoechoic pelvic masses can easily be mistaken for garden variety ovarian cysts. Attention to subtle sonographic clues and sometimes correlation with other imaging modalities is necessary to avoid misdiagnosis which can adversely affect ...

PURPOSE/AIM Adrenal cysts include epithelial, endothelial, parasitic and pseudocysts. Other adren... more PURPOSE/AIM Adrenal cysts include epithelial, endothelial, parasitic and pseudocysts. Other adrenal or extra-adrenal lesions can simulate benign adrenal cysts. This exhibit will depict CT and MRI features of adrenal cysts and their mimickers. CONTENT ORGANIZATION Examples of the following will be included but are not limited to: 1. Adrenal pseudocyst 2. Epithelial cyst 3. Endothelial Cyst/Lymphangioma 4. Infection (Parasitic cyst and Adrenal abscess) 5. Lipid rich adenoma 6. Cystic degeneration of adrenal adenoma 7. Exophytic renal cyst 8. Subdiaphragmatic bronchogenic cyst 9. Gastric fundal diverticulum 10. Cystic pheochromocytoma 11. Necrotic metastases 12. Bilateral adrenal cystic hyperplasia SUMMARY TEACHING POINTS: 1. Review classic CT and MRI appearances of benign adrenal cysts. 2. Highlight subtle imaging features of mimicking conditions. SUMMARY: Most adrenal cystic lesions are benign and require no further management. However, the radiologist must be aware of subtle imaging...

PURPOSE/AIM It is important to be familiar with the CT and MRI appearances of typical and atypica... more PURPOSE/AIM It is important to be familiar with the CT and MRI appearances of typical and atypical hepatocellular carcinoma. Entities that can mimic these malignant tumors will be presented and imaging pearls to aid in their differentiation will be highlighted. CONTENT ORGANIZATION A. Review of LI-RADS. B. Examples of the following will be included but are not limited to: 1. Typical and atypical hepatocellular carcinoma 2. Hypervascular metastases 3. Cholangiohepatoma 4. Hepatic adenoma 5. Hepatic sarcoma 6. Dysplastic nodule 7. Sclerosing hemangioma 8. Transient hepatic attenuation differences /arterioportal shunting in cirrhosis 9. Focal confluent fibrosis 10. Peliosis SUMMARY TEACHING POINTS: 1. To review LI-RADS. 2. To identify typical and atypical features of HCC. 3. To distinguish typical hepatocellular carcinoma from its mimics. 4. Highlight pitfalls and pearls to aid in accurate diagnosis of HCC and similar lesions.

PURPOSE/AIM Ischemia is a common cause of acute abdominal pain. Our objective is to review the CT... more PURPOSE/AIM Ischemia is a common cause of acute abdominal pain. Our objective is to review the CT imaging features of arterial and venous ischemia in various abdominal organ systems to aid in confident diagnosis and help guide appropriate management. Correlation with MRI and ultrasound will be provided in selected cases. CONTENT ORGANIZATION Review of key pathophysiologic facts and examples of the following will be included but are not limited to: 1. Bowel ischemia (low flow state, arterial or venous occlusion) 2. Splenic infarction 3. Gangrenous cholecystitis 4. Omental infarction and epiploic appendagitis 5. Liver infarction 6. Necrotizing pancreatitis with acute necrotic collections and walled-off necrosis 7. Renal ischemia (arterial and venous) 8. Adrenal infarction 9. Ovarian torsion 10. Post embolization and spontaneous uterine fibroid infarction SUMMARY TEACHING POINTS: 1. Review CT appearances of ischemia and infarction in various abdominal organ systems. 2. Highlight imagin...

Ultrasound in Medicine & Biology, 2015

Clinical Imaging, 2014

Ultrasound is the primary imaging modality used in the evaluation of first-trimester vaginal blee... more Ultrasound is the primary imaging modality used in the evaluation of first-trimester vaginal bleeding and pelvic pain. This article will summarize the ultrasound findings in normal first-trimester pregnancy, failed pregnancy, ectopic pregnancy, subchorionic hemorrhage, retained products of conception, and gestational trophoblastic disease. Mastery of the spectrum of sonographic findings in the normal and abnormal first-trimester pregnancy allows the radiologist to make accurate diagnoses and helps to appropriately guide patient management.

Radiology, 2006

To determine retrospectively whether relative cerebral blood volume (CBV) measurements can be use... more To determine retrospectively whether relative cerebral blood volume (CBV) measurements can be used to predict clinical response in patients with low-grade gliomas. Approval for this retrospective HIPAA-compliant study was obtained from the Institutional Board of Research Associates, with waiver of informed consent. Thirty-five patients (23 male and 12 female patients; median age, 39 years; range, 4-80 years) with histologically diagnosed low-grade gliomas (21 low-grade astrocytomas and 14 low-grade oligodendrogliomas and low-grade mixed oligoastrocytomas) were examined with dynamic susceptibility-weighted contrast material-enhanced perfusion magnetic resonance (MR) imaging. Wilcoxon tests were used to compare patients in different response categories (complete response, stable, progressive, death) with respect to baseline relative CBV. Kaplan-Meier survival curves, log-rank tests, and Weibull survival models were used to characterize and evaluate the association of baseline relative CBV with time to progression. Tumor volumes and relative CBV measurements were obtained at initial examination and follow-up. Lesions with relative CBV less than 1.75 had a median time to progression of 4620 days +/- 433 (standard deviation), and lesions with relative CBV more than 1.75 had a median time to progression of 245 days +/- 62. Patients who had an adverse event (either death or progression) had significantly higher (P = .003) relative CBV than did patients without adverse events (either complete response or stable disease). Lesions with low baseline relative CBV had stable tumor volumes at follow-up over time, whereas those with high baseline relative CBV (>1.75) had progressively increasing tumor volumes over time. Dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging can help to identify low-grade gliomas that will progress rapidly and a subset of low-grade gliomas that have a propensity for malignant transformation.

Pediatric Radiology, 2008

Background Gastric volvulus in children is uncommon, and characteristic radiographic findings mig... more Background Gastric volvulus in children is uncommon, and characteristic radiographic findings might not be recognized. Objective To present the spectrum of clinical and imaging findings, correlate the type of gastric volvulus with clinical outcome, and identify imaging findings to aid in early diagnosis. Materials and methods Medical records and imaging findings of ten children with gastric volvulus were reviewed. Imaging included abdominal radiographs, upper gastrointestinal (UGI) series, and CT. The diagnosis (organoaxial, mesenteroaxial or mixed type) was made on the UGI series (n=9) and CT (n=1), and confirmed surgically in seven children. Results Patients were classified based on presentation: four acute, four chronic, and two neonatal. All of the acute group (three mesenteroaxial and one mixed type) had abnormal radiographic findings: three spherical gastric distension, four paucity of distal gas, three elevated left hemidiaphragm, one overlapping pylorus and gastric fundus, one unusual naso-gastric tube course, and one situs inversus. All underwent emergent surgery. Three had diaphragmatic abnormalities. One had heterotaxy. Patients in the chronic group (three organoaxial, one mesenteroaxial) had long-standing symptoms. Most had associated neurologic abnormalities. In the neonatal group, organoaxial volvulus was found incidentally on the UGI series. Conclusion A spectrum of findings in gastric volvulus exists. Mesenteroaxial volvulus has greater morbidity and mortality. Radiographic findings of spherical gastric dilatation, paucity of distal gas and diaphragmatic elevation are suggestive of acute volvulus, particularly in patients with predisposing factors.

Neurosurgery, 2006

OBJECTIVE: To determine whether relative cerebral blood volume (rCBV) can predict patient outcome... more OBJECTIVE: To determine whether relative cerebral blood volume (rCBV) can predict patient outcome, specifically tumor progression, in low-grade gliomas (LGGs) and thus provide a second reference standard in the surgical and postsurgical management of LGGs. METHODS: Thirty-five patients with histologically diagnosed LGGs (21 low-grade astrocytomas and 14 low-grade oligodendrogliomas and low-grade mixed oligoastrocytomas) were studied with dynamic susceptibility contrast-enhanced perfusion magnetic resonance imaging. Wilcoxon tests were used to compare patients in different response categories (complete response, stable, progressive, death) with respect to baseline rCBV. Log-rank tests were used to evaluate the association of rCBV with survival and time to progression. Kaplan-Meier time-to-progression curves were generated. Tumor volumes and CBV measurements were obtained at the initial examination and again at follow-up to determine the association of rCBV with tumor volume progressi...

Pediatric …, 2008

Background Gastric volvulus in children is uncommon, and characteristic radiographic findings mig... more Background Gastric volvulus in children is uncommon, and characteristic radiographic findings might not be recognized. Objective To present the spectrum of clinical and imaging findings, correlate the type of gastric volvulus with clinical outcome, and ...

American Journal of Roentgenology, 2014

Although ultrasound is the primary modality used in the diagnosis of ectopic pregnancy, various f... more Although ultrasound is the primary modality used in the diagnosis of ectopic pregnancy, various forms of this condition and their complications may occasionally be further evaluated with MRI or may be incidentally detected on CT or MRI when an alternative diagnosis is suspected. Various types of ectopic pregnancy have characteristic imaging features. Radiologists should be familiar with these features and should always consider the possibility of ectopic pregnancy in the setting of hemoperitoneum or a pelvic mass in a woman of child-bearing age. Familiarity with the typical CT and MRI appearances of various forms of ectopic pregnancy facilitates prompt and accurate diagnosis and treatment.

American Journal of Roentgenology, 2013

The purpose of this article is to determine the natural history of adrenal cysts on the basis of ... more The purpose of this article is to determine the natural history of adrenal cysts on the basis of long-term imaging follow-up. This retrospective study included patients with adrenal cysts who had at least 12 months of imaging follow-up (1993-2010). Medical records were reviewed. Two radiologists reviewed imaging examinations in consensus and recorded wall thickness (thin, ≤ 3 mm; thick, > 3 mm), septations, and calcification. CT attenuation value, MRI signal intensity, the presence or absence of enhancement, and typical sonographic features were used to confirm fluid content of the lesions. Cyst wall enhancement was recorded (thin, ≤ 3 mm and smooth; thick, > 3 mm). Cyst diameter on the initial and most remote follow-up examinations was compared. The Wilcoxon matched-pairs signed rank test was applied to assess statistically significant differences in size and CT attenuation on follow-up examinations. Twenty patients with unilateral adrenal cysts (seven male and 13 female patients; mean age, 44 years; range, 10-75 years) had a mean imaging follow-up period of 64 months (range, 12-198 months). CT, MRI, and ultrasound examinations were obtained in 19, 11, and 13 patients, respectively. Cysts were diagnosed by lack of enhancement on CT or MRI in 12 patients, typical sonographic features in three patients, and combination of CT and sonographic or MRI features in five patients. Signal intensities typical for fluid were found on all MRI examinations, attenuations of less than 20 HU on 17 of 19 (89%) CT examinations, and features of either simple or mildly complicated cysts on all sonograms. Thin walls, wall calcifications, and thin septations were found in 20 (100%), 12 (60%), and four (20%) lesions, respectively. During the follow-up of 20 lesions, the median cyst diameter increased by 26.0% (interquartile range, 6.8-68.4%) in 12 (60%) patients, decreased by 32.9% (interquartile range, 7.1-42.8%) in six (30%) patients, and was unchanged in two (10%) patients. The median baseline CT attenuation values did not significantly change on follow-up CT examinations (p = 0.72). No patient developed a complication of adrenal cyst. Four patients had histologically confirmed benign adrenal cysts. Interval enlargement of an adrenal cyst is frequent and as an isolated finding does not indicate malignancy or presence of a complication. However, some adrenal cysts may decrease or remain stable in size over time.

Radiology

Materials and Methods: Approval for this retrospective HIPAA-compliant study was obtained from th... more Materials and Methods: Approval for this retrospective HIPAA-compliant study was obtained from the Institutional Board of Research Associates, with waiver of informed consent. Thirty-five patients (23 male and 12 female patients; median age, 39 years; range, 4–80 years) with ...

Journal of Clinical Imaging Science, 2011

Orthotopic liver transplantation is an important treatment option for patients with end-stage liv... more Orthotopic liver transplantation is an important treatment option for patients with end-stage liver disease. Advances in surgical technique, along with improvements in organ preservation and immunosuppression have improved patient outcomes. Postoperative complications, however, can limit this success. Ultrasound is the primary imaging modality for evaluation of hepatic transplants, providing real-time information about vascular flow in the graft. Graft vascular complications are not uncommon, and their prompt recognition is crucial to allow for timely graft salvage. A multimodality approach including CT angiography, MRI, or conventional angiography may be necessary in cases of complex transplant vascular anatomy or when sonography and Doppler are inconclusive to diagnose the etiologies of these complications. The purpose of this article is to familiarize radiologists with the normal post-transplant vascular anatomy and the imaging appearances of the major vascular complications that may occur within the hepatic artery, portal vein, and venous outflow tract, with an emphasis on ultrasound.

ABSTRACT PURPOSE/AIM The purpose of this educational exhibit is to review the sonographic appeara... more ABSTRACT PURPOSE/AIM The purpose of this educational exhibit is to review the sonographic appearance of common and uncommon types of ectopic pregnancies and discuss surgical and medical management. Specific tips will be provided to differentiate ectopic pregnancies from its mimickers. CONTENT ORGANIZATION 1) Introduction to ectopic pregnancy and risk factors. 2) The following locations with imaging examples will be provided: a) Tubal b) Cornual c) Cervical d) Abdominal e) C-Section f) Ovarian g) Heterotopic 3) Discussion of the following pitfalls: a) Corpus luteum vs. Tubal Ectopic b) Abortion in Progress vs. Cervical Ectopic c) Gestational sac vs. Pseudosac 4) Discussion of medical and surgical management. SUMMARY Knowledge of the full imaging spectrum of ectopic pregnancies, their mimickers and technical and interpretative pearls is essential to achieve diagnostic accuracy.

Clinical Imaging, 2016

Acute hollow organ ischemia commonly presents with acute pain prompting radiologic evaluation and... more Acute hollow organ ischemia commonly presents with acute pain prompting radiologic evaluation and almost always requires urgent treatment. Despite different risk factors and anatomic differences, ischemia is commonly due to low flow states but can also be due to arterial and venous occlusion. Radiologic diagnosis is critical as many present with nonspecific symptoms. Contrast-enhanced computed tomography (CT) is the modality of choice. Magnetic resonance imaging (MRI) is preferred in suspected appendicitis in pregnant patients and is superior in biliary necrosis. This article provides a pictorial review of the CT/MRI features of hollow abdominal organ ischemia while highlighting key clinical features, pathogenesis, and management.

Clinical Imaging, 2016

Solid organ abdominal ischemia commonly presents with acute pain prompting radiologic evaluation ... more Solid organ abdominal ischemia commonly presents with acute pain prompting radiologic evaluation and often requires urgent treatment. Despite different risk factors and anatomic differences, most solid organ ischemia is due to arterial or venous occlusion and, less frequently, a low-flow state. Radiologic diagnosis is critical, as clinical presentations are often nonspecific. Contrast-enhanced computed tomography (CT) is the modality of choice (except in adnexal torsion) with magnetic resonance imaging (MRI) useful in equivocal cases or follow-up of ischemic disease. This article will provide a pictorial review of the CT and MRI features of solid abdominal organ ischemia while highlighting key clinical features, etiology, and management.

PURPOSE/AIM The purpose of this educational exhibit is to review the sonographic appearance of co... more PURPOSE/AIM The purpose of this educational exhibit is to review the sonographic appearance of common and uncommon types of ectopic pregnancies and discuss surgical and medical management. Specific tips will be provided to differentiate ectopic pregnancies from its mimickers. CONTENT ORGANIZATION 1) Introduction to ectopic pregnancy and risk factors. 2) The following locations with imaging examples will be provided: a) Tubal b) Cornual c) Cervical d) Abdominal e) C-Section f) Ovarian g) Heterotopic 3) Discussion of the following pitfalls: a) Corpus luteum vs. Tubal Ectopic b) Abortion in Progress vs. Cervical Ectopic c) Gestational sac vs. Pseudosac 4) Discussion of medical and surgical management. SUMMARY Knowledge of the full imaging spectrum of ectopic pregnancies, their mimickers and technical and interpretative pearls is essential to achieve diagnostic accuracy.

PURPOSE/AIM Ovarian cysts can be mimicked on ultrasound by less common gynecologic and non-gyneco... more PURPOSE/AIM Ovarian cysts can be mimicked on ultrasound by less common gynecologic and non-gynecologic conditions. We will discuss specific sonographic technical and interpretative pearls to differentiate these entities. Correlation with CT and MRI will be provided when necessary. CONTENT ORGANIZATION Simple/ hemorrhagic ovarian cysts Ovarian Mimics • Endometrioma • Cystic ovarian neoplasm Tubal Mimics • Hydrosalpinx/pyosalpinx/tuboovarian abscess • Ectopic pregnancy Extra-ovarian/Extra-tubal Pelvic Mimics • Peritoneal Inclusion Cyst • Paratubal/Paraovarian Cyst Non-gynecologic Mimics • Mesenteric Cyst • Urachal Cyst • Abscess, Seroma, Lymphocele • Varix • Lymph Nodes • Bladder Diverticulum • Fluid Filled Bowel SUMMARY Several less common cystic or hypoechoic pelvic masses can easily be mistaken for garden variety ovarian cysts. Attention to subtle sonographic clues and sometimes correlation with other imaging modalities is necessary to avoid misdiagnosis which can adversely affect ...

PURPOSE/AIM Adrenal cysts include epithelial, endothelial, parasitic and pseudocysts. Other adren... more PURPOSE/AIM Adrenal cysts include epithelial, endothelial, parasitic and pseudocysts. Other adrenal or extra-adrenal lesions can simulate benign adrenal cysts. This exhibit will depict CT and MRI features of adrenal cysts and their mimickers. CONTENT ORGANIZATION Examples of the following will be included but are not limited to: 1. Adrenal pseudocyst 2. Epithelial cyst 3. Endothelial Cyst/Lymphangioma 4. Infection (Parasitic cyst and Adrenal abscess) 5. Lipid rich adenoma 6. Cystic degeneration of adrenal adenoma 7. Exophytic renal cyst 8. Subdiaphragmatic bronchogenic cyst 9. Gastric fundal diverticulum 10. Cystic pheochromocytoma 11. Necrotic metastases 12. Bilateral adrenal cystic hyperplasia SUMMARY TEACHING POINTS: 1. Review classic CT and MRI appearances of benign adrenal cysts. 2. Highlight subtle imaging features of mimicking conditions. SUMMARY: Most adrenal cystic lesions are benign and require no further management. However, the radiologist must be aware of subtle imaging...

PURPOSE/AIM It is important to be familiar with the CT and MRI appearances of typical and atypica... more PURPOSE/AIM It is important to be familiar with the CT and MRI appearances of typical and atypical hepatocellular carcinoma. Entities that can mimic these malignant tumors will be presented and imaging pearls to aid in their differentiation will be highlighted. CONTENT ORGANIZATION A. Review of LI-RADS. B. Examples of the following will be included but are not limited to: 1. Typical and atypical hepatocellular carcinoma 2. Hypervascular metastases 3. Cholangiohepatoma 4. Hepatic adenoma 5. Hepatic sarcoma 6. Dysplastic nodule 7. Sclerosing hemangioma 8. Transient hepatic attenuation differences /arterioportal shunting in cirrhosis 9. Focal confluent fibrosis 10. Peliosis SUMMARY TEACHING POINTS: 1. To review LI-RADS. 2. To identify typical and atypical features of HCC. 3. To distinguish typical hepatocellular carcinoma from its mimics. 4. Highlight pitfalls and pearls to aid in accurate diagnosis of HCC and similar lesions.

PURPOSE/AIM Ischemia is a common cause of acute abdominal pain. Our objective is to review the CT... more PURPOSE/AIM Ischemia is a common cause of acute abdominal pain. Our objective is to review the CT imaging features of arterial and venous ischemia in various abdominal organ systems to aid in confident diagnosis and help guide appropriate management. Correlation with MRI and ultrasound will be provided in selected cases. CONTENT ORGANIZATION Review of key pathophysiologic facts and examples of the following will be included but are not limited to: 1. Bowel ischemia (low flow state, arterial or venous occlusion) 2. Splenic infarction 3. Gangrenous cholecystitis 4. Omental infarction and epiploic appendagitis 5. Liver infarction 6. Necrotizing pancreatitis with acute necrotic collections and walled-off necrosis 7. Renal ischemia (arterial and venous) 8. Adrenal infarction 9. Ovarian torsion 10. Post embolization and spontaneous uterine fibroid infarction SUMMARY TEACHING POINTS: 1. Review CT appearances of ischemia and infarction in various abdominal organ systems. 2. Highlight imagin...

Ultrasound in Medicine & Biology, 2015

Clinical Imaging, 2014

Ultrasound is the primary imaging modality used in the evaluation of first-trimester vaginal blee... more Ultrasound is the primary imaging modality used in the evaluation of first-trimester vaginal bleeding and pelvic pain. This article will summarize the ultrasound findings in normal first-trimester pregnancy, failed pregnancy, ectopic pregnancy, subchorionic hemorrhage, retained products of conception, and gestational trophoblastic disease. Mastery of the spectrum of sonographic findings in the normal and abnormal first-trimester pregnancy allows the radiologist to make accurate diagnoses and helps to appropriately guide patient management.

Radiology, 2006

To determine retrospectively whether relative cerebral blood volume (CBV) measurements can be use... more To determine retrospectively whether relative cerebral blood volume (CBV) measurements can be used to predict clinical response in patients with low-grade gliomas. Approval for this retrospective HIPAA-compliant study was obtained from the Institutional Board of Research Associates, with waiver of informed consent. Thirty-five patients (23 male and 12 female patients; median age, 39 years; range, 4-80 years) with histologically diagnosed low-grade gliomas (21 low-grade astrocytomas and 14 low-grade oligodendrogliomas and low-grade mixed oligoastrocytomas) were examined with dynamic susceptibility-weighted contrast material-enhanced perfusion magnetic resonance (MR) imaging. Wilcoxon tests were used to compare patients in different response categories (complete response, stable, progressive, death) with respect to baseline relative CBV. Kaplan-Meier survival curves, log-rank tests, and Weibull survival models were used to characterize and evaluate the association of baseline relative CBV with time to progression. Tumor volumes and relative CBV measurements were obtained at initial examination and follow-up. Lesions with relative CBV less than 1.75 had a median time to progression of 4620 days +/- 433 (standard deviation), and lesions with relative CBV more than 1.75 had a median time to progression of 245 days +/- 62. Patients who had an adverse event (either death or progression) had significantly higher (P = .003) relative CBV than did patients without adverse events (either complete response or stable disease). Lesions with low baseline relative CBV had stable tumor volumes at follow-up over time, whereas those with high baseline relative CBV (>1.75) had progressively increasing tumor volumes over time. Dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging can help to identify low-grade gliomas that will progress rapidly and a subset of low-grade gliomas that have a propensity for malignant transformation.

Pediatric Radiology, 2008

Background Gastric volvulus in children is uncommon, and characteristic radiographic findings mig... more Background Gastric volvulus in children is uncommon, and characteristic radiographic findings might not be recognized. Objective To present the spectrum of clinical and imaging findings, correlate the type of gastric volvulus with clinical outcome, and identify imaging findings to aid in early diagnosis. Materials and methods Medical records and imaging findings of ten children with gastric volvulus were reviewed. Imaging included abdominal radiographs, upper gastrointestinal (UGI) series, and CT. The diagnosis (organoaxial, mesenteroaxial or mixed type) was made on the UGI series (n=9) and CT (n=1), and confirmed surgically in seven children. Results Patients were classified based on presentation: four acute, four chronic, and two neonatal. All of the acute group (three mesenteroaxial and one mixed type) had abnormal radiographic findings: three spherical gastric distension, four paucity of distal gas, three elevated left hemidiaphragm, one overlapping pylorus and gastric fundus, one unusual naso-gastric tube course, and one situs inversus. All underwent emergent surgery. Three had diaphragmatic abnormalities. One had heterotaxy. Patients in the chronic group (three organoaxial, one mesenteroaxial) had long-standing symptoms. Most had associated neurologic abnormalities. In the neonatal group, organoaxial volvulus was found incidentally on the UGI series. Conclusion A spectrum of findings in gastric volvulus exists. Mesenteroaxial volvulus has greater morbidity and mortality. Radiographic findings of spherical gastric dilatation, paucity of distal gas and diaphragmatic elevation are suggestive of acute volvulus, particularly in patients with predisposing factors.

Neurosurgery, 2006

OBJECTIVE: To determine whether relative cerebral blood volume (rCBV) can predict patient outcome... more OBJECTIVE: To determine whether relative cerebral blood volume (rCBV) can predict patient outcome, specifically tumor progression, in low-grade gliomas (LGGs) and thus provide a second reference standard in the surgical and postsurgical management of LGGs. METHODS: Thirty-five patients with histologically diagnosed LGGs (21 low-grade astrocytomas and 14 low-grade oligodendrogliomas and low-grade mixed oligoastrocytomas) were studied with dynamic susceptibility contrast-enhanced perfusion magnetic resonance imaging. Wilcoxon tests were used to compare patients in different response categories (complete response, stable, progressive, death) with respect to baseline rCBV. Log-rank tests were used to evaluate the association of rCBV with survival and time to progression. Kaplan-Meier time-to-progression curves were generated. Tumor volumes and CBV measurements were obtained at the initial examination and again at follow-up to determine the association of rCBV with tumor volume progressi...

Pediatric …, 2008

Background Gastric volvulus in children is uncommon, and characteristic radiographic findings mig... more Background Gastric volvulus in children is uncommon, and characteristic radiographic findings might not be recognized. Objective To present the spectrum of clinical and imaging findings, correlate the type of gastric volvulus with clinical outcome, and ...

American Journal of Roentgenology, 2014

Although ultrasound is the primary modality used in the diagnosis of ectopic pregnancy, various f... more Although ultrasound is the primary modality used in the diagnosis of ectopic pregnancy, various forms of this condition and their complications may occasionally be further evaluated with MRI or may be incidentally detected on CT or MRI when an alternative diagnosis is suspected. Various types of ectopic pregnancy have characteristic imaging features. Radiologists should be familiar with these features and should always consider the possibility of ectopic pregnancy in the setting of hemoperitoneum or a pelvic mass in a woman of child-bearing age. Familiarity with the typical CT and MRI appearances of various forms of ectopic pregnancy facilitates prompt and accurate diagnosis and treatment.

American Journal of Roentgenology, 2013

The purpose of this article is to determine the natural history of adrenal cysts on the basis of ... more The purpose of this article is to determine the natural history of adrenal cysts on the basis of long-term imaging follow-up. This retrospective study included patients with adrenal cysts who had at least 12 months of imaging follow-up (1993-2010). Medical records were reviewed. Two radiologists reviewed imaging examinations in consensus and recorded wall thickness (thin, ≤ 3 mm; thick, > 3 mm), septations, and calcification. CT attenuation value, MRI signal intensity, the presence or absence of enhancement, and typical sonographic features were used to confirm fluid content of the lesions. Cyst wall enhancement was recorded (thin, ≤ 3 mm and smooth; thick, > 3 mm). Cyst diameter on the initial and most remote follow-up examinations was compared. The Wilcoxon matched-pairs signed rank test was applied to assess statistically significant differences in size and CT attenuation on follow-up examinations. Twenty patients with unilateral adrenal cysts (seven male and 13 female patients; mean age, 44 years; range, 10-75 years) had a mean imaging follow-up period of 64 months (range, 12-198 months). CT, MRI, and ultrasound examinations were obtained in 19, 11, and 13 patients, respectively. Cysts were diagnosed by lack of enhancement on CT or MRI in 12 patients, typical sonographic features in three patients, and combination of CT and sonographic or MRI features in five patients. Signal intensities typical for fluid were found on all MRI examinations, attenuations of less than 20 HU on 17 of 19 (89%) CT examinations, and features of either simple or mildly complicated cysts on all sonograms. Thin walls, wall calcifications, and thin septations were found in 20 (100%), 12 (60%), and four (20%) lesions, respectively. During the follow-up of 20 lesions, the median cyst diameter increased by 26.0% (interquartile range, 6.8-68.4%) in 12 (60%) patients, decreased by 32.9% (interquartile range, 7.1-42.8%) in six (30%) patients, and was unchanged in two (10%) patients. The median baseline CT attenuation values did not significantly change on follow-up CT examinations (p = 0.72). No patient developed a complication of adrenal cyst. Four patients had histologically confirmed benign adrenal cysts. Interval enlargement of an adrenal cyst is frequent and as an isolated finding does not indicate malignancy or presence of a complication. However, some adrenal cysts may decrease or remain stable in size over time.

Radiology

Materials and Methods: Approval for this retrospective HIPAA-compliant study was obtained from th... more Materials and Methods: Approval for this retrospective HIPAA-compliant study was obtained from the Institutional Board of Research Associates, with waiver of informed consent. Thirty-five patients (23 male and 12 female patients; median age, 39 years; range, 4–80 years) with ...