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Biomedical subjects

E S Siegelman

Publications and source records attributed to E S Siegelman.

At least 19 recordsLinked to original sources
PubMed2001

The evaluation of human breast lesions with magnetic resonance imaging and proton magnetic resonance spectroscopy.

PURPOSE: MR spectroscopy (MRS) assists in lesion characterization and diagnosis when combined with magnetic resonance imaging (MRI). Cancerous lesions demonstrate elevated composite choline levels arising from increased cellular proliferation. Our study investigated if MR spectroscopy of the breast would be useful for characterizing benign and malignant lesions. MATERIALS AND METHODS: Single voxel proton MR spectroscopy (MRS) was acquired as part of an MR imaging protocol in 38 patients referred upon surgical consultation. The MR spectra were read independently in a blinded fashion without the MR images by three spectroscopists. The MRI exam was interpreted in two settings: (a) as a clinical exam with detailed histories and results from previous imaging studies such as mammography or ultrasound included and (b) as a blinded study without prior histories or imaging results. RESULTS: Elevated choline levels were demonstrated by MRS in 19 of the 23 confirmed cancer patients. The sensitivity and specificity for determining malignancy from benign breast disease with MRS alone were 83 and 87%, respectively, while a blinded MRI review reported 95 and 86%, respectively. CONCLUSIONS: Proton MR spectroscopy provides a noninvasive, biochemical measure of metabolism. The technique can be performed in less than 10 min as part of an MRI examination. MRI in combination with MRS may improve the specificity of breast MR and thereby, influence patient treatment options. This may be particularly true with less experienced breast MRI readers. In exams where MRI and MRS agree, the additional confidence measure provided by MRS may influence the course of treatment.

Adolescent↗
PubMed2001

Imaging of hepatic steatosis.

Hepatic steatosis is a common finding encountered during cross-sectional imaging examinations. This article reviews the imaging findings of hepatic steatosis as revealed by sonography, computed tomography, magnetic resonance imaging, and magnetic resonance spectroscopy. Focal fatty sparing and focal hepatic steatosis are conditions that can create potential diagnostic challenges for the radiologist. The typical findings, distribution, and etiology of these focal processes are presented. In the setting of diffuse hepatic steatosis, hepatic mass lesions can be difficult to discern on both computed tomography and sonography, with reported decreased sensitivity and specificity of lesion detection. In such cases, magnetic resonance imaging may be the imaging procedure of choice for the detection and characterization of both hepatic steatosis and coexistent hepatic masses. Some hepatocellular neoplasms, particularly hepatic adenoma and well-differentiated hepatocellular carcinoma, can have intratumoral lipid. By demonstrating the lipid content of these masses, imaging can add specificity in characterizing them as hepatocellular in origin because nonhepatocellular neoplasms in general do not contain intracellular lipid.

Diagnostic Imaging↗
PubMed2001

Magnetic resonance imaging of the ovary.

Magnetic resonance imaging (MRI) of the pelvis can characterize a wide variety of ovarian lesions. We discuss MRI strategies for identification and characterization of ovarian neoplasms and correlate MRI findings with lesion gross pathological and histopathological structure.

Female↗
PubMed2001

MR imaging of the penis.

The signal intensity of the corpora cavernosa of the penis at magnetic resonance (MR) imaging may vary from that of the corpus spongiosum; this difference is dependent on the rate of blood flow within the cavernous spaces that constitute the corporal bodies. Also visible at MR imaging are the layers of fibrous tissue that envelop the corporal bodies, the deep arteries and veins, subcutaneous connective tissue, tunica dartos, epidermis, and urethra. While the iliac, pudendal, perineal, and common penile arteries can be evaluated with three-dimensional MR angiography, the smaller end arteries of the penis have not yet been reliably demonstrated. MR imaging may be used to detect and stage penile and urethral cancers, identify and characterize benign penile masses, evaluate arteriogenic impotence, identify penile fractures, evaluate penile prostheses, localize periurethral abscesses, and identify plaques of Peyronie disease. With its direct multiplanar imaging capabilities, superb soft-tissue contrast, and excellent spatial resolution, high-field surface coil MR imaging can show the soft-tissue and vascular anatomy of the penis, as well as the appearance of many penile diseases.

Diagnosis, Differential↗
PubMed2001

Pulmonary arteriovenous malformations: three-dimensional gadolinium-enhanced MR angiography-initial experience.

PURPOSE: To determine whether three-dimensional gadolinium-enhanced magnetic resonance (MR) angiography could be used to identify pulmonary arteriovenous malformations (PAVMs) and to accurately identify the size and number of feeding arteries. MATERIALS AND METHODS: Eight patients suspected of having PAVM were examined with three-dimensional MR angiography at 1.5 T. Images were reviewed by a single radiologist blinded to conventional angiographic findings who evaluated each image for the size, number, and location of PAVMs, as well as for the size and number of feeding arteries. Five patients underwent conventional angiography with embolization therapy, and one patient underwent lobectomy. Two patients did not undergo either surgery or angiography. RESULTS: Three-dimensional MR angiography revealed nine (90%) of 10 PAVMs that were confirmed at conventional angiography (n = 9) or examination of a surgical specimen (n = 1). The single PAVM that was not identified prospectively at MR angiography was small (3-4 mm) and peripheral. Two additional PAVMs were identified in the two patients who did not undergo surgery or angiography. CONCLUSION: Three-dimensional MR angiography is a promising technique for use in the diagnosis of PAVM, although small (<5-mm) PAVMs may be more difficult to identify with the technique. The technique is a particularly useful means of noninvasively demonstrating the size and number of feeding arteries prior to treatment.

Adolescent↗
PubMed2001

Metastatic prostate cancer to the spine and a PSA of 5666: a case report.

Prostate cancer is the most commonly diagnosed cancer and the second most common cause of cancer death among American men. To our knowledge, the highest reported prostate specific antigen (PSA) level on initial presentation is 3280 ng/mL. In this case report, we discuss a 46-year-old African-American man with back pain of 1-month's duration. A magnetic resonance imaging study of the lumbar spine revealed numerous osseous metastatic lesions, and the PSA level was found to be 5666 ng/mL. He was treated with oral narcotics and a Duragesic patch to achieve analgesia and bicalutamide (Casodex) and leuprolide acetate (Lupron) therapy for androgen blockade. Later in his course, he required chemotherapy due to hormone-refractory prostate cancer. The patient has done well as shown at his latest follow-up at 48 months. The objective of this report is to discuss the first patient with metastatic prostate cancer to the spine with PSA level greater than 3,500 ng/mL.

Journal Article↗
PubMed2000

Budd-Chiari syndrome: spectrum of appearances of acute, subacute, and chronic disease with magnetic resonance imaging.

The purpose of this study was to describe our collective experience in the magnetic resonance (MR) investigation of patients with proven acute, subacute, and chronic Budd-Chiari syndrome and to demonstrate the spectrum of appearances on T1- and T2-weighted as well as dynamic post-gadolinium spoiled gradient-echo imaging. All patients with proven Budd-Chiari syndrome who underwent MR examinations between June, 1992 and October, 1998 were included in the study. Fourteen patients were included in the study: four with acute, three with subacute, three with chronic, and four with acute superimposed on either subacute (two) or chronic (two) Budd-Chiari syndrome. MR imaging features were retrospectively evaluated to determine: a) liver morphology, b) pattern of signal intensity (SI) on T1-weighted images, c) pattern of SI on T2 weighted images, d) dynamic enhancement characteristics, e) presence or absence of visible venous thrombosis, and f) presence or absence of venous macroscopic collaterals. The MR findings were correlated with surgical, histopathological, and laboratory data to determine imaging characteristics related to the chronicity of the disease process. Hepatic venous thrombosis or absence of hepatic venous flow was demonstrated in all patients in the study. In the four patients with acute Budd-Chiari syndrome, the liver periphery was moderately low signal on T1 and moderately high signal on T2-weighted images relative to the central liver; both early and late gadolinium-enhanced images revealed diminished peripheral enhancement. In the three patients with subacute Budd-Chiari syndrome, the liver periphery was moderately low signal on T1, and moderately high signal on T2-weighted images, while early and late gadolinium-enhanced images revealed heterogenously increased enhancement within the liver periphery. In the three patients with chronic Budd-Chiari syndrome, the SI differences between peripheral and central liver were minimal on T1- and T2-weighted images, and enhancement differences were also minimal. Extensive bridging intrahepatic and capsular venous collaterals were visualized in chronic cases. In the four patients with acute Budd-Chiari syndrome superimposed on more chronic disease, a combination of gadolinium enhancement patterns was observed on MR images. Enhancement patterns between central and peripheral liver were different for acute, subacute, and chronic Budd-Chiari syndromes, suggesting differentiation between these phases of the disease process. Application of this pattern approach permitted recognition of acute changes superimposed on more chronic disease.

Acute Disease↗
PubMed2000

Subacute clot mimicking flow in a thrombosed arterial bypass graft on two-dimensional time-of-flight and three-dimensional contrast-enhanced MRA.

Subacute intravascular thrombus can contain methemoglobin, which results in very short spin-lattice (T1) relaxation times. We describe a case of a 78-year-old man with increasing right lower extremity claudication. The patient had a thrombosed arterial bypass graft showing high signal intensity that mimicked flow on both two-dimensional time-of-flight and three-dimensional contrast-enhanced MR angiography. Misinterpretation of the high signal thrombus as flowing blood can be avoided by obtaining a precontrast T1-weighted sequence.

Aged↗
PubMed2000

MRI of the knee: value of short echo time fast spin-echo using high performance gradients versus conventional spin-echo imaging for the detection of meniscal tears.

OBJECTIVE: Fast spin-echo (FSE) sequences reduce imaging time compared with conventional spin-echo (CSE) sequences, but may result in blurring. High-performance gradients permit shorter interecho spacing and use of the second echo as the effective TE (20 ms); both improvements reduce blurring. This randomized observer study compared a short TE, second-echo FSE sequence obtained using high-performance gradients and a CSE sequence with similar TR/TE for the detection of meniscal tears in the knee. DESIGN AND PATIENTS: One hundred consecutive MR examinations of the knee using FSE and CSE sequences at 1.5 T were evaluated. The FSE sequence used an effective TE of 20 ms (centered on the second echo at 2 times minimal interecho spacing) and an echo train length of 4. FSE and CSE parameters were otherwise similar. Four independent, masked readers reviewed randomized sagittal FSE and CSE sequences. RESULTS: Cases were assessed for the presence or absence of meniscal tears and, if present, whether tears were medial or lateral and anterior or posterior. Sequence concordance was 93.5% (1496 of 1600 meniscal segments); the intermethod kappa value was 0.78. Sequence quality was graded from 1 to 5. Average quality of CSE images was slightly but statistically significantly preferred by three of the four readers. CONCLUSION: There was no statistically significant difference between CSE imaging and FSE imaging centered on the second echo (20 ms) using high-performance gradients for the detection of meniscal tears in the knee. There was a small preference for the quality of CSE images.

Adolescent↗
PubMed2000

MR imaging features of pelvic mucinous carcinomas.

Mucinous carcinomas in the pelvis differ from non-mucinous tumors because of the differences in clinical outcome and imaging appearance. Mucinous rectal carcinomas, for example, are to be higher in stage at the time of the diagnosis because they are more likely to be infiltrative and show a greater tendency for recurrence. These factors may lead to a poorer prognosis in patients with the mucinous as compared with non-mucinous carcinomas. Mucinous carcinomas of all types typically show high signal intensity on T2-weighted MR images, and therefore mimic other conditions such as necrotic tumors, fluid collections, cysts, or liver hemangiomas. To familiarize readers with the MRI appearance, and to avoid pitfalls, this paper illustrates the MRI features of the mucinous adenocarcinomas in various pelvic organs.

Adenocarcinoma, Mucinous↗
PubMed2000

Angiomyolipoma of the renal sinus: diagnosis by percutaneous biopsy.

We report a case of angiomyolipoma of the renal sinus discovered incidentally during an evaluation for microscopic hematuria. Diagnosis was confirmed by percutaneous aspiration biopsy performed with magnetic resonance imaging control allowing differentiation of this entity from other fatty tumors of the renal sinus including liposarcoma, lipoma, and sinus lipomatosis.

Angiomyolipoma↗
PubMed2000

Focal nodular hyperplasia contiguous with an echinococcal cyst.

We report the first case of an Echinococcal cyst and focal nodular hyperplasia, two usually isolated hepatic lesions, in direct contiguity. The patient presented with right upper quadrant pain and subsequent imaging studies found a cystic and solid lesion. These studies suggested that this lesion was an hepatic adenoma, which had bled forming a hematoma. Pathological examination of the surgical resection showed Echinococcus multilocularis with contiguous focal nodular hyperplasia. Because focal nodular hyperplasia is a benign hepatic lesion the etiology of which is thought to be abnormal arterial blood flow, we postulate that the parasitic hepatic infection by E. multilocularis may have incited the formation of this contiguous hepatic lesion.

Adult↗
PubMed2000

Role of endoscopic ultrasound and magnetic resonance imaging in the preoperative staging of pancreatic adenocarcinoma.

OBJECTIVE: Endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) have both been assessed individually as staging modalities for pancreatic cancer. The aim of our study was to assess whether tumor staging by both EUS and MRI in the same cohort of patients could predict resectability and unresectability in patients with pancreatic cancer. METHODS: A review of 63 patients evaluated preoperatively with both EUS and MRI for pancreatic adenocarcinoma between January 1995 and December 1998 was done. Patients were staged as resectable or unresectable by predefined criteria. Preoperative staging by both modalities was compared to surgical outcome and the sensitivity and predictive values of each modality for determining resectability and unresectability was determined. RESULTS: EUS did not allow for complete T- and N-staging in 10 patients; therefore, for EUS, the final analysis was done on 63 of 73 patients (86%). EUS correctly staged 22 of 36 patients with resectable tumors. The sensitivity of EUS for resectability was 61%, with a positive predictive value of 69%. All 73 patients had complete MRI examinations; therefore, the final analysis was done on all 73 patients. MRI correctly staged 30 of 41 patients with resectable tumors. The sensitivity of MRI for predicting resectability was 73% with a positive predictive value of 77%. MRI and EUS both predicted resectability in 18 patients, of whom 16 (89%) were found to be resectable on surgical exploration. MRI and EUS both predicted unresectability in 17 (27%) patients, of whom 4 (24%) were found to be resectable on surgical exploration. When both MRI and EUS agreed on resectability, the positive predictive value for resectability was 89%. When both MRI and EUS agreed on unresectability, the positive predictive value for unresectability was 76%. CONCLUSIONS: Neither MRI nor EUS alone were highly sensitive or predictive of resectability. However, when both tests agreed on resectability, nearly all patients were found to be resectable on surgical exploration.

Adenocarcinoma↗
PubMed2000

Endometrial polyps: MR imaging features and distinction from endometrial carcinoma.

PURPOSE: To determine the magnetic resonance (MR) imaging characteristics of endometrial polyps and the accuracy of MR imaging in distinguishing endometrial polyps from endometrial carcinomas in a case-control study. MATERIALS AND METHODS: Cross-referencing pathology records with MR studies from two institutions disclosed 35 patients with surgically proved endometrial polyp or carcinoma after controlling for tumor size. All MR examinations were performed at 1.5 T with T2-weighted fast spin-echo sequences in multiple planes. Three independent readers blinded to histologic diagnoses and clinical data scored each image for the presence of several defined findings. RESULTS: A central fibrous core (low signal intensity on T2-weighted images) and intratumoral cysts (high signal intensity on T2-weighted images) were seen more frequently in endometrial polyps than in carcinomas; myometrial invasion and necrosis showed high predictive value for carcinomas. The readers' responses showed a mean sensitivity of 79%, specificity of 89%, accuracy of 86%, positive predictive value of 82%, and negative predictive value of 88% for diagnosis of carcinoma. The mean area under the receiver operating characteristic curve for the three readers was 0.87 for the diagnosis of carcinoma. CONCLUSION: MR images can help to distinguish most polyps from endometrial carcinomas on the basis of morphologic features. Accuracy does not appear to be sufficient to obviate biopsy, partly because carcinomas and polyps frequently coexist.

Adult↗
PubMed2000

MR imaging in patients with nipple discharge: initial experience.

PURPOSE: To investigate the potential of magnetic resonance (MR) imaging in patients with nipple discharge. MATERIALS AND METHODS: Between February 1992 and December 1998, 23 patients with nipple discharge underwent contrast material-enhanced MR imaging at 1.5 T. Mammographic findings were negative in 22 of 23 patients and revealed asymmetry in one patient. Galactography was attempted in two patients, with negative findings in one patient and no success in the other. Fifteen of 23 patients underwent excisional biopsy-seven of 15 with MR imaging-guided localization, and one of 15 with mammographic localization. Eight of 23 patients were followed up clinically (range, 7-24 months; mean, 20 months). RESULTS: In 11 of the 15 (73%) patients who underwent excisional biopsy, MR imaging findings correlated with histopathologic findings. MR imaging demonstrated four of six benign papillomas and one of two fibroadenomas as circumscribed, enhancing subareolar masses. Findings of one MR imaging examination were negative, and benign tissue was found at excisional biopsy. MR imaging findings were suspicious in six of the seven patients with excisional biopsy findings of malignancy (regional enhancement [n = 2], ductal enhancement [n = 2], peripherally enhancing mass [n = 1], and spiculated mass [n = 1]). In one of the seven patients, a benign-appearing intraductal mass was identified at MR imaging; excisional biopsy revealed a benign papilloma with an adjacent focus of DCIS. CONCLUSION: MR imaging can help identify both benign and malignant causes of nipple discharge. It potentially offers a noninvasive alternative to galactography.

Adult↗
PubMed2000

Suppression of intravascular signal on fat-saturated contrast-enhanced thoracic MR arteriograms.

PURPOSE: To assess the prevalence of artifactual signal intensity loss within the aortic arch and proximal branch vessels on fat-saturated contrast material-enhanced magnetic resonance (MR) arteriograms of the thoracic aorta and to hypothesize about the cause of the loss of signal intensity. MATERIALS AND METHODS: Between January and June 1998, 105 consecutive MR arteriograms of the thoracic aorta were acquired in 103 patients at 1.5 T. Imaging included an arterial phase three-dimensional (3D) fat-saturated contrast-enhanced gradient-echo (GRE) sequence followed by a delayed two-dimensional (2D) transverse fat-saturated GRE sequence. All MR images were reviewed by two radiologists who were blinded to patient history and results of imaging studies and who evaluated the images for the presence of intraluminal loss of signal intensity in the aortic arch and the proximal branch vessels. RESULTS: Intravascular loss of signal intensity was present in at least one vessel on 23 of the 105 arterial phase 3D studies. Seventy-one of 91 left subclavian arterial segments had loss of signal intensity on the delayed 2D studies. CONCLUSION: Intravascular signal intensity loss can be present on contrast-enhanced fat-saturated images of the aortic arch and proximal branch vessels, particularly the left subclavian artery. This phenomenon, which is to the authors' knowledge previously unreported and which is hypothesized to result from undesired water saturation, should not be misinterpreted as stenotic or occlusive vascular disease.

Adolescent↗