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Biomedical subjects

Frank H Miller

Publications and source records attributed to Frank H Miller.

14 recordsLinked to original sources

Adrenal lesions with heterogeneous suppression on chemical shift imaging: clinical implications.

PURPOSE: To investigate the frequency and significance of adrenal lesions that demonstrate heterogeneous suppression on chemical shift magnetic resonance imaging (MRI). MATERIALS AND METHODS: A retrospective search of adrenal lesions identified on MR from November 1997-July 2001 was performed. The adrenal lesions were classified as having suppression typical for an adenoma, nonsuppression, or atypical heterogeneous suppression. Lesions with heterogeneous suppression were further reviewed. Follow-up for the heterogeneous lesions consisted of imaging studies or pathology from surgical excision. RESULTS: Adrenal lesions were identified in 242 patients. Heterogeneously suppressing lesions were seen in 34 (14%) patients. Several different patterns of heterogeneous suppression were identified. Imaging or pathologic follow-up was available for 18 of the heterogeneously suppressing lesions (one patient had both). Fifteen patients with follow-up imaging showed stability of the lesion over a significant interval, suggesting a benign lesion. Pathology was available for four patients revealing two patients with adenomas and two patients with nodular hyperplasia. Thus, all 18 patients with heterogeneous suppression had a benign lesion. CONCLUSION: Adrenal lesions that have a heterogeneous pattern of suppression on out-of-phase chemical shift MR images are a common finding. Our small series suggest that these lesions are probably benign.

Adenoma↗

The nonvisualized appendix: incidence of acute appendicitis when secondary inflammatory changes are absent.

OBJECTIVE: The objective of our study was to assess the importance of nonvisualization of the appendix and its association with acute appendicitis on helical CT when secondary inflammatory changes are absent. MATERIALS AND METHODS: After we received institutional review board approval, CT scans of 366 consecutive patients obtained for lower abdominal or right lower quadrant pain and to rule out appendicitis were retrospectively reviewed. Images were reviewed by an experienced abdominal radiologist and compared with the formal interpretation. The amount of right lower quadrant and pericecal fat was quantified on a scale of 0 (none) to 2 (abundant). Patients with a nonvisualized appendix and other findings compatible with acute appendicitis-such as abscess formation, localized perforation, periappendiceal fat stranding, or appendicolith-were excluded. RESULTS: The appendix could not be visualized by both reviewers in 46 (13%) of 366 cases. CT findings indicated another cause for the patient's symptoms in 12 cases (26%), including gastrointestinal and genitourinary processes. An alternate diagnosis was subsequently reached in 11 additional patients (24%) with follow-up imaging or clinical evaluation. Only one patient (2%) with a nonvisualized appendix had acute appendicitis, proven by surgical pathology. In this patient, there was paucity of fat in the right lower quadrant. CONCLUSION: In the absence of a distinctly visualized appendix and secondary inflammatory changes, the incidence of acute appendicitis is low. Nonvisualization of the appendix even when a small amount of fat is present in the right lower quadrant may safely exclude acute appendicitis if no secondary CT findings are present.

Abdomen, Acute↗

Endometriosis presenting as a urethral diverticulum: a case report.

BACKGROUND: Pelvic pain is a common complaint among women of childbearing age. It has an extensive differential diagnosis that at times can make it difficult to determine its etiology. One must therefore rely on the characteristics of the physical examination, symptoms and imaging studies. However, in doing so, one should keep in mind that many diseases mimic one another. Physicians must be careful not to fall into the trap of simply assigning a specific disease to a given group of symptoms. CASE: A 35-year-old woman, gravida 2, para 0020, presented to a clinic complaining of left lower abdominal pain. She had a history of dyspareunia, dysmenorrhea, urinary frequency and numerous urinary tract infections. Previous laparoscopies had been negative for endometriosis. Physical examination demonstrated a 1.5-cm mass left of the midurethra. No pus was expressed through the urethra with cyst massage. Imaging showed a 1.1 x 1.1-cm lesion in the left posterolateral aspect of the urethra consistent with a urethral diverticulum. Uterine adenomyosis was also noted. Although clinical symptoms, physical examination and imaging suggested a urethral diverticulum, a vaginal endometriotic cyst was encountered at surgery. Pathologic evaluation of the surgically excised lesion revealed endometriosis, revealed endometriosis. CONCLUSION: In this case, clinical findings, location and imaging characteristics of a periurethral endometriotic lesion suggested a urethral diverticulum. Endometriosis should be considered in patients with a history of pelvic pain who present with urinary frequency and a periurethral lesion.

Adult↗

Computerized tomographic colonography: performance evaluation in a retrospective multicenter setting.

BACKGROUND & AIMS: No multicenter study has been reported evaluating the performance and interobserver variability of computerized tomographic colonography. The aim of this study was to assess the accuracy of computerized tomographic colonography for detecting clinically important colorectal neoplasia (polyps >or=10 mm in diameter) in a multi-institutional study. METHODS: A retrospective study was developed from 341 patients who had computerized tomographic colonography and colonoscopy among 8 medical centers. Colonoscopy and pathology reports provided the standard. A random sample of 117 patients, stratified by criterion standard, was requested. Ninety-three patients were included (47% with polyps >or=10 mm; mean age, 62 years; 56% men; 84% white; 40% reported colorectal symptoms; 74% at increased risk for colorectal cancer). Eighteen radiologists blinded to the criterion standard interpreted computerized tomography colonography examinations, each using 2 of 3 different software display platforms. RESULTS: The average area under the receiver operating characteristic curve for identifying patients with at least 1 lesion >or=10 mm was 0.80 (95% lower confidence bound, 0.74). The average sensitivity and specificity were 75% (95% lower confidence bound, 68%) and 73% (95% lower confidence bound, 66%), respectively. Per-polyp sensitivity was 75%. A trend was observed for better performance with more observer experience. There was no difference in performance across software display platforms. CONCLUSIONS: Computerized tomographic colonography performance compared favorably with reported performance of fecal occult blood testing, flexible sigmoidoscopy, and barium enema. A prospective study evaluating the performance of computerized tomography colonography in a screening population is indicated.

Colonic Neoplasms↗

Magnetic resonance imaging in patients with pancreatitis: evaluation of signal intensity and enhancement changes.

PURPOSE: To evaluate the utility of unenhanced and enhanced T1-weighted fat-suppressed (T1-FS) magnetic resonance imaging (MRI) in detecting pancreatitis. MATERIALS AND METHODS: 1.5-T MRI was performed in 25 patients with acute and 23 patients with chronic pancreatitis and in 20 control subjects without known pancreatic disease. T1-FS spin-echo and contrast-enhanced arterial-predominant (DYN1) and portal-predominant (DYN2) fast multiplanar spoiled gradient-echo (FMPSPGR) sequences were evaluated. These three sets of images were evaluated both subjectively for decreased or heterogeneous signal intensity (rating scale, 0-3) and objectively (region of interest (ROI)) in the head, body, and tail of the pancreas, in each patient. RESULTS: Good correlation between subjective assessment and objective data was demonstrated. The T1-FS sequence showed an abnormality with greater frequency (T1-FS > DYN1, 81/144 scores; T1-FS = DYN1, 63/144 scores; T1-FS < DYN1, 0/144 scores) and magnitude (average subjective score, 2.48 vs. 1.74; P < 0.0003) than that of the contrast-enhanced FMPSPGR (decreased or heterogeneous enhancement). The overall sensitivity and specificity of MRI was 92% and 50%, respectively. On the basis of signal intensity and enhancement, MRI was not able to differentiate acute from chronic pancreatitis. CONCLUSION: MRI was highly sensitive for disease detection, particularly using the T1-FS sequence, but using the sequences described, was not able to differentiate acute from chronic pancreatitis.

Acute Disease↗

Imaging benign and malignant disease of the gallbladder.

This article reviews the imaging of various benign and malignant diseases of the gallbladder. Clinical findings and imaging features using ultrasound, CT, and MR for the detection and evaluation of gallstones, acute cholecystitis, xanthogranulomatous cholecystitis, adenomyomatosis, and carcinoma of the gallbladder among other disorders are discussed.

Cholangiography↗

Imaging of cystic diseases of the pancreas.

Although the majority of cystic lesions of the pancreas seen in clinical practice represent postinflammatory pseudocysts, it is important for the radiologist to be knowledgeable of the wide spectrum of cystic masses of the pancreas and the variable prognoses they possess. As a result of similarities in the imaging features of these lesions, a definitive diagnosis is often not possible. By combining imaging features with clinical history, a reasonable differential diagnosis can be offered to the referring physician. In some cases, biopsy or fluid aspiration may be required prior to surgery. In a patient without the appropriate history of pancreatitis and the presence of a cystic pancreatic mass, it is incumbent upon the radiologist to offer alternative diagnoses of cystic neoplasms of the pancreas.

Cysts↗

MR imaging of the pancreas: a practical approach.

This article reviews the current practical MRI techniques in assessment of the pancreas. With the comprehensive "one-stop-shopping" approach, the great majority of pancreatic diseases can be detected and characterized by the use of a combination of T1, T2-weighted, MRCP, and fat-suppressed T1-weighted dynamic post-gadolinium SGE sequences. This approach may provide the clinician with information regarding the site, nature, and staging of pancreatic tumor in a single setting. In many institutions worldwide, however, including our own, CT remains the main imaging method for the assessment of acute pancreatic diseases, due largely to its wide availability. MR imaging is reserved for the indications listed above, most importantly, the detection of small and non-organ-deforming pancreatic ductal adenocarcinoma, islet cell tumors, choledocholithiasis and pancreatic duct calculi, cholangiocarcinomas, and in cases of pancreatic head enlargement with no mass discernable on CT.

Acute Disease↗

Gadolinium-enhanced 3D MR angiography of renal artery stenosis: a pilot comparison of maximum intensity projection, multiplanar reformatting, and 3D volume-rendering postprocessing algorithms.

RATIONALE AND OBJECTIVES: The authors compared diagnostic accuracy of maximum intensity projection (MIP), multiplanar reformatting (MPR), and three-dimensional (3D) volume rendering (VR) in the evaluation of gadolinium-enhanced 3D magnetic resonance (MR) angiography of the renal arteries. They hypothesized that VR is as accurate as or more accurate than MIP and MPR at depicting renal artery stenosis. MATERIALS AND METHODS: The study group comprised 28 consecutive patients who underwent gadolinium-enhanced 3D MR angiography of the renal arteries. Studies were postprocessed to display images in MIP, MPR, and VR formats. Digital subtraction angiography (DSA), when performed (nine of 28 patients), was the standard for comparison. For each main renal artery, an estimate of percentage stenosis was made for any stenoses detected by three independent radiologists. For calculation of sensitivity, specificity, and accuracy, MR angiographic stenosis estimates were categorized as mild (0%-39%), moderate (40%-69%), or severe (> or = 70%). DSA stenosis estimates of 70% or greater were considered hemodynamically significant. RESULTS: Analysis of variance demonstrated MIP estimates of stenosis were statistically greater than VR estimates in two readers and greater than MPR estimates in all readers for all patients. MIP images also showed the largest mean difference from DSA stenosis estimates for all three readers. For both VR and MPR, mean differences between MR angiographic stenoses estimates and DSA estimates reached significance for only one reader, whereas, for MIP versus DSA, mean differences reached significance for all three readers. Although not statistically significant compared with DSA, accuracies of VR (87%) and MPR (89%) were greater than that of MIP (81%). CONCLUSION: In this pilot study, MIP was the least accurate of the three image display algorithms tested. VR and MPR yielded similar values for each method of comparison.

Adult↗

Accidental ureteral ligation during an inguinal hernia repair of patient with crossed fused renal ectopia.

Because most of the presenting symptoms of ureteral herniation and crossed renal ectopia are nonspecific, it is important to be aware of their presence and association to avoid iatrogenic injuries to the kidneys and/or the ureters. We present the imaging findings of a patient with ureteral ligation whose ureteral herniation and crossed renal ectopia were identified after undergoing hernia repair.

Hernia, Inguinal↗

An initial experience: using helical CT imaging to detect obscure gastrointestinal bleeding.

Obscure gastrointestinal (GI) bleeding is a common but frustrating disease for clinicians because of its elusive nature despite extensive work-up. We evaluate the role of helical computed tomography (CT) imaging using rapid infusion of intravenous contrast and water as oral contrast in the work-up of patients who are actively bleeding. Helical CT may be a useful noninvasive, alternative study to consider when routine work-up fails to determine the cause of active GI bleeding. Our preliminary study shows that helical CT was able to identify a wide variety of causes of obscure GI bleeding.

Administration, Oral↗