Acute appendicitis: comparison of helical CT diagnosis focused technique with oral contrast material versus nonfocused technique with oral and intravenous contrast material.

PURPOSE: To compare the diagnostic accuracy of focused helical computed tomography (CT) with orally administered contrast material with that of nonfocused helical CT with orally and intravenously administered contrast material. MATERIALS AND METHODS: After receiving oral contrast material, 228 patients with clinically suspected appendicitis underwent focused appendiceal CT (5-mm section thickness, 15-cm coverage in the right lower quadrant). Immediately thereafter, helical CT of the entire abdomen and pelvis was performed following intravenous administration of contrast material (abdomen, 7-mm section thickness; pelvis, 5-mm section thickness). Studies were separated and independently interpreted by three observers who were blinded to patient names. Diagnoses were established by means of surgical and/or clinical follow-up findings. RESULTS: Fifty-one (22.4%) of 228 patients had acute appendicitis. Readers diagnosed appendicitis with 83.3%, 73.8%, and 71.4% sensitivity and 93.0%, 92.3%, and 97.9% specificity with focused nonenhanced appendiceal CT. Readers diagnosed appendicitis with 92.9%, 92.9%, and 88.1% sensitivity and 93.7%, 95.1%, and 96.5% specificity with nonfocused enhanced CT. Summary areas under the receiver operating characteristic curve estimates for focused nonenhanced and nonfocused enhanced CT were 0.916 and 0.964, respectively; the differences were statistically significant (P <.05) for two of three readers. All readers demonstrated higher sensitivities for detecting the inflamed appendix with nonfocused enhanced CT. Appendicitis was missed with focused CT in two patients whose inflamed appendix was not included in the imaging of the right lower quadrant. All readers were significantly more confident in diagnosing alternative conditions with nonfocused enhanced CT. CONCLUSION: Diagnostic accuracy of helical CT for acute appendicitis improved significantly with use of intravenous contrast material.

Clustered pulmonary nodules: highly suggestive of benign disease.

Thirty-one adult patients with a cluster of small, noncalcified, pulmonary nodules identified on chest computed tomography (CT) examinations were studied retrospectively. Pathology revealed an infectious/inflammatory etiology in all cases in which a surgical resection of the involved lung was performed. None of the patients in our study group showed evidence of malignancy in the region of a cluster of pulmonary nodules over the follow-up period. The authors conclude that an isolated cluster of small pulmonary nodules is strongly suggestive of benign disease. Although exceptions may rarely occur, most cases represent incidental infectious or inflammatory disease.

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.

Distribution of thrombi in acute lower extremity deep venous thrombosis: implications for sonography and CT and MR venography.

OBJECTIVE: Our objective was to determine the typical distribution of thrombi in acute lower extremity deep venous thrombosis as a means of evaluating the validity of imaging techniques that only include the common femoral and popliteal veins, but not the superficial femoral vein. MATERIALS AND METHODS: The results of 2704 lower extremity venous sonograms, obtained in 2026 consecutive patients over a 4-year interval, were reviewed retrospectively. The distribution of acute deep venous thromboses across various lower extremity venous segments was analyzed for this population, which consisted of both symptomatic and asymptomatic patients. RESULTS: Of 2704 lower extremities studied with duplex sonography, acute deep venous thrombosis was identified in 269 (9.9%). Of these 269 cases, acute deep venous thrombosis was isolated to the superficial femoral vein in 60 (22.3%). The remaining 209 cases (77.7%) showed thrombus that extended into the common femoral or popliteal veins (or both). CONCLUSION: An abbreviated imaging study that evaluates only the common femoral and popliteal veins would fail to identify more than 20% of lower extremity acute deep venous thromboses in a population like ours. Although evaluation of the superficial femoral vein requires additional time and resources, evaluation of this segment may prevent a substantial number of thrombi from being missed.

Injected periurethral collagen for postprostatectomy urinary incontinence: MR and CT appearance.

BACKGROUND: Urinary incontinence, a disturbing complication of radical prostatectomy, is often treated with periurethral collagen injections to increase urethral closure and resistance to urinary outflow. METHODS: Using magnetic resonance imaging and computed tomography, we studied the appearance of glutaraldehyde cross-lined bovine collagen endoscopically injected into the periurethral tissues in four men who developed urinary incontinence after radical prostatectomy. Collagen was also scanned in vitro to verify its magnetic resonance appearance. RESULTS: Collagen deposits appear as well-circumscribed nodules of low to intermediate signal intensity on both T1- and T2-weighted images in the periurethral tissues or in the base of the subjacent penile bulb (base of corpus spongiosum). On contrast-enhanced computed tomography, collagen appears as a hypoattenuating nodular-filling defect within the penile bulb. CONCLUSION: These imaging characteristics should allow differentiation of collagen from locally recurrent prostate carcinoma and avoid inappropriate work-up of benign findings.

Patterns of disease spread in metastatic breast carcinoma: influence of estrogen and progesterone receptor status.

BACKGROUND AND PURPOSE: It is widely recognized that tumor hormone receptor status correlates with overall survival in metastatic breast carcinoma; however, the influence of hormone receptors on the pattern of disease spread is not well known. PURPOSE: We set out to determine the common distributions of metastatic disease spread in metastatic breast carcinoma, and to evaluate tumor hormone receptor status as predictor of disease spread. METHODS: Thirty-six patients being imaged for possible metastatic breast carcinoma between 1995 and 1998, in whom the presence or absence of tumor estrogen and progesterone receptors (ER+ or ER- / PR+ or PR-) was known, who underwent both contrast-enhanced MR of the brain and total body skeletal scintigraphy, were studied retrospectively. RESULTS: Of twelve patients with skeletal metastases but no brain metastases, 83% were ER+/PR+. Ten patients had brain metastases but no skeletal involvement, 80% of which were ER-/PR-. Seven patients had no brain or osseous metastases, but had metastatic disease in the chest or abdomen. Eighty-six percent of patients in this group were ER-/PR-. The tumor receptor status was statistically different between these three distribution groups (P = .01). A final group, consisting of seven patients, showed widespread disease, with diffuse metastases to the brain, viscera, and skeleton. In this group, no patients were ER+/PR+. CONCLUSION: There are two major patterns of disease spread in metastatic breast carcinoma, excluding patients with extensive diffuse metastases. Patients with ER+/PR+ tumors tend to develop osseous but not brain metastases. Patients with ER-/PR- tumors tend to develop brain but not osseous metastases. Appreciation of these distributions can aid the radiologist in detecting metastatic lesions, and will help the clinician to estimate the likelihood of metastases to various organ systems, as well as to potentially target therapy.

Renal cyst pseudoenhancement: beam-hardening effects on CT numbers.

PURPOSE: To determine if simple renal cysts may be accurately characterized with helical computed tomography (CT) during peak levels of renal enhancement. MATERIALS AND METHODS: Water-filled "cysts" were suspended in varying concentrations of iodine solution, meant to simulate varying levels of renal enhancement, within an abdominal phantom. Volume-averaging effects were minimized by scanning cylindric 5-30-mm cysts with a helical technique (collimation, 5 mm; pitch, 1:1). Axial and helical techniques were then compared, and volume-averaging effects were evaluated by scanning 10- and 20-mm round cysts with 3-, 5-, and 7-mm collimation at background attenuation levels of 100 and 200 HU. RESULTS: Cylindric cyst attenuation increased consistently with increasing background attenuation. As background attenuation increased by 90 HU, attenuation increased by 11-17 HU in small (5- or 10-mm) cysts, and by 7-9 HU in large (15-30-mm) cysts. As background attenuation increased by 180 HU, attenuation increased by 18-28 HU in small cysts and by 10-15 HU in large cysts. Spherical cyst attenuation differences were maximized when smaller cysts were imaged with larger collimation, which is when volume-averaging effects became apparent. Axial and helical CT numbers did not differ substantially. Computer simulation studies showed that the observed effect could not be explained by beam hardening alone. CONCLUSION: Pseudoenhancement of renal cysts may occur if helical CT is performed during peak renal enhancement. CT algorithm modification may be necessary to correct for this effect, which is likely related to an inadequate algorithmic correction for beam hardening.

Recent advances in pulmonary imaging.

Recent years have witnessed an explosion in imaging technology applicable to chest medicine. These include CT and magnetic resonance angiography (MRA) for the diagnosis of pulmonary embolism, and high-resolution CT for the detection and characterization of diffuse lung diseases and the quantification of emphysema. Newly developed approaches to pulmonary functional imaging using CT and MRI have been applied to the evaluation of pulmonary ventilation and perfusion and to the detection of small airways disease. Volumetric CT imaging techniques together with advanced image processing have made possible "virtual bronchoscopy." Positron emission tomography provides an important new approach to the accurate detection and staging of chest malignancies and to the evaluation of pulmonary nodules. Finally, new digital imaging techniques, which are rapidly replacing conventional x-ray film, offer the possibility of computer-aided diagnosis.

Advanced emphysema: preoperative chest radiographic findings as predictors of outcome following lung volume reduction surgery.

PURPOSE: To determine whether preoperative chest radiographic findings alone can reliably predict which patients will achieve the best functional outcome of lung volume reduction surgery. MATERIALS AND METHODS: The preoperative chest radiographs obtained in 57 patients who had undergone lung volume reduction surgery were retrospectively scored by five blinded readers for severity and distribution of emphysema, evidence of lung compression, disease heterogeneity, and other features. Comparisons were made with the 3-6-month postoperative functional outcome for each patient. RESULTS: High disease heterogeneity (score > 2) and unequivocal lung compression (score 1) both were 100% predictive of a favorable outcome (FEV1 increase, > or = 30%). Low heterogeneity (score < 1) was 94% predictive of an unfavorable outcome (FEV1 increase < 30%), as was a lack of lung compression, which was 92% predictive of an unfavorable outcome. These two features also correlated with an improved 6-minute walk test result, although this correlation was weaker. CONCLUSION: Chest radiography alone may be sufficient for initial screening. High disease heterogeneity and lung compression on chest radiographs are highly predictive of a favorable functional outcome.

Spontaneous tension pneumopericardium complicating staphylococcal pneumonia.

The authors describe a patient with spontaneous pneumopericardium complicating staphylococcal pneumonia and empyema that resulted in cardiac tamponade. Spontaneous pneumopericardium is an unusual disorder. The causes and clinical findings of pneumopericardium are reviewed, as are the radiographic features that differentiate this condition from pneumomediastinum. Early recognition of pneumopericardium is important, because emergent pericardiocentesis may be required if there is clinical evidence of tamponade.

MR imaging of Dejerine-Sottas disease.

We report the MR findings in two patients with clinically and histologically proved Dejerine-Sottas disease. One patient had spinal involvement with multiple thickened and clumped nerve roots of the cauda equina; the second had multiple enlarged and enhancing cranial nerves. Although these findings are not specific for Dejerine-Sottas disease, they are suggestive of the diagnosis, which is further corroborated with history and confirmed with sural nerve biopsy and laboratory studies.

Diffuse lymphangiomatosis of bone.

Two cases of lymphangiomatosis of bone, a very rare systemic condition characterized by both skeletal and parenchymal lesions, are presented. The skeletal changes have an appearance similar to haemangiomas in the spine, and soap-bubbly lesions in the flat bones. One case carried the diagnosis of eosinophilic granuloma for 18 years. The findings on MRI, which have not been previously well-established, are discussed.

Hartmann's pouch: radiographic evaluation of postoperative findings.

OBJECTIVE: The purpose of this study was to determine the usefulness of contrast-enhanced radiography of the Hartmann's pouch for evaluating postoperative abnormalities. MATERIALS AND METHODS: We performed a retrospective study of 84 patients with a Hartmann's pouch who underwent contrast-enhanced radiography of the pouch during a recent 7-year period. Sixty-four patients underwent single-contrast barium studies of the pouch, 17 underwent studies with a water-soluble contrast medium, and three underwent both types of studies. The radiographic studies were reviewed to determine the types and frequency of abnormalities involving the pouch. Medical records were also reviewed to determine clinical presentation and course. RESULTS: Abnormalities of the Hartmann's pouch were detected on contrast-enhanced radiography in 16 (19%) of the 84 patients. Of the 70 patients who underwent routine contrast-enhanced radiography of the pouch, 11 (16%) had abnormalities, including diversion colitis in three, leaks in two, adhesions in two, recurrent carcinoma in two, ulcerative colitis involving the pouch in one, and a stricture in one. In both patients with clinically silent leaks, the contrast-enhanced radiography was performed 3 months or more after creation of the pouch. Of the remaining 14 patients who underwent contrast-enhanced radiography because of suspected complications involving the pouch, five (36%) had abnormalities revealed, including leaks in two, fistulas in two, and recurrent carcinoma in one. CONCLUSION: Contrast-enhanced radiography of the Hartmann's pouch revealed abnormalities of the pouch in 19% of patients, including leaks or fistulas, diversion colitis, adhesions, strictures, and recurrent tumor. Because two patients had clinically silent leaks that were detected during the late postoperative period, it may be prudent to perform these studies with a water-soluble contrast medium to avoid the problems associated with extravasation of barium into the extra- or intraperitoneal spaces.

Calcaneal fractures in diabetic patients.

We would like to present 23 calcaneal fractures in 22 patients of whom 21 had type I diabetes mellitus. There appear to be three basic fracture types: (1) a superiorly displaced extra-articular avulsion fracture of the posterior calcaneus (or Iowa fracture), which occurred in 12 patients (five men, seven women); (2) a mid-calcaneal compression fracture in six patients (four men, two women), and (3) a cleavage or "wedge" type fracture in four patients extending from the calcaneal tubercle (one man, 3 women). All four of this last group of patients had a history of a chronic penetrating ulcer, and this is noteworthy since only one other patient out of the remaining 18 in groups 1 and 2 had a similar history. Most patients had decreased bone mineralization: 15 patients were on long-term, high-dose steroids, and 18 patients had either poor renal function or complete renal failure (11 of 12). Fourteen patients had received either renal or pancreas transplants. Eight patients were on restricted weight bearing prior to their fractures. We believe that diabetic patients are more prone to calcaneal fractures than the general population, and early diagnosis is imperative, followed by early treatment to prevent significant bony deformity.

The selectivity of inclusion and exclusion criteria in bulimia nervosa treatment studies.

OBJECTIVE: To examine the rates of exclusion and inclusion in various research studies for a series of 51 treatment-seeking patients. METHOD: The inclusion and exclusion criteria employed in a sample of 41 studies were applied to a series of 51 treatment-seeking bulimia nervosa patients. RESULTS: Of the sample of 51, 11, (21.6%) would have been excluded from 16 (39%) of the studies because of an age greater than 30; 13 (32%) of the studies would have excluded 8 (16%) of our patients because of weight > 110% ideal body weight. Thirteen (26%) would have been excluded from 22 (54%) of the studies because of active psychotropic drug use, despite the lack of response. DISCUSSION: Some of the patients who may be most difficult to work with may be excluded from treatment studies.

The prevalence of diffuse idiopathic skeletal hyperostosis (DISH) in two large American Midwest metropolitan hospital populations.

OBJECTIVE: There are no published large-scale studies of the overall prevalence of diffuse idiopathic skeletal hyperostosis (DISH) and it has been proposed that the prevalence is greater than previously reported. We thus decided to review chest radiographs in a population of patients over 50 years of age seen at two large but differing metropolitan hospitals in a major American Mid-west city. DESIGN AND PATIENTS: The posterior-anterior and lateral chest radiographs of 1363 patients were reviewed for evidence of DISH at the University of Minnesota Hospital and Clinic. There were 500 consecutive inpatient admissions, 540 consecutive patients who attended the outpatient clinics and 326 patients collected from our film archive. A population of 1001 patients seen at Hennepin County Medical Center was also studied. It was possible to subclassify this latter group with respect to race. RESULTS AND CONCLUSION: Using strict criteria, i.e., four or more levels involved, the overall prevalence of DISH in the male population over age 50 years was 25% and in the female population over age 50 years was 15%. This prevalence climbed to 28% in males over 80 years and to over 35% in males over age 70 years. In females over 80 years, the prevalence was found to be 26%. Although our population base was small, DISH was found to be less common in the black, Native-American and Asian populations. The prevalence of DISH was also found to be far lower in a similar white population with osteoporosis. The overall prevalence of DISH was higher than expected in a predominantly white population over age 50 years with a lesser incidence in the black, Native-American and Asian populations, suggesting a genetic origin of the condition.