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Biomedical subjects

I R Francis

Publications and source records attributed to I R Francis.

At least 19 recordsLinked to original sources
PubMed1995

Scintigraphy of incidentally discovered bilateral adrenal masses.

The purpose of this study was to determine the patterns of iodine-131 6 beta-iodomethylnorcholesterol (NP-59) imaging and the correlation with computed tomography (CT)-guided adrenal biopsy and follow-up in patients with bilateral adrenal masses. To this end we investigated a consecutive sample of 29 euadrenal patients with bilateral adrenal masses discovered on CT for reasons other than suspected adrenal disease. Adrenal scintigraphy was performed using 1 mCi of NP-59 injected intravenously, with gamma camera imaging 5-7 days later. In 13 of the 29 patients bilateral adrenal masses were the result of metastatic involvement from lung carcinoma (5), lymphoma (3), adrenocarcinoma of the colon (3), squamous cell carcinoma of the larynx (1), and anaplastic carcinoma of unknown primary (1). Among these cases the NP-59 scan demonstrated either bilaterally absent tracer accumulation (in eight, all with bilateral metastases proven by CT-guided biopsy or progression on follow-up CT) or marked asymmetry of adrenocortical NP-59 uptake (in five). Biopsy of the adrenal demonstrating the least NP-59 uptake documented malignant involvement of that gland in five of five patients. In two patients an adenoma was found simultaneously in one adrenal with a contralateral malignant adrenal mass. In each of these cases, the adenoma demonstrated the greatest NP-59 uptake. In 16 patients diagnosis of adenoma was made on the basis of (a) CT-guided adrenal biopsy of the gland with the greatest NP-59 uptake of the pair (n = 4), or (b) adrenalectomy (n = 2), or (c) absence of change in the size of the adrenal mass on follow-up CT scanning performed 6 months to 3 years later (n = 10).(ABSTRACT TRUNCATED AT 250 WORDS)

Adosterol↗
PubMed1995

Adrenal imaging.

CT is the imaging procedure of choice for detecting adrenal masses. In patients with biochemical evidence of an adrenal endocrine syndrome, CT can detect or exclude an adrenal mass in a high percentage of cases. Radionuclide scintigraphy is a useful adjunct in selected cases to characterize an adrenal mass as functional cortical (NP-59) or medullary (MIBG) tissue. In this article, the spectrum of adrenal imaging findings in patients with Cushing's syndrome, Conn's syndrome (primary aldosteronism), and pheochromocytoma is described and illustrated. In patients without an adrenal endocrine syndrome, an adrenal mass is detected on CT as an incidental finding or during a search for metastatic disease. Although pathognomonic findings of adrenal hemorrhage or myelolipoma are occasionally demonstrated, most adrenal masses have nonspecific morphological CT features. Differentiation of common benign adenomas from nonadenomatous adrenal masses, including metastases, remains an important clinical problem. This article reviews the current status, advantages, and limitations of the following methods to characterize an adrenal mass: (1) percutaneous adrenal biopsy, (2) NP-59 scintigraphy, (3) unenhanced CT densitometry, and (4) opposed-phase chemical shift MRI.

Adenoma↗
PubMed1995

Pseudoaneurysms of the intraparenchymal splenic artery after blunt abdominal trauma: a complication of nonoperative therapy and its management.

The presentation, diagnosis, and successful management of posttraumatic pseudoaneurysms of the intraparenchymal splenic artery after nonoperative therapy in an adult patient is described. Pseudoaneurysm formation of the intraparenchymal splenic artery is a rare complication of traumatic splenic injury, which is a potential mechanism of delayed splenic rupture and demonstrates the importance of follow-up in the nonoperative therapy of blunt injury to the spleen.

Adult↗
PubMed1995

Pancreatic adenocarcinoma: CT versus MR imaging in the evaluation of resectability--report of the Radiology Diagnostic Oncology Group.

PURPOSE: To compare findings with computed tomography (CT) and magnetic resonance (MR) imaging in pancreatic adenocarcinoma and to determine optimal pulse sequences for MR imaging. MATERIALS AND METHODS: CT scans and MR images were compared of 189 adult patients with known or suspected adenocarcinoma of the pancreas. Levels of confidence were correlated with surgical and pathologic results. RESULTS: The accuracy of CT was 0.73 and of MR imaging was 0.70. The negative predictive value of CT was 0.28 and of MR imaging was 0.23. The positive predictive value of CT was 0.89 and of MR imaging was 0.88. Gradient-echo and T1-weighted spin-echo sequences ranked equally in evaluation of vascular invasion, T1-weighted spin-echo sequences were preferred for assessing lymphadenopathy, and T2-weighted spin-echo sequences were preferred for detecting hepatic metastases. CONCLUSIONS: Cross-sectional imaging modalities are useful in the identification of unresectable pancreatic carcinoma. CT is recommended for initial imaging assessment.

Adenocarcinoma↗
PubMed1995

Nodular sarcoidosis of the liver and spleen: analysis of 32 cases.

PURPOSE: To describe the computed tomographic (CT) appearance of nodular hepatosplenic sarcoidosis and its association with stage with chest radiography and clinical status. MATERIALS AND METHODS: Thirty-two patients (21 women, 11 men; aged 25-68 years) with nodular hepatosplenic sarcoidosis were evaluated. CT findings were described along with chest radiographic stage, clinical status, and level of angiotensin-converting enzyme (ACE). RESULTS: Nodules were small, multiple, and of low attenuation. Organomegaly was common. Abdominal adenopathy was present in 76% of the patients. Chest radiographs were normal in 25%; 61% had stage 1 or 2 radiographs. Abdominal or systemic symptoms were present in 66%. ACE level was elevated in 10 (91%) of 11 patients tested. No change in chest radiographic stage was noted in 74% of patients with follow-up radiographs. CONCLUSION: Nodular hepatosplenic sarcoidosis is associated with organomegaly, adenopathy, and symptoms. Nodules were not associated with advanced lung disease and did not herald a change in chest radiographic stage. An elevated ACE level may be helpful in diagnosis.

Adult↗
PubMed1995

Dynamic three-dimensional imaging with partial k-space sampling: initial application for gadolinium-enhanced rate characterization of breast lesions.

PURPOSE: To evaluate a method to monitor gadolinium enhancement patterns at magnetic resonance (MR) imaging with high temporal resolution and full coverage through both breasts. MATERIALS AND METHODS: In 12 patients with 13 masses, including nine carcinoma, nonenhanced three-dimensional MR imaging was performed with full-matrix resolution. At dynamic imaging, 32 serial passes were made during bolus administration of contrast material, and temporal resolution was reduced to 12 seconds by collecting the central (low spatial frequency) 32 x 16 or 16 x 16 phase-encode views. Full-matrix dynamic images were reconstructed by complementing central phase-encode data with precontrast data from peripheral high-spatial-frequency views. RESULTS: Results at time-course analysis with a mono-exponential saturation model indicated malignant lesions tend to show rapid (< 60 seconds) contrast change relative to benign masses and normal tissues. One cancer displayed an exceptionally slow contrast change (260 seconds). CONCLUSION: The technical objectives of full tissue coverage, rapid temporal sampling, and quantification of enhancement curves are met with this method for certain lesions (> 5 mm in largest diameter).

Adult↗
PubMed1995

Renal masses: assessment of corticomedullary-phase and nephrographic-phase CT scans.

PURPOSE: To evaluate the role of thin-section helical computed tomography (CT) performed during the corticomedullary phase (CMP) and nephrographic phase (NP) of contrast enhancement in the detection and characterization of renal masses. MATERIALS AND METHODS: Renal CT scans and medical records of 33 patients were retrospectively reviewed. In all examinations, 5-mm-thick, contiguous, helical-mode scans were obtained before and 40 seconds after initiation of dynamic bolus injection of contrast material (CMP images); 5-mm-thick, contiguous, axial-mode scans were obtained after completion of CMP scanning (NP images). RESULTS: At review of CMP, NP, and combination images, 259, 389, and 417 lesions, respectively, were identified. The greatest difference in detection occurred in the renal medulla, with 25 lesions identified on CMP images and 111 lesions identified on NP images. False-positive results occurred when CMP images were reviewed without NP images. CONCLUSION: CT scans obtained only during the CMP of contrast enhancement fail to depict many renal masses that are easily seen on NP images.

False Positive Reactions↗
PubMed1995

Characterization of adrenal masses with chemical shift and gadolinium-enhanced MR imaging.

PURPOSE: To assess the potential role of chemical shift and dynamic gadolinium-enhanced magnetic resonance (MR) imaging in the characterization of adrenal masses. MATERIALS AND METHODS: Fifty-one adrenal masses (35 adenomas and 16 nonadenomas) in 43 patients were evaluated with chemical shift MR imaging, dynamic gadolinium-enhanced MR imaging, or both. The relative change in the signal intensity (SI) ratio of the adrenal mass to liver and paraspinal muscles was quantitatively and qualitatively assessed. Opposed-phase gradient-echo (GRE) images were compared with in-phase images. RESULTS: With qualitative visual inspection, only adenomas showed a decrease in relative SI ratio on opposed-phase chemical shift images (specificity, 100%; sensitivity, 81%). Quantitative ratios corresponding to 100% specificity were also observed, with similar sensitivities. Adenomas could not be differentiated from nonadenomas with visual assessment of maximum SI after contrast material administration or washout. CONCLUSION: Characterization of an adrenal mass as an adenoma can be made with high specificity and acceptable sensitivity by visually comparing opposed-phase with in-phase GRE images.

Adenoma↗
PubMed1995

Preoperative staging of non-small-cell carcinoma of the lung: imaging methods.

Preoperative tumor staging in patients with non-small-cell lung cancer is important for selecting those patients with localized disease who are likely to benefit from surgical resection. The TNM staging system of the American Joint Committee on Cancer is the most widely accepted and used classification system for preoperative and postoperative staging [1] (Table 1). Small-cell carcinoma has a very different biologic behavior and is classified and treated differently; it will not be discussed in this imaging review. Chest radiography is the preferred initial imaging technique for patients with known or suspected lung cancer because of its availability, low cost, low radiation dose, and sensitivity [2]. CT and MR imaging of the chest and abdomen are often used to stage a known or suspected lung carcinoma. Various nuclear medicine procedures may be used to aid in the staging process and to assess the patient's medical status for surgery, including cardiac and pulmonary function. This article reviews the major imaging techniques that are currently used to stage primary non-small-cell carcinoma of the lung. Although evaluation of distant metastatic disease is highly important in these patients, discussion of the imaging methods used for this purpose is beyond the scope of this article.

Carcinoma, Non-Small-Cell Lung↗
PubMed1995

High-dose localized radiation therapy for treatment of hepatic malignant tumors: CT findings and their relation to radiation hepatitis.

OBJECTIVE: High-dose radiation therapy of the liver performed using overlapping portals defined by a three-dimensional treatment-planning system (conformal radiation therapy) is a new method of treating hepatic tumors. This study was performed to delineate the differences in the CT appearances of the liver after therapy compared with other methods of radiotherapy and to correlate imaging findings to clinical findings of radiation hepatitis. MATERIALS AND METHODS: Contrast-enhanced CT scans were obtained at 8- to 12-week intervals on 31 consecutive patients with primary or metastatic hepatic malignant tumors. All had undergone high-dose conformal radiation therapy and injection of fluorodeoxyuridine into the hepatic artery as part of the treatment for unresectable hepatic neoplasms. Tumor size, location, presence of changes within the target volume after therapy, presence of atrophy of the treated segments or hypertrophy of the untreated segments, ascites, and any changes in adjacent organs seen on serial CT scans obtained before and after treatment were recorded. Clinical records were reviewed for evidence of radiation hepatitis (nonmalignant ascites evident on physical examination and a twofold elevation of alkaline phosphatase in the anicteric patient). RESULTS: In 23 (74%) of the 31 patients, follow-up CT studies after treatment showed a low-attenuation area adjacent to the hepatic tumor in the target volume. In two patients with fatty infiltration of the liver, CT showed relative increased density in the treatment portal. A sharp, straight interface was rarely seen at the treatment margin. Maximal effect was seen 2-3 months after completion of therapy and persisted for up to 3 months. Atrophy in the treated segment or lobe was seen in four patients, hypertrophy of the untreated liver was seen in four patients, and both effects were seen in seven patients. Extrahepatic effects included segmental right renal atrophy in three patients and duodenal wall thickening in two patients. Only two patients (6%) in this series had clinical evidence of radiation hepatitis. CONCLUSION: High-dose localized radiotherapy of the liver results in reversible hypodense regions in the liver parenchyma within the target volume that do not have a sharp interface delineating the radiation portal. This appearance should not be confused with tumor progression or irreversible liver injury. The changes evident on CT scans after therapy are not predictive of radiation hepatitis.

Adult↗
PubMed1995

Implications of unsuspected pulmonary embolism detected by computed tomography.

OBJECTIVE: To describe the computed tomography (CT) findings and clinical implications of pulmonary thromboembolism noted incidentally on CT. PATIENTS AND METHODS: The authors reviewed the CT studies and medical records for nine patients in whom CT had shown clinically unsuspected pulmonary thromboembolism. The study group consisted of seven men and two women ranging in age from 51 to 75 years, who were referred for CT over a 5-year period for a variety of indications. The location of the emboli and the presence and location of parenchymal and pleural abnormalities were determined. Subsequent changes in patient care were analysed. RESULTS: The locations of the thromboemboli were described according to pulmonary zone. One case involved zone 1 (main pulmonary artery to a lung), all involved zone 2 (first-order branches), and four involved extension into zone 3 (second-order branches). No emboli were distinguished in zone 4 (beyond the segmental arteries). Four patients had pleural-based opacities characteristic of infarcts, and three had pleural effusions. Eight patients underwent confirmatory testing. A vena cava filter was placed in three patients, one of whom also received anticoagulation therapy. The other six patients were treated by anticoagulation alone. All of the patients survived and were discharged. CONCLUSION: Radiologists should watch carefully for occult pulmonary thromboembolism when interpreting CT studies of the thorax. Establishing this diagnosis can result in immediate changes to treatment and possibly a reduction in the substantial morbidity and mortality associated with untreated pulmonary emboli.

Aged↗
PubMed1994

Visual acuity and pupillary reactions after peribulbar anaesthesia.

The effect of peribulbar anaesthesia on optic nerve function in 20 patients, before and after cataract surgery, was measured. All the patients had decreased visual acuity. Five (25%) had no perception of light. Seventeen (85%) developed a relative afferent pupil defect (RAPD). No patients saw the operating instruments. Seven (35%) had improved visual acuity immediately postoperatively. Patients should be warned that they may lose vision completely on being given a peribulbar anaesthetic; however their vision will improve, but not necessarily immediately, postoperatively. Examination for an RAPD is a good method of providing reassurance that the operating instruments will not be seen.

Aged↗
PubMed1994

Retroperitoneal plexiform neurofibromas: CT findings.

OBJECTIVE: CT findings in retroperitoneal plexiform neurofibromas have been described previously only in a few case reports. This study was performed to characterize the CT features in a larger group of patients with this benign neoplasm and to delineate those findings that suggest the presence of concurrent malignant tumors of the nerve sheath. MATERIALS AND METHODS: From a review of CT scans showing retroperitoneal masses in 25 patients with neurofibromatosis type 1, we identified 16 patients whose clinical and CT features suggested the diagnosis of plexiform neurofibromas. The diagnosis was confirmed by biopsy of the mass in three patients. In the remaining 13 patients, the diagnosis was supported by long-term follow-up in eight and by biopsy confirmation of either a neurofibroma or a plexiform neurofibroma elsewhere in the body in the other five patients. Concurrent retroperitoneal malignant tumors of the nerve sheath were confirmed by biopsy in five patients. RESULTS: CT showed bilateral, remarkably symmetric masses extending along the medial and posterior aspects of the psoas muscles in 15 of the 16 patients. Parapsoas masses tended to be long and cylindrical. In addition to parapsoas masses, eight patients had bilateral, symmetric masses extending along the anterior aspect of the sacrum in a sheetlike fashion. Masses were identified in the region of the celiac axis and the origin of the superior mesenteric artery in four patients. Only one patient had an isolated celiac/superior mesenteric artery mass without associated parapsoas or presacral masses. Retroperitoneal masses were of homogeneous, low attenuation when compared with adjacent muscle on CT images of 14 patients. Two patients had an unusual swirling and serpiginous pattern of increased attenuation superimposed on a low-attenuation background. Asymmetry in size and attenuation was due to malignant nerve sheath tumors in five patients. CONCLUSION: Retroperitoneal plexiform neurofibromas have a characteristic appearance on CT scans. They are typically bilateral, symmetric, low-attenuation masses in a parapsoas or presacral location. Asymmetry in size and attenuation of a larger mass suggests the possibility of a malignant tumor of the nerve sheath. Recognition of the CT features of a retroperitoneal plexiform neurofibroma can obviate the expense, pain, and risk of an unnecessary biopsy. Conversely, detection of findings suggestive of malignant tumor can lead to appropriate recommendation of biopsy.

Adult↗
PubMed1994

Scintigraphic evaluation of clinically silent adrenal masses.

UNLABELLED: We studied 229 patients with abnormal adrenal anatomy depicted by CT who were without biochemical evidence of endocrine dysfunction using the presence of 131I-6 beta-iodomethyl-nor-cholesterol (NP-59) adrenal gland uptake as an index of differential adrenal function in the evaluation of the clinically "silent" adrenal mass lesion. METHODS: NP-59 (1 mCi) was injected intravenously with posterior and lateral abdominal images obtained 5-7 days postinjection. RESULTS: One-hundred and fifty-nine of 185 patients with unilateral adrenal enlargement on CT had scintigraphic evidence that the mass represented a functioning (NP-59 avid) but not hypersecretory, (biochemically normal) adrenal cortical adenoma (concordant imaging pattern). Forty-one of 44 patients with intra-adrenal neoplasms were depicted on scintigraphy as decreased or absent NP-59 accumulation on the side of the adrenal mass (discordant imaging pattern). In this study, sensitivity was 71% (41 of 58 patients; 95% confidence interval (CI), 58% to 88%); specificity was 100% (171 of 171 patients; 95% CI, 95% to 100%) and accuracy was 93% (212 of 229 patients; 95% CI, 88% to 96%). CONCLUSIONS: These data confirm our earlier observations that the functional information depicted by scintigraphy complements the morphological evaluation by CT and in the absence of hormonal dysfunction, the presence of concordant CT and 131I-NP-59 scans are characteristic of functioning, but not hypersecretory, benign adrenocortical adenomas. Conversely, discordant CT and 131I-NP-59 scans are suggestive of nonfunctioning, space-occupying, adrenal lesions.

Adenoma↗
PubMed1994

Multiple chemodectomas. Carotid body tumor masked by salivary gland uptake on I-123 MIBG scintigraphy.

Chemodectomas resemble pheochromocytomas in that they are derived from neural crest tissue. Their distribution in the body may be quite different, however, as chemodectomas are more frequently found in the aortic and carotid bodies, while pheochromocytomas are most common in the adrenal medulla. The authors present a case of a patient with a known history of chemodectoma, imaged with I-123 MIBG to rule out recurrent disease. Images of the chest revealed a thoracic tumor representing recurrent periaortic tumor, but an additional carotid body tumor (which was later demonstrated by angiography) was masked by salivary gland uptake. In patients with chemodectomas, SPECT imaging of the neck may be necessary to distinguish normal salivary gland uptake from tumoral uptake of MIBG. In general, knowledge of the characteristics of the individual neural crest derived tumor is mandatory for maximal effectiveness of I-123 MIBG scintigraphy.

3-Iodobenzylguanidine↗
PubMed1993

Radioimmunotherapy of B-cell lymphoma with [131I]anti-B1 (anti-CD20) antibody.

BACKGROUND: Many patients with non-Hodgkin's lymphomas are not cured by current therapies, and new approaches to treatment are needed. As part of an ongoing phase 1 study, we examined the effect of radioimmunotherapy with 131I-labeled B-cell-specific anti-CD20 monoclonal antibody in 10 patients with CD20-positive B-cell lymphomas in whom primary chemotherapy had failed. METHODS AND RESULTS: Anti-B1 (anti-CD20) mouse monoclonal antibody trace-labeled with 131I (15 mg containing 5 mCi) was given intravenously at approximately one-week intervals: first, without pretreatment with unlabeled anti-B1 antibody, to all 10 patients; then, with pretreatment with 135 mg of unlabeled antibody, to 8 patients; and then, with pretreatment with 685 mg, to 2 patients. Serial quantitative gamma-camera images and measures of whole-body radioactivity were obtained after each tracer dose. All known disease sites larger than 2 cm could be imaged. The effect of a pretreatment dose of unlabeled anti-B1 antibody on targeting of the tumor with the radiolabeled antibody was variable. The pretreatment dose of unlabeled antibody that produced the highest ratio of the tumor dose to the whole-body dose in tracer studies was then used to deliver higher doses of radioactivity for radioimmunotherapy in nine patients. Three patients received doses designed to deliver 25 cGy to the whole body (two patients treated twice, six to eight weeks apart), four patients received 35 cGy (one patient treated twice), and two patients received 45 cGy (one patient treated twice); each dose contained 34 to 66 mCi of activity. Six of the nine treated patients had tumor responses, including patients with bulky or chemotherapy-resistant disease: four patients had complete remissions, and two had partial responses. Three patients had objective responses to tracer infusions before they received radioimmunotherapeutic doses. Of the four patients with complete remissions, one remained in remission for eight months and the other three continue to have no disease progression (for 11, 9, and 8 months). There was mild or no myelosuppression. CONCLUSIONS: Radioimmunotherapy with [131I]anti-B1 antibody is a promising new treatment for lymphoma.

Adult↗