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Coronary angiography is nowadays the diagnostic standard in the evaluation of coronary artery anatomy, in the identification of stenoses and in the follow-up of revascularization procedures (PTCA-stenting, bypass). The limitations of such technique in terms of invasivity and high cost has targeted research efforts towards the development of non invasive diagnostic tools. Technological evolution in the field of helical CT has provided 2, 4, 8 and 16 detector-row multislice scanners characterized by progressive improvements in terms of spatial and temporal resolution that have made them increasingly suitable for the analysis of moving structures with high quality anatomic detail. The main cardiologic applications of multislice CT include coronary calcium scoring, the evaluation of coronary vascular anatomy and disease, follow-up of revascularization procedures (stenting, bypass), and the evaluation of cardiac walls and chambers. The aim of this paper is to describe the applications of sixteen detector-row multisclice CT in non invasive evaluation of cardiac and coronary diseases.

Purpose: Spontaneous dissection of the carotid and vertebral arteries represents a rare pathology. Its pathogenesis, probably multi-factorial, can be related to neck trauma and to a genetic basis, extensively demonstrated in the cases of association with type IV fibromuscular dysplasia, Ehlers-Danlos syndrome, Marfan's syndrome, pseudoxanthoma elasticum and osteogenesis imperfecta. Onset symptoms include neck, facial pain and diffuse headache. Cranial nerve palsy has been also described. The aim of this study was to evaluate MR angiography and MR findings in a population of patients with carotid and vertebral artery dissections., Materials and Methods: We reviewed the MR angiography and MR exams of 15 patients (10 males, 5 females, average age 42.0, age range 30-55) with carotid and/or vertebral artery dissection; the serial MR follow-up studies were also examined., Results: Twelve internal carotid arteries (ICA) showed the presence of an irregular stenosis; three of these showed complete occlusion. In two patients both ICA were involved. Six vertebral arteries (VA) showed irregular stenosis (only one patient suffered from both CI and VA dissection); in one case there was also a pseudoaneurysm of the VA. Follow-up studies showed vessel lumen re-opening in 5/11 ICA (one patient underwent vascular stent positioning) and in 3/6 VA., Conclusions: The present study confirms the usefulness of MR angiography and MR in the diagnosis and follow-up of patients with carotid and vertebral artery dissection.

Purpose: To evaluate a patient population affected by Neurofibromatosis type 1 (NF1) with special reference to optic pathway gliomas., Material and Methods: A total of 419 NF1 patients (222 men, 197 women) were retrospectively evaluated to show incidence, biological behaviour, neuroradiological and clinical presentation of optic pathway gliomas. Central Nervous System MR and ophthalmologic evaluations were reviewed., Results: Thirty-two patients out of 419 (7.6%) showed the presence of optic pathway gliomas. Of these, 28 (87.2%) patients showed tumoral involvement of the optic chiasma. The right intracranial optic nerve was involved in 15 patients (46.8%), the left intracranial optic nerve in 18 (56.2%), the right extracranial optic nerve in 11 (34.3%), the left extracranial optic nerve in 10 (31.2%) and the right and left optic tracts in 6 (18.7%) patients. Geniculate body and optic radiation were not involved by tumour diffusion. Visual acuity testing was positive in 26/32 (81.2%), the fundus oculi in 11/32 (34.3%) patients and the visual field evaluation in 12/32 (37.5%) patients., Conclusions: In this study we showed an high correlation between optic pathway tumours and ophthalmologic abnormalities confirming the usefulness of an integrated clinical-neuroradiological approach in patients affected by NF1. We also described the biological behaviour of these tumours in our NF1 patient population.

Purpose: To assess the role of CT in diagnosing and characterizing gastric fatty tumors., Material and Methods: We reviewed the CT scans of 16 patients (8 men, 8 women, mean age 52 years) with gastric fatty tumors (11 lipomas, 3 liposarcomas, 1 angiolipoma, 1 teratoma) examined from 1990 to 1999. The differential diagnosis considered primary and secondary lipomatosis, carcinoma engulfing the perivisceral fat and thus mimicking a liposarcoma, mesenchymal gastric and primary peritoneal tumors., Results: Lipomas involved the fundus (7/11), the body (3/11), the antrum (1/11). Multifocality was found in one case. Lesions size ranged 25 to 65 mm (mean 35 mm). All the lipomas showed homogeneous structure with negative (-30 -100) HU values. A pseudocapsule was demonstrated in 7/11 cases. No infiltrative growth was demonstrated. The angiolipoma located in the fundus showed a vascular component with strong contrast enhancement. All the liposarcomas were bigger than 10 cm and there was a strong correlation between pathologic specimen and CT findings. The differentiated liposarcomas showed the classic heterogeneous fatty density; on the contrary the myxoid and the pleomorphic types showed an aspecific structure with necrotic/cystic changes, mostly demonstrated in the myxoid type. The teratoma was a solid mass with fatty, solid, necrotic and calcified components., Conclusion: CT allows the diagnosis and characterization of gastric fatty tumors. The preoperative diagnosis of lipomas plays a major clinical role because it often makes surgery unnecessary.

Purpose: To investigate the relationship between Magnetic Resonance (MR) findings and the presence of isolated growth hormone deficiency (IGHD) or multiple pituitary hormone deficiency (MPHD)., Material and Methods: 39 children, 27 boys and 12 girls (mean age 9.6 years) were enrolled. The growth hormone deficiency and MPHD were defined by standard laboratory methods. MR scans of the hypothalamo-hypophyseal tract were carried out on all patients before the therapy. Perinatal histories were reviewed., Results: The pituitary anterior lobe was considered small in 13/39 (33%). Twenty-six of 39 (66%) patients did not show any abnormalities of the hypothalamohypophyseal tract. An ectopic neurohypophysis was found in 8/39 patients (20%). Only 2 patients among those with an ectopic neurohypophysis showed a small anterior pituitary lobe. Thirty-three of 39 (84.6%) patients showed IGHD while 6/39 (15.4%) patients showed MPHD. Twenty-eight of 39 (71%) patients had a severe deficiency while 11/39 (28%) patients had a moderate deficiency., Conclusion: Our study confirms the usefulness of MRI in the diagnostic and therapeutic approach to short stature in children; in fact 48% of patients in our series showed MR findings reasonably related to hormonal deficiency.

Purpose: To describe CT findings of calcified renal metastases focusing on differential diagnosis problems., Material and Methods: We retrospectively reviewed abdominal CT scans of 8000 patients with tumor, performed from 1984 to 1998. Among the 58 renal metastases, 9 showed a calcific component. We evaluated the location, morphostructural pattern, histology of the primary lesion, the synchronous or metachronous character and the type of treatment. All the lesions were pathologically proved., Results: The primary histotype of the 9 metastases was as follows: 4 mucin-producing adenocarcinomas of the large bowel, 1 gastric mucinous adenocarcinoma, 1 chondrosarcoma, 1 osteosarcoma, 1 melanoma, 1 papillary thyroid carcinoma. In all the cases the renal metastasis was unilateral and unifocal. Granular multiple calcifications were demonstrated within the metastases of mucin-producing adenocarcinoma of the large bowel (3), within the metastasis of chondrosarcoma (1) and of melanoma (1). Diffuse "star-like" calcifications were demonstrated in renal metastases of mucin-producing adenocarcinoma of the large bowel and of gastric mucinous adenocarcinoma (1). Peripheral "egg-shell" calcifications were demonstrated in renal metastasis from papillary thyroid carcinoma (1). Completely calcified monofocal calcification was demonstrated in renal metastasis from osteosarcoma (1)., Discussion and Conclusions: Calcified renal metastases are rare lesions related to specific oncotypes. The differential diagnosis (carcinoma with calcifications, osteosarcoma, chondrosarcoma, nephrocalcinosis, granulomatosis, hydatidosis etc.) is particularly difficult because of the aspecificity of the morphostructural pattern. Diagnosis is based on a history of specific oncotypes (papillary and mucin-secreting carcinomas, osteosarcoma and chondrosarcoma), but in most cases it requires pathologic confirmation.

Purpose: Gastric stromal tumors are an ill-defined group of lesions arising from muscle wall cells and characterized by extremely variable biological patterns. Thanks to modern immunohistochemical and ultrastructural techniques, four main classes of these lesions have been identified, namely: 1) tumors with differentiation toward smooth muscle cells; 2) tumors with differentiation toward neural elements; 3) tumors with dual differentiation toward both cell types; 4) tumors lacking differentiation toward either cell type. We investigated the yield of CT in diagnosing and characterizing gastric stromal tumors., Material and Methods: We retrospectively reviewed the CT findings of 38 patients (15 men and 23 women; mean age 51 years) with pathologically proven gastric stromal tumors, namely 31 of myoid origin, 4 of neural origin, 2 with both muscle and neural differentiation, 1 lacking differentiation with either cell type. Morphological (size, margins, growth pattern, enlarged lymph nodes, metastases) and structural (density, calcifications, necrosis, cystic changes, enhancement patterns) parameters were evaluated and compared with histopathologic diagnosis., Results: The myoid tumors involved gastric fundus in 9/13 and 5/7 benign lesions and lesions with variable biological patterns, respectively, while the malignant tumors exhibited diffuse involvement in 7/11 of cases. Eleven of 13 benign lesions had regular shape and a diameter +/- 5 cm, while 5/7 intermediate tumors and 7/11 malignant ones were 6-10 cm and over 10 cm (1/7 and 3/11, respectively). Tumor growth was intramural (6/13) or mixed (5/13) in the benign lesions, mainly exophytic in the malignant ones, and finally variable (2/7 intramural, 3/7 exophytic and 2/7 mixed) in the tumors with intermediate patterns. Calcifications were identified only in 3 benign lesions. Structure was homogeneous in 11/13 of the benign lesions with regular contrast enhancement (10/12), heterogeneous due to necrotic areas in nearly all (10/11) or most (5/7) malignant and intermediate forms, respectively. Enlarged lymph nodes (4/11) or synchronous metastases (7/11) were found in the malignant lesions. Our two schwannomas had a pseudocystic structure with regular peripheral contrast enhancement; the neurofibroma was characterized by multiple, markedly hypodense and hypovascular lesions. Both the malignant neurogen form and the two tumors with dual differentiation showed a diffuse, aspecific and infiltrating pattern. The lesion without differentiation had a "benign" shape and structure even though it developed metastases two years after radical surgery., Conclusions: Despite the lack of specificity of CT patterns of gastric stromal tumors, these parameters are useful in differentiating benign from overtly malignant forms. The definition "gastric stromal tumor with benign, variable, or malignant macroscopic appearance" should be used in the radiologic report.

Purpose: Computed tomography (CT) and, more recently, ultrasound (US), have proved excellent tools for quantifying adipose tissue distribution. Body fat distribution is an important factor in the treatment of obesity and its complications. We investigated the correlation between CT and US measurements in pediatric obesity., Material and Methods: Forty obese children and adolescents aged 4.1-14.8 years were submitted to CT and US. Intra-abdominal, subcutaneous and total body fat were calculated (in cm2), with the CT image analysis software. The rectus muscle-spine and rectus muscle-aorta distances, as indicative of visceral fat thickness, were measured on US images with(out) compression. The distance between skin-fat and fat-rectus muscle interfaces was measured as subcutaneous fat thickness. We also compared US-CT findings with other morphometric variables--i.e., patient's (ideal) body weight and skin fold measures., Results: At US, the rectus muscle-aorta and rectus muscle-spine distances ranged 2.4-7.5 cm (mean: 4.47 cm) and 3.6-8.9 cm (mean: 5.79 cm), respectively. The skin-rectus muscle distance ranged 1.2-7.5 cm (mean: 3.14 cm). A statistically significant correlation was found between the CT measurement of visceral fat and the aorta-rectus muscle and rectus muscle-spine distances (r = 0.80 and 0.74, respectively). The US measurements of subcutaneous fat were correlated with CT subcutaneous fat area (r = 0.82). No correlation was found between overweight, as calculated by body mass index, and CT or US fat., Conclusion: Our findings indicate that US is as useful as CT in evaluating body fat distribution in pediatric obesity.

Purpose: Missing cervical spine fractures during the initial plain film study may lead to severe neurological complications for patients and to medicolegal responsibilities for the physician. The upper cervical spine tract (C1-C2) is considered to be at high risk for misdiagnoses. We decided to investigate the possible causes of mistake in the cases of missed fractures on the initial plain film, performed in the emergency room., Material and Methods: We retrospectively reviewed the radiological reports, the original plain films and the CT findings, of 32 patients with upper cervical (C1-C2) fractures, admitted January 1994 to December 1998. Twenty-eight of these patients (87.5%) had multisystem trauma, 4 (12.5%) had minor craniocervical trauma. None of these patients had neurological signs correlated to the cervical injuries, 30 of them had normal consciousness and reported only neck pain, 2 of them were unconscious for the associated head trauma and were hospitalized in the intensive care unit. All the patients with normal consciousness underwent conventional three-view cervical spine radiography; the two unconscious patients in the intensive care unit were submitted to bedside examination with an anteroposterior and a lateral views of the cervical spine. All patients underwent spiral CT of the upper cervical tract., Results: In 9 of 32 patients (28%) a cervical fracture was missed on the plain film and CT was performed only because of persistent neck pain. We found 2 Jefferson's fractures, 2 type II dens fractures, one type I dens fracture and 4 hangman's fractures. In 8 of the 9 patients (89%) the fracture was potentially unstable. Misdiagnoses resulted from overlapping bone structures (3%), suboptimal film quality (3%), satisfaction of search phenomenon (3%), missed mild tilting of the dens (6%), missed double cortex sign (16%), missed C1-C2 lateral subluxation (6%) and marked osteoporosis (3%). Prevertebral soft tissue swelling was not seen in any of the 9 cases of missed fractures. Considering the group of patients with C1-C2 fractures separately, the false negative rate is 28%, which corresponds to 10.7% of the total number of patients with cervical fractures and dislocations examined during the same period., Conclusions: Among the causes of false-negative interpretation, osteoporosis, suboptimal film quality due to associated fractures and overlapping bone structures must be considered unavoidable. On the other hand these possibilities should be indicated on the X-ray report because, if painful symptoms persist, a CT exam is strongly advised. Subtle alterations like dens tilting, double cortex sign, lateral subluxation of C1 and prevertebral soft tissue swelling should be regarded as highly suspicious for fracture. Missing these lesions might be considered a true diagnostic mistake with possible legal consequences, which may also expose the patient to the risk of neurological complications. The satisfaction of search phenomenon can be avoided only by trying to use a search pattern for every film, which includes checking all the visible anatomical structures even in the presence of a particularly evident lesion. In all questionable cases or high-risk fracture patients, even with an apparently negative plain film, it is advisable to perform CT instead of additional plain films. Finally, in all the patients treated in the intensive care unit for head trauma, an upper cervical CT scan should be routinely carried out at the same time as the brain scan.

Purpose: To report the CT patterns of pancreatic mesenchymal lesions and to investigate the capabilities and limitations of this technique in terms of characterization., Material and Methods: We selected the CT examinations of 23 patients from all CT examinations of the pancreas performed from 1986 to 1998. The patients were 10 to 85 years old and all lesions but two (1 lipoma and 1 lymphoma) had pathologic confirmation. Two lymphangiomas, 2 lipomas, 4 Schwannomas (SCH), 1 plexiform neurofibroma, 1 cystic teratoma, 1 pancreatoblastoma, 9 non-Hodgkin's lymphomas (NHL), 1 undifferentiated sarcoma and 2 leiomyosarcomas were diagnosed., Results: Lipomas had typically homogeneous negative HU values, and NHL a homogeneous hypodense pattern with mild contrast enhancement, with no necrosis or calcifications in both diffuse and nodular forms; SCH had variable appearance, with water/slightly negative HU numbers or highly enhanced patterns with a central necrotic core depending on the main Antoni A or B histology. Lymphangiomas appeared as complex cysts, with thin and regular or calcified walls and intracystic septa, while the plexiform neurofibroma had near-water homogeneous density with mild contrast enhancement and an infiltrating growth pattern. Our teratoma had multiple calcifications, mucinous and lipid components. The pancreatoblastoma, sarcomas, and leiomyosarcomas exhibited no specific findings., Conclusions: In selected cases, CT can provide virtually diagnostic information (lipoma and teratoma), or at least highly suggestive findings (NHL, plexiform neurofibroma, lymphangioma). Moreover, knowledge of the variable morphostructural patterns of mesenchymal histotypes (SCH, sarcoma etc.) permits to include them in the differential diagnosis of pancreatic masses.

Purpose: To analyze the extracerebral manifestations of type 1 neurofibromatosis (NF-1), with special reference to peripheral nerve tumors., Material and Methods: The findings of 376 NF-1 patients (194 men and 182 women; age range: 0.1-48 years, mean: 8.1) were retrospectively reviewed. The patients had been submitted to abdominopelvic and superficial US and, in case of abnormal US findings or in the presence of symptoms, to CT and/or MRI. In addition, we considered 5 more patients (2 men and 3 women; age range: 50-72 years, mean: 64.4) with incomplete forms of NF-1 diagnosed after the finding of nerve sheath tumors. Biopsy (12 cases), surgery (10 cases), or clinical-instrumental follow-up were the study criteria., Results: In the first group of patients we identified 91 cutaneous, 222 subcutaneous, 11 pendulous and 25 internal neurofibromas. Plexiform neurofibromas were found in the neck (1 case), chest (6 cases), abdomen (16), pelvis (8). We also found 1 benign and 1 malignant Schwannomas, 2 nerve sheath fibrosarcomas, 1 dopamine-producing sympatoma and 1 spermacytoma. As for the second group of patients, we had 2 Schwannomas, 1 pulmonary neurofibroma, and 2 multiple plexiform neurofibromas. The neurofibromas exhibited homogeneous US hypoechogenicity or slight echogenicity, with little contrast enhancement at CT. MR showed peripheral hyperintensity and central hypointensity on T2-weighted sequences and marked contrast enhancement after gadolinium, sometimes with mostly central uptake. The plexiform neurofibromas, which are typical of NF-1, had poorly-defined or infiltrating margins, with similar findings to the previous ones but sometimes with less homogeneous patterns at both US and CT. The Schwannomas, which are a less common finding in NF-1, exhibited different features at MRI and CT, namely pseudo-liquid or solid-inhomogeneous patterns with irregular and inhomogeneous contrast enhancement relative to the Antoni A/B tumor component. In the malignant lesions we observed infiltrating patterns, with irregular and inhomogeneous contrast enhancement, arranged asymmetrically relative to the contralateral lesion., Conclusions: Extra-axial neoplasms are a frequent finding in NF-1. Despite the extremely variable appearances of some lesions (particularly Schwannomas), the typical plexiform neurofibroma exhibits characteristic patterns. The diagnosis of malignancy often requires bioptic confirmation.

Purpose: To analyze the lung damage caused by anticancer drug toxicity comparing the pathologic mechanisms, histopathologic response and CT features., Material and Methods: Twenty-one patients (15 men and 6 women aged 21-75 years, mean: 41) were selected from the cancer patients treated with chemotherapy 1990 to 1997 (1400 lung examinations in all). The primary tumors consisted of: 6 testicular, 2 ovarian, 2 breast and 1 renal cancers; 3 non-Hodgkin lymphomas; 1 acute myeloid and 1 chronic lymphatic leukemia; 1 melanoma, 1 uterine leiomyosarcoma, 1 liposarcoma, 1 osteosarcoma and 1 head and neck carcinoma. All the patients underwent a CT examination with contiguous 8-10 mm slices and thin (4-5 mm) detail slices or with the high resolution technique. All the cases had clinical, laboratory and pathologic confirmation of the drug-related lung damage., Results: Four alveolar opacities, 11 interstitial opacities, 2 solitary and 4 multiple nodular lesions were demonstrated. Bleomycin was the most toxic drug in 14/21 cases, the total dose always exceeding 450 mg. Methotrexate followed and then cytosine-arabinoside (both 2/21). Bleomycin was responsible for all nodular lesions, cytosine-arabinoside and interleukin-2 for pulmonary edema. After drug discontinuation and appropriate treatment in 14 cases, we found favourable evolution with restitutio ad integrum (9 cases) or CT findings of clear improvement (5 cases); fibrosis progressed in 6 cases and one patient died., Conclusions: CT provides important information for the diagnosis of drug-induced lung damage. Despite the nonspecific patterns of the lesions, CT can demonstrate the early, and thus potentially reversible, stages of lung damage. CT is also very helpful in monitoring the onset, resolution, or progression of fibrosis.

Purpose: Lymphomatous ovarian involvement is an uncommon event, both for primary and systemic lymphoma. It presents different diagnostic and therapeutic implications from the more common ovarian epithelial cancer. We investigated the role of imaging techniques in the diagnosis of these lesions., Material and Methods: Eight patients, aged 13 to 70 years (mean: 47) were selected from all the CT examinations performed from 1986 to 1996 to assess the most typical imaging patterns. All the patients underwent a CT examination, with contiguous 8 or 10 mm thick slices and thin (4-5 mm) detailing slices; iodinated contrast agents were administered in 6 cases. Six patients were also examined with sonography (US). Lastly, 3 patients underwent a MR examination, 2 of them with paramagnetic contrast agent., Results: All the patients were affected with non-Hodgkin lymphoma (6 diffuse lymphomas--1 lymphoplasmocytoid, 2 Burkitt, 1 large cells, 1 large and oat cells, 1 immunoblastic large cells, 2 follicular large cells lymphomas). Two patients had primary lesions and the other 6 had a systemic lymphoma; ovarian involvement was bilateral in 6 cases. The lesion size always exceeded 5 cm. Ascitis was present in only one case. The US patterns of the lesions were aspecific, homogeneous and hypoechoic; color Doppler US showed mild vascularization. CT showed clear-cut lesions, hypodense and with mild contrast enhancement in all cases. Spin-echo MRI showed homogeneous masses which were moderately hypointense on T1-weighted images and slightly hyperintense on T2-weighted images. Gd-T1-weighted images showed mild enhancement., Discussion: The differential diagnosis of ovarian primary lymphoma is usually made with ovarian epithelial neoplasms, which normally have a complex structure with cystic or necrotic areas and solid components usually enhancing after contrast agent administration. Also sarcomas and, in children, neuroblastomas usually have an inhomogeneous structure. In ovarian involvement with systemic lymphoma the concrurrent finding of adenopathy can help the diagnosis., Conclusions: Despite the absence of typical imaging patterns, we emphasize the importance of considering ovarian lymphoma in the differential diagnosis of ovarian cancers, especially if bilateral and homogeneous, without ascitis. These findings, uncommon in ovarian epithelial tumors, can help to make the correct diagnosis.

Purpose: We studied the CT and MR appearance of thymic carcinoids and compared the morphostructural patterns of this tumor with those of other anterior mediastinal masses particularly involving the thymic area., Material and Methods: We retrospectively reviewed all the chest CT scans performed 1985-1996. Four patients (2 women and 2 men; age range: 25-51 years, mean: 36.5) had thymic carcinoid. MR findings were also available for 3 of 4 patients. The pathologic diagnosis was made in all cases, by CT-guided needle biopsy (1 case), by surgical biopsy (2 cases), or directly at surgery (1 case)., Results: CT showed capsulated, quite enhanced tumors with no local spread or distant metastases in 1 case; 2 tumors appeared as complex masses with necrotic components and calcifications, massively invading mediastinal structures; another case appeared as an infiltration of mediastinal fat and vessels with no definite tumor mass. Thrombosis of the superior vena cava and right atrium and some lung metastases were found in one case. MR signal was hypointense on T1 and PD images and inhomogeneously hyperintense on T2 images in all the 3 patients. One patient had Cushing syndrome and another mild adrenocortical hyperfunction. The other patients had no endocrine dysfunctions. Both the patients treated with surgery and subsequent irradiation are alive and free of relapse at 48 and 17 months, while the other 2 patients died 25 and 39 months after the diagnosis., Conclusions: The CT and MR patterns of thymic carcinoids are not specific because other mediastinal and particularly thymic tumors present similar patterns. However, a thymic carcinoid must be suspected when a thymic mass is associated with clinical laboratory findings of endocrine dysfunction.

Purpose: The modern integrated approach to neoplastic diseases permits to detect metastatic lesions in uncommon sites, such as the thyroid gland. We reviewed the ultrasonographic (US) and Computed Tomographic (CT) patterns of secondary thyroid lesions, comparing imaging findings with primary tumor histopathologic diagnosis., Material and Methods: We reviewed a series of 10 thyroid metastases diagnosed from 1986 to 1995 at staging (4 cases) or follow-up (6 cases) examinations; in the latter, metastases were diagnosed 39 to 89 months (mean: 58 months) after the primary tumor. The patients were 7 women and 3 men, 55 to 94 years old (mean: 65 years). The final diagnosis was made at cytology (4 cases), histology (5 cases) or surgery (1 case)., Results: The primary tumors were breast cancer (2 cases), melanoma (2 cases), small cell lung cancer, bronchioalveolar carcinoma, mucoid stomach adenocarcinoma, renal carcinoma, colon carcinoma and leiomyosarcoma (1 case each). The thyroid lesion was unifocal in 6 patients and multifocal in 2; the gland was diffusely involved in 2 patients. Dysphagia was found in all patients. Thyroid function was normal in 6/7 patients and one had hyperthyroidism; normofunctional goiter was found in another patients. US showed focal or diffusely infiltrating hypoechoic lesions; likewise, inhomogeneously hypodense areas with mild contrast enhancement were observed at CT. Thyroid secondary lesions exhibited variable patterns when necrotic, hemorrhagic or calcific areas were included; correlations with primary tumor-pathogenetic and histologic features were often observed. Survival rate was 2-60 months (mean: 19 months)., Conclusion: Since imaging findings in thyroid metastases are often not specific and sometimes atypical, fine needle biopsy of suspicious lesions should be carried out for both staging and follow-up.

Although high-grade non-Hodgkin's lymphoma (NHL) and an unusually aggressive form of Kaposi's sarcoma (KS) remain the most common malignancies seen in AIDS patients, other tumors such as cervical cancer, Hodgkin's disease and others, have been increasingly observed, probably because these patients now live longer. We report the imaging findings of 80 AIDS patients with pathologically confirmed neoplasms from a series of 340 AIDS patients examined 1986-1994. Twenty-four of 80 patients had NHL, 4 Hodgkin's disease, 31 KS, 4 cervical cancer, 2 leukemia, 2 testicular, 1 larynx, 2 lung, 2 breast, 1 esophagus, 1 stomach, 1 liver, 2 kidney and 3 adrenal carcinomas. Twenty of 24 NHLs exhibited extranodal involvement--to the liver (13/24), brain (9/24), lung (7/24) and gastrointestinal tract (6/24). Visceral KS involved the gastrointestinal tract (6/32), lung (4/32) and liver (2/32). The most accredited pathogenetic theories concerning the role of HIV infection in oncogenesis advocate the effect of multiple growth factors produced by HIV-infected lymphocytes (KS) or the disregulation of B-cells caused by T-cell destruction (NHL). The atypical morphostructural features of AIDS-related tumors are discussed--e.g., atypical presentation, occurrence in younger individuals, aggressive clinical course and poor response to conventional therapy--together with the differential diagnostic problems, especially vs. opportunistic infections.

One thousand mammograms of non-preselected patients were reviewed in order to assess in how many and which cases an equivocal diagnosis can be made unquestionable and to test the value of follow-up exams with direct radiographic magnification. Direct radiographic magnification was used in all questionable cases (3%): 18 lesions were characterized by microcalcifications and 12 by nodules. Four cases were diagnosed as unquestionable (13%)-1 microcalcification and 3 nodules-while 13 patients were reexamined with mammography only. Even though the percentage variation from equivocal to unquestionable diagnoses is modest but significant, direct radiographic magnification is always useful in the follow-up.

Hemosiderosis, which results from transfusional therapy and from increased absorption of dietary iron, is a severe complication of thalassemia major. The complication is also very difficult to manage. An accurate determination of the total amount and of the distribution of body iron stores is essential for prognostic purposes and to evaluate the efficacy of chelation therapy. Therefore, a suitable tool for the noninvasive depiction of iron overload is to be hoped for. MR imaging has been usefully employed, of late, to this purpose. Sixteen thalassemic patients have been studied to evaluate iron depositions using a 1.5 T magnet. Signal intensities from liver, pancreas, spleen, bone marrow, and heart were considered. The signals were dramatically lower than the normal values obtained in a sex- and age-matched group; the differences were due to the iron. Iron distribution appeared inhomogeneous, with the highest overload in liver and bone marrow. Since cardiomyopathy represents the first cause of death in thalassemic patients, the relationship between cardiac function and iron overload in the heart has been thoroughly investigated. Finally, the authors conclude that MR will become a widely employed method for assessing iron overload and will contribute to improve the management of thalassemia major.

A sonographic and a computed tomographic study of 29 patients was performed in order to assess the possibilities of these imaging techniques in tissue characterization of renal angiomyolipoma. From the review of the results the authors, confirming the very high accuracy of the two associated methods for a correct diagnosis, underline the possibility to identify the hamartoma mesenchymal components with the possibility of more prognostic and therapeutic informations.