[Meniscal injuries of the knee. Diagnostic imaging]

Nowadays, treatment of meniscal tears is conservative with removal only of the broken part of meniscus. For this reason, before arthroscopy, the orthopaedic surgeon needs for an accurate preoperative diagnosis that could be obtained with computed tomography (CT) and magnetic resonance (MR). Our purpose is to value the actual role of CT and MR in diagnosis of meniscal tears. We retrospectively evaluated CT and MR images of 128 patients (average age 32 years) who then underwent arthroscopy. On the basis of our findings CT and MR have been shown to be very accurate to detect meniscal tears, even if with both methodics false positives and false negatives are possible. Nevertheless, MR is able to give high resolution multiplanar images without using ionising radiations and is preferable because of its high accuracy in recognising associated lesions of ligaments or articular cartilage.

[Tridimensional (3D) reconstruction in the osteoarticular area]

Three-dimensional reconstruction techniques have been used since the development of computed tomography. In skeletal radiology they have been used to better visualize fractures and spatial relationships between fragments in maxillo-facial surgery. Aim of this paper is to illustrate the most important reconstruction techniques and their application in skeletal radiology. Images can be obtained by means of a Spiral CT scanner with the following parameters: collimation/pitch/reconstruction interval 2/1/1. Acquired images are sent to a workstation with a software running on a Window NT platform Vitrea 2.01 (Vital Images, USA) equipped with Volume Rendering algorithm. SSD as well as MPR and curved reformatted reconstruction algorithms is available at the CT console. Three-dimensional reconstruction have been shown to be useful for the diagnosis and for a preoperative planning. Other applications of three-dimensional reconstruction techniques are prosthesis engineering and biomechanic research. 3D images help the communication between radiologist and surgeons. Technical advances in acquisition methods and in reconstruction algorithms are needed to improve image quality and use in skeletal radiology.

[Spiral CT and MR in injuries of the ankle and the foot]

Conventional radiography is the first radiological examination in injuries of ankle and foot, but often it has normal findings or it is difficult to execute for critical conditions of patients. Our purpose was to assess the value of CT and MRI in injuries of ankle and foot; we retrospectively reviewed the MR and CT images from 48 patients (age range 18-55 years), whose 16 had a major trauma with other skeletal segment lesions and the remaining a minor trauma limited to ankle and foot. On the basis of our results and experience, we think that in major trauma CT and MRI have similar findings about preoperative evaluation of fractures even if MR better identifies ischemia of fragments, subcortical contusions and lesions of ligaments, capsula or tendons. In minor trauma, MR is superior to CT because it can diagnose lesions of bone and periarticular structures that are difficult or impossible to identify with other instrumental examinations.

[Cervical spine injuries: diagnostic imaging]

In past few years, traumas of cervical spine have increased, chiefly owing to rise of road accidents. Nevertheless, only in a small percentage of cases lesions of cervical spine occur and, in order to reduce many negative radiographs, a careful clinical examination is required. Our purpose is to verify the value of radiology in evaluation of acute trauma of cervical spine and to propose an adequate radiological protocol. In the course of two years (1998-99), 376 patients were admitted in consequence of cervical trauma of different degree of gravity. In all patients, conventional radiographs were obtained, in 93 a computed tomography (CT) examination was executed and only in 18 patients with neurological symptoms a magnetic resonance (MR) was required. Fractures of cervical spine wee identified in 91 cases and in patients in which MR images were obtained, neurological lesions of various severity were diagnosed. On the basis of our results, we think that, in a clinical suspicion of cervical spine lesions, a conventional radiographic study has first to be performed even if often good radiographs aren't obtained for technical difficulties. If doubts persist on conventional radiographs or a fractures has already been diagnosed on radiographs but we want to verify its stability, a CT needs to be performed. MR is required if neurological symptoms are present in order to diagnose lesions of spinal marrow, nerve roots or ligaments.

[Spiral CT in maxillo-facial trauma]

Fractures of facial skeleton are common in a busy emergency department in often requires careful radiological study before surgical treatment. Radiographic evaluation of facial injuries is especially challenging because the complex facial structure results in a confusing overlapping of densities on the radiograph. Instead Spiral-CT enables obtaining images on different planes so that even subtle or complex fractures may be evaluated in the best way. Moreover, associated lesions of important organs can be diagnosed. Our purpose is to verify the value of Spiral-CT in traumatology of facial skeleton. We have evaluated retrospectively the images of 82 patients admitted for facial trauma. On the basis of our findings we think that conventional radiography should be reserved only for light traumas of superficial structures (nose, zygomatic arch, body of jaw); in the remaining cases Spiral-CT should be the first radiological examination.

[Femoro-patellar instability: radiologic assessment]

To propose a simple and reproducible radiological evaluation of the patellofemoral instability that enables the orthopaedic in choosing the best therapy. The radiographs and CT examinations of 55 patients, 38 female and 17 male (range 18-32 years) have been evaluated retrospectively. Twenty-height of them underwent surgical treatment for patellar instability. A radiological protocol which includes conventional radiographs in two projections and a CT examination both in extension, with and without quadriceps contraction, and in flexion at 20 degrees allows to give all the informations one's need for evaluating patellar height and mobility, trochlear dysplasia, valgism of the knee and the degree of excessive lateral position of the anterior tibial tuberosity. It's a simple, quick, accurate and reproducible protocol to do, even with different radiological systems.

[Wrist trauma: diagnostic imaging]

Wrist injury is common throughout life and, although history and physical examination provide important information regarding the type of lesion, a radiological study is essential to determine a specific diagnosis. Conventional radiography plays a central role in the wrist injuries but the diffusion of more sensitive methodics offers new possibilities. Our purpose is to evaluate the role of computed tomography (CT), magnetic resonance (MR) and arthrography in wrist trauma. We retrospectively examined the images of 45 patients with wrist injuries: in every patients a radiological examination in 4 standard projections was executed while in 25, 9 and 11 patients CT,MR and arthrography were performed. On the basis of our findings we think that conventional radiography is often sufficient for diagnosis of bone lesions even if CT sometimes is required to detect subtle fractures. MR has an high sensitivity not only for abnormalities of soft tissues, including interosseous ligaments and triangular fibrocartilage, but also bony abnormalities such as occult fractures and early osteonecrosis. Arthrography still remains the best procedure for evaluating lesions of triangular fibrocartilage and intercarpal ligaments especially in a preoperative phase.

[Rotator cuff rupture. Diagnostic imaging]

Conventional radiography, ultrasound, Magnetic Resonance (MR), Arthrography Computed Tomography (Arthro-CT) and Arthrography Magnetic Resonance (Arthro-MR) are available for diagnosis of rotator cuff tears. Our purpose is to assess the specificity and sensitivity of these examinations and if they could give to the surgeon all the informations to select the more accurate treatment. We have evaluated retrospectively the images of 68 patients, 43 male and 25 female (average age 51 years), which then have been surgically treated for rotator cuff pathology. On the basis of our findings, we think that conventional radiography and ultrasound are excellent in a first evaluation. MR images, particularly in the coronal and sagittal oblique planes, are able to demonstrate partial or complete rotator cuff tears. The use of intra-articular contrast medium (arthro-CT, arthro-MR) should be reserved for partial lesions on specific cases.

Cerebral imaging changes in patients with chronic renal failure treated conservatively or in hemodialysis

BACKGROUND

Nonuremic patients with apparently normal memory and behavior, studied by means of cerebral computed tomography and found to have cerebral atrophy (CA), evidenced functional intellectual deficits when they underwent psychometric testing. The finding of CA has been repeatedly reported in limited case groups of uremic patients who also demonstrated functional intellectual deficits on the basis of the same tests. This retrospective study considered all diagnostic cerebral computed tomography scans done in our department between 1981 and 1998. Fifty-five uremic patients in conservative treatment (CT) and 111 patients in hemodialysis treatment (HT) were selected on the basis of the following two criteria: primary nephropathy as the cause of uremia and an age < or =55 years to exclude involutive brain changes occurring with age.

AIMS

The aims of the study were to determine the percent of uremic patients with CA, the characteristics of their CA (cortical or subcortical), and eventual associated morphological lesions.

RESULTS

CA was detected in 50.9% (cortical atrophy in 47.3% and subcortical atrophy in 3.6%) of the uremic patients in CT and in 77.5% of those in HT (cortical atrophy in 65.7% and subcortical atrophy in 7.7%). The average degree of CA was 0.872 in the patients in CT and 1.765 in the patients in HT. Thirty-four of the patients in the CT group and 46 in the HT group were hypertensive: these patients had a more severe degree of CA than the nonhypertensive subjects. In the CT group, the degree of CA in the hypertensive patients was 1.205 versus 0.428 for the nonhypertensive subjects. In the HT group, the degree of CA was 2.087 for the hypertensive patients versus 1.538 for the nonhypertensive patients. Of the overall population, 7.8% had ischemic lesions, 9.6% had endocranial calcifications, and 5.4% evidenced periventricular white matter hyperintensities.

CONCLUSIONS

The high percent of CA found in young uremic patients increased in subjects in HT and, even more so in hypertensive patients. Vascular calcifications, focal ischemia and leukoaraiosis, well-known expressions of a chronic state of cerebrovascular insufficiency, were also found in HT patients; hypertension alone is a recognized accelerator of vascular damage. Thus, early and severe atherosclerosis and related hypoperfusion can be considered as the paramount causes of parenchymal cerebral damage in uremia.

[Radiologic assessment of femoro-patellar instability. Personal experience and review of the literature]

PURPOSE

To propose a simple and reproducible radiological evaluation of patellofemoral instability to enable the orthopaedic surgeon to choose the best therapy.

MATERIAL AND METHODS

We have evaluated retrospectively the radiographs and CT examinations of 25 patients, 15 female and 10 male, aged between 18 and 32 years. They underwent surgical treatment for patellar instability in the past 4 years. Lateral retinacular release has been performed in every patient, medial transposition of the anterior tibial tuberosity has been performed in 23 patients and in 5 of them also its distal replacement, proximal Insall's realignement was performed in 20 cases and only 1 patient underwent trochleoplasy. Preoperative conventional radiographs included antero-posterior view, true lateral view (exact superimposition of the posterior trochlear edges) and axial views at 30 degrees of knee flexion. On lateral view, the patellar height was evaluated based on Caton-Deshamps index and trochlear dysplasia assessed using the methods suggested by Dejour. A CT examination of both knees was performed: the images were taken first with knees in extension, with and without quadriceps contraction, then in flexion at 20 degrees. Patellar "bascùle" angles were measured both with quadriceps relaxed and contracted as an index of quadriceps dysplasia; the TAGT in extension was evaluated as an index of the degree of lateral position of the anterior tibial tuberosity. Preoperative conventional and CT findings were compared with those obtained postoperatively at 30.4 months from the surgical intervention.

RESULTS

All patients were free from complaints after surgery. In 5 patients a high patella was corrected by distal realignement of anterior tibial tuberosity. A trochlear dysplasia with different degrees of severity was present in all cases and it was not modified by surgical treatment, with the exception of the patient who underwent trochleoplasty. In the 20 patients who underwent proximal Insall's realignment, patellar "bascùle" angles--pathological before surgery--were restored to normal values with the exception of 3 cases. In 23 patients who underwent medial transposition of anterior tibial tuberosity, the values of the TAGT were all normalized: nevertheless, in three patients low values of the TAGT were found after surgery and this condition may predispose to the development of medial patellofemoral by iperpression syndrome.

CONCLUSIONS

In patients suffering from patellofemoral instability, a radiological protocol which includes conventional radiographs in two projections and a CT examination both in extension, with and without quadriceps contraction, and in flexion at 20 degrees supplies all the information needed for evaluating patellar height and mobility, trochlear dysplasia, valgism of the knee and the degree of excessive lateral position of the anterior tibial tuberosity. Careful evaluation of such abnormalities is important for selecting the best surgical treatment for each patient. It's a simple, quick, and accurate protocol that may be reproduced, even using different radiographic equipment. The collaboration between the radiologist and the orthopaedic surgeon is crucial for the correct interpretation of radiological findings, which must be evaluated together with clinical findings so that an adequate therapeutical plan could be proposed.

[Radiologic diagnosis of spondylodiscitis: role of magnetic resonance]

PURPOSE

To report the Magnetic Resonance Imaging (MRI) features of acute and chronic spontaneous spondylodiscitis as well as any typical patterns which can be useful for the differential diagnosis between pyogenic and tuberculous forms.

MATERIAL AND METHODS

Eleven patients affected with spontaneous spondylodiscitis were selected for the study; they were 7 men and 4 women ranging in age 33-87 years (mean: 64). We excluded the patients with iatrogenic spondylodiscitis. MR images were acquired with a superconductive magnet at 1.5, with the following sequences: sagittal PD and T2-weighted TSE, sagittal T1-weighted SE, axial PD and T2-weighted TSE for the lumbar spine, axial T2-weighted GRE for the cervical and dorsal spine and axial and sagittal T1-weighted SE after contrast agent (gadolinium DTPA) injection. MR images were reviewed by three experienced radiologists and morphological and signal intensity changes of vertebral body and disk were recorded on a standard form. In 9 patients it was possible to compare MR to CT findings.

RESULTS

At the time of our observation all patients reported pain at the spine level, associated with fever and weight loss in 50% of cases and with increased values of the inflammatory markers. Three patients had infectious diseases in other organs and 2 were diabetics. Biopsy was performed in two cases only and demonstrated Staphylococcus aureus in one and Mycobacterium tuberculosis in the other patient. MRI allowed the correct diagnosis to be made in all cases, demonstrating the pathological involvement of the paravertebral structures and into the spinal canal earlier and more accurately than CT. A common finding in pyogenic and tuberculous spondylodiscitis was the low signal of the subcortical bone marrow on T1-weighted sagittal images, which enhanced after Gd-DTPA administration and became intermediate or high on T2-weighted images. Moreover, the steady high signal intensity of the disk on T2-weighted images and its contrast enhancement on T1-weighted images is typical for an acute inflammatory process.

CONCLUSIONS

Based on our personal experience and literature data, we believe MRI to be the most sensitive technique for the diagnosis of spondylodiscitis in the acute phase, whereas it is comparable to CT in the chronic stage of the disease. At present MRI does not allow to differentiate pyogenic from tuberculous forms.

[Shoulder instability: diagnostic imaging]

Shoulder instability is often diagnosed among athletes; two clinical forms are distinguished: anatomical instability, with recurrent luxation of the shoulder, and functional instability, with pain, articular "click" and sensation of instability. Lesions of periarticular soft tissues (capsula, fibrocartilaginous labrum, gleno-humeral ligaments and rotator cuff) are common in both forms, while lesions of bone structures (humeral head and glenoid of scapula) are typical of shoulder with previous dislocation. Purpose of our retrospective study was to verify the value of magnetic resonance (MRI) and computed arthrography (arthro-CT) in diagnosing these lesions in 57 patients suffering from shoulder instability. On the basis of our results and experience we think that in a preoperative evaluation of an unstable shoulder, arthro-CT and arthro-MRI are more accurate because the intra-articular injection of a contrast medium better identifies lesions of capsula, gleno-humeral ligaments and fibrocartilaginous labrum. In other circumstances, such as the study of the shoulder for legal purposes, MRI is preferable because it offers an accurate and global evaluation of periarticular structures.

[Shoulder diseases in throwing athletes: radiologic assessment and surgical correlation]

Lesions of the shoulder, especially rotator cuff tears and glenoid labrum (SLAP) lesions, are commonly caused by traumatic episodes in athletes such as repeated trauma from throwing. The available radiological methods are MRI, CT and MR arthrography. Twelve athletes suffering from shoulder pain or instability have been studied and then underwent successful treatment in arthroscopy. On the basis of our results and experience, we think that MR, especially with intra-articular injection of contrast medium, is the best examination because it offers an accurate evaluation of both rotator cuff and glenoid labrum. Nevertheless difficulties are often encountered and definitive diagnosis sometime rests on arthroscopic exploration.

[Injuries of the cruciate ligament of the knee: diagnostic contribution of MR and spiral CT]

Lesions of cruciate ligament are common after knee trauma of different degree of gravity. Lesions evaluation is possible thanks to CT and MRI. Our purpose is to verify their value in diagnosis of cruciate ligaments lesions. We retrospectively evaluated 160 patients (80 CT and 80 MRI) with subsequent diagnosis of cruciate ligaments injury. CT and MRI were performed in the acute phase and in the subacute phase within 2-3 weeks from trauma. On the basis of our results CT and MRI shown a reduced sensitivity in acute phase owing to the intraarticular haemorrhage; in this phase MRI gives more information about fibres interruption. In subacute or chronic phase, both methods are correct in recognising the lesions but MRI is more sensitive and accurate. It is a real wish that, with more MRI machines diffusion, this method will be preferred in the study of cruciate ligaments both in acute phase and subacute-chronic phase.

[Upper cervical spine fracture: sources of misdiagnosis]

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.

[Mesenchymal tumors of the pancreas: computed tomography patterns]

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.

Hypertension as an etiopathological factor in the development of cerebral atrophy in hemodialyzed patients

Twenty-five patients on long-term regular hemodialysis treatment (RDT) at our dialysis unit who underwent diagnostic cerebral computed tomography (CCT) participated in a study aimed at clarifying the pathogenesis of cerebral atrophy occasionally found at their original scan. The upper age limit was 55 years to exclude the physiological involutive brain changes occurring with age. Cerebral atrophy (CA), as defined morphologically (enlargement of cerebral sulci or an increased Evan's Index), was detected in all cases. Seventeen patients underwent magnetic resonance imaging (MRI) to define possible white matter changes more accurately. No significant correlation was found between the degree of atrophy and the following uremia-altered hematoseric parameters: creatinine, hematocrit, cholesterol, triglyceridemia, albumin, PTH, calcium, inorganic phosphate. There was no correlation between degree of atrophy and number of months the patients had been on RDT or time that passed between the finding of a creatinine clearance <30 ml/min and the start of RDT. Very high correlations were found between the degree of CA and predialytic blood pressure values, and between CA and the duration of hypertension (n = 13, r = 0.66, p < 0.013). Thus, hypertension seems to be an early cause of cerebral parenchymal damage in RDT patients, and should be promptly corrected.

[Physiopathology, clinical aspects and prevention of renal insufficiency caused by contrast media]

Contrast-media associated nephropathy (CMAN) consists in a sudden impairment of glomerular filtration rate following exposure to radiographic contrast materials. Damage may be limited to an asymptomatic mild increase of blood creatinine, or reach the highest levels of nitrogen retention compatible with acute renal failure. Some preexisting clinical conditions or pathologies may lead to CMAN: not only renal insufficiency, diabetes mellitus, multiple myeloma, congestive heart failure and severe hypertension, but also simple dehydration and a growing series of immunologic diseases are recognized as predisposing condition. The exact mechanism responsible for renal injury is still doubtful but recently animal models have shown substantial ischemic changes that may be added to the traditional presumed pathogenesis of direct tubular toxicity and intra-tubular obstruction. As renal ischemia stimulates both endogenous vasoconstrictor and vasodilator substances, it is now supposed that CMAN acts similarly to non-steroidal anti-inflammatory agents, selectively inhibiting the vasodilatory prostaglandin phase and therefore causing a derangement of the physiologic vasoconstriction/vasodilatation balance of renal circulation. The role of oxygen free radicals to contribute to renal dysfunction is considered. Low osmolality non ionic contrast media when compared to conventional high osmolality ionic contrast media have reduced but not eliminated CMAN. Simple but effective lines of prevention include the previous selection of patients predisposed to CMAN for concomitant pathology, suspension of FANS or any other recognized nephrotoxic substance, the least amount of contrast media compatible with radiologic visualization of the patient's problem, careful hydration of the patient before contrast injection and sustained diuresis afterwards. The usefulness of pre-treatment with Ca-channel blockers or atrial natriuretic factors remains sub judice.

Progression of cerebral atrophy in patients on regular hemodialysis treatment: long-term follow-up with cerebral computed tomography

Fifteen patients (10 males, 5 females) on regular hemodialysis treatment (average age 43.6 +/- 4.0 years, average time on dialysis 100.7 +/- 62.8 months) underwent cerebral computed tomography between 1981 and 1984. Ten patients showed mild cerebral atrophy (CA) on the basis of cortical sulci exceeding 3 mm in breadth and an Evans ratio exceeding 0.31, for a total of 14 degrees of CA (mean 0.9 +/- 1). The same 15 patients underwent a second cerebral computed tomography during 1991/92 (101 +/- 23.7 months later). At that time, the patients exhibited a degree of CA of 2.6 +/- 1.4, for a total of 39 degrees with an overall increase of 25 degrees. Since CA is not detected before the age of 55 years in the normal population, we conclude that the CA in this patient group can only be attributed to uremia-related pathology and that it tends to worsen as regular hemodialysis treatment continues. Nevertheless, no evident cognitive, affective, or behavioural changes were verified in these patients. To our knowledge, this is the first presentation of radiologically documented progression of CA in the same patient population over time.

Peripheral arteriography with a new nonionic agent: comparison of iomeprol with iopamidol

Aim of this randomized, double-blind, parallel group study was to compare the safety, tolerance and diagnostic efficacy of iomeprol and iopamidol, both at iodine concentration of 150 mgI/ml, in 100 adult patients undergoing peripheral intra-arterial digital subtraction angiography (IA-DSA). All patients underwent extensive pre- and post-contrast clinical, instrumental and laboratory evaluation for safety assessments. The tolerance to the test compounds was evaluated in terms of discomfort associated with the injection of the test compounds. Image quality was prospectively graded by two independent readers according to a five-point scale as 1, insufficient; 2, sufficient; 3, good; 4, excellent; or E, excessive. At the end of the study, two experienced radiologists working at institutions other than the study centre and not aware of patients identity, clinical profile or results of other imaging procedures, jointly evaluated study images using the same ordinal scale. The procedure was always well tolerated. None of the studied patients experienced adverse events. All angiographic examinations were rated as diagnostic. The quality of the radiographs was judged as excellent or good in most individual patient studies, without significant differences between the two study groups. No significant differences between the results of prospective on-site assessment and retrospective external assessment were detected. The results of our study show that iomeprol and iopamidol are equally effective, well tolerated and safe contrast agents when used for peripheral IA-DSA.

MR cisternography of the cerebello-pontine angle and internal auditory canal in diagnosis of intracanalicular acoustic neuroma

One hundred and fifteen patients, suffering from sensorineural hearing loss were tested with a 1.5 T superconducting magnet. The authors describe utility of both T1-weighted multiple slice and T2-weighted multiple echo images for the evaluation of cerebello-pontine angle, internal auditory canal and their neurovascular content. In seventy-three cases MR cisternography was normal. The remaining forty-two cases were subdivided into twenty extracanalicular masses, eleven small intra-extracanalicular and nine purely intracanalicular lesions. All the lesions were histologically proven acoustic neuromas, except one intracanalicular mass which was a meningioma. Examination was inconclusive only in two cases and decision was then made to follow the clinical course. Advantages of MR cisternography over CT and air CT cisternography, such as absence of ionizing radiation and contrast material, easy multiplanar evaluation of the region of interest and the possibility to delineate both the cisternal and canalar extremities of the tumor mass are pointed out.

[The optic pathways: a magnetic resonance study at 1.5 tesla. I. Anatomy]

The authors retrospectively examined one hundred and twenty-nine patients who had undergone MR examination of the sellar, parasellar and orbital regions, to evaluate MR capabilities in demonstrating the optic pathways and their relationship to the most important anatomical structures nearby. T1-weighted images allowed a very good evaluation not only of the optic pathways as a whole, but also of the intracanalicular and intracranial segments of the optic nerve; the optic tracts and geniculate bodies were also clearly demonstrated. Optic radiations were clearly visible on both T1- and T2-weighted images. The orbital portion of the optic nerve could be evaluated with T1-weighted images, which showed its external profile. However, only multi-echo T2-weighted images allowed the nerve to be differentiated from perineural spaces, filled with cerebrospinal fluid, thus giving a true cisternographic effect.

MR findings in Meige syndrome

A 65-year-old woman was diagnosed clinically to have Meige syndrome in the oromandibular dystonic clinical variant of Marsden. On magnetic resonance imaging a reduced signal intensity in the head of the caudate nuclei, more prominent on the right, and in both putamina was shown.

[Dissection of the internal carotid artery. Personal case reports and a review of the literature]

The clinical and angiographic features of 20 patients affected by internal carotid artery dissection are reported. In one patient the neurological signs were related to a traumatic event, in two cases the symptoms presented after hyperextension of the neck during athletic events, while their onset was apparently spontaneous in the remaining 17 patients. Plain CT was normal in 14 cases and positive for ischemic necrosis in 6 patients. Angiography demonstrated extensive/segmental stenosis of the internal carotid lumen in 12 cases (60%), pseudoaneurysmal dilatation in 3 cases (15%), and complete carotid occlusion in 5 patients (25%). The "double lumen" feature was seen in 3 cases at the origin of the dissection. One patient died, surgical ligature of the internal carotid artery was performed in two cases, while the other patients received medical treatment with platelet inhibitors, except for the young patient affected by post-traumatic artery dissection. Complete recovery was observed in 82% of the patients. Follow-up angiograms demonstrated normal recanalization of the internal carotid artery in 4 out of 6 patients; one of them had two false aneurysms which following angiograms demonstrated to be completely resolved. Regression of stenosis was observed in 6 of the remaining patients by Doppler US. On the whole, the recanalization of the internal carotid artery was observed in 59% of cases. Angiographic findings seemed not to play a decisive role in the prognosis of carotid dissections, which largely depends on the overall patient's condition and on the presence/absence of ischemic cerebral damages.

[Preoperative embolization of angiomas of the face. Remote angiographic results]

Preoperative embolization was performed on 27 patients with facial angiomas supplied by the external carotid branches. Sixteen were males and 11 females; 13 of these angiomas were high-flow arteriovenous (A-V), 14 were low-flow capillary malformations. Fourteen patients underwent surgical removal after preoperative embolization; in this group embolization was carried out with Spongel in 3 cases and with Lyodura in 11 cases. In 12 of these patients the last angiographic examination was performed 3-6 years later: angiography evidenced no recurrence in 8 cases (67%), while in 3 cases (25%) there was capillary residual angioma of negligible size. Treatment was unsuccessful in one patient only, due to the large recurrent A-V angioma. Thirteen patients underwent embolization only, which was carried out with Lyodura in 10 cases, and with Ivalon in 3 cases. On 12 of these patients the last angiographic study was performed 2-14 months later: there was recurrent A-V angioma in 5 patients (42%), who underwent a subsequent embolization; angiography evidenced no recurrence in the other 7 patients (58%). In both series, the best results were obtained in the patients with low-flow capillary angiomas. Embolization and subsequent surgical removal are the treatment of choice for facial angiomas; embolization alone is useful in the management of surgically inaccessible vascular malformations, and it can be the only treatment in patients with small low-flow angiomas when distal occlusion of the feeding vessels with Lyodura or Ivalon particles is performed.

[The role of computerized tomography in the diagnosis of osteoid osteoma]

Radiological diagnosis of osteoid-osteoma is based upon conventional radiographic techniques, i.e. plain film and tomography, scintigraphy and Computed Tomography (CT). The authors report on the use of CT in 13 patients affected by histologically verified osteoid-osteoma, in different locations, as related to their main clinical and epidemiological signs. A comparison is made of the diagnostic contribution of the different techniques, including scintigraphy and tomography, when available. CT results were evaluated referring to fundamental semiologic elements, such as the presence of the nidus--with or without calcifications--of perilesional sclerosis, hyperostosis and periosteosis. As a rule, we can affirm that CT allows a better spatial location in the metaphysodiaphyso-epiphyseal areas, the only exception being represented by location in the metacarpal and phalangeal bones, which are better evaluated in the axial plane due to their thinness. CT is otherwise indispensable for a correct evaluation of the posterior vertebral arch.

Cerebral computed tomography in uremic and hemodialyzed patients

Sixty-nine uremic patients, 19 on conservative and 50 on regular hemodialysis treatment (RDT), showing no clinical symptoms attributable to central nervous system impairment, were examined by cerebral CT to discover morphological modifications in brain structure and determine their incidence. A CT picture indicative of cortical atrophy was observed in 56.5% of the cases, associated with ventricular atrophy (15.9%), especially in patients on long-term RDT. In addition, CT revealed areas of low density related to past episodes of cerebral ischemia in 10.1% of the cases and some small calcifications in the brain parenchyma in 4.5% of the patients. The degree of these lesions seems to correlate with the duration of uremia.

Diastematomyelia in adults

The authors report two cases of diastematomyelia in adults. One patient had a congenital kyphoscoliosis; the other had undergone surgery at birth for a myelomeningocele. The occurrence of diastematomyelia in patients with congenital scoliosis and myelomeningocele is discussed. Diastematomyelia is regarded as one of the causes of late deterioration of neurological function in such cases.

Cerebral atrophy in patients on long-term regular hemodialysis treatment

The presence of Cerebral Atrophy in the form of cortical damage (Cortical Atrophy) or subcortical damage (enlargement of ventricular cavities) was explored by computed tomography (CT) scans in 30 patients maintained on regular hemodialysis treatment (RDT) for not less than 10 years, and less than 50 years of age. Whereas a group of 50 normal subjects of the same age, used as control, gave no evidence of cerebral atrophy, 46.6% of the patients maintained on RDT showed cortical atrophy, evenly diffuse in half the cases and predominantly frontal in the other half. In addition 16.6% of the patients showed subcortical atrophy, even in the absence of evident central neurologic or neuropsychic symptoms. In a search for the possible causes of this high incidence of cerebral atrophy in chronic hemodialysis patients we reviewed the last five years' profiles of clinical and blood biochemistry parameters known or suspected to produce brain damage when altered, as stored in a computer system available to our Hemodialysis Unit: these were mean blood pressure before and after hemodialysis, blood cholesterol and triglyceride assays, and mean daily oral intake of A1(OH)3. The status of arterial blood vessels in terms of vascular calcification in soft tissue roentgenograms was also defined; then we correlated these clinical and biochemical indices with the findings of cerebral CT scans by the Fisher test and Discriminant Analysis. The Fisher test revealed a decreasing correlation of cerebral atrophy with mean blood pressure, A1(OH)3 intake, blood cholesterol content, arterial calcifications and blood trygliceride assay in that order.(ABSTRACT TRUNCATED AT 250 WORDS)

High resolution O2 computed meatocisternography in the differential diagnosis of internal auditory canal pathology

Recent introduction of O2 computed tomography cisternography and imaging with high resolution program have greatly improved the detection and preoperative evaluation of acoustic neuromas and other possible pathologies of the internal auditory canal. Sixty patients have been evaluated following the diagnostic protocol given in the text. Based on our results and on the experience as reported in literature HRO2CTC proved to be the most reliable method for detection and exclusion of intracanalicular and small extracanalicular acoustic neuromas and other pathologies at the internal auditory canal level.

Cluster headache: remission following ascending aorta/innominate artery bypass surgery. Case report

A 51-year-old man with cluster headache has been free from cluster attacks for over two years following ascending aorta/innominate artery bypass surgery for correction of an atherosclerotic narrowing at the origin of the innominate artery. Surgery may have been a causal factor in the remission of these attacks.

[Clinical and angiographic aspects of medullary angiomas]

The authors present six personal cases of medullary angiomas: three cases of retromedullary, one of intramedullary and two of intra-retromedullary vascular malformations. One of two last cases was associated with a paravertebral arteriovenous malformation. The neuroradiologic investigations include a water-soluble myelography, with hypocicloidal tomography, and spinal cord selective angiography. The latter present many advantages of the aortography, for feeding arteries visualization, but the site of the shunt inside the intervertebral foramen can be localized only by angiotomography. In our cases neurological complications or clinical worsening were not found.

[Correlations between Doppler velocimetry, arteriography and intraoperative findings in the study of carotid vascular diseases]

The present paper reports the results obtained in 54 patients who underwent a non invasive cerebral vascular examination by doppler technique, followed by a cerebral angiography: a total of 86 carotid arteries were compared. An overall accuracy between arteriographic and ultrasonographic results was found in 69 arteries whereas in 15 arteries there was a discordance; and in only 3 cases ultrasonographic findings resulted false negative. The Authors have also considered the emodinamic and anatomo pathological results obtained in 23 carotid arteries operated on, in order to evaluate ophthalmic test accuracy and noninvasive evaluation of Willis's circle. The Authors have reached the conclusion that doppler technique appears to be inadequate in case of turbulent flow due to arterial dilatation or to non significant stenosis. In addition they have noticed a better reliability of emodinamic findings and a poor accuracy of the ophthalmic test.

[Controlled clinical study of the treatment of chronic bronchitis with guacetisal]

Controlled clinical research has been carried out on the activity and tolerance of a new active principle, guacetisal (Broncaspin) obtained from the esterification of acetylsalicylic acid with guaiacol, in the treatment of chronic bronchitis. The drug's therapeutic response was evaluated with respect to that of bromexine. Guacetisal was generally well tolerated. It had no unwanted side-effects on the main haematochemical parameters or on the function of organs and systems. It was found to have considerable therapeutic effectiveness, at times even superior to that of the control drug, with respect to general symptomatology and at respiratory system level. It produced early, lasting reduction in temperature, heart frequency, dyspnoea, duration of expirium and in the intensity and number of coughing attacks. It also led to an appreciable improvement in thoracic objectivity and the X-ray picture. Variations in respiratory functional parameters were of considerable interest and from these it is concluded that guacetisal exerts its polyvalent activity to a proportionately higher extent in the bronchial districts more seriously involved in the inflammatory process, inducing an elective improvement in bronchial permeability, a reduction in total pulmonary resistances--with consequent tendency for ventilation-perfusion relations to normalise--as well as an improvement in gas exchanges and patient oxygenation.