Volumetric quantitation by MRI in primary progressive multiple sclerosis: volumes of plaques and atrophy correlated with neurological disability.

In primary progressive multiple sclerosis (PPMS) abnormalities in brain magnetic resonance imaging (MRI) differ from abnormalities in other subtypes of multiple sclerosis (MS). It was investigated whether the extent of brain and spinal cord MRI abnormalities is reflected in the neurological disability in PPMS. Focal and diffuse changes and atrophy in central nervous system (CNS) in patients with PPMS (n = 28) and healthy controls (n = 20) were assessed by semi-automatic MRI segmentation and volumetric analysis. The measurements were related to neurological disability as expressed by the expanded disability status scale (EDSS), the regional functional scoring system (RFSS), the arm index and the ambulation index. Plaques in T1- and/or T2-weighted images were seen in all brains, while spinal plaques were detected in 23 of 28 patients (82%). The total volumes of brain and spinal cord were significantly smaller in patients than in controls (P = 0.001 and 0.000, respectively). The volumes of T1 or T2 lesions in the brain correlated to the ambulation index (r = 0.51, P = 0.005 and r = 0.53, P = 0.004, respectively). No correlations were detected between MRI measurements and total EDSS score, but relative brain atrophy correlated inversely with the total RFSS scores, poor arm index and higher cerebral disturbances (r = -0.53, P = 0.004; r = -0.53, P = 0.004; and r = -0.52, P = 0.005, respectively). Although the number of spinal T2 lesions correlated with sensory disturbances (r = 0.60, P = 0.001), no correlations were found between EDSS subscores and spinal cord atrophy. These findings show that marked atrophy of brain and spinal cord detected by volumetric quantitation correlates with neurological disability. This observation indicates the importance of neurodegenerative events in PPMS.

Virtual endoscopy imaging of the middle ear cavity and ossicles.

Ten cadaver temporal bone blocks were studied with high-resolution computed tomography (HRCT) in order to produce topographic images, which are more informative than ordinary CT slices. Virtual endoscopic images were produced with separate, commercially available software, paying attention to the middle ear cavity and ossicles. Four major viewing locations for virtual endoscopy (the ear canal, hypotympanum, attic and eustachian tube) developed images acceptably. The malleus and incus were visualized properly. Small structures such as the lenticular process and the stapes sometimes failed to have good imaging. The eustachian tube and attic virtual views, which are usually not receptive to ordinary endoscopy, gave proper visualization of middle ear structures. Even the smallest structure, the stapes, can produce a virtual image.Virtual endoscopic images, or topographic images, of the middle ear and ossicles contribute to the understanding of the anatomy of the middle ear, thus enhancing the chances for successful surgery.

Comparison of CT and fiberoptic video-endoscopy findings in congenital dysplasia of the external and middle ear.

Twenty-six ears (of 25 patients) with congenital dysplasia of the external and middle ear were studied with two different types of imaging technologies in order to find out if it is possible to improve the anatomical overview of the dysplastic middle ears by combining the imaging methods. All the 26 ears were studied with computed tomography (CT), which gave cross-sectional images of the tympanic cavity. A fiberoptic video-endoscope (FVE) was introduced through the nose and via the Eustachian tube into the middle ear so that the topographic view of the anatomical structures of the middle ear could be visualized. Some structures were visualized better with FVE than with CT and vice versa. We concluded that the combined information obtained from these two imaging technologies provided a better understanding of the structural anatomy of a congenital dysplastic middle ear.

Magnetic resonance imaging based volume estimation of ovarian tumours: use of a segmentation and 3D reformation software.

The application of a new segmentation software, Anatomatic in the evaluation of volumetric measurements of ovarian tumours and the new Medimag three-dimensional (3D) software in the evaluation of 3D image representation of ovarian tumours with 1.5 T magnetic resonance imaging (MRI) is described. Our goal was to compare MRI based volumetry with operative findings at laparotomy for six consecutive patients with suspected ovarian tumours. Volumetric analysis and three dimensional image reconstructions of the tumours were obtained. At laparotomy, the tumour sizes were measured in situ, and the volumes were calculated. Using Anatomatic, reproducible tumour volumes were achieved with ease and within a reasonably fast time in patients with ovarian tumours without ascites. Medimag helped achieve realistic 3D representations of the tumours. For the four solitary tumours segmentation based volumetry and laparotomy findings agreed in three cases. In one patient with an oval shaped tumour, the segmented volume was double as compared to that estimated at laparotomy. Of the two patients with multiple tumours, both patients had significant ascites, and volumetry misinterpreted the fluid as tumour cyst fluid and markedly overestimated the tumour size. In conclusion, the MRI based segmentation volumetry and 3D image reconstructions are rapid, and reproducible methods of measuring ovarian tumours in patients without significant ascites.

Magnetic resonance imaging compared to ultrasonography in fetal weight and volume estimation in diabetic and normal pregnancy.

OBJECTIVE: To estimate fetal volume and weight in diabetic and normal pregnancy using high-resolution magnetic resonance imaging. METHODS: T1-weighted magnetic resonance imaging was combined with semiautomatic segmentation technique. The accuracy of fetal volume estimations thus obtained was compared with conventional ultrasound-based weight estimations in ten pregnant women with insulin-dependent diabetes mellitus and ten women with normal pregnancy. Examinations were made within 48 hours before delivery. RESULTS: Ultrasound-based estimations of fetal weight showed a correlation rate of r=0.77 with the actual birth weights in the whole material, while volume determinations based on magnetic resonance imaging showed a significantly better correlation rate of r=0.95. Diabetic women did not differ from the normal pregnancy group with regard to birth weight or the accuracy of weight estimations. CONCLUSIONS: High-resolution magnetic resonance imaging combined with semiautomatic segmentation software was found to be accurate in determining fetal volume and, consequently, better than conventional ultrasound-based techniques in estimating fetal weight. The use of magnetic resonance imaging in fetal weight estimation may be recommended for clinical situations where an accurate weight estimate is considered essential.

MR angiography with three-dimensional time-of-flight and targeted maximum-intensity-projection reconstructions in the follow-up of intracranial aneurysms embolized with Guglielmi detachable coils.

BACKGROUND AND PURPOSE: Intra-arterial contrast angiographies are generally used to confirm treatment results of endovascular neurointerventions such as aneurysm obliteration. We compared MR angiography with digital subtraction angiography (DSA) as a follow-up technique for the detection of aneurysmal remnant cavities and arterial patency in patients treated for intracranial aneurysms with Guglielmi detachable coils (GDCs). METHODS: In 20 consecutive patients, follow-up MR angiography and routine intra-arterial cerebral angiography were performed on the same day 1 to 7 months (mean, 4.5 months) after embolization with GDCs. MR angiographic data were postprocessed for subvolume maximum intensity projections centered on the region of the treated aneurysm. Hard copies of both imaging studies were interpreted independently in a blinded fashion to record and compare remnant cavities, location of residual flow, and adjacent arterial narrowing, using DSA as the standard of reference. The interpreters also established an occlusion grade for the treated aneurysms as evidenced on DSA images and evaluated MR angiograms for artifactual effects. RESULTS: Overall sensitivity and positive predictive value of MR angiography in revealing aneurysmal remnant cavities were both 90%. Specificity in ruling out a remnant cavity with MR angiography was 91%. One remnant cavity was missed by MR angiography, and in five patients, false adjacent arterial encroachments were reported. CONCLUSION: MR angiography may be useful in the long-term follow-up of successfully treated small and medium-sized aneurysms after concurrent primary verification of their occlusion with DSA.

Volumes of brain atrophy and plaques correlated with neurological disability in secondary progressive multiple sclerosis.

The objectives of the present study was to correlate the segmented magnetic resonance imaging (MRI) volumes of intracranial cerebrospinal fluid (CSF) spaces (expressing the extent of brain atrophy) and cerebral plaques with the neurological disability in secondary progressive multiple sclerosis (MS). Earlier studies have mainly correlated MS plaques and neurological disability measured by expanded disability status scale (EDSS). The data on the association between brain atrophy and EDSS or regional functional scoring scale (RFSS) are very limited. We measured the volumes of intracranial CSF spaces in 28 patients with secondary progressive MS using MRI, and semiautomatic segmentation software. The volumes of T1-weighted hypointense and T2-weighted hyperintense MS plaques were also measured. In multiple regression analysis, increasing volumes of total (P=0.006) and relative (P=0.005) intracranial CSF spaces were significantly associated with worsening neurological disability as expressed by EDSS. No associations were found between these intracranial CSF space volumes and total RFSS scores. The mean volume of T2-weighted plaques showed a tendency to associate with total RFSS score (r=0.40, P=0.03), but no correlations were detected between T1- or T2-weighted plaque volumes and EDSS. The application of a new segmentation technique in quantifying intracranial cerebrospinal fluid spaces allowed an exact and sensitive way of assessing brain atrophy. The associations between brain atrophy and neurological disability expressed by EDSS suggests that the effect of MS therapies should be evaluated by measurement of brain atrophy.

Semi-automatic segmentation of computed tomographic images in volumetric estimation of nasal airway.

The objective of this study was to determine nasal cavity volumes and cross-sectional profiles from segmented coronal high-resolution computed tomography (HRCT) images. Pathological mucosal changes and congenital sinonasal variants were quantitated and three-dimensional (3D) images for determining sinonasal airway diseases evaluated by using the new semiautomatic segmentation software, Anatomatic. Anterior to posterior cross-sectional profiles of the sinonasal airway were obtained from acoustic rhinometry and segmented coronal HRCT images and compared in five patients having complaints of nasal obstruction and chronic sinusitis. Results showed that accurate volumes of air spaces in the nasal cavity and paranasal sinuses were obtained. When compared, the cross-sectional profiles of the nasal cavities obtained from acoustic rhinometry and the segmentation technique were similar in the anterior portion, but differed in the posterior portion. The results obtained by coronal HRCT and segmentation were more reliable than those produced with acoustic rhinometry. 3D images acquired from segmented images were found to help make a good pre-operative assessment of the whole sinonasal compartment. Segmentation and volumetric analysis using the Anatomatic technique also proved to be well suited to the evaluation of the nasal cavity and paranasal sinus geometry in patients with sinonasal diseases.

Patient outcome after endovascular treatment of intracranial aneurysms with reference to microsurgical clipping.

OBJECTIVES: Endovascular treatment of intracranial aneurysms with Guglielmi detachable coils (GDC) has found growing acceptance worldwide, and partially replaced conventional microsurgery. In this study clinical and angiographical results of embolization are reviewed. In addition, long-term neuropsychological patient outcome with reference to surgery is assessed. Indications for screening and follow-up of the patients as limitations and recent achievements of aneurysm embolization are discussed. MATERIAL AND METHODS: Angiographical and clinical follow-up of the first 44 patients with 48 GDC-coiled aneurysms are reviewed. Postprocedural clinical, emotional and social (CES) outcome on disability scale as scored from postal questionnaire data is presented and compared to 106 currently operated patients. RESULTS: In 75% of the embolized aneurysms successful occlusion was achieved, procedural mortality was 2.3% and morbidity 18.2%. Clinical status of all 15 patients with unruptured aneurysms preserved. Of the surviving 29 patients with ruptured aneurysms 12 improved and the rest preserved their clinical status. In 91% of the embolized patients and in 85% of the operated patients CES outcome was categorized as good or excellent. The difference was statistically nonsignificant. CONCLUSION: Embolization with GDC is a feasible, effective and safe mini-invasive method in small aneurysms with a small neck. However, intentional parent artery occlusion, novel endovascular techniques and embolic agents or supplementary surgery may be necessary in selected cases. Neuropsychological long-term outcome of the patients treated for an intracranial aneurysm does not differ much between GDC embolization and microsurgical clipping.

Nasal airway volumetric measurement using segmented HRCT images and acoustic rhinometry.

Semiautomatic segmentation methods using High Resolution Computed Tomography (HRCT) or Magnetic Resonance Imaging give accurate and reproducible volumetric measurements in various intracranial diseases. In this prospective study, for the first time in literature, with the help of a new semiautomatic segmentation technique and coronal HRCT, we correlated the volumes and cross-sectional areas of the nasal cavity with those obtained by clinical acoustic rhinometry in 14 patients with chronic sinusitis. The measurements obtained by both techniques showed statistically significant correlations between volumes in the anterior and middle parts, but statistically poor correlations between the volumes in the posterior part of the nasal cavity. Coronal HRCT and our new microcomputer applicable semiautomatic segmentation software proved compatible with daily clinical practice. Based on the promising results of our study, we recommend the use of this technique in the validation studies of acoustic rhinometry and in complicated cases as a complementary examination in the evaluation of nasal cavity.

Endovascular treatment of carotid-cavernous fistulae.

INTRODUCTION: In the embolotherapy for the treatment of carotid-cavernous fistulae (CCF) several embolic agents and techniques have been reported. In this series the efficiency of transarterial electrothrombosis with Guglielmi detachable coils (GDC) in direct fistulae and the occlusion with particles, tissue glue and platinum coils in indirect fistulae is studied and the implications of these findings is discussed regarding classification, conservative therapy and follow-up. MATERIAL AND METHODS: Eleven consecutive patients were reviewed retrospectively. Four patients had direct high flow fistulae from the internal carotid arteries and the rest had low flow dural fistulae. Postprocedural clinical outcome and angiographical follow-up are presented. RESULTS: Six patients became symptom free, in 4 patients the symptoms resolved and 1 patient suffered a minor procedural complication. In the 8 follow-up angiographies the fistulae of 7 patients were totally closed, including the 4 patients with direct fistulae. CONCLUSION: Progressive clinical manifestations require embolization to alleviate the symptoms and to prevent further complications of the arteriovenous shunting. Embolization with GDC is a feasible, effective and safe method in direct fistulae.

Visualization of the middle ear with high resolution computed tomography and superfine fiberoptic videomicroendoscopy.

Ten temporal bone blocks were dissected from fresh postmortem specimens from patients succumbing to diseases unrelated to the ears. A superfine fiberoptic videomicroendoscope (SFV) was introduced through the eustachian tube into the middle ear, and middle ear structures were visualized. The cadaver temporal bone blocks were also studied with high-resolution computed tomography (HRCT). When HRCT gave good results SFV did not succeed well and vice versa. However, SFV provided topographic anatomical information of the middle ear structures while HRCT gave cross-sectional images of the anatomy of the tympanic cavity. The different types of information obtained by the two imaging technologies supplement each other and were found to improve diagnosis in such cases as external ear canal atresia.

Applicability of semi-automatic segmentation for volumetric analysis of brain lesions.

This project involves the development of a fast semi-automatic segmentation procedure to make an accurate volumetric estimation of brain lesions. This method has been applied in the segmentation of demyelination plaques in Multiple Sclerosis (MS) and right cerebral hemispheric infarctions in patients with neglect. The developed segmentation method includes several image processing techniques, such as image enhancement, amplitude segmentation, and region growing. The entire program operates on a PC-based computer and applies graphical user interfaces. Twenty three patients with MS and 43 patients with right cerebral hemisphere infarctions were studied on a 0.5 T MRI unit. The MS plaques and cerebral infarctions were thereafter segmented. The volumetric accuracy of the program was demonstrated by segmenting Magnetic Resonance (MR) images of fluid filled syringes. The relative error of the total volume measurement based on the MR images of syringes was 1.5%. Also the repeatability test was carried out as inter-and intra-observer study in which MS plaques of six randomly selected patients were segmented. These tests indicated 7% variability in the inter-observer study and 4% variability in the intra-observer study. Average time used to segment and calculate the total plaque volumes for one patient was 10 min. This simple segmentation method can be utilized in the quantitation of anatomical structures, such as air cells in the sinonasal and temporal bone area, as well as in different pathological conditions, such as brain tumours, intracerebral haematomas and bony destructions.

Diagnosis and embolizing of spinal arteriovenous malformations.

Spinal arteriovenous malformations are uncommon disorders associated with considerable difficulty in diagnosis and treatment. They are divided into dural arteriovenous fistulas and intradural medullary spinal cord angiomas. In this retrospective series of six patients the clinical outcome of embolization is presented. The patient material consisted of three dural fistulas and three cord angiomas, one of which bled causing sudden paresis, pain and incontinence. In the remaining five patients the symptoms were progressive consisting of paraesthaesias, paraparesis, pain and incontinence. The clinical status of four patients was not changed after the treatment, one deterioriated and one improved. There were no bleedings after the therapy. In one patient spinal angiography for follow-up was performed and recanalization was seen in the dural fistula after particle embolization. Also, in one cord angioma embolized with particles reflow appeared in the immediately repeated angiography. For permanent angioma occlusion tissue adhesive is preferred as embolic material. Surgical therapy as an alternative or adjuvant to embolization is discussed with a review of the literature. Early timing of the therapeutic intervention is stressed to avoid the development of irreversible ischaemic medullopathy and to prevent haemorrhage. The therapeutic procedures at the early stage of the disease may be curable or, at least, halt the progression of the symptoms. Cross-sectional imaging studies and myelographies may reveal the lesion. For the definitive diagnosis of spinal angioma with its vascular feeders and for the evaluation of its occlusion grade after the therapy selective spinal angiography is needed.

Emergency CT in blunt abdominal trauma of multiple injury patients.

Multiple injury patients with blunt abdominal trauma (n = 110) were examined by abdominal CT. An i.v., but not peroral, contrast medium was used, thereby eliminating the delay caused by administering peroral contrast medium and any subsequent delay in making the diagnoses and beginning operative treatment. Eighteen patients underwent emergency laparotomy after the initial CT examination. The preoperative CT findings were compared to the laparotomy findings. CT revealed all but one of the severe parenchymal organ lesions requiring surgery. The one liver laceration that went undetected had caused hemoperitoneum, which was diagnosed by CT. The bowel and mesenteric lesions presented as intra-abdominal blood, and the hemoperitoneum was discovered in every patient with these lesions. Fourteen patients also initially had positive abdominal CT findings; 10 of them underwent an additional abdominal CT within 3 days, but the repeat studies did not reveal any lesions in need of surgery. Omission of the oral contrast medium did not jeopardize making the essential diagnoses, but it did save time.

Metabolic control and progression of complications in insulin-dependent diabetic patients after kidney transplantation.

Patient survival and progression of complications were monitored for 3 years after kidney transplantation in 29 type-1 diabetic patients. Ten age-matched, non-diabetic kidney-transplanted patients served as controls. Five diabetic patients died during follow-up (three cardiovascular events, two infections), three diabetic patients had a non-fatal myocardial infarction and four developed cerebrovascular complications after transplantation. Of the diabetic patients, 69% suffered from proliferative retinopathy before transplantation; 20% of them improved, 65% remained unchanged and 15% deteriorated after transplantation. Motor but not sensory conduction velocity measured from the nervus medianus improved after transplantation. Autonomic neuropathy was observed in 50% of the patients and was unaffected by transplantation. Glycaemic control did not improve significantly during follow-up (HbA1, 10.6 +/- 0.5% before and 9.5 +/- 0.6% 3 years after transplantation). Body weight increased in both diabetic and non-diabetic patients within 3 years after transplantation (from 68 +/- 2 to 77 +/- 6 kg in diabetics, P less than 0.01; from 167 +/- 4 to 77 +/- 6 kg in non-diabetics, P less than 0.01). Subcutaneous fat thickness measured from computer tomography scans of the calf increased in diabetic patients from 5.0 +/- 0.6 to 6.1 +/- 0.9 mm (P less than 0.05). However, the cross-sectional areas of triceps and calf muscles did not increase, suggesting that the increase in body weight was solely due to an increase in fat. It is clear that diabetes-related complications continue to progress and are not influenced by a successful kidney transplant.

Delayed diagnosis of extremity injuries in patients with multiple injuries.

A total of 340 patients treated in the Intensive Care Unit of the Department of Orthopedics and Traumatology at Helsinki University Central Hospital were analyzed in this study. They had in all 1,071 fractures and luxations of the pelvis and extremities, of which the trauma surgeons and radiologists on duty initially missed 45 injuries, i.e., 4.2%. Taking into account the eventual late symptoms, the most severe delayed diagnoses were of injuries located around the hip and knee joints. The patients with delayed diagnoses were, on the average, the most severely ill: their needs for primary blood transfusions and assisted respiration resembled the needs of patients who later died of their trauma or its complications. The most common causes of the delay in diagnosis were: radiographs not done in 60% of patients, and no notation of visible injury in radiographs in 31%. Inferior quality of radiographs, unnoticed radiologists' reports, a fracture visible at the outermost corner of a radiograph, a fracture hidden by other fractures, or excessive obesity of the patient may also contribute to a delay. The study presents measures for improving diagnostic strategies, but it would appear that delayed diagnoses cannot be totally eradicated.

Ten-year results of operations for rheumatoid cervical spine disorders.

The outcome of operations performed on 38 patients for rheumatoid disorders of the cervical spine were analysed 10 or more years later. The mean age of the patients at the time of operation was 56 years (35 to 77); 32 had seropositive disease. The mean duration of the disease was 17 years (four to 36). Twenty-seven patients had painful anterior atlanto-axial subluxation (AAS), nine had subaxial subluxation alone and two had severe cranial subluxation of the odontoid, one also with subaxial subluxation. One patient died from postoperative staphylococcal septicaemia and another 18 died during the follow-up period. Patients with coincident cardiac or other diseases, and those with cranial subluxation of the odontoid of more than 3 mm had an increased mortality. Neither the patients' age nor the magnitude of AAS correlated with mortality. Of the 37 patients with occipitocervical pain, 30 were relieved and all the six patients with tetraparesis were improved. Of the 24 Gallie fusions only 12 were solidly united; patients with long-term cortisone treatment were more likely to develop pseudarthrosis. There was no correlation between clinical outcome and radiological result. Four patients had further operations to treat subluxation which developed below the fused segments.