MR Diagnosis of Bone Metastases at 1.5 T and 3 T: Can STIR Imaging Be Omitted?

OBJECTIVE: To date, no prospective comparative study of the diagnostic value of STIR versus T1-weighted (T1w) sequences at both 1.5 T and 3 T has been performed with special focus on the detectability of bone metastases. MATERIALS AND METHODS: 212 oncological patients had a whole-body MRI at 1.5 T and/or at 3 T. The standard protocol comprised STIR and T1w sequences. All patients who showed typical signs of bone metastases were included in the study. Evaluation of the images was performed by the calculation of the number of metastases by three independent readers and by visual assessment on a 4-point scale. RESULTS: 86 patients fulfilled the inclusion criteria. The total number of metastases was significantly higher on T1w than on STIR images at both field strengths (p < 0.05). T1w revealed a sensitivity of 99.72% (3 T) and 100.00% (1.5 T) versus STIR with 70.99 % (3 T) and 79.34 % (1.5 T). In 53% (38/72) of all patients, STIR detected fewer bone metastases in comparison with T1w at 3 T. At 1.5 T, STIR showed inferior results in 37.5 % (18/48) of all patients. Qualitative analysis indicated a significantly better lesion conspicuity, lesion delineation and an improved image quality on T1w compared to STIR imaging at both field strengths (p < 0.05) with similar results for T1w at 1.5 T and 3 T, but inferior results for STIR especially at 3 T. CONCLUSION: The whole-body MRI protocol for the detection of bone metastases could safely be limited to the T1w sequence in adults, especially at 3 T. There is no need for an additional STIR sequence. These initial results will have a major impact on the department's workflow if confirmed by larger studies as they will help reduce examination time and therefore save financial resources. KEY POINTS: In a routine MR protocol, T1w imaging is sufficient for the detection of bone metastases. In case of differential diagnostic problems, other appropriate sequences can be added to the protocol. STIR is inferior to T1w in the detection of metastases, especially at 3 T.

The management of histologically unverified presumed cerebral gliomas with radiotherapy.

PURPOSE: To define the natural history, and prognostic factors of patients with histologically unverified presumed gliomas diagnosed on CT or MR imaging, and treated with external beam radiotherapy. METHODS AND MATERIALS: Retrospective review of 111 adults with histologically unverified presumed cerebral glioma treated with radiotherapy between 1974 and 1990. Using CT or MRI criteria alone 41 were presumed low grade, 63 high grade gliomas and 7 were unclassified. Survival results were compared to a cohort of 82 adults with histologically verified low grade gliomas treated over the same period with surgery and radiotherapy. RESULTS: The 5 year survival probability of the whole cohort was 31%. Age, performance status, and the degree of contrast enhancement were independent prognostic factors for survival. Patients with presumed low grade glioma had a 5 year survival of 41% compared to 52% for patients with verified low grade glioma. After correction for prognostic factors no significant difference was found in the survival between patients with verified and unverified low grade tumors. One of 15 cases with subsequent histology, obtained at autopsy or salvage surgery, had nonglial pathology. CONCLUSION: Patients diagnosed on the basis of clinical features and imaging as having presumed glioma have similar natural history and clinical behavior after treatment with radiotherapy to those with histologically confirmed gliomas. However, the results should not be taken as justification for avoiding biopsy. A proportion of patients may have nonglial pathology and new more effective treatment strategies for patients with glial tumors can only evolve on the basis of full diagnostic information including pathology.

Computed tomography and magnetic resonance imaging findings in primitive neuroectodermal tumours in adults.

Primitive neuroectodermal tumours (PNET) are highly malignant, undifferentiated supratentorial neoplasms arising from germinal matrix cells of the primitive neural tube. PNET occur primarily in young children; they are extremely rare in adults. PNET frequently seed within the central nervous system and may be multicentric at the time of diagnosis. Previous reports of the neuroradiological findings refer solely to PNET in children. We describe the computed tomography (CT) and magnetic resonance imaging (MRI) appearances in five adult patients with pathologically proven PNET. In our series, PNET were mostly seen as rather large, heterogeneous masses with cystic and necrotic areas, intratumoral haemorrhage and focal calcification. The prominent contrast enhancement on both CT and MRI scans reflects the increased vascularity of PNET.

Focal areas of increased renal tracer uptake on bone scans can mimic metastases in the lower ribs.

Focal renal concentration of radioactivity can simulate metastatic deposits in the lower ribs on bone scintigrams. 400 consecutive bone scintigrams were reviewed for focal areas of increased tracer activity in the kidneys. 62 patients (15.5%) had at least one renal hot spot. In 42 of these 62 patients (67.7%) there was an increased focal uptake in the left kidney (18 upper pole, 18 middle pole and six lower pole). 50 out of 62 bone scans (80.7%) showed increased activity in the right kidney (14 upper pole, 32 middle pole and four lower pole). With the incidence of focal areas of activity in the upper poles of the kidneys being 8%, the interpretation of a single focal abnormality projected over the lower ribs should be made with particular care, especially in cancer patients.

Imaging of recurrent esthesioneuroblastoma.

Esthesioneuroblastoma is an uncommon neoplasm arising from the olfactory epithelium and characterized by frequent local recurrences. The purpose of this study was to determine the role of CT and MRI in the diagnosis of recurrent esthesioneuroblastoma. A total of 14 histologically confirmed recurrent esthesioneuroblastomas referred to our institution between 1986 and 1998 was retrospectively reviewed. All patients underwent both CT and MRI. The tumour recurrences displayed a variety of imaging characteristics and aggressiveness. They were typically expansile and destructive in their growth patterns. Erosion of the cribriform plate and involvement of the anterior cranial fossa were common findings. The CT and MRI appearances of recurrent esthesioneuroblastoma do not differ significantly from tumours imaged at initial presentation. Patients should receive close follow-ups and CT/MRI examinations for several years beyond diagnosis, as early diagnosis of recurrent disease predicts survival.

Intracardiac metastases from germ cell tumours--an unusual but important site of metastasis.

Two cases of intracardiac deposits from testicular teratomas diagnosed by echocardiography and angiocardiography, respectively, are described. The importance of recognizing this as an uncommon site of metastasis from germ cell tumours is discussed.

Vertigo after stapes surgery: the role of high resolution CT.

CT findings in patients with vertigo after stapes surgery include a prosthesis shaft entering the vestibule and compressing the saccule, a complete dislocation of the stapes prosthesis, air bubbles and fluid collections within the vestibule and outside the oval window indicating a perilymphatic fistula, and bony fragments leading to compression of the basal saccule. Although immediate post-operative vertigo is often transient, patients with persistent or recurrent vertigo should be imaged as high resolution CT will determine the underlying cause in the majority of cases.

Value of spiral CT in patients with cricothyroid approximation.

Cricothyroid approximation raises the vocal pitch by simulating contraction of the cricothyroid muscle with sutures. The aim of this study was to determine the role of spiral CT in patients scheduled for cricothyroid approximation. 29 transsexual patients were examined with spiral CT prior to and after laryngoplastic surgery. CT findings were correlated with phonographic findings in all patients. The average reduction of the cricothyroid distance was 6 mm (range 2-10 mm). Vocal pitch elevation was greatest in patients with the largest reduction of the cricothyroid distance. CT accurately determines the cricothyroid distance prior to and after surgery and is an ideal method for follow-up, especially in post-operative reversion towards a lower pitch. In addition, CT provides important data in determining the most appropriate extent and site of intracordal intervention to achieve a desired pitch elevation.

Unenhanced spiral CT for evaluating acute appendicitis in daily routine. A prospective study.

BACKGROUND/AIMS: The purpose of this study was to define in a routine setting the role of spiral computed tomography in patients with suspected acute appendicitis and to determine the effect of computed tomography on the treatment of such patients. METHODOLOGY: Appendiceal computed tomography was performed in 120 consecutive patients with acute appendicitis in the differential diagnosis, whose clinical findings were insufficient to perform surgery or to discharge from the hospital. Each scan was obtained in a single breath hold from the lower abdomen to the upper pelvis using a 5-mm collimation and a pitch of 1.6. Computed tomography results were correlated with surgical and pathologic findings at appendectomy or clinical follow-up. RESULTS: Eighty-eight of the 93 patients with acute appendicitis were correctly diagnosed by computed tomography, 24 of the 27 patients without acute appendicitis were correctly diagnosed by computed tomography (95% sensitivity, 89% specificity). Computed tomography signs of acute appendicitis included fat stranding (100%), enlarged appendix (> 6 mm) (97%), adenopathy (63%), appendicoliths (43%), abscess (10%), and phlegmon (5%). CONCLUSIONS: The use of spiral computed tomography in patients with equivocal clinical presentation suspected of having acute appendicitis led to a significant improvement in the preoperative diagnosis and a lower negative appendectomy rate. Appendiceal computed tomography is an accurate technique even if performed in the daily routine of scanning.

Detection of choledocholithiasis: comparison of unenhanced spiral CT, US, and ERCP.

BACKGROUND/AIMS: ERCP is an established method for the diagnosis and treatment of common bile duct stones, however, it is invasive, time-consuming, and expensive. The purpose of this study was to determine whether unenhanced spiral CT and US, compared with ERCP, have sufficient sensitivity and negative predictive value to be useful screening techniques in patients suspected of having choledocholithiasis. METHODOLOGY: Over a period of 2 years, 82 patients with clinically suspected choledocholithiasis underwent unenhanced spiral computed tomography and US immediately before undergoing endoscopic retrograde cholangiopancreatography. CT/US scans and ERCP images were evaluated for the presence of bile duct stones, ampullary stones, and extrahepatic biliary dilatation. RESULTS: Unenhanced spiral computed tomography (US) depicted common bile duct stones in 24 (23) of 28 patients found to have stones at endoscopic retrograde cholangiopancreatography. Five patients had stones impacted at the ampulla, all (two) of which were detected with CT (US). Computed tomography (US) had a sensitivity of 86% (82%) and a specificity of 98% (98%) in the diagnosis of choledocholithiasis. CONCLUSIONS: Both unenhanced spiral CT and US are useful for evaluating suspected common bile duct stones. Unenhanced spiral CT is especially useful when the patient is likely to have ampullary stones and is a safe, more available and less expensive alternative to magnetic resonance cholangiography.

Neurosarcoidosis: evaluation with MRI.

Clinical studies report a rate of 5% and autopsy results a rate of 25% of brain involvement in sarcoidosis. The aim of this study was to evaluate the role of magnetic resonance imaging (MRI) in the diagnosis of patients with neurosarcoidosis. The MRI brain scans of 22 patients with sarcoidosis were retrospectively reviewed, along with the clinical information that was provided in the request form. All patients had signs and symptoms referable to the head and were examined with gadolinium enhancement. Cranial (facial) nerve paralysis was the most common clinical manifestation identified in 10 patients. A wide spectrum of MR findings was noted: Periventricular and white matter lesions on T2W spin echo images, mimicking multiple sclerosis (46%); multiple supratentorial and infratentorial brain lesions, mimicking metastases (36%); solitary intraaxial mass, mimicking high grade astrocytoma (9%); solitary extraaxial mass, mimicking meningioma (5%); leptomeningeal enhancement (36%). These findings are not specific for sarcoidosis and one must consider appropriate clinical circumstances in arriving at the correct diagnosis. In selected cases with isolated brain involvement, meningeal or cerebral biopsy may be required.

[Diagnostic value of whole-body MRI and bone scintigraphy in the detection of osseous metastases in patients with breast cancer--A Prospective Double-Blinded Study at two Hospital Centers]. / Diagnostischer Stellenwert der Ganzkörper-MRT und der Skelettszintigrafie in der ossären Metastasendetektion bei Mammakarzinompatientinnen--eine prospektive Doppelblindstudie an zwei Klinikzentren.

PURPOSE: The purpose of this study was to compare the diagnostic accuracy of whole-body MRI (WB-MRI) and bone scintigraphy (BS) for the screening of bone metastases for the first time in a large and homogeneous patient collective with breast cancer in a systematic and controlled study. MATERIALS AND METHOD: 213 breast cancer patients were evaluated for bone metastases under randomized, double-blinded and prospective conditions at two hospitals. All participants were examined by WB-MRI and BS over an average period of four days. The examinations were performed separately at two different locations. The WB-MRI protocol included T 1-TSE and STIR sequences. WB-MRI and BS were reviewed independently by experienced radiologists and nuclear medicine specialists in a consensus reading. RESULTS: In 66 % of cases bone metastases were excluded by both procedures, and bone metastases were detected concordantly in 2 % of cases. In 7 % of cases there were discrepant results: in 7 cases BS was false-positive when WB-MRI was negative. In 5 / 7 cases BS was negative when WB-MRI identified bone metastases. In 89 % of cases BS was uncertain when WB-MRI was true-negative. In 17 % of cases WB-MRI showed important (non-) tumor-associated findings. The sensitivity, specificity, positive and negative predictive value and diagnostic accuracy for WB-MRI were 90 %, 94 %, 82 %, 98 % and 99 % and for BS those were 40 %, 81 %, 36 %, 91 % and 93 %. CONCLUSION: It could be demonstrated that WB-MRI is superior to BS for detecting bone metastases in breast cancer patients. These results should be considered for the next version of the S 3 guideline "Diagnosis, Therapy and Follow-Up of Breast Cancer".

[Variations of the anatomical position of the internal carotid artery as an important differential diagnosis of parapharyngeal tumors]. / Verlaufsvarianten der Arteria carotis interna als wichtige Differenzialdiagnose von Raumforderungen im Pharynxbereich.

PATIENT: A case of a 78-year-old man with globus syndrome is reported who was referred to our department because of a tumor of the right parapharyngeal wall. Radiological and endoscopic examination revealed that the tumor was caused by an extracranial kinking of the right internal carotid artery. DISCUSSION: Variations of the anatomical position of the internal carotid artery in the parapharyngeal space are potentially at risk during routine ENT-procedures such as adenoidectomy and tonsillectomy or during endoscopic procedures with diagnostic biopsies. Data about the frequency of variations of the clinical course of the internal carotid artery dorsolateral of the lateral pharyngeal wall vary in literature from 4% to 66%. By cost-effective ultrasound and duplex-ultrasound, computed-tomography, magnetic resonance imaging with angiography or by conventional angiography a wide variety of different diagnostic imaging methods is available. While coiling of the internal carotid artery is ascribed to embryological malformation, elongation and kinking of the artery are due to atherosclerosis or fibromuscular dysplasia. These variations are often asymptomatic but they can also cause symptoms from globus syndrome to cerebrovascular insufficiency producing ischemic attacks or infarction. This case report emphasizes the clinical importance of variations of the clinical course of the internal carotid artery as a differential diagnosis of parapharyngeal tumors since iatrogenic injuries during routine pharyngeal surgery with disastrous outcome were frequently reported in literature. Unexperienced ENT-surgeons should be warned and experienced ENT-surgeons should be reminded of those dangerous variations.

Selected versus routine use of intraoperative cholangiography during laparoscopic cholecystectomy.

Routine use of intraoperative cholangiography during laparoscopic cholecystectomy is still widely advocated and standard in many departments, however, this is discussed controversially. We have developed a new diagnostic strategy to detect bile duct stones. The concept is based on an ultrasound examination and on a screening for the presence of six risk indicators of choledocholithiasis. 120 consecutive patients undergoing laparoscopic cholecystectomy were prospectively screened for the presence of six risk indicators of choledocholithiasis: history of jaundice; history of pancreatitis; hyperbilirubinemia; hyperamylasemia; dilated bile duct; unclear ultrasound findings. The sensitivity of ultrasound and of intraoperative cholangiography in diagnosing bile duct stones was also evaluated. For the detection of bile duct stones, the sensitivity was 77% for ultrasound and 100% for intraoperative cholangiography. 20% of all patients had at least one risk indicator. The presence of a risk indicator correlated significantly with the presence of choledocholithiasis (p < 0.01, chi-square-test). The negative predictive value of the total set of risk indicators was 100%. Following our diagnostic concept, we would have avoided 80% of intraoperative cholangiographies without missing a stone in the bile duct. This study lends further support to the view that the routine use of intraoperative cholangiography in patients undergoing laparoscopic cholecystectomy is not necessary.

Radiologic diagnosis of common bile duct stones.

Unenhanced spiral CT and, in the hands of the experienced, US are accurate noninvasive methods of imaging the common bile duct. This is particularly true when there is a low clinical and laboratory probability of a common bile duct stone being present. In the diagnosis of bile duct stones, CT and US are effective and readily available screening techniques and may aid in the selection of patients who require MRCP or treatment with ERCP. Avoiding ERCP and the associated expense and morbidity is a goal that is becoming attainable with optimized CT, US, and MRCP techniques and an awareness of subtle findings.

[Selective intraoperative cholangiography in laparoscopic cholecystectomy]. / Selektive intraoperative Cholangiographie bei laparoskopischer Cholezystektomie.

Routine use of intraoperative cholangiography during laparoscopic cholecystectomy is still widely advocated and standard in many departments; however, it is controversial. We have developed a new diagnostic strategy for the detection of bile duct stones. The concept is based on an ultrasound examination and on screening for the presence of six risk indicators of choledocholithiasis. A total of 120 patients undergoing laparoscopic cholecystectomy were prospectively screened for the presence of these six risk indicators: history of jaundice, history of pancreatitis, hyperbilirubinemia, hyperamylasemia, dilated bile duct, and unclear ultrasound findings. The sensitivity of ultrasound and intraoperative cholangiography in diagnosing bile duct stones was also evaluated. For the detection of bile duct stones, the sensitivity was 77% for ultrasound and 100% for intraoperative cholangiography. Twenty percent of all patients had at least one risk indicator. The presence of a risk indicator correlated significantly with the presence of choledocholithiasis (P < 0.01, chi-square test). The negative predictive value of the total set of risk indicators was 100%. Following our diagnostic concept, we would have avoided 80% of intraoperative cholangiographies without missing a stone in the bile duct. This study lends further support to the view that routine use of intraoperative cholangiography is not necessary.

[Role of magnetic resonance imaging in the diagnosis of neurosarcoidosis]. / Wertigkeit der Magnetresonanztomographie in der Diagnostik der Neurosarkoidose.

Neurological involvement is a significant cause of morbidity and mortality in patients with sarcoidosis. The aim of this study was to evaluate the role of magnetic resonance imaging (MRI) in the diagnosis of patients with neurosarcoidosis. The MRI brain scans of 22 patients with sarcoidosis were retrospectively reviewed, along with the clinical information provided in the request form. All patients had signs and symptoms referable to the head and were examined with gadolinium enhancement. Cranial (facial) nerve paralysis was the most common clinical manifestation identified in 10 patients. A wide spectrum of MR findings was noted: periventricular and white matter lesions on T2 W spin echo images, mimicking multiple sclerosis (46%); multiple supratentorial and infratentorial brain lesions, mimicking metastases (36%); solitary intraaxial mass, mimicking high-grade astrocytoma (9%); solitary extraaxial mass, mimicking meningioma (5%); leptomeningeal enhancement (36%). The diagnosis of neurosarcoidosis is often difficult, particularly so in patients who lack either pulmonary or systemic manifestations of sarcoidosis. MRI shows a wide spectrum of brain abnormalities associated with neurosarcoidosis. These findings, however, are not specific for sarcoidosis and one must consider appropriate clinical circumstances in arriving at the correct diagnosis. In selected cases with isolated brain involvement, meningeal or cerebral biopsy may be required.

Computed tomography and magnetic resonance imaging features of olfactory neuroblastoma: an analysis of 22 cases.

The computed tomography (CT) and magnetic resonance imaging (MRI) studies of 22 patients with a histologically proven olfactory neuroblastoma were retrospectively reviewed. The tumours displayed a variety of imaging characteristics and aggressiveness. The expansile tendency of olfactory neuroblastoma is characterised by bowing of the sinus walls. The destructive aspect is manifested as tumour replacing the turbinates, septum, and sinus walls with extension into contiguous areas. The density/signal and enhancement characteristics are non-specific. Olfactory neuroblastoma should be suspected in all ages following identification of a mass in the superior nasal cavity demonstrating both expansile and destructive growth patterns. The otorhinolaryngologist and the radiologist should be aware of this tumour entity, as early diagnosis appropriately guides therapy and predicts survival.

[Routine skull CT in psychiatric diagnosis]. / "Routine"-Schädel-CT in der psychiatrischen Diagnostik.

PURPOSE: To prospectively assess the spectrum of brain CT findings in psychiatric patients and to determine the number of patients that had an underlying cause for the symptoms. PATIENTS AND METHODS: Over a period of six months, 142 patients (78 males, 64 females; median age 61 [18-91] years) were referred for CT brain scans. Their scans were reviewed, along with the clinical information that was provided in the request form. All the hard copies were reviewed to assess areas of ischaemia, infarction, atrophy, tumours, and haematomas. The majority of requests were to exclude vascular event or space-occupying lesions. Clinical indications included mood disorders (depression, mania), schizophrenic disorders, dementia, personality and behavioural disorders. RESULTS: 31 (22%) were normal. 111 (78%) had varying degrees of ischaemia, infarction and cerebral/cerebellar atrophy. 7 (4.9%) had space-occupying lesions which included two gliomas and five meningiomas. There were two chronic subdural haematomas and one arteriovenous malformation. CONCLUSION: 1. In our series, pathologic findings in "routine" brain CT's were encountered in 78%. 2. The incidence of brain tumours was 4.9%, compared with 0.00005% of the general population. 3. CT scanning in psychiatric patients is cost-effective and especially indicated when there is an atypical presentation, or inadequate response to standard treatment.

Role of radiology in the diagnosis of neurosarcoidosis.

Clinical studies report a rate of 5% and autopsy results a rate of 25% of brain involvement in sarcoidosis. The aim of this study was to evaluate the role of radiology in the diagnosis of patients with neurosarcoidosis. The chest radiographs and MRI brain scans of 22 patients with sarcoidosis were retrospectively reviewed, along with the information that was provided in the request form and clinical charts. All patients had neurological signs and symptoms; 21 patients were examined with contrast enhancement. Facial nerve paralysis was the most common clinical manifestation identified in 10 patients. A wide spectrum of MR findings was noted: periventricular high-signal lesions on T2-weighted images (46%); multiple supratentorial and infratentorial brain lesions (36%); solitary intra-axial mass (9%); solitary extra-axial mass (5%); and leptomeningeal enhancement (36%). Neurological signs and symptoms can be significant manifestations of sarcoidosis. Magnetic resonance imaging shows a wide spectrum of brain abnormalities associated with neurosarcoidosis. The patient's history and chest X-ray are helpful in arriving at the correct diagnosis, but in selected cases with isolated brain involvement biopsy may still be required.