Computed tomography in patients with psychiatric illnesses: advantage of a "rule-in" approach

Diagnostic yield of head CT in pediatric emergency department patients with acute psychosis or hallucinations

BACKGROUND

Children presenting to the emergency department with acute psychosis or hallucinations sometimes undergo a head CT to evaluate for a causative lesion. The diagnostic yield of head CT in this scenario has not been reported.

OBJECTIVE

To determine the yield for head CT in children with acute psychosis or hallucinations.

MATERIALS AND METHODS

We retrospectively searched the radiology report database over a 7.5-year period for head CT reports for pediatric emergency department patients using the following keywords: hallucination, psychosis, psychotic or "hearing voices." All reports were categorized as normal or abnormal, and we reviewed and categorized the abnormal cases. We calculated the 95% confidence interval for abnormal CTs using the method of Clopper and Pearson.

RESULTS

We identified 397 pediatric emergency department head CTs. We excluded one non-diagnostic exam. We excluded 34 additional cases (which were all normal) because of clinical indications that might have independently triggered a head CT. Of the remaining 362 cases, 12 reports described abnormalities or variants and we reviewed them individually. Based on consensus review, four were normal, four had congenital malformations, three had encephalomalacia versus demyelination and one demonstrated cortical atrophy. There were no cases with actionable findings such as mass, hemorrhage, infection or hydrocephalus. The 95% confidence interval for a CT demonstrating causative findings was calculated at 0-0.82%.

CONCLUSION

In the absence of concerning factors such as focal neurological deficits, evidence of central nervous system infection, trauma or headache, routine screening head CT might not be warranted in children presenting with acute psychosis or hallucinations.

The quality of computerised tomography use in two psychogeriatric services

The aim of medical audit is to improve the quality of medical care (Department of Health, 1989). There was concern that patients referred to a psychogeriatric service (Service X) did not have adequate access to computerised tomography. The nearest computerised tomography scanner was located in a neighbouring district and direct referrals were not accepted. Computerised tomography scans could be obtained indirectly by referral to neurosurgeons. Because of these difficulties “potentially treatable structural lesions” (such as cerebral tumours and subdural haematomas) may have been missed. We decided to compare the use of computerised tomography scans with a nearby service (Service Y) which had a computerised tomography scanner on site. Service X had a catchment population of 33,000 aged over 65 and Service Y a catchment population of 23,420 aged over 65.

The impact of CT head scans on ED management and length of stay in bizarre behavior patients

METHODS

A 5-year retrospective chart review was conducted at 3 EDs. Inclusion criteria were patients ≥18years old triaged as "mental health - bizarre behavior" (deviation from normal cognitive behaviour with no obvious cause) with a CT head scan ordered in the ED. Exclusion criteria were focal neurologic deficits on exam, alternative medical etiology (i.e. delirium, trauma) and/or pre-existing CNS disease. Clinical, demographic and administrative data were extracted with 10% of charts independently reviewed by an Emergency Physician for inter-rater reliability.

RESULTS

266 cases met study criteria. Population demographics: 49% percent female, average age 51years old, 28% homeless, 58% arrived by police or ambulance. CT head results: 1 (0.4%) case with possible acute findings, 105 (39%) with incidental findings (i.e. cerebral atrophy) that did not impact clinical management. Average time to physician assessment was 1:48 (hour:min) (sd 1:11), time to CT completion was 5:05 (sd 7:28) and an average delay of 3:17 awaiting results. Subgroup analysis revealed a net increase in ED length of stay (ED LOS) of 5:02 from obtaining neuroimaging. 85% of patients were referred to a consultant, 92% were to psychiatry.

CONCLUSIONS

CT head results prolonged ED LOS, delayed patient disposition and did not change the patient's clinical management. A prospective trial for ordering CT head scans in these patients is warranted.

The clinical value of brain computerised tomography in a general hospital psychiatric service

Background

The use of neuroimaging modalities in psychiatry has been evaluated in several studies. The vast majority seem to suggest that neuroimaging may be overutilised in psychiatry. There is a significant constraint on availability and cost related to neuroimaging of patients at general state medical facilities. The routine use of computerised tomography (CT) scanning is thus questioned.

Methods

A retrospective analysis was undertaken of all psychiatric inpatients who had CT scans performed from 01 January 2011 to 31 December 2012. Demographic data, mental state examination, physical examination findings, substance use and diagnosis upon admission were recorded. The relationship between these variables and CT scan findings was analysed.

Results

A total of 897 admissions were retrospectively analysed. One hundred and three patients had documented CT scan imaging. In total, 17 of the 23 patients with abnormal findings on CT scan were found to be psychotic (74.0%). The remaining 26.0% included depression and dementia. There was no statistically significant difference between the normal and abnormal CT scan groups with regard to gender, age, family history, substance use and physical examination. The majority (65.2%) had cerebral atrophy and/or cerebral calcifications. A smaller group of other documented findings was noted.

Conclusions

Selective indications and clinical markers may be utilised in order to justify brain imaging studies rather than performing them routinely. That being true, a multicentre study with a larger sample size is indicated to further improve the statistical significance and assist in formulating a more concrete guideline for neuroimaging of psychiatric patients.

Psychiatric presentation of frontal meningiomas

Patients with frontal lobe meningioma may present to psychiatric services. Clinical diagnostic sensitivity, particularly in the absence of neurological signs, remains central to diagnosis.

Two-year study of the use of neuroimaging in a psychiatric inpatients unit

OBJECTIVES

Neuroimaging is being used increasingly in the investigation of psychiatric disorders. Previous studies have found abnormalities in about two-thirds of all scans done in psychiatry. The aim of our study was to investigate the use of CT and MRI in the management of inpatients in psychiatry department Adelaide & Meath hospital, Tallaght and to examine the relationship between diagnosis and abnormalities seen on scans.

METHOD

We did a two-year retrospective study of all inpatient referrals for CT scans/MRI scans. A case note review of bio-demographic data, diagnosis, relevant medical history, substance misuse history, indication for tests and results of scans was done. We found that 66 CTs and MRI scans were done over the study period.

RESULTS

Fourteen (21%) of the scans had abnormal results which were mostly atrophic changes. Of the 14 abnormal scans, seven had abnormal findings on neurological examination. We found a lower number of abnormal scans compared to previous studies.

CONCLUSIONS

Radiological abnormalities were not disease specific. We wish to propose guidelines on the indications for using neuroimaging in psychiatric patients.

Use of brain imaging (computed tomography and magnetic resonance imaging) in first-episode psychosis: review and retrospective study

OBJECTIVE

To identify and review available evidence on the diagnostic yield of brain computed tomographies (CTs) and magnetic resonance images (MRIs) in first-episode psychosis, and examine yield in our own institution (Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Quebec).

METHOD

Using MEDLINE (1966 to October 2007) and EMBASE (1980 to October 2007), we identified and analyzed studies that examined imaging yields in first-episode psychosis; yield being defined as the percentage of scans showing abnormalities that may result in psychosis. We also retrospectively analyzed diagnostic yields in 46 patients hospitalized in our institution between 2001 and 2006 for first-episode psychosis.

RESULTS

Five studies were deemed relevant. Including our own series, the sample comprised 384 CT and 184 MRI scans. Point estimate for diagnostic yield was 1.3% for CT and 1.1% for MRI scans. These yields likely overestimate clinical usefulness of findings. MRI scans also resulted in a sizeable number of fortuitous, clinically irrelevant findings.

CONCLUSIONS

In first-episode psychosis, routine CT or MRI scans are of little benefit and should be reserved for situations where history or examination suggests neurological causation, or possibly for people aged 50 years and older.

Is computed tomography still useful as a neuroimaging tool in psychiatry?

BACKGROUND

Computed tomography (CT) has played a pivotal role in psychiatry from its inception; however with the advent of other high-resolution noninvasive neuroimaging techniques such as MRI, the field has gone through a dramatic transformation.

OBJECTIVE

This article will explore the current role of CT in psychiatry.

METHODS

An extensive search of the published literature (1970 - 2008) was conducted, employing a number of databases and terms relevant to CT and imaging.

RESULTS/CONCLUSION

At present CT is primarily used as a screening tool to exclude intracranial pathology. This is partly because it is widely available and less expensive than other imaging modalities. CT is unable to provide region-specific information like MRI and this has restricted its use in disorders in which functional disturbances are suspected, however it remains the preferred mode of investigation where gross structural abnormalities are suspected.

Brain imaging in psychiatry - a study of 435 psychiatric in-patients at a university clinic

OBJECTIVE

The use of brain imaging in psychiatry still lacks clear guidelines. We investigated the referral practice, outcome and predictive factors of neuroimaging in a Swiss psychiatric university clinic.

METHOD

Medical files were reviewed retrospectively for 435 consecutively hospitalized patients who were subjected to neuroimaging. The association between the sociodemographic and clinical characteristics and the scan results was analyzed using bivariate and multivariate analyses.

RESULTS

Of overall examinations, 69.4% were normal, 16.3% equivocal and 14.3% abnormal; 2.9% of scans ordered for screening only showed pathology. Neurologic signs and advanced age of patients predicted abnormal scan findings, whereas other variables such as EEG results showed no significant association.

CONCLUSION

Our results support the need for clear indications for using brain imaging in psychiatric in-patients. Focal neurologic signs and advanced patient age seems to predict abnormal scan results. However, these criteria are not sufficiently sensitive to predict significant scan findings in all patients.

An investigation of criteria used to indicate cranial CT in males with schizophrenia

BACKGROUND

With the increased accessibility of the CT scanner, psychiatrists managing schizophrenia and first-episode psychosis have incorporated this imaging technique into their diagnostic work-up. This practice has been reinforced by published criteria for CT scanning in psychiatric patients suggesting that cranial CT should be used as a screening tool to exclude intracranial pathology in all patients with a first presentation of schizophrenia or first psychotic episode.

OBJECTIVES

This study reviews the performance of these criteria.

METHOD

This consisted of a 3-year retrospective case-note audit, using published criteria, of all male in-patients with an established diagnosis of schizophrenia who had a cranial CT during the review period.

RESULTS

The efficacy of the published criteria is not supported. In addition, non-specific abnormalities on cranial CT are related to duration of illness and not age in this sample.

CONCLUSIONS

There is a need to establish new and clinically meaningful approaches for the use of cranial CT and similar technologies in clinical psychiatry. Cranial CT performs poorly as a universal screening tool in this population. The decision to use such imaging techniques should be made on a case-by-case basis using all available clinical evidence.

Incidental radiological findings on brain magnetic resonance imaging in first-episode psychosis and chronic schizophrenia

OBJECTIVE

To investigate whether patients with first-episode psychosis or chronic schizophrenia have an increased incidence of magnetic resonance imaging (MRI) brain abnormalities compared with control subjects.

METHOD

Totally 340 clinical MRI reports [Controls (n=98), first-episode psychoses (n=152), chronic schizophrenia (n=90)] were reported by a neuroradiologist blind to diagnosis and subsequently categorized using referral criteria (immediate, urgent, routine or no referral).

RESULTS

Thirty percent of all scans were reported by a neuroradiologist as abnormal, but the majority required no referral. Patients with chronic schizophrenia were more likely to have clinically significant abnormal scans than patients with first episode psychosis or control subjects. In four patients the MRI findings led to the discovery of previously unsuspected pathology.

CONCLUSION

Patients with chronic schizophrenia have an increased prevalence of incidental brain abnormalities. A small proportion of patients with chronic schizophrenia and first-episode psychosis benefitted directly from MRI scanning.

Increasing the clinical yield of computerized tomography for psychiatric patients

Computerized tomography (CT) continues to be extensively utilized to exclude intracranial pathology in psychiatric practice, but little is known about clinical risk factors, which might predict those patients most likely to benefit from the procedure. We reviewed 150 cases of psychiatric patients who received CT scans to exclude intracranial pathology. We assessed the relationships of patient age, psychiatric diagnosis, and findings from neurologic and cognitive examinations to CT results that influenced patient care, and overall normal and abnormal CT results. Fifty-three percent of the CT scans were abnormal, 11% influenced patient care, and only 2% identified potentially reversible lesions. Cognitive exam results and, to a lesser extent, neurologic exam results, were sensitive predictors of CT findings that influenced patient care. All patients with clinically influential CT results had cognitive deficits and all but one had neurologic deficits. Patients older than 60 years of age and those with organic mental syndromes were most likely to have clinically influential CT findings. Our results suggest that utilizing specific clinical risk factors such as findings from clinical examinations, patient age, and psychiatric diagnosis, to guide the ordering of CT scans, can greatly increase the yield of the procedure for psychiatric patients, without excess medical morbidity.

Qualitative cerebral morphology in schizophrenia: a magnetic resonance imaging study and systematic literature review

Patients with schizophrenia have larger lateral ventricles, less cerebral substance and smaller mesial temporal lobe structures than groups of normal controls, but it has proved difficult to link these volumetric abnormalities with clinical features of the illness. Such quantitative techniques may overlook qualitative abnormalities of importance. We therefore compared a neuroradiologists' clinical assessment of gross structural abnormalities, generalised 'atrophy' and high intensity signal (HIS) foci, as detected on the first and second echo of a long TR sequence, in 42 patients with schizophrenia (22 treatment responsive, 20 treatment resistant) and 50 normal controls. The schizophrenic group included two (5%) subjects with gross lesions, two (5%) with cerebellar atrophy, 21 (52%) with at least a mild degree of cerebral atrophy, and 15 (38%) with one or more HIS foci; the comparable figures in the controls being 2, 0, 2 and 14%, respectively. Controlling for age, patients with schizophrenia had a substantially elevated rate of cerebral atrophy (odds ratio (OR) = 11.7, p < 0.0001). Treatment-resistant schizophrenics showed a tendency (OR = 2.8, p = 0.06) to greater atrophy than those who were treatment responsive, whereas our previous volumetric study showed no such difference. In contrast, the presence of HIS foci was only related to age. The degree of atrophy was correlated with the number of HIS foci (r = 0.31, p = 0.014). Taken together with previous studies, these findings demonstrate the value of qualitative examination of MRI images in patients with schizophrenia.

Diagnostic utility of endocrine and neuroimaging screening tests in first-onset adolescent psychosis

OBJECTIVE

To determine the diagnostic utility of endocrine and neuroimaging screening tests in first-onset adolescent psychosis.

METHOD

111 consecutively admitted adolescents (aged 13 through 19 years) who presented with a first-onset psychosis and who had an unremarkable medical history and normal physical examination were given a battery of endocrine and neuroimaging screening tests. Diagnostic utility of a screening test was defined as an abnormal result (a positive test) that either led to a previously unknown or unsuspected medical diagnosis or played an important role in the clinical care of the patient.

RESULTS

15.4% of the endocrine screening tests and 11.0% of the neuroimaging screening tests were identified as positive. However, no endocrine and no neuroimaging tests met criteria for diagnostic utility. The direct cost of this screening battery was $636.95 per patient.

CONCLUSION

Routine endocrine and neuroimaging screening tests in first-onset adolescent psychosis provide no diagnostic utility and are not cost-effective. Selective use of appropriate endocrine and neuroimaging diagnostic tests in populations with symptoms suggestive of organic disorders should replace routine screening procedures.

Results of computerised tomography during first admission for psychosis

A cohort of 168 psychotic patients underwent computerised tomography (CT) during their first admission. Cortical atrophy was present in 40% of patients. The frequency of atrophy increased with age, but did not differ between patients with schizophrenia, schizoaffective disorder, bipolar disorder or psychotic depression. Other CT findings of note were present in 6.6% of patients, and included four infarctions, three arachnoid cysts, and one each of venous angioma, colloid cyst, cavum vergae and post-traumatic changes. The frequency of CT findings other than atrophy was increased in the psychotic depression group. The findings support the proposal of the onset of psychosis being an indication for CT.

Psychiatric manifestations of frontal lobe tumours

In a recent article in the British Medical Journal Maurice-Williams & Dunwoody (1988) reported two patients with frontal meningiomas who presented initially to psychiatrists. The correct diagnosis was made in one of them after prolonged, perhaps unnecessary, psychiatric treatment. In the other the diagnosis was made at autopsy. In this case psychiatrists were only briefly involved and neurosurgical referral had been made promptly. The authors, who treat these reports as a cautionary tale, conclude by warning psychiatrists to pay special attention to a number of features in the history and examination of psychiatric patients. In particular we are told that suspicion should arise in the presence of gradual non-remitting symptoms such as irritability, memory loss, self-neglect, dysphasia or incontinence in patients without a previous history of psychiatric disease or clear precipitating factors. They also suggest that we pay attention to the views of relatives when they feel the patient suffers from a physical rather than a psychiatric illness, and emphasise that early diagnosis leads to easier surgical removal and better outcome.

An evaluation of cranial CT scanning in clinical psychiatry

From 6,300 psychiatric admissions over a 37 month period, all 54 patient referrals for CT were identified and their charts reviewed. CT influenced diagnosis, management or prognosis in 11.7 percent of patients scanned. There was poor correlation between organicity on CT scan and findings on physical examination, laboratory testing, EEG and psychological testing. The mental state examination was the single significant correlate of CT abnormality. We suggest that the use of a formalised mental state examination such as the Mini Mental State, in addition to the usual clinical assessment of mental state, may improve the accuracy of prediction of abnormality on CT scan. The introduction of X-ray computed tomography (CT) is recognised to be one of the most important innovations in the recent history of clinical medicine. In neurology the value of a non-invasive technique for examining the intracranial contents was quickly realised in the areas of diagnosis, particularly in the detection of vascular accidents and tumours. CT has also attained a significant place in psychiatry. In research studies, it has provided important information on schizophrenia, alcoholism and chronic organic reactions. The place of CT in clinical psychiatry is less clear. As its availability has increased, such scans are being requested with increasing frequency in psychiatric patients. Cranial CT is a highly sensitive diagnostic procedure which, when used unselectively, may result in the discovery of incidental findings. Until recently, a function of the psychiatrist in relation to diagnosis was to first seek to distinguish symptoms produced by organic pathology from those produced by functional illness.(ABSTRACT TRUNCATED AT 250 WORDS)

Utility of the CAT scan in a first psychotic episode

The authors CAT-scanned 45 people admitted to the psychiatric ward of a large general hospital with a first episode of psychosis. Forty-two scans showed no evidence of intracranial pathology, and three scans showed positive findings that correlated with neuropsychiatric symptomatology. Ordering a head CAT scan in a first episode psychotic illness remains an option based on clinical judgment as opposed to routine protocol.

Guidelines for the clinical and economic evaluation of health care technologies

The health care system is routinely confronted with promising new technologies. In the past, most new technologies have been integrated into clinical practice without a rigorous demonstration of their effectiveness or efficiency. In order to provide a more rational approach to the adoption and utilization of health technology a comprehensive set of guidelines for both clinical and economic evaluation is proposed. While conceived of as an ideal that is unlikely to be universally met in practice, it is argued that decision making can be improved by striving towards this goal. The clinical guidelines stress the advantages of subjecting major new technologies to randomized controlled trials and insisting upon a demonstration of patient benefit in the application of diagnostic technologies. The economic guidelines stress comparisons with relevant alternative uses of the resources and the assessment of the impact on the quality of life. While application of the guidelines will produce rigorous and useful evidence, the final decisions concerning the allocation of health care resources must rest fundamentally on social value judgements and not solely, or even primarily, on informed expert opinion.

Metachromatic leukodystrophy manifesting as a schizophrenic disorder: computed tomographic correlation

A 32-year-old woman with a 12-year history of schizophrenia demonstrated symmetrical bifrontal and biparietal periventricular hypodensities on computed tomographic scan. Sural nerve biopsy and urine and leukocyte enzyme assay confirmed the diagnosis of metachromatic leukodystrophy. The computed tomographic correlate in an adult with metachromatic leukodystrophy in whom the psychiatric manifestations were the predominant clinical feature is described.

The use of the C.A.T. head scanner in clinical psychiatry

Three hundred and twenty-three patients were referred by psychiatrists for scanning with a 160 X 160 matrix CT 1010 Head Scanner at the Maudsley Hospital during the first year this machine was in use (1977/1978). Two hundred and one referrals were for clinical and 122 for research reasons, 50% of the former and 57% of the latter showed some abnormality on their scans. Review of the patients' notes identified data that were significantly predictive of abnormal scan results; and the referring psychiatrists were significantly more able to predict the scan results correctly during the second six months of the study. Diagnosis, management, and/or prognosis were influenced in 11.7% of those patients scanned for clinical reasons.

DSM-III and the diagnosis of organic mental disorders

Among the many emergency patients who complain of behavioral symptoms, a significant proportion suffer from a physical illness manifesting as an organic mental disorder. Dementia and delirium should be considered in the presence of an impairment of orientation, alertness, or cognition. Effort is required to remain aware of the organic differential diagnoses of hallucinatory, delusional, amnestic, and affective disorders or of personality changes not associated with overt changes of sensorium or cognitive abilities. We review the DSM-III classification of organic mental disorders published by the American Psychiatric Association, and consider the usefulness of historical data, mental status examination, physical examination, laboratory investigations, and hospitalization in the differentiation of organic from functional disorders.