Contextualizing the use of oncologic imaging within treatment phases: imaging trends and modality preferences, 2000-2014.

BACKGROUND: In the present study, we retrospectively evaluated the use of tomographic imaging in adult cancer patients to clarify how recent growth plateaus in the use of tomographic imaging in the United States might have affected oncologic imaging during the same period. METHODS: At a U.S. academic cancer centre, 12,059 patients with dates of death from January 2000 through December 2014 were identified. Imaging was restricted to brain and body computed tomography (ct), brain and body magnetic resonance (mr), and body positron-emission tomography (pet) with and without superimposed ct. Trends during the staging (1 year after diagnosis), monitoring (18-6 months before death), and end-of-life (final 6 months before death) phases were analyzed. RESULTS: Comparing the 2005-2009 with the 2010-2014 period, mean intensity of pet imaging increased 21% during staging (p = 0.0000) and 27% during end of life (p = 0.0019). In the monitoring phase, mean intensity for ct brain, ct body, and mr body imaging decreased by 26% (p = 0.0133), 11% (p = 0.0118), and 26% (p = 0.0008), respectively. Aggregate mean intensity of imaging increased in the 13%-27% range every 3 months from 18 months before death to death, reaching 1.43 images in the final 3 months of life. Patients diagnosed in the final 18 months of life had an average of 1 additional image during both the 3 months after diagnosis (p = 0.0000) and the final 3 months before death (p = 0.0000). CONCLUSIONS: Imaging increased as temporal proximity to death decreased, and patients diagnosed near death received more staging imaging, suggesting that imaging guidelines should consider imaging intensity within the context of treatment phase. Despite the development, by multiple organizations, of appropriateness criteria to reduce imaging utilization, aggregate per-patient imaging showed insignificant changes. Simultaneous fluctuations in the intensity of imaging by modality suggest recent changes in the modalities preferred by providers.

Malpractice Litigation Related to Diagnosis and Treatment of Intracranial Aneurysms.

BACKGROUND AND PURPOSE: Approaches to management of intracranial aneurysms are inconsistent, in part due to apprehension relating to potential malpractice claims. The purpose of this article was to review the causes of action underlying medical malpractice lawsuits related to the diagnosis and management of intracranial aneurysms and to identify the factors associated and their outcomes. MATERIALS AND METHODS: We consulted 2 large legal databases in the United States to search for cases in which there were jury awards and settlements related to the diagnosis and management of patients with intracranial aneurysms in the United States. Files were screened to include only those cases in which the cause of action involved negligence in the diagnosis and management of a patient with an intracranial aneurysm. RESULTS: Between 2000 and 2020, two hundred eighty-seven published case summaries were identified, of which 133 were eligible for inclusion in the analysis. Radiologists constituted 16% of 159 physicians sued in these lawsuits. Failure to diagnose was the most common medical malpractice claim referenced (100/133 cases), with the most common subgroups being "failure to include cerebral aneurysm as a differential and thus perform adequate work-up" (30 cases), and "failure to correctly interpret aneurysm evidence on CT or MR imaging" (16 cases). Only 6 of these 16 cases were adjudicated at trial, with 2 decided in favor of the plaintiff (awarded $4,000,000 and $43,000,000, respectively). CONCLUSIONS: Incorrect interpretation of imaging is relatively infrequent as a cause of malpractice litigation compared with failure to diagnose aneurysms in the clinical setting by neurosurgeons, emergency physicians, and primary care providers.

Posterior fossa imaging in 158 children with ataxia.

OBJECTIFS: To propose a MRI cerebellar algorithm that may be applied to guide genetic/malformative or biochemical investigations for patients with cerebellar ataxia. PATIENTS AND METHODS: Cerebral MRI of 158 patients with cerebellar ataxia and no supratentorial abnormality were examined according to a new categorization system based on posterior fossa imaging. The clinical and radiological findings were confronted to biochemical and/or genetic results using the MR cerebellar algorithm. Seven groups of cerebellar MRI pattern were described: vermian dysgenesis (n=27), cerebellar hypoplasia (n=15), hemispheric cerebellar dysgenesis (n=6), unilateral hemispheric atrophy (n=5), global cerebellar atrophy (n=84), signal abnormalities (n=11) and normal MRI (n=10). Cerebellar hypoplasia, vermian dysgenesis and hemispheric cerebellar dysgenesis groups were classified as malformative disorders. Global atrophy and signal abnormality groups were classified as metabolic disorders. RESULTS: In the vermian dysgenesis group, a specific genetic diagnosis was obtained in eight children (8/27) and all of the mutated genes (AHI1 (JBS3), CEP290 (JBS5), TMEM67 (JBS6), and RPGRIP1L (JBS7)) are involved in primary cilia function. In the group of pontocerebellar hypoplasia specific genetic diagnosis was obtained in one patient (PCH2) (1/15). Thus, nine of 42 children classified as malformative disorder had a molecular diagnosis. Global atrophy and signal abnormality groups were classified as metabolic disorders, specific biochemical was obtained in 46/95 children. In global atrophy group, respiratory chain deficiency was diagnosed in 18 children (18/84). In 21 children a congenital disorders of glycosylation type 1a (CDG Ia) was diagnosed (21/84) and infantile neuroaxonale dystrophy (INAD) was diagnosed in one child. In signal abnormalities group, specific biochemical diagnosis was obtained in six out of 11 children, five children with respiratory chain deficiency and one child with sulphite oxidase deficiency. In hemispheric cerebellar dysgenesis and normal MRI groups, no biological diagnosis was found for any of the patients. In the group of unilateral hemispheric atrophy, we hypothesized a clastic prenatal injury. CONCLUSION: The proposed MR cerebellar algorithm was useful to guide genetic/malformative or biochemical investigations, allowing an etiological diagnosis in 55 children.

Performance measures in neuroradiology.

Performance measurement has been added to the Medicare payment scheme as of July 2007. Two performance measures are applicable to neuroradiology, pertaining to brain and vascular imaging in stroke. These measures are early attempts to rigorously define the meaning of effective performance of neuroradiology.

A study of the quantal (all-or-none) change in reflex latency produced by opiate analgesics.

The properties of opiate-induced changes of tail-flick latency were studied in the rat. (1) Morphine and pentazocine produced a stepwise increase in latency which rose from near baseline to cut-off (usually greater than 20 sec) in less than 30 sec. Abrupt return to pre-treatment latencies was observed either spontaneously or when the rat was back-titrated with the narcotic antagonist naloxone. (2) The proportion of rats showing this stepwise change increased with increasing dose; however, the step itself was independent of dose. The same step was produced by a slow, constant infusion of morphine but was not produced by ice-water stress or barbiturate administration. (3) Increasing heat intensity to the tail shortened the baseline latency and raised the mean dose of morphine required to produce a step latency increase. (4) A step increase in latency was also observed when paw withdrawal instead of tail-flick was measured. We hypothesize that the analgesic behavior described partly defines the operating characteristics of an intrinsic endorphin-mediated analgesia system which mediates narcotic suppression of withdrawal reflexes.

Thrombogenicity of Teflon versus copolymer-coated guidewires: evaluation with scanning electron microscopy.

Utilizing the scanning electron microscope, we compared a new guidewire with copolymer coating with standard Teflon-coated, coiled-spring guidewires in both clinical and in vitro settings. Intense thrombogenicity was observed with the Teflon-coated guidewires with formed thrombi ranging in size from 50-100 microns. No formed thrombus was noted on any of the specimens of the copolymer guidewire, although isolated clumps of platelets and erythrocytes without fibrin strands were seen infrequently. We conclude that the copolymer guidewire is markedly less thrombogenic than Teflon-coated guidewires.

MR and CT in cytoplasmically inherited striatal degeneration.

A rare, cytoplasmically inherited striatal degeneration associated with Leber's optic atrophy exhibited selective symmetric low-density lesions in the putamen on the CT scan in five patients. The CT findings, however, were asymmetric (one patient) and subtle in the early phases of the disease. Occasionally, caudate lesions were demonstrable. On MR imaging, the lesions had high signal intensity on T2-weighted images and low signal intensity on T1-weighted images. This group of patients was distinguished from patients with other causes of striatal degeneration by a lack of hemispheric, brainstem, or cerebellar atrophy.

Vein of Galen malformation: correlation of clinical presentation, arteriography, and MR imaging.

To test the value of currently proposed angiographic categorizations of vein of Galen malformations and a hypothesis regarding the causes of vein of Galen malformations and of accompanying hydrocephalus, as well as to assess the relative utility of MR imaging and CT in clinical evaluation, we reviewed the clinical and radiologic records of 34 patients with vein of Galen malformations. Patients were divided into two groups on the basis of the angiographic demonstration of either an arteriovenous malformation nidus or a direct arteriovenous fistula to the wall of the vein of Galen or one of its tributaries. Patients with such a nidus (n = 17) could be distinguished from those with arteriovenous fistulas alone (n = 17) on the basis of age at presentation (p less than .01) and presenting symptoms. Venous constraints, thought to be etiologically important, were identified in 31 of 34 patients. The presence or absence of hydrocephalus was explainable by mass effect in only 24 of 32 patients. In seven of 32 cases, no obvious mass effect was seen in the presence of hydrocephalus, but arteriographic evidence of venous hypertension was present in all patients with hydrocephalus. MR provided improved depiction of both arterial and venous anatomy as compared with CT. Parenchymal abnormalities were uncommon. No patients had subarachnoid hemorrhages. We conclude that MR is superior to CT in the clinical evaluation of vein of Galen malformations, that the angiographic finding of a nidus separates patients with vein of Galen malformations into clinical and therapeutically relevant groups, and that simple mass effect on the aqueduct is not an adequate explanation for all cases of hydrocephalus in patients with this disease.

Adult-onset neurologic dysfunction associated with cortical malformations.

BACKGROUND AND PURPOSE: Malformations of cerebral cortical development are common anomalies of the brain, typically causing developmental delay or seizures that are classically thought to begin in childhood. We present clinical and MR imaging data of 16 patients with cortical malformations in whom evidence of neurologic dysfunction was first noted in adulthood, and attempt to determine whether these malformations had any differentiating features from those presenting in childhood. METHODS: Imaging studies and clinical records of 16 patients with adult-onset neurologic dysfunction were reviewed retrospectively. The patients ranged in age from 17 to 64 years (mean age, 35 years) at the time of imaging. Imaging findings were correlated with seizure history. RESULTS: Fourteen patients had subependymal heterotopia (seven women, seven men), and two patients had closed-lip schizencephalies. Eleven patients had epilepsy, with age of onset ranging from 14 to 45 years (mean age, 22 years); four of them were successfully controlled by medication. The remaining five patients had no seizure disorder. All patients, except one, had normal intelligence. The bilaterality or multiplicity of location of heterotopias was not associated with the presence or absence of seizures, seizure frequency, or electroencephalographic results. CONCLUSION: Subependymal heterotopia and small closed-lip schizencephaly may have minor clinical manifestations that are not evident until adulthood, or may, occasionally, never cause neurologic signs or symptoms whatsoever.

Abnormal temporal lobe metabolism in violent subjects: correlation of imaging and neuropsychiatric findings.

PURPOSE: To search for metabolic correlates of clinical and electrophysiological abnormalities in violent subjects. METHODS: Seven subjects with histories of extremely violent behavior were studied with positron emission tomography (PET) with fludeoxyglucose F 18 (FDG), brain electrical area mapping, MR imaging, neuropsychiatric and neuropsychological testing, and clinical examination during medical evaluation associated with legal proceedings. Nine control subjects without evidence of organic brain disease were also studied with FDG-PET. Quantitative PET data were calculated as standardized uptake values comparing the highest occipital region with the lowest temporal region. RESULTS: Temporal lobe metabolism was decreased in the study group relative to the control subjects. Medial temporal lobe metabolism was 39% lower than that in the occipital cortex in study subjects and only 27% lower than that in control subjects. These groups differed by Mann-Whitney U test and Wilcoxon's two-sample test. Metabolic differences correlated with limbic neuropsychiatric and electrophysiological abnormalities in the violent group. CONCLUSION: In this selected population of violent subjects, FDG-PET scans showed metabolic abnormalities in the temporal lobes. These abnormalities correlated with limbic abnormalities seen at electrophysiological and neuropsychiatric evaluation.

Left-right temporal region asymmetry in infants and children.

Thirty-two consecutive cranial computed tomographic (CT) scans in normal infants ranging from 1 day to 3 years of age were evaluated for asymmetry of the temporal lobes as evidenced by differences in the size of the sylvian fissures. The left sylvian fissure was larger than the right in 23 of the 32 cases, which was statistically significant (p less than 0.0001). In five other cases the two sides were equal; in the four remaining cases, the right side was larger than the left. The results show that asymmetry of the temporal lobes can be demonstrated in vivo even at birth and that this asymmetry is a normal developmental difference between the two hemispheres and not secondary to an acquired abnormality.

Cost utility analysis of radiographic screening for an orbital foreign body before MR imaging.

BACKGROUND AND PURPOSE: Our purpose was to evaluate the cost-effectiveness of clinical versus radiographic screening for an orbital foreign body before MR imaging. METHODS: Costs of screening were determined on the basis of published reports, disability rating guides, and a practice survey. Base case estimates were derived from published guidelines. A single-state change model was constructed using social cost as the unit of analysis. Sensitivity analysis was performed for each variable. The benefit of screening was avoidance of immediate, permanent, nonameliorable, unilateral blindness. RESULTS: Using base case estimates and a discount rate of zero, we calculated the cost of the current guideline as $328,580 per quality-adjusted life-year saved. Sensitivity analysis identified screening cost as a critical variable. Discount rates and effectiveness of foreign body removal also were found to be important factors. Probability of injury and prevalence of foreign body may impact the analysis. CONCLUSION: Clinical screening before radiography increases the cost-effectiveness of foreign body screening by an order of magnitude, assuming base case ocular foreign body removal rates. Asking the patient "Did a doctor get it all out?" serves this purpose. Occupational history by itself is not sufficient to mandate radiographic orbital screening. Current practice guidelines for foreign body screening should be altered.

Socioeconomic aspects of spinal imaging: impact of radiological diagnosis on lumbar spine-related disability.

Low back pain presents a difficult problem for patients and their doctors. The symptom affects the majority of people at some point in their lives and usually has a benign natural history. However, as a society, we consume tremendous resources to diagnose and treat painful spinal disorders. Magnetic resonance imaging (MRI) facilitates the "medicalization" of low back pain due to its exquisitely sensitive depiction of pathoanatomy. Unfortunately, many of these findings are present in normal subjects. Radiologists should recognize the poor correlation between MRI findings and significant, treatable disease and support the use of evidence-based guidelines for patient referral. MRI studies should be interpreted stringently, to avoid unnecessary patient labeling and potentially inappropriate treatment.

Evaluation of meniscal tears: fast spin-echo versus conventional spin-echo magnetic resonance imaging.

RATIONALE AND OBJECTIVES: We compared the performance of fast spin-echo (FSE) with conventional spin-echo (CSE) magnetic resonance (MR) imaging sequences in the detection of meniscal tears. METHODS: Seventy-three patients underwent MR examination of the knee for suspected internal derangement. Each patient was scanned with a CSE sequence and one of two FSE sequences. The primary difference between the two FSE sequences consisted of the echo train length (ETL). Thirty-seven patients (group 1) were scanned with the FSE I sequence (ETL = 8), and 36 patients (group 2) were scanned with the FSE II sequence (ETL = 4). Menisci were graded as torn or not torn on the basis of their MR appearance. The sequences were compared with each other and with the surgical findings in 31 patients who underwent arthroscopy. RESULTS: In group 1, there was a significant discrepancy between the CSE and FSE I techniques (p = .006). The FSE I sequence detected only 11 of 19 surgically proven torn menisci as opposed to 18 of 19 detected with the CSE sequence. The FSE II sequence performed significantly better in group 2, with an accuracy equal to that of the CSE sequence. CONCLUSION: FSE sequences are extremely technique dependent with regard to detecting meniscal tears and should not replace CSE sequences in this setting until further studies are performed to optimize the technique.

Limited ischemic necrosis despite prolonged basilar artery occlusion treated with local thrombolysis: a clinicopathologic study.

Based on published case series, intra-arterial thrombolysis for basilar artery occlusion reduces mortality and improves outcome even when performed after considerable delays. In contrast, the current use of intravenous thrombolysis is limited to a 3-hour time window. The longer time window for intervention in patients with basilar artery occlusion may vary based on individual clinical features, such as collateral circulation and the site of the occlusion. Clinicopathologic evidence is presented from a patient with a distal basilar artery occlusion treated with local thrombolysis who later expired from a myocardial infarction complicated by cardiac tamponade. Autopsy showed infarction limited to the right pons despite symptom duration of over 72 hours and directly observed neurologic deficits for 27 hours.

Neuroimaging and deep brain stimulation.

Deep brain stimulation (DBS) is a new neurosurgical method principally used for the treatment of Parkinson disease (PD). Many new applications of DBS are under development, including the treatment of intractable psychiatric diseases. Brain imaging is used for the selection of patients for DBS, to localize the target nucleus, to detect complications, and to evaluate the final electrode contact position. In patients with implanted DBS systems, there is a risk of electrode heating when MR imaging is performed. This contraindicates MR imaging unless specific precautions are taken. Involvement of neuroradiologists in DBS procedures is essential to optimize presurgical evaluation, targeting, and postoperative anatomic results. The precision of the neuroradiologic correlation with anatomic data and clinical outcomes in DBS promises to yield significant basic science and clinical advances in the future.