Use Of New Imaging Techniques Research Articles

The solitary pulmonary nodule

The solitary pulmonary nodule will be found increasingly by the use of newer imaging techniques, including computed tomography (CT) screening. The aim must be to have an approach that avoids unnecessary surgery or biopsy with their attendant risks. Plain films characterisation, CT assessment, including densitometry and enhancement, and growth patterns are discussed and evaluated. The use of Bayes theorem to guide these assessment strategies is also described.

Early response to chemotherapy: a surrogate for final outcome of Hodgkin's disease patients that should influence initial treatment length and intensity?

Early adjustment of treatment may benefit the patient. In order to guide treatment adjustment, use of early response (ER) or early complete response (ECR), judged after the few initial cycles of chemotherapy, is common in pediatric and also adult Hodgkin's and non-Hodgkin's studies. Paradoxically, almost no data support this strategy. The influence of ECR on outcome was evaluated in three series of advanced Hodgkin's disease (HD), leading to a series of questions. The 1982 EORTC study assessed prospectively the time frame needed to reach an apparent complete response (CR) through repeated tumor measurements. In patients assessed at mid-treatment before the fifth cycle, both 15 year freedom from progression (FFP) and overall survival (OS) were superior in ECR patients compared with other patients continued on the same treatment (61% versus 37%; P < 0.001). A series of questions arise from these observations. Question 1: is the shortening of treatment detrimental? In a randomized Swedish trial, in one arm treatment was shortened in patients evaluated from the fifth cycle as ECR as compared with the standard eight cycles arm, 10 year cause-specific-survival (CSS) was 53 versus 69% [not significant (ns)]; 10 year OS 49% versus 58% (ns). Conversely, in the EORTC 20884 study, ECR patients given only six cycles did as well as patients entering CR later and, for this reason, given eight cycles (identical 6 year event-free survival 75%). Question 2: is early treatment adaptation in patients who failed to reach ER beneficial? In the French MDH 90 trial, 15% of children failed to reach ECR after four cycles; in these children only, anthracyclines plus alkylating agents were given and the dose of radiotherapy increased, improving the results observed in the previous trial. In the EORTC 20884 study, patients who failed to reach an ECR were switched earlier to involved field RT: their results matched those of ECR patients, at the difference of the previous trial. Question 3: is ER a predicting factor that can be used with any type of treatment? Probably not, based on the German Hodgkin's Lymphoma Study Group trial HD 9: ECR is highly dependent on specific interval from treatment start and on treatment intensity. More general questions stem from these results. Question 4: is the definition of ER secured? With conventional imaging, the different methods for response assessment at end treatment also lead to different response rates; the assessment in the middle of treatment itself and the use of newer imaging techniques may further increase the variation. Indeed, question 5 is: is ER a concept based on any biology? Correlation to markers, 99mTc uptake, PET and hematological tolerance might help to pinpoint how and why ER represents a surrogate for final outcome. ER is a surrogate for final outcome, reflecting both tumor burden and activity. This predictability may, and possibly should, impact on treatment.

Extrarenal manifestations of autosomal dominant polycystic kidney disease.

Recently, with the widespread use of new imaging techniques, the diagnosis of autosomal dominant polycystic kidney disease (ADPKD) is increasing. To analyze the extrarenal manifestations of ADPKD in Korean patients, we retrospectively studied the clinical characteristics of 30 patients with ADPKD. Thirty Patients with ADPKD who had been diagnosed at Yongdong Severance Hospital from 1988 through 1994 were recruited for this study. All patients' past and family histories were re-evaluated, and charts and radiologic images were reviewed retrospectively. The male to female ratio was 9:21, and the age of initial diagnosis was 39.2 +/- 13.8 (mean +/- SD) years. In 15 cases (50%), ADPKD had been diagnosed by renal symptoms; in 8 cases (26.7%), by chance during evaluation of extrarenal diseases; in 5 cases (16.7%), by family screening; and in 2 cases (6.7%), by uremic symptoms. Extrarenal involvement included hepatic cysts (70%), pancreatic cysts (16.7%), splenic cysts (6.7%), thyroid cysts (6.7%), inguinal hernia (3.3%), and colonic diverticula (3.3%). In 5 cases (16.7%), cardiac valvular abnormalities were noted by echocardiography. Seven patients underwent hemodialysis, and the duration from the initial diagnosis to initiation of dialysis was 9.9 +/- 8.5 (mean +/- SD) years. We investigated the extrarenal manifestations of 30 cases of ADPKD in Koreans, which were also common and clinically important as renal manifestations. Renal cysts are only one of a myriad of renal and extrarenal manifestations of ADPKD. ADPKD should be managed systematically since this disorder is a systemic disease with clinically important involvement of the cardiovascular system, the gastrointestinal tract, the genitourinary system, and the musculoskeletal system.

Magnetic resonance imaging in the assessment of medullary compression in achondroplasia.

Children with achondroplasia may be at increased risk of developing apneic episodes and of dying unexpectedly. The risks seem to be related to neural axis compression by an abnormal cranial base and may be complicated by the development of hydrocephalus. We used magnetic resonance imaging to study five children with achondroplasia. All of them demonstrated a discrepancy between the size of the brain stem and the foramen magnum. Comprehensive prospective assessment of infants with achondroplasia, including the use of new imaging techniques, will provide important information concerning the natural history of the relationship of the neural axis to the bony posterior fossa and upper cervical spine in this condition. It may also help to identify those patients at risk before the development of life-threatening medullary compression.

New Brain Imaging Techniques and Psychopharmocology

This collection of ten papers is devoted entirely to the use of new imaging techniques in psychopharmacology. It includes chapters on cerebral blood flow measured by such methods as xenon inhalation; cerebral blood flow and metabolism measured by positron emission tomography; and magentic resonance imaging. Also included are chapters examining the potential of using these techniques to explore the way that psychotropic drugs influence the central nervous system in a variety of conditions. Schizophrenia, affective disorder, epilepsy and dementia are all considered, as are research findings which specifically relate to psychopharmacology.

Diagnosis and management of cavernous hemangioma of the liver.

Cavernous hemangiomas are the most common benign tumors of the liver, which are now seen more often thanks to common use of newer imaging techniques. A review of the literature on cavernous hemangiomas of the liver, including our own experience with 14 cases, provides data as a touchstone for discussion of the incidence, etiology, symptoms, pathology, diagnosis including ultrasound, radionuclide imaging, computed tomography and angiography, management including resection, hepatic artery ligation, radiation and corticosteroid, and the natural history of these lesions. The author concludes that surgical resection of cavernous hemangiomas should be undertaken with due concern for the relation between the severity of symptoms and the operative risks involved.