History and Profile of Diagnosis Procedure Combination (DPC): Development of a Real Data Collection System for Acute Inpatient Care in Japan

DPC, which is an acronym for “Diagnosis Procedure Combination,” is a patient classification method developed in Japan for inpatients in the acute phase of illness. It was developed as a measuring tool intended to make acute inpatient care transparent, aiming at standardization of Japanese medical care, as well as evaluation and improvement of its quality. Subsequently, this classification method came to be used in the Japanese medical service reimbursement system for acute inpatient care and appropriate allocation of medical resources. Furthermore, it has recently contributed to the development and maintenance of an appropriate medical care provision system at a regional level, which is accomplished based on DPC data used for patient classification. In this paper, we first provide an overview of DPC. Next, we will look back at over 15 years of DPC history; in particular, we will explore how DPC has been refined to become an appropriate medical service reimbursement system. Finally, we will introduce an outline of DPC-related research, starting with research using DPC data.Key words: Diagnosis Procedure Combination (DPC), DPC-based Per-Diem Payment System (DPC/PDPS), patient classification system, health policy, Japan     

Cortical Distribution of Fragile Periventricular Anastomotic Collateral Vessels in Moyamoya Disease: An Exploratory Cross-Sectional Study of Japanese Patients with Moyamoya Disease

BACKGROUND AND PURPOSE:Collateral vessels in Moyamoya disease represent potential sources of bleeding. To test whether these cortical distributions vary among subtypes, we investigated cortical terminations using both standardized MR imaging and MRA.MATERIALS AND METHODS:Patients with Moyamoya disease who underwent MR imaging with MRA in our institution were enrolled in this study. MRA was spatially normalized to the Montreal Neurological Institute space; then, collateral vessels were measured on MRA and classified into 3 types of anastomosis according to the parent artery: lenticulostriate, thalamic, and choroidal. We also obtained the coordinates of collateral vessel outflow to the cortex. Differences in cortical terminations were compared among the 3 types of anastomosis.RESULTS:We investigated 219 patients with Moyamoya disease, and a total of 190 collateral vessels (lenticulostriate anastomosis, n = 72; thalamic anastomosis, n = 21; choroidal anastomosis, n = 97) in 46 patients met the inclusion criteria. We classified the distribution patterns of collateral anastomosis as follows: lenticulostriate collaterals outflowing anteriorly (P < .001; 95% CI, 67.0–87.0) and medially (P < .001; 95% CI, 11.0–24.0) more frequently than choroidal collaterals; lenticulostriate collaterals outflowing anteriorly more frequently than thalamic collaterals (P < .001; 95% CI, 34.0–68.0); and choroidal collaterals outflowing posteriorly more frequently than thalamic collaterals (P < .001; 95% CI, 14.0–34.0). Lenticulostriate anastomoses outflowed to the superior or inferior frontal sulcus and interhemispheric fissure. Thalamic anastomoses outflowed to the insular cortex and cortex around the central sulcus. Choroidal anastomoses outflowed to the cortex posterior to the central sulcus and the insular cortex.CONCLUSIONS:Cortical distribution patterns appear to differ markedly among the 3 types of collaterals.

Collateral vessels in Moyamoya disease develop as the disease progresses.¹ Lenticulostriate arteries (LSAs), perforators from the posterior communicating artery (PcomA), and anterior and posterior choroidal arteries (choAs) are representative collateral vessels that supply the cortex.^2-4 Development of such collateral vessels represents a risk factor for intracerebral hemorrhage,^3,5-7 and these vessels have frequently been considered as the vessels responsible for bleeding in recent reports.^8-10 These collateral vessels connect with medullary arteries near the lateral ventricle and thus supply the cortex via the medullary arteries.^3,4 However, no reports have addressed the cortical distributions of these collateral vessels.Bypass surgery reduces the risk of rebleeding in patients with hemorrhagic onset of Moyamoya disease^7,11-13 and also shrinks collateral vessels in Moyamoya disease.^7,12,14,15 Augmentation of cerebral blood flow via bypass seems to decrease the necessity for development of collateral flow and shrinks existing collaterals.¹⁵ To shrink risky collateral vessels effectively and prevent hemorrhage, well-designed and planned bypass surgeries may be required.¹⁶ Comprehension of the nature and cortical distribution of collateral vessels may thus be clinically useful.MRA performed using a 3T scanner has proved useful for detecting the abnormally extended collateral vessels in Moyamoya disease.² We investigated the cortical distribution of collateral vessels using 3T MR imaging and MRA to clarify whether cortical distributions vary among anastomotic subtypes and to better understand collateral networks.     

Estimation of the timing of carotid artery flow using peripheral pulse wave-gated MRI

Purpose:

To investigate the relationship between peripheral pulse wave (PPW)‐gating and the carotid systolic pulse wave in a large clinical patient cohort, and to establish a process for correct estimation of delay time from PPW‐gating to foot (ie, beginning) or peak times of carotid systolic pulse waves.

Materials and Methods:

Subjects comprised 209 patients scanned using 3T magnetic resonance imaging (MRI) for PPW‐gated phase contrast images at the common carotid artery. Stepwise multiple regression analysis was conducted for the relationship between foot or peak times and the following factors after excluding correlated factors with coefficients ≥0.5: pulse rate (PR); systolic blood pressure; diastolic blood pressure; height; body weight; body mass index; Brinkman index; diabetes mellitus; hypertension; and hyperlipidemia.

Results:

PR showed significant correlation with foot (r = ?0.86, P < 0.001) and peak (r = ?0.87, P < 0.001) times. The following equations were derived: foot time (msec) = ?8.55 × PR + 993.1 and peak time (msec) = ?9.21 × PR + 1142.3. No other factors showed significant correlations.

Conclusion:

PR was the only factor showing significant relationships to foot and peak times of carotid artery flow. The derived equations will facilitate various kinds of noncontrast MR acquisition with simple PPW‐gating. J. Magn. Reson. Imaging 2012;36:454–458. © 2012 Wiley Periodicals, Inc.