diff --git a/IRaCIS.Core.Application/Service/Common/TrialImageDownloadService.cs b/IRaCIS.Core.Application/Service/Common/TrialImageDownloadService.cs
index 6ba580e20..ac35dd052 100644
--- a/IRaCIS.Core.Application/Service/Common/TrialImageDownloadService.cs
+++ b/IRaCIS.Core.Application/Service/Common/TrialImageDownloadService.cs
@@ -60,6 +60,14 @@ namespace IRaCIS.Core.Application.Service
         {
             try
             {
+
+                #region 方式一  有的必须在内存中，不能用这种
+                //await using var source = await sourceFactory();
+                //// 如果你是从 stream 打开
+                //var dicomFile = await DicomFile.OpenAsync(source);
+                #endregion
+
+                #region 方式二
                 await using var source = await sourceFactory();
 
                 // 【关键修复】将 OSS 流缓冲到 MemoryStream
@@ -79,6 +87,8 @@ namespace IRaCIS.Core.Application.Service
 
                 // 如果你是从 stream 打开
                 var dicomFile = await DicomFile.OpenAsync(source.CanSeek ? source : bufferedStream);
+                #endregion
+
 
                 //获取像素是否为封装形式
                 var syntax = dicomFile.Dataset.InternalTransferSyntax;
@@ -211,8 +221,12 @@ namespace IRaCIS.Core.Application.Service
 
             #endregion
 
+            var oldVisits = MiniExcel.Query<SubjectVisitExcel>(Path.Combine(rootFolder, "Old.xlsx")).ToList();
 
-            var downloadVisits = MiniExcel.Query<SubjectVisitExcel>(Path.Combine(rootFolder, "download.xlsx")).ToList().Where(t => t.SubjectCode.IsNotNullOrEmpty() && t.VisitName.IsNotNullOrEmpty());
+            var downloadVisits = MiniExcel.Query<SubjectVisitExcel>(Path.Combine(rootFolder, "download.xlsx")).ToList().Where(t => t.SubjectCode.IsNotNullOrEmpty() && t.VisitName.IsNotNullOrEmpty()).ToList();
+
+            downloadVisits= downloadVisits.Where(t => !oldVisits.Any(old => old.VisitNum == t.VisitNum && old.SubjectCode == t.SubjectCode &&
+            old.VisitName.Trim().ToLower() == t.VisitName.Trim().ToLower())).ToList();
 
             var downloadJobs = new List<DownloadJob>();
 
@@ -308,6 +322,7 @@ namespace IRaCIS.Core.Application.Service
                         continue;
                     }
 
+                    Log.Logger.Warning($"开始获取访视信息准备下载任务：{visitItem.SubjectCode} {visitItem.VisitName} {visitItem.VisitNum}");
 
                     foreach (var studyInfo in visitItem.StudyList)
                     {
@@ -502,6 +517,7 @@ namespace IRaCIS.Core.Application.Service
                             return Task.CompletedTask;
                         }
                     });
+
                 }
 
 
@@ -515,14 +531,14 @@ namespace IRaCIS.Core.Application.Service
 
 
 
-
-
+            Log.Logger.Warning($"访视信息准备完毕: {downloadVisits.Count},后端开始下载任务......");
+            
             #region 异步方式处理
 
             int totalCount = downloadJobs.Count;
             int downloadedCount = 0;
 
-            Log.Logger.Warning($"开始下载总数: {totalCount}");
+            Log.Logger.Warning($"下载文件总数: {totalCount}");
             foreach (var job in downloadJobs)
             {
                 try
diff --git a/IRaCIS.Core.Application/Service/ImageAndDoc/StudyService.cs b/IRaCIS.Core.Application/Service/ImageAndDoc/StudyService.cs
index 70458f08a..cb899be04 100644
--- a/IRaCIS.Core.Application/Service/ImageAndDoc/StudyService.cs
+++ b/IRaCIS.Core.Application/Service/ImageAndDoc/StudyService.cs
@@ -82,9 +82,35 @@ namespace IRaCIS.Core.Application.Service.ImageAndDoc
         {
             try
             {
+                #region 方式一  有的必须在内存中，不能用这种
+                //await using var source = await sourceFactory();
+                //// 如果你是从 stream 打开
+                //var dicomFile = await DicomFile.OpenAsync(source);
+                #endregion
+
+                #region 方式二
+
                 await using var source = await sourceFactory();
+
+                // 【关键修复】将 OSS 流缓冲到 MemoryStream
+                using var bufferedStream = new MemoryStream();
+
+                if (source.CanSeek)
+                {
+                    source.Position = 0;
+
+                }
+                else
+                {
+                    // 完全复制到内存流
+                    await source.CopyToAsync(bufferedStream);
+                    bufferedStream.Position = 0; // 重置位置
+                }
+
                 // 如果你是从 stream 打开
-                var dicomFile = await DicomFile.OpenAsync(source);
+                var dicomFile = await DicomFile.OpenAsync(source.CanSeek ? source : bufferedStream);
+
+                #endregion
 
                 //获取像素是否为封装形式
                 var syntax = dicomFile.Dataset.InternalTransferSyntax;