diff --git a/app/Models/OrthancHost.php b/app/Models/OrthancHost.php
index fa76b66..6266b30 100644
--- a/app/Models/OrthancHost.php
+++ b/app/Models/OrthancHost.php
@@ -20,11 +20,6 @@ public function facility(): BelongsTo
         return $this->belongsTo(Facility::class);
     }
 
-    private function restEndpoint(string $path): Uri
-    {
-        return Uri::of($this->rest_api_endpoint)->withPath($path);
-    }
-
     public function stoneViewerUrl(): Uri
     {
         return $this->restEndpoint($this->stone_viewer_path);
@@ -34,4 +29,9 @@ public function ohifViewerUrl(): Uri
     {
         return $this->restEndpoint($this->ohif_viewer_path);
     }
+
+    private function restEndpoint(string $path): Uri
+    {
+        return Uri::of($this->rest_api_endpoint)->withPath($path);
+    }
 }
diff --git a/app/Models/Study.php b/app/Models/Study.php
index b66ed58..b31847e 100644
--- a/app/Models/Study.php
+++ b/app/Models/Study.php
@@ -9,6 +9,7 @@
 use App\Models\Traits\HashableId;
 use App\Services\Pacs\PacsUrlGen;
 use Carbon\Carbon;
+use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Concerns\HasTimestamps;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\HasMany;
@@ -47,19 +48,19 @@ public function shares(): HasMany
         return $this->hasMany(SharedStudy::class);
     }
 
-    public function scopeActive($query)
+    public function scopeActive(Builder $query): Builder
     {
-        return $query->where('is_archived', false);
+        return $query->whereNull('archived_at');
     }
 
-    public function scopeArchived($query)
+    public function scopeArchived(Builder $query): Builder
     {
-        return $query->where('is_archived', true);
+        return $query->whereNotNull('archived_at');
     }
 
-    public function scopeUnlocked($query)
+    public function scopeUnlocked(Builder $query): Builder
     {
-        return $query->where('is_locked', false);
+        return $query->whereNotNull('locked_at');
     }
 
     public function getHistoryLink(): string
@@ -129,7 +130,12 @@ public function isAssigned(int $rad_id): bool
 
     public function isActive(): bool
     {
-        return $this->is_archived === false;
+        return $this->archived_at === null;
+    }
+
+    public function isArchived(): bool
+    {
+        return $this->archived_at !== null;
     }
 
     public function getReportStatusLedAttribute(): string
diff --git a/app/Services/Pacs/Sync/Pipes/FilterStudies.php b/app/Services/Pacs/Sync/Pipes/FilterStudies.php
index f631b93..33f3330 100644
--- a/app/Services/Pacs/Sync/Pipes/FilterStudies.php
+++ b/app/Services/Pacs/Sync/Pipes/FilterStudies.php
@@ -15,7 +15,7 @@ public function __invoke(StudiesSync $sync, Closure $next): StudiesSync
         $sync->resetQueues();
 
         $studies = DB::table('studies')
-            ->where('is_archived', false)
+            ->whereNull('archived_at')
             ->get(['orthanc_uuid', 'study_status'])
             ->pluck('study_status', 'orthanc_uuid');
 
diff --git a/database/migrations/2024_12_27_060234_create_studies_table.php b/database/migrations/2024_12_27_060234_create_studies_table.php
index 320ca58..712fbf4 100644
--- a/database/migrations/2024_12_27_060234_create_studies_table.php
+++ b/database/migrations/2024_12_27_060234_create_studies_table.php
@@ -16,7 +16,6 @@ public function up(): void
             $table->id();
             $table->foreignIdFor(OrthancHost::class)->index();
             $table->string('orthanc_uuid')->index();
-            $table->boolean('is_archived')->default(false);
             $table->unsignedTinyInteger('priority')->default(Priority::Routine);
 
             $table->string('patient_uuid')->nullable()->index();