feat(b-values): implement parsing for multiple b-value formats and update default setting

dicom-viewer/public/penra-test.html

@@ -123,6 +123,64 @@
                     "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_596_stFfHXn.dcm",
                   ],
                 },
+                {
+                 i: [
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_792_og2P5S6.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_793_3tKkg87.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_794_s8FB3dq.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_795_8HeRpXV.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_796_tllvzjH.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_797_AXieNgu.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_798_L8YapjK.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_799_kvuLUsW.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_800_i2eSNzF.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_801_dR3KPL5.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_802_cDgm138.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_803_Bj3PZyX.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_804_CEqcWo2.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_805_5R2LmiA.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_806_RgmKU6b.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_807_BKTkmJv.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_808_OQOf2MC.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_809_lxnU3mr.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_810_8vG5Ett.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_811_poX6D2s.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_812_k46Ws88.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_813_7Ft4JOE.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_814_V5lJKxR.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_815_1hFehRl.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_816_34UqY7Z.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_817_YG28gpL.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_818_wonhIz5.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_819_bv3zaOx.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_820_xEjnfcI.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_821_cH9fPxl.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_822_lWmBHxs.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_823_ybix6Gz.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_824_q430lCK.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_825_28trFVc.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_826_7BF6HBF.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_827_ipmO3HH.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_828_Zuppb9h.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_829_TMuror5.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_830_Mnaj7oR.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_831_2U6zI7M.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_832_V9fvVdM.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_833_AAFaoOW.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_834_vxBJLIn.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_835_ZppFa6u.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_836_adRHoD3.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_837_jjfHCn3.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_838_N21h3ne.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_839_n6FWmeX.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_840_dErur0M.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_841_PcoTakk.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_842_UmTu7Fg.dcm",
+      "wadouri:https://www.penracourses.org.uk/media/atlas/dicom/IMG_843_USByQXH.dcm",
+
+                ],
+
+                }
               ],
               stackIdx: [0, 2, 1],
               stackPos: [0, 0, 2],

dicom-viewer/src/App.tsx

@@ -232,7 +232,7 @@ const GROUPING_RULE_DEFINITIONS: GroupingRuleDefinition[] = [
     id: "contentTime",
     label: "Content/Acquisition time",
     description: "Content Time (0008,0033) / Acquisition Time (0008,0032)",
-    defaultEnabled: true,
+    defaultEnabled: false,
   },
   {
     id: "echoTime",
@@ -296,6 +296,66 @@ function parseNumericValueList(raw?: string | null): number[] {
     .filter((value) => Number.isFinite(value));
 }
 
+/**
+ * Extract b-value(s) from a dicomParser DataSet. Handles multiple VR encodings:
+ * - (0018,9087) DiffusionBValue — VR FD (double) in Enhanced MR, DS (string) in some classic MR
+ * - (0019,100C) GE private — VR DS
+ * - (0043,1039) GE legacy — VR IS/DS
+ * - (2001,1003) Philips private — VR FL (32-bit float)
+ */
+function parseBValuesFromDataSet(dataSet: any): number[] {
+  if (!dataSet || typeof dataSet !== "object") return [];
+
+  const tryNumeric = (tagId: string): number | null => {
+    // DS/IS string form
+    if (typeof dataSet.string === "function") {
+      const raw = dataSet.string(tagId);
+      if (raw != null && raw !== "") {
+        const vals = parseNumericValueList(raw);
+        if (vals.length > 0 && Number.isFinite(vals[0]) && vals[0] >= 0) return vals[0];
+      }
+    }
+    // FD — 64-bit double (standard DiffusionBValue in Enhanced MR)
+    if (typeof dataSet.double === "function") {
+      try {
+        const v = dataSet.double(tagId);
+        if (Number.isFinite(v) && v >= 0) return v;
+      } catch (_) {}
+    }
+    // FL — 32-bit float (Philips private (2001,1003))
+    if (typeof dataSet.float === "function") {
+      try {
+        const v = dataSet.float(tagId);
+        if (Number.isFinite(v) && v >= 0) return v;
+      } catch (_) {}
+    }
+    return null;
+  };
+
+  // Standard (0018,9087) DiffusionBValue
+  const v1 = tryNumeric("x00189087");
+  if (v1 !== null) return [v1];
+
+  // GE private (0019,100C)
+  const v2 = tryNumeric("x0019100c");
+  if (v2 !== null) return [v2];
+
+  // GE legacy (0043,1039) — IS format, first value is b-value
+  if (typeof dataSet.string === "function") {
+    const raw = dataSet.string("x00431039");
+    if (raw) {
+      const parts = parseNumericValueList(raw);
+      if (parts.length > 0 && Number.isFinite(parts[0]) && parts[0] >= 0) return [parts[0]];
+    }
+  }
+
+  // Philips private (2001,1003) — VR FL
+  const v3 = tryNumeric("x20011003");
+  if (v3 !== null) return [v3];
+
+  return [];
+}
+
 function normalizeToWadouriOrExternal(imageId: string): string {
   if (imageId.startsWith("wadouri:") || imageId.startsWith("external:")) {
     return imageId;
@@ -1439,19 +1499,6 @@ export default function App({ container_id, imageStacks, autoCacheStack, annotat
     const cached = bValuesByBaseImageRef.current[baseUrl];
     if (cached) return cached;
 
-    const parseBValuesFromDataSet = (dataSet: any): number[] => {
-      if (!dataSet || typeof dataSet.string !== "function") return [];
-      const standard = parseNumericValueList(dataSet.string("x00189087")); // DiffusionBValue
-      if (standard.length > 0) return standard;
-      const gePrivate = parseNumericValueList(dataSet.string("x0019100c"));
-      if (gePrivate.length > 0) return gePrivate;
-      const geLegacyPrivate = parseNumericValueList(dataSet.string("x00431039"));
-      if (geLegacyPrivate.length > 0) return geLegacyPrivate;
-      const privatePhilips = parseNumericValueList(dataSet.string("x20011003"));
-      if (privatePhilips.length > 0) return privatePhilips;
-      return [];
-    };
-
     try {
       const cacheManager = cornerstoneDICOMImageLoader?.wadouri?.dataSetCacheManager;
       if (cacheManager?.get) {
@@ -1466,13 +1513,42 @@ export default function App({ container_id, imageStacks, autoCacheStack, annotat
       // Continue with fetch fallback.
     }
 
+    // Helper: parse bytes tolerating truncation (header-only range requests)
+    const tryParseBytes = (bytes: Uint8Array): number[] => {
+      try {
+        return parseBValuesFromDataSet(dicomParser.parseDicom(bytes));
+      } catch (e: any) {
+        // dicomParser throws on truncation but attaches partial dataSet
+        if (e?.dataSet) {
+          const partial = parseBValuesFromDataSet(e.dataSet);
+          if (partial.length > 0) return partial;
+        }
+        return [];
+      }
+    };
+
+    // Range request — first 64 KB is enough to find b-value tags in the header
+    try {
+      const rangeResponse = await fetch(baseUrl, { headers: { Range: "bytes=0-65535" } });
+      if (rangeResponse.ok || rangeResponse.status === 206) {
+        const buf = await rangeResponse.arrayBuffer();
+        const result = tryParseBytes(new Uint8Array(buf));
+        if (result.length > 0 || rangeResponse.status === 200) {
+          bValuesByBaseImageRef.current[baseUrl] = result;
+          return result;
+        }
+      }
+    } catch (e) {
+      // Fall through to full fetch.
+    }
+
+    // Full fetch fallback (only if range request failed or server doesn't support Range)
     try {
       const response = await fetch(baseUrl);
-      const arrayBuffer = await response.arrayBuffer();
+      const buf = await response.arrayBuffer();
-      const dataSet = dicomParser.parseDicom(new Uint8Array(arrayBuffer));
+      const result = tryParseBytes(new Uint8Array(buf));
-      const fromFetch = parseBValuesFromDataSet(dataSet);
+      bValuesByBaseImageRef.current[baseUrl] = result;
-      bValuesByBaseImageRef.current[baseUrl] = fromFetch;
+      return result;
-      return fromFetch;
     } catch (e) {
       bValuesByBaseImageRef.current[baseUrl] = [];
       return [];
@@ -1656,8 +1732,15 @@ export default function App({ container_id, imageStacks, autoCacheStack, annotat
             .map((candidate) => candidate.ruleValues[ruleId])
             .filter((value): value is string => !!value);
           const distinct = new Set(values);
-          // Ignore rules that are constant (or effectively unique per image) to avoid over-fragmentation.
+          // Only activate when:
-          return distinct.size > 1 && distinct.size < Math.max(2, candidates.length);
+          // 1. Multiple distinct values (not constant across the series)
+          // 2. Not effectively unique per-image (would produce a group of 1 per image)
+          // 3. At least 70% of images have a value for this rule — avoids fragmenting when
+          //    only a handful of images returned metadata (e.g., b-value fetch failed for most)
+          const coverage = values.length / candidates.length;
+          return distinct.size > 1
+            && distinct.size < Math.max(2, candidates.length)
+            && coverage >= 0.7;
         })
       : [];