What Does A Normal CT Scan Showing Low DLCO Indicate?

Question: What conditions could cause an isolated reduced dlco but a normal ct?

I have had intermittent shortness of breath for 1 1/2 years after getting iron infusions. I have a normal hemoglobin count, just low ferritin. My hematologist said a very rare reaction could cause pulmonary fibrosis but my HRCT was normal. I have had so many tests done (pulmonary and cardiac) and nothing significant has been found and they can't seem to find a cause for the shortness of breath. However, the DLCO was reduced on both PFTs I had done . So I was wondering ..Could a DLCO 60-75 % of predicted be considered normal or insignificant? Or is it something that should be followed?

Yes you can ask anything. I am just trying to figure this out

1. Reading, PA
2. Not a high altitude
3. I'm not obese, my BMI is 19.5

Here is my PFT report:

FVC Measured     4.32 Liters     Liters
FVC % Pre Pred     99 %     %
FVC Post     4.23 Liters     Liters
FVC %PostPred     97 %     %
FVC % Change     -2 %     %
FEV1 Measured     3.65 Liters     Liters
FEV1 %Pre Pred     101 %     %
FEV1 Post     3.75 Liters     Liters
FEV1 %Post Pred     104 %     %
FEV1%Chng     3 %     %
FEV1/FVC Pre     84 %     %
FEV1/FVC Post     89 %     %
TLC Post     5.60 Liters     Liters
TLC %Postpred     97 %     %
RV Post     1.20 Liters     Liters
RV % Post Pred     70 %     %
DLCO Post     24.7 mL/mmHg/min     mL/mmHg/min
DLCO %Post Pred     78 %     %
DLCO/Va Post     4.12 mL/mHg/min/L     mL/mHg/min/L
DLCO/VA %Post Pred     72 %     %
PI XXXXXXX Post     88 cmH2O     cmH2O
PI XXXXXXX % Post Pred     102 %     %
PE XXXXXXX Post     107 cmH2O     cmH2O
Pe XXXXXXX %Post Pred     70 %     %
pre     2 %     %
VOL EXTRAP/FVC Post     2 %     %


My DLCO on the other was in the 60s. I do not have that report though.

My life isn't really stressful. I work in a hospital and I am not exposed to any gases or chemicals. This had all started after iron infusions. I felt like I had the flu after getting them and also began with delayed shortness of breath after the 2nd infusion. They stopped for a month for the concern of fibrosis but when my CT came back normal they started me again with a small dose. Later that night the shortness of breath happened again. But really it does not make sense medically that I would continue with the shortness of breath. It happens randomly and when going up an incline or stairs. I am seeing an endocrinologist soon because I have these episodes of a "fight or flight" response and slightly elevated norepinephrine and epinephrine levels. They are unsure if this is related at all.

It is not anxiety. I have seen a psychiatrist multiple times and he says its not psychiatric. I will follow up with endo. Thanks for answering all my questions.